drivers/usb/core/hub.c

   1 /*
   2  * USB hub driver.
   3  *
   4  * (C) Copyright 1999 Linus Torvalds
   5  * (C) Copyright 1999 Johannes Erdfelt
   6  * (C) Copyright 1999 Gregory P. Smith
   7  * (C) Copyright 2001 Brad Hards (bhards@bigpond.net.au)
   8  *
   9  * Released under the GPLv2 only.
  10  * SPDX-License-Identifier: GPL-2.0
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/errno.h>
  15 #include <linux/module.h>
  16 #include <linux/moduleparam.h>
  17 #include <linux/completion.h>
  18 #include <linux/sched/mm.h>
  19 #include <linux/list.h>
  20 #include <linux/slab.h>
  21 #include <linux/ioctl.h>
  22 #include <linux/usb.h>
  23 #include <linux/usbdevice_fs.h>
  24 #include <linux/usb/hcd.h>
  25 #include <linux/usb/otg.h>
  26 #include <linux/usb/quirks.h>
  27 #include <linux/workqueue.h>
  28 #include <linux/mutex.h>
  29 #include <linux/random.h>
  30 #include <linux/pm_qos.h>
  31
  32 #include <linux/uaccess.h>
  33 #include <asm/byteorder.h>
  34
  35 #include "hub.h"
  36 #include "otg_whitelist.h"
  37
  38 #define USB_VENDOR_GENESYS_LOGIC                0x05e3
  39 #define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND        0x01
  40
  41 /* Protect struct usb_device->state and ->children members
  42  * Note: Both are also protected by ->dev.sem, except that ->state can
  43  * change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
  44 static DEFINE_SPINLOCK(device_state_lock);
  45
  46 /* workqueue to process hub events */
  47 static struct workqueue_struct *hub_wq;
  48 static void hub_event(struct work_struct *work);
  49
  50 /* synchronize hub-port add/remove and peering operations */
  51 DEFINE_MUTEX(usb_port_peer_mutex);
  52
  53 /* cycle leds on hubs that aren't blinking for attention */
  54 static bool blinkenlights;
  55 module_param(blinkenlights, bool, S_IRUGO);
  56 MODULE_PARM_DESC(blinkenlights, "true to cycle leds on hubs");
  57
  58 /*
  59  * Device SATA8000 FW1.0 from DATAST0R Technology Corp requires about
  60  * 10 seconds to send reply for the initial 64-byte descriptor request.
  61  */
  62 /* define initial 64-byte descriptor request timeout in milliseconds */
  63 static int initial_descriptor_timeout = USB_CTRL_GET_TIMEOUT;
  64 module_param(initial_descriptor_timeout, int, S_IRUGO|S_IWUSR);
  65 MODULE_PARM_DESC(initial_descriptor_timeout,
  66                 "initial 64-byte descriptor request timeout in milliseconds "
  67                 "(default 5000 - 5.0 seconds)");
  68
  69 /*
  70  * As of 2.6.10 we introduce a new USB device initialization scheme which
  71  * closely resembles the way Windows works.  Hopefully it will be compatible
  72  * with a wider range of devices than the old scheme.  However some previously
  73  * working devices may start giving rise to "device not accepting address"
  74  * errors; if that happens the user can try the old scheme by adjusting the
  75  * following module parameters.
  76  *
  77  * For maximum flexibility there are two boolean parameters to control the
  78  * hub driver's behavior.  On the first initialization attempt, if the
  79  * "old_scheme_first" parameter is set then the old scheme will be used,
  80  * otherwise the new scheme is used.  If that fails and "use_both_schemes"
  81  * is set, then the driver will make another attempt, using the other scheme.
  82  */
  83 static bool old_scheme_first;
  84 module_param(old_scheme_first, bool, S_IRUGO | S_IWUSR);
  85 MODULE_PARM_DESC(old_scheme_first,
  86                  "start with the old device initialization scheme");
  87
  88 static bool use_both_schemes = 1;
  89 module_param(use_both_schemes, bool, S_IRUGO | S_IWUSR);
  90 MODULE_PARM_DESC(use_both_schemes,
  91                 "try the other device initialization scheme if the "
  92                 "first one fails");
  93
  94 /* Mutual exclusion for EHCI CF initialization.  This interferes with
  95  * port reset on some companion controllers.
  96  */
  97 DECLARE_RWSEM(ehci_cf_port_reset_rwsem);
  98 EXPORT_SYMBOL_GPL(ehci_cf_port_reset_rwsem);
  99
 100 #define HUB_DEBOUNCE_TIMEOUT    2000
 101 #define HUB_DEBOUNCE_STEP         25
 102 #define HUB_DEBOUNCE_STABLE      100
 103
 104 static void hub_release(struct kref *kref);
 105 static int usb_reset_and_verify_device(struct usb_device *udev);
 106 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state);
 107
 108 static inline char *portspeed(struct usb_hub *hub, int portstatus)
 109 {
 110         if (hub_is_superspeedplus(hub->hdev))
 111                 return "10.0 Gb/s";
 112         if (hub_is_superspeed(hub->hdev))
 113                 return "5.0 Gb/s";
 114         if (portstatus & USB_PORT_STAT_HIGH_SPEED)
 115                 return "480 Mb/s";
 116         else if (portstatus & USB_PORT_STAT_LOW_SPEED)
 117                 return "1.5 Mb/s";
 118         else
 119                 return "12 Mb/s";
 120 }
 121
 122 /* Note that hdev or one of its children must be locked! */
 123 struct usb_hub *usb_hub_to_struct_hub(struct usb_device *hdev)
 124 {
 125         if (!hdev || !hdev->actconfig || !hdev->maxchild)
 126                 return NULL;
 127         return usb_get_intfdata(hdev->actconfig->interface[0]);
 128 }
 129
 130 int usb_device_supports_lpm(struct usb_device *udev)
 131 {
 132         /* Some devices have trouble with LPM */
 133         if (udev->quirks & USB_QUIRK_NO_LPM)
 134                 return 0;
 135
 136         /* USB 2.1 (and greater) devices indicate LPM support through
 137          * their USB 2.0 Extended Capabilities BOS descriptor.
 138          */
 139         if (udev->speed == USB_SPEED_HIGH || udev->speed == USB_SPEED_FULL) {
 140                 if (udev->bos->ext_cap &&
 141                         (USB_LPM_SUPPORT &
 142                          le32_to_cpu(udev->bos->ext_cap->bmAttributes)))
 143                         return 1;
 144                 return 0;
 145         }
 146
 147         /*
 148          * According to the USB 3.0 spec, all USB 3.0 devices must support LPM.
 149          * However, there are some that don't, and they set the U1/U2 exit
 150          * latencies to zero.
 151          */
 152         if (!udev->bos->ss_cap) {
 153                 dev_info(&udev->dev, "No LPM exit latency info found, disabling LPM.\n");
 154                 return 0;
 155         }
 156
 157         if (udev->bos->ss_cap->bU1devExitLat == 0 &&
 158                         udev->bos->ss_cap->bU2DevExitLat == 0) {
 159                 if (udev->parent)
 160                         dev_info(&udev->dev, "LPM exit latency is zeroed, disabling LPM.\n");
 161                 else
 162                         dev_info(&udev->dev, "We don't know the algorithms for LPM for this host, disabling LPM.\n");
 163                 return 0;
 164         }
 165
 166         if (!udev->parent || udev->parent->lpm_capable)
 167                 return 1;
 168         return 0;
 169 }
 170
 171 /*
 172  * Set the Maximum Exit Latency (MEL) for the host to initiate a transition from
 173  * either U1 or U2.
 174  */
 175 static void usb_set_lpm_mel(struct usb_device *udev,
 176                 struct usb3_lpm_parameters *udev_lpm_params,
 177                 unsigned int udev_exit_latency,
 178                 struct usb_hub *hub,
 179                 struct usb3_lpm_parameters *hub_lpm_params,
 180                 unsigned int hub_exit_latency)
 181 {
 182         unsigned int total_mel;
 183         unsigned int device_mel;
 184         unsigned int hub_mel;
 185
 186         /*
 187          * Calculate the time it takes to transition all links from the roothub
 188          * to the parent hub into U0.  The parent hub must then decode the
 189          * packet (hub header decode latency) to figure out which port it was
 190          * bound for.
 191          *
 192          * The Hub Header decode latency is expressed in 0.1us intervals (0x1
 193          * means 0.1us).  Multiply that by 100 to get nanoseconds.
 194          */
 195         total_mel = hub_lpm_params->mel +
 196                 (hub->descriptor->u.ss.bHubHdrDecLat * 100);
 197
 198         /*
 199          * How long will it take to transition the downstream hub's port into
 200          * U0?  The greater of either the hub exit latency or the device exit
 201          * latency.
 202          *
 203          * The BOS U1/U2 exit latencies are expressed in 1us intervals.
 204          * Multiply that by 1000 to get nanoseconds.
 205          */
 206         device_mel = udev_exit_latency * 1000;
 207         hub_mel = hub_exit_latency * 1000;
 208         if (device_mel > hub_mel)
 209                 total_mel += device_mel;
 210         else
 211                 total_mel += hub_mel;
 212
 213         udev_lpm_params->mel = total_mel;
 214 }
 215
 216 /*
 217  * Set the maximum Device to Host Exit Latency (PEL) for the device to initiate
 218  * a transition from either U1 or U2.
 219  */
 220 static void usb_set_lpm_pel(struct usb_device *udev,
 221                 struct usb3_lpm_parameters *udev_lpm_params,
 222                 unsigned int udev_exit_latency,
 223                 struct usb_hub *hub,
 224                 struct usb3_lpm_parameters *hub_lpm_params,
 225                 unsigned int hub_exit_latency,
 226                 unsigned int port_to_port_exit_latency)
 227 {
 228         unsigned int first_link_pel;
 229         unsigned int hub_pel;
 230
 231         /*
 232          * First, the device sends an LFPS to transition the link between the
 233          * device and the parent hub into U0.  The exit latency is the bigger of
 234          * the device exit latency or the hub exit latency.
 235          */
 236         if (udev_exit_latency > hub_exit_latency)
 237                 first_link_pel = udev_exit_latency * 1000;
 238         else
 239                 first_link_pel = hub_exit_latency * 1000;
 240
 241         /*
 242          * When the hub starts to receive the LFPS, there is a slight delay for
 243          * it to figure out that one of the ports is sending an LFPS.  Then it
 244          * will forward the LFPS to its upstream link.  The exit latency is the
 245          * delay, plus the PEL that we calculated for this hub.
 246          */
 247         hub_pel = port_to_port_exit_latency * 1000 + hub_lpm_params->pel;
 248
 249         /*
 250          * According to figure C-7 in the USB 3.0 spec, the PEL for this device
 251          * is the greater of the two exit latencies.
 252          */
 253         if (first_link_pel > hub_pel)
 254                 udev_lpm_params->pel = first_link_pel;
 255         else
 256                 udev_lpm_params->pel = hub_pel;
 257 }
 258
 259 /*
 260  * Set the System Exit Latency (SEL) to indicate the total worst-case time from
 261  * when a device initiates a transition to U0, until when it will receive the
 262  * first packet from the host controller.
 263  *
 264  * Section C.1.5.1 describes the four components to this:
 265  *  - t1: device PEL
 266  *  - t2: time for the ERDY to make it from the device to the host.
 267  *  - t3: a host-specific delay to process the ERDY.
 268  *  - t4: time for the packet to make it from the host to the device.
 269  *
 270  * t3 is specific to both the xHCI host and the platform the host is integrated
 271  * into.  The Intel HW folks have said it's negligible, FIXME if a different
 272  * vendor says otherwise.
 273  */
 274 static void usb_set_lpm_sel(struct usb_device *udev,
 275                 struct usb3_lpm_parameters *udev_lpm_params)
 276 {
 277         struct usb_device *parent;
 278         unsigned int num_hubs;
 279         unsigned int total_sel;
 280
 281         /* t1 = device PEL */
 282         total_sel = udev_lpm_params->pel;
 283         /* How many external hubs are in between the device & the root port. */
 284         for (parent = udev->parent, num_hubs = 0; parent->parent;
 285                         parent = parent->parent)
 286                 num_hubs++;
 287         /* t2 = 2.1us + 250ns * (num_hubs - 1) */
 288         if (num_hubs > 0)
 289                 total_sel += 2100 + 250 * (num_hubs - 1);
 290
 291         /* t4 = 250ns * num_hubs */
 292         total_sel += 250 * num_hubs;
 293
 294         udev_lpm_params->sel = total_sel;
 295 }
 296
 297 static void usb_set_lpm_parameters(struct usb_device *udev)
 298 {
 299         struct usb_hub *hub;
 300         unsigned int port_to_port_delay;
 301         unsigned int udev_u1_del;
 302         unsigned int udev_u2_del;
 303         unsigned int hub_u1_del;
 304         unsigned int hub_u2_del;
 305
 306         if (!udev->lpm_capable || udev->speed < USB_SPEED_SUPER)
 307                 return;
 308
 309         hub = usb_hub_to_struct_hub(udev->parent);
 310         /* It doesn't take time to transition the roothub into U0, since it
 311          * doesn't have an upstream link.
 312          */
 313         if (!hub)
 314                 return;
 315
 316         udev_u1_del = udev->bos->ss_cap->bU1devExitLat;
 317         udev_u2_del = le16_to_cpu(udev->bos->ss_cap->bU2DevExitLat);
 318         hub_u1_del = udev->parent->bos->ss_cap->bU1devExitLat;
 319         hub_u2_del = le16_to_cpu(udev->parent->bos->ss_cap->bU2DevExitLat);
 320
 321         usb_set_lpm_mel(udev, &udev->u1_params, udev_u1_del,
 322                         hub, &udev->parent->u1_params, hub_u1_del);
 323
 324         usb_set_lpm_mel(udev, &udev->u2_params, udev_u2_del,
 325                         hub, &udev->parent->u2_params, hub_u2_del);
 326
 327         /*
 328          * Appendix C, section C.2.2.2, says that there is a slight delay from
 329          * when the parent hub notices the downstream port is trying to
 330          * transition to U0 to when the hub initiates a U0 transition on its
 331          * upstream port.  The section says the delays are tPort2PortU1EL and
 332          * tPort2PortU2EL, but it doesn't define what they are.
 333          *
 334          * The hub chapter, sections 10.4.2.4 and 10.4.2.5 seem to be talking
 335          * about the same delays.  Use the maximum delay calculations from those
 336          * sections.  For U1, it's tHubPort2PortExitLat, which is 1us max.  For
 337          * U2, it's tHubPort2PortExitLat + U2DevExitLat - U1DevExitLat.  I
 338          * assume the device exit latencies they are talking about are the hub
 339          * exit latencies.
 340          *
 341          * What do we do if the U2 exit latency is less than the U1 exit
 342          * latency?  It's possible, although not likely...
 343          */
 344         port_to_port_delay = 1;
 345
 346         usb_set_lpm_pel(udev, &udev->u1_params, udev_u1_del,
 347                         hub, &udev->parent->u1_params, hub_u1_del,
 348                         port_to_port_delay);
 349
 350         if (hub_u2_del > hub_u1_del)
 351                 port_to_port_delay = 1 + hub_u2_del - hub_u1_del;
 352         else
 353                 port_to_port_delay = 1 + hub_u1_del;
 354
 355         usb_set_lpm_pel(udev, &udev->u2_params, udev_u2_del,
 356                         hub, &udev->parent->u2_params, hub_u2_del,
 357                         port_to_port_delay);
 358
 359         /* Now that we've got PEL, calculate SEL. */
 360         usb_set_lpm_sel(udev, &udev->u1_params);
 361         usb_set_lpm_sel(udev, &udev->u2_params);
 362 }
 363
 364 /* USB 2.0 spec Section 11.24.4.5 */
 365 static int get_hub_descriptor(struct usb_device *hdev,
 366                 struct usb_hub_descriptor *desc)
 367 {
 368         int i, ret, size;
 369         unsigned dtype;
 370
 371         if (hub_is_superspeed(hdev)) {
 372                 dtype = USB_DT_SS_HUB;
 373                 size = USB_DT_SS_HUB_SIZE;
 374         } else {
 375                 dtype = USB_DT_HUB;
 376                 size = sizeof(struct usb_hub_descriptor);
 377         }
 378
 379         for (i = 0; i < 3; i++) {
 380                 ret = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
 381                         USB_REQ_GET_DESCRIPTOR, USB_DIR_IN | USB_RT_HUB,
 382                         dtype << 8, 0, desc, size,
 383                         USB_CTRL_GET_TIMEOUT);
 384                 if (hub_is_superspeed(hdev)) {
 385                         if (ret == size)
 386                                 return ret;
 387                 } else if (ret >= USB_DT_HUB_NONVAR_SIZE + 2) {
 388                         /* Make sure we have the DeviceRemovable field. */
 389                         size = USB_DT_HUB_NONVAR_SIZE + desc->bNbrPorts / 8 + 1;
 390                         if (ret < size)
 391                                 return -EMSGSIZE;
 392                         return ret;
 393                 }
 394         }
 395         return -EINVAL;
 396 }
 397
 398 /*
 399  * USB 2.0 spec Section 11.24.2.1
 400  */
 401 static int clear_hub_feature(struct usb_device *hdev, int feature)
 402 {
 403         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 404                 USB_REQ_CLEAR_FEATURE, USB_RT_HUB, feature, 0, NULL, 0, 1000);
 405 }
 406
 407 /*
 408  * USB 2.0 spec Section 11.24.2.2
 409  */
 410 int usb_clear_port_feature(struct usb_device *hdev, int port1, int feature)
 411 {
 412         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 413                 USB_REQ_CLEAR_FEATURE, USB_RT_PORT, feature, port1,
 414                 NULL, 0, 1000);
 415 }
 416
 417 /*
 418  * USB 2.0 spec Section 11.24.2.13
 419  */
 420 static int set_port_feature(struct usb_device *hdev, int port1, int feature)
 421 {
 422         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 423                 USB_REQ_SET_FEATURE, USB_RT_PORT, feature, port1,
 424                 NULL, 0, 1000);
 425 }
 426
 427 static char *to_led_name(int selector)
 428 {
 429         switch (selector) {
 430         case HUB_LED_AMBER:
 431                 return "amber";
 432         case HUB_LED_GREEN:
 433                 return "green";
 434         case HUB_LED_OFF:
 435                 return "off";
 436         case HUB_LED_AUTO:
 437                 return "auto";
 438         default:
 439                 return "??";
 440         }
 441 }
 442
 443 /*
 444  * USB 2.0 spec Section 11.24.2.7.1.10 and table 11-7
 445  * for info about using port indicators
 446  */
 447 static void set_port_led(struct usb_hub *hub, int port1, int selector)
 448 {
 449         struct usb_port *port_dev = hub->ports[port1 - 1];
 450         int status;
 451
 452         status = set_port_feature(hub->hdev, (selector << 8) | port1,
 453                         USB_PORT_FEAT_INDICATOR);
 454         dev_dbg(&port_dev->dev, "indicator %s status %d\n",
 455                 to_led_name(selector), status);
 456 }
 457
 458 #define LED_CYCLE_PERIOD        ((2*HZ)/3)
 459
 460 static void led_work(struct work_struct *work)
 461 {
 462         struct usb_hub          *hub =
 463                 container_of(work, struct usb_hub, leds.work);
 464         struct usb_device       *hdev = hub->hdev;
 465         unsigned                i;
 466         unsigned                changed = 0;
 467         int                     cursor = -1;
 468
 469         if (hdev->state != USB_STATE_CONFIGURED || hub->quiescing)
 470                 return;
 471
 472         for (i = 0; i < hdev->maxchild; i++) {
 473                 unsigned        selector, mode;
 474
 475                 /* 30%-50% duty cycle */
 476
 477                 switch (hub->indicator[i]) {
 478                 /* cycle marker */
 479                 case INDICATOR_CYCLE:
 480                         cursor = i;
 481                         selector = HUB_LED_AUTO;
 482                         mode = INDICATOR_AUTO;
 483                         break;
 484                 /* blinking green = sw attention */
 485                 case INDICATOR_GREEN_BLINK:
 486                         selector = HUB_LED_GREEN;
 487                         mode = INDICATOR_GREEN_BLINK_OFF;
 488                         break;
 489                 case INDICATOR_GREEN_BLINK_OFF:
 490                         selector = HUB_LED_OFF;
 491                         mode = INDICATOR_GREEN_BLINK;
 492                         break;
 493                 /* blinking amber = hw attention */
 494                 case INDICATOR_AMBER_BLINK:
 495                         selector = HUB_LED_AMBER;
 496                         mode = INDICATOR_AMBER_BLINK_OFF;
 497                         break;
 498                 case INDICATOR_AMBER_BLINK_OFF:
 499                         selector = HUB_LED_OFF;
 500                         mode = INDICATOR_AMBER_BLINK;
 501                         break;
 502                 /* blink green/amber = reserved */
 503                 case INDICATOR_ALT_BLINK:
 504                         selector = HUB_LED_GREEN;
 505                         mode = INDICATOR_ALT_BLINK_OFF;
 506                         break;
 507                 case INDICATOR_ALT_BLINK_OFF:
 508                         selector = HUB_LED_AMBER;
 509                         mode = INDICATOR_ALT_BLINK;
 510                         break;
 511                 default:
 512                         continue;
 513                 }
 514                 if (selector != HUB_LED_AUTO)
 515                         changed = 1;
 516                 set_port_led(hub, i + 1, selector);
 517                 hub->indicator[i] = mode;
 518         }
 519         if (!changed && blinkenlights) {
 520                 cursor++;
 521                 cursor %= hdev->maxchild;
 522                 set_port_led(hub, cursor + 1, HUB_LED_GREEN);
 523                 hub->indicator[cursor] = INDICATOR_CYCLE;
 524                 changed++;
 525         }
 526         if (changed)
 527                 queue_delayed_work(system_power_efficient_wq,
 528                                 &hub->leds, LED_CYCLE_PERIOD);
 529 }
 530
 531 /* use a short timeout for hub/port status fetches */
 532 #define USB_STS_TIMEOUT         1000
 533 #define USB_STS_RETRIES         5
 534
 535 /*
 536  * USB 2.0 spec Section 11.24.2.6
 537  */
 538 static int get_hub_status(struct usb_device *hdev,
 539                 struct usb_hub_status *data)
 540 {
 541         int i, status = -ETIMEDOUT;
 542
 543         for (i = 0; i < USB_STS_RETRIES &&
 544                         (status == -ETIMEDOUT || status == -EPIPE); i++) {
 545                 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
 546                         USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_HUB, 0, 0,
 547                         data, sizeof(*data), USB_STS_TIMEOUT);
 548         }
 549         return status;
 550 }
 551
 552 /*
 553  * USB 2.0 spec Section 11.24.2.7
 554  * USB 3.1 takes into use the wValue and wLength fields, spec Section 10.16.2.6
 555  */
 556 static int get_port_status(struct usb_device *hdev, int port1,
 557                            void *data, u16 value, u16 length)
 558 {
 559         int i, status = -ETIMEDOUT;
 560
 561         for (i = 0; i < USB_STS_RETRIES &&
 562                         (status == -ETIMEDOUT || status == -EPIPE); i++) {
 563                 status = usb_control_msg(hdev, usb_rcvctrlpipe(hdev, 0),
 564                         USB_REQ_GET_STATUS, USB_DIR_IN | USB_RT_PORT, value,
 565                         port1, data, length, USB_STS_TIMEOUT);
 566         }
 567         return status;
 568 }
 569
 570 static int hub_ext_port_status(struct usb_hub *hub, int port1, int type,
 571                                u16 *status, u16 *change, u32 *ext_status)
 572 {
 573         int ret;
 574         int len = 4;
 575
 576         if (type != HUB_PORT_STATUS)
 577                 len = 8;
 578
 579         mutex_lock(&hub->status_mutex);
 580         ret = get_port_status(hub->hdev, port1, &hub->status->port, type, len);
 581         if (ret < len) {
 582                 if (ret != -ENODEV)
 583                         dev_err(hub->intfdev,
 584                                 "%s failed (err = %d)\n", __func__, ret);
 585                 if (ret >= 0)
 586                         ret = -EIO;
 587         } else {
 588                 *status = le16_to_cpu(hub->status->port.wPortStatus);
 589                 *change = le16_to_cpu(hub->status->port.wPortChange);
 590                 if (type != HUB_PORT_STATUS && ext_status)
 591                         *ext_status = le32_to_cpu(
 592                                 hub->status->port.dwExtPortStatus);
 593                 ret = 0;
 594         }
 595         mutex_unlock(&hub->status_mutex);
 596         return ret;
 597 }
 598
 599 static int hub_port_status(struct usb_hub *hub, int port1,
 600                 u16 *status, u16 *change)
 601 {
 602         return hub_ext_port_status(hub, port1, HUB_PORT_STATUS,
 603                                    status, change, NULL);
 604 }
 605
 606 static void kick_hub_wq(struct usb_hub *hub)
 607 {
 608         struct usb_interface *intf;
 609
 610         if (hub->disconnected || work_pending(&hub->events))
 611                 return;
 612
 613         /*
 614          * Suppress autosuspend until the event is proceed.
 615          *
 616          * Be careful and make sure that the symmetric operation is
 617          * always called. We are here only when there is no pending
 618          * work for this hub. Therefore put the interface either when
 619          * the new work is called or when it is canceled.
 620          */
 621         intf = to_usb_interface(hub->intfdev);
 622         usb_autopm_get_interface_no_resume(intf);
 623         kref_get(&hub->kref);
 624
 625         if (queue_work(hub_wq, &hub->events))
 626                 return;
 627
 628         /* the work has already been scheduled */
 629         usb_autopm_put_interface_async(intf);
 630         kref_put(&hub->kref, hub_release);
 631 }
 632
 633 void usb_kick_hub_wq(struct usb_device *hdev)
 634 {
 635         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
 636
 637         if (hub)
 638                 kick_hub_wq(hub);
 639 }
 640
 641 /*
 642  * Let the USB core know that a USB 3.0 device has sent a Function Wake Device
 643  * Notification, which indicates it had initiated remote wakeup.
 644  *
 645  * USB 3.0 hubs do not report the port link state change from U3 to U0 when the
 646  * device initiates resume, so the USB core will not receive notice of the
 647  * resume through the normal hub interrupt URB.
 648  */
 649 void usb_wakeup_notification(struct usb_device *hdev,
 650                 unsigned int portnum)
 651 {
 652         struct usb_hub *hub;
 653
 654         if (!hdev)
 655                 return;
 656
 657         hub = usb_hub_to_struct_hub(hdev);
 658         if (hub) {
 659                 set_bit(portnum, hub->wakeup_bits);
 660                 kick_hub_wq(hub);
 661         }
 662 }
 663 EXPORT_SYMBOL_GPL(usb_wakeup_notification);
 664
 665 /* completion function, fires on port status changes and various faults */
 666 static void hub_irq(struct urb *urb)
 667 {
 668         struct usb_hub *hub = urb->context;
 669         int status = urb->status;
 670         unsigned i;
 671         unsigned long bits;
 672
 673         switch (status) {
 674         case -ENOENT:           /* synchronous unlink */
 675         case -ECONNRESET:       /* async unlink */
 676         case -ESHUTDOWN:        /* hardware going away */
 677                 return;
 678
 679         default:                /* presumably an error */
 680                 /* Cause a hub reset after 10 consecutive errors */
 681                 dev_dbg(hub->intfdev, "transfer --> %d\n", status);
 682                 if ((++hub->nerrors < 10) || hub->error)
 683                         goto resubmit;
 684                 hub->error = status;
 685                 /* FALL THROUGH */
 686
 687         /* let hub_wq handle things */
 688         case 0:                 /* we got data:  port status changed */
 689                 bits = 0;
 690                 for (i = 0; i < urb->actual_length; ++i)
 691                         bits |= ((unsigned long) ((*hub->buffer)[i]))
 692                                         << (i*8);
 693                 hub->event_bits[0] = bits;
 694                 break;
 695         }
 696
 697         hub->nerrors = 0;
 698
 699         /* Something happened, let hub_wq figure it out */
 700         kick_hub_wq(hub);
 701
 702 resubmit:
 703         if (hub->quiescing)
 704                 return;
 705
 706         status = usb_submit_urb(hub->urb, GFP_ATOMIC);
 707         if (status != 0 && status != -ENODEV && status != -EPERM)
 708                 dev_err(hub->intfdev, "resubmit --> %d\n", status);
 709 }
 710
 711 /* USB 2.0 spec Section 11.24.2.3 */
 712 static inline int
 713 hub_clear_tt_buffer(struct usb_device *hdev, u16 devinfo, u16 tt)
 714 {
 715         /* Need to clear both directions for control ep */
 716         if (((devinfo >> 11) & USB_ENDPOINT_XFERTYPE_MASK) ==
 717                         USB_ENDPOINT_XFER_CONTROL) {
 718                 int status = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 719                                 HUB_CLEAR_TT_BUFFER, USB_RT_PORT,
 720                                 devinfo ^ 0x8000, tt, NULL, 0, 1000);
 721                 if (status)
 722                         return status;
 723         }
 724         return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
 725                                HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
 726                                tt, NULL, 0, 1000);
 727 }
 728
 729 /*
 730  * enumeration blocks hub_wq for a long time. we use keventd instead, since
 731  * long blocking there is the exception, not the rule.  accordingly, HCDs
 732  * talking to TTs must queue control transfers (not just bulk and iso), so
 733  * both can talk to the same hub concurrently.
 734  */
 735 static void hub_tt_work(struct work_struct *work)
 736 {
 737         struct usb_hub          *hub =
 738                 container_of(work, struct usb_hub, tt.clear_work);
 739         unsigned long           flags;
 740
 741         spin_lock_irqsave(&hub->tt.lock, flags);
 742         while (!list_empty(&hub->tt.clear_list)) {
 743                 struct list_head        *next;
 744                 struct usb_tt_clear     *clear;
 745                 struct usb_device       *hdev = hub->hdev;
 746                 const struct hc_driver  *drv;
 747                 int                     status;
 748
 749                 next = hub->tt.clear_list.next;
 750                 clear = list_entry(next, struct usb_tt_clear, clear_list);
 751                 list_del(&clear->clear_list);
 752
 753                 /* drop lock so HCD can concurrently report other TT errors */
 754                 spin_unlock_irqrestore(&hub->tt.lock, flags);
 755                 status = hub_clear_tt_buffer(hdev, clear->devinfo, clear->tt);
 756                 if (status && status != -ENODEV)
 757                         dev_err(&hdev->dev,
 758                                 "clear tt %d (%04x) error %d\n",
 759                                 clear->tt, clear->devinfo, status);
 760
 761                 /* Tell the HCD, even if the operation failed */
 762                 drv = clear->hcd->driver;
 763                 if (drv->clear_tt_buffer_complete)
 764                         (drv->clear_tt_buffer_complete)(clear->hcd, clear->ep);
 765
 766                 kfree(clear);
 767                 spin_lock_irqsave(&hub->tt.lock, flags);
 768         }
 769         spin_unlock_irqrestore(&hub->tt.lock, flags);
 770 }
 771
 772 /**
 773  * usb_hub_set_port_power - control hub port's power state
 774  * @hdev: USB device belonging to the usb hub
 775  * @hub: target hub
 776  * @port1: port index
 777  * @set: expected status
 778  *
 779  * call this function to control port's power via setting or
 780  * clearing the port's PORT_POWER feature.
 781  *
 782  * Return: 0 if successful. A negative error code otherwise.
 783  */
 784 int usb_hub_set_port_power(struct usb_device *hdev, struct usb_hub *hub,
 785                            int port1, bool set)
 786 {
 787         int ret;
 788
 789         if (set)
 790                 ret = set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
 791         else
 792                 ret = usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
 793
 794         if (ret)
 795                 return ret;
 796
 797         if (set)
 798                 set_bit(port1, hub->power_bits);
 799         else
 800                 clear_bit(port1, hub->power_bits);
 801         return 0;
 802 }
 803
 804 /**
 805  * usb_hub_clear_tt_buffer - clear control/bulk TT state in high speed hub
 806  * @urb: an URB associated with the failed or incomplete split transaction
 807  *
 808  * High speed HCDs use this to tell the hub driver that some split control or
 809  * bulk transaction failed in a way that requires clearing internal state of
 810  * a transaction translator.  This is normally detected (and reported) from
 811  * interrupt context.
 812  *
 813  * It may not be possible for that hub to handle additional full (or low)
 814  * speed transactions until that state is fully cleared out.
 815  *
 816  * Return: 0 if successful. A negative error code otherwise.
 817  */
 818 int usb_hub_clear_tt_buffer(struct urb *urb)
 819 {
 820         struct usb_device       *udev = urb->dev;
 821         int                     pipe = urb->pipe;
 822         struct usb_tt           *tt = udev->tt;
 823         unsigned long           flags;
 824         struct usb_tt_clear     *clear;
 825
 826         /* we've got to cope with an arbitrary number of pending TT clears,
 827          * since each TT has "at least two" buffers that can need it (and
 828          * there can be many TTs per hub).  even if they're uncommon.
 829          */
 830         clear = kmalloc(sizeof *clear, GFP_ATOMIC);
 831         if (clear == NULL) {
 832                 dev_err(&udev->dev, "can't save CLEAR_TT_BUFFER state\n");
 833                 /* FIXME recover somehow ... RESET_TT? */
 834                 return -ENOMEM;
 835         }
 836
 837         /* info that CLEAR_TT_BUFFER needs */
 838         clear->tt = tt->multi ? udev->ttport : 1;
 839         clear->devinfo = usb_pipeendpoint (pipe);
 840         clear->devinfo |= udev->devnum << 4;
 841         clear->devinfo |= usb_pipecontrol(pipe)
 842                         ? (USB_ENDPOINT_XFER_CONTROL << 11)
 843                         : (USB_ENDPOINT_XFER_BULK << 11);
 844         if (usb_pipein(pipe))
 845                 clear->devinfo |= 1 << 15;
 846
 847         /* info for completion callback */
 848         clear->hcd = bus_to_hcd(udev->bus);
 849         clear->ep = urb->ep;
 850
 851         /* tell keventd to clear state for this TT */
 852         spin_lock_irqsave(&tt->lock, flags);
 853         list_add_tail(&clear->clear_list, &tt->clear_list);
 854         schedule_work(&tt->clear_work);
 855         spin_unlock_irqrestore(&tt->lock, flags);
 856         return 0;
 857 }
 858 EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer);
 859
 860 static void hub_power_on(struct usb_hub *hub, bool do_delay)
 861 {
 862         int port1;
 863
 864         /* Enable power on each port.  Some hubs have reserved values
 865          * of LPSM (> 2) in their descriptors, even though they are
 866          * USB 2.0 hubs.  Some hubs do not implement port-power switching
 867          * but only emulate it.  In all cases, the ports won't work
 868          * unless we send these messages to the hub.
 869          */
 870         if (hub_is_port_power_switchable(hub))
 871                 dev_dbg(hub->intfdev, "enabling power on all ports\n");
 872         else
 873                 dev_dbg(hub->intfdev, "trying to enable port power on "
 874                                 "non-switchable hub\n");
 875         for (port1 = 1; port1 <= hub->hdev->maxchild; port1++)
 876                 if (test_bit(port1, hub->power_bits))
 877                         set_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER);
 878                 else
 879                         usb_clear_port_feature(hub->hdev, port1,
 880                                                 USB_PORT_FEAT_POWER);
 881         if (do_delay)
 882                 msleep(hub_power_on_good_delay(hub));
 883 }
 884
 885 static int hub_hub_status(struct usb_hub *hub,
 886                 u16 *status, u16 *change)
 887 {
 888         int ret;
 889
 890         mutex_lock(&hub->status_mutex);
 891         ret = get_hub_status(hub->hdev, &hub->status->hub);
 892         if (ret < 0) {
 893                 if (ret != -ENODEV)
 894                         dev_err(hub->intfdev,
 895                                 "%s failed (err = %d)\n", __func__, ret);
 896         } else {
 897                 *status = le16_to_cpu(hub->status->hub.wHubStatus);
 898                 *change = le16_to_cpu(hub->status->hub.wHubChange);
 899                 ret = 0;
 900         }
 901         mutex_unlock(&hub->status_mutex);
 902         return ret;
 903 }
 904
 905 static int hub_set_port_link_state(struct usb_hub *hub, int port1,
 906                         unsigned int link_status)
 907 {
 908         return set_port_feature(hub->hdev,
 909                         port1 | (link_status << 3),
 910                         USB_PORT_FEAT_LINK_STATE);
 911 }
 912
 913 /*
 914  * Disable a port and mark a logical connect-change event, so that some
 915  * time later hub_wq will disconnect() any existing usb_device on the port
 916  * and will re-enumerate if there actually is a device attached.
 917  */
 918 static void hub_port_logical_disconnect(struct usb_hub *hub, int port1)
 919 {
 920         dev_dbg(&hub->ports[port1 - 1]->dev, "logical disconnect\n");
 921         hub_port_disable(hub, port1, 1);
 922
 923         /* FIXME let caller ask to power down the port:
 924          *  - some devices won't enumerate without a VBUS power cycle
 925          *  - SRP saves power that way
 926          *  - ... new call, TBD ...
 927          * That's easy if this hub can switch power per-port, and
 928          * hub_wq reactivates the port later (timer, SRP, etc).
 929          * Powerdown must be optional, because of reset/DFU.
 930          */
 931
 932         set_bit(port1, hub->change_bits);
 933         kick_hub_wq(hub);
 934 }
 935
 936 /**
 937  * usb_remove_device - disable a device's port on its parent hub
 938  * @udev: device to be disabled and removed
 939  * Context: @udev locked, must be able to sleep.
 940  *
 941  * After @udev's port has been disabled, hub_wq is notified and it will
 942  * see that the device has been disconnected.  When the device is
 943  * physically unplugged and something is plugged in, the events will
 944  * be received and processed normally.
 945  *
 946  * Return: 0 if successful. A negative error code otherwise.
 947  */
 948 int usb_remove_device(struct usb_device *udev)
 949 {
 950         struct usb_hub *hub;
 951         struct usb_interface *intf;
 952
 953         if (!udev->parent)      /* Can't remove a root hub */
 954                 return -EINVAL;
 955         hub = usb_hub_to_struct_hub(udev->parent);
 956         intf = to_usb_interface(hub->intfdev);
 957
 958         usb_autopm_get_interface(intf);
 959         set_bit(udev->portnum, hub->removed_bits);
 960         hub_port_logical_disconnect(hub, udev->portnum);
 961         usb_autopm_put_interface(intf);
 962         return 0;
 963 }
 964
 965 enum hub_activation_type {
 966         HUB_INIT, HUB_INIT2, HUB_INIT3,         /* INITs must come first */
 967         HUB_POST_RESET, HUB_RESUME, HUB_RESET_RESUME,
 968 };
 969
 970 static void hub_init_func2(struct work_struct *ws);
 971 static void hub_init_func3(struct work_struct *ws);
 972
 973 static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 974 {
 975         struct usb_device *hdev = hub->hdev;
 976         struct usb_hcd *hcd;
 977         int ret;
 978         int port1;
 979         int status;
 980         bool need_debounce_delay = false;
 981         unsigned delay;
 982
 983         /* Continue a partial initialization */
 984         if (type == HUB_INIT2 || type == HUB_INIT3) {
 985                 device_lock(&hdev->dev);
 986
 987                 /* Was the hub disconnected while we were waiting? */
 988                 if (hub->disconnected)
 989                         goto disconnected;
 990                 if (type == HUB_INIT2)
 991                         goto init2;
 992                 goto init3;
 993         }
 994         kref_get(&hub->kref);
 995
 996         /* The superspeed hub except for root hub has to use Hub Depth
 997          * value as an offset into the route string to locate the bits
 998          * it uses to determine the downstream port number. So hub driver
 999          * should send a set hub depth request to superspeed hub after
1000          * the superspeed hub is set configuration in initialization or
1001          * reset procedure.
1002          *
1003          * After a resume, port power should still be on.
1004          * For any other type of activation, turn it on.
1005          */
1006         if (type != HUB_RESUME) {
1007                 if (hdev->parent && hub_is_superspeed(hdev)) {
1008                         ret = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
1009                                         HUB_SET_DEPTH, USB_RT_HUB,
1010                                         hdev->level - 1, 0, NULL, 0,
1011                                         USB_CTRL_SET_TIMEOUT);
1012                         if (ret < 0)
1013                                 dev_err(hub->intfdev,
1014                                                 "set hub depth failed\n");
1015                 }
1016
1017                 /* Speed up system boot by using a delayed_work for the
1018                  * hub's initial power-up delays.  This is pretty awkward
1019                  * and the implementation looks like a home-brewed sort of
1020                  * setjmp/longjmp, but it saves at least 100 ms for each
1021                  * root hub (assuming usbcore is compiled into the kernel
1022                  * rather than as a module).  It adds up.
1023                  *
1024                  * This can't be done for HUB_RESUME or HUB_RESET_RESUME
1025                  * because for those activation types the ports have to be
1026                  * operational when we return.  In theory this could be done
1027                  * for HUB_POST_RESET, but it's easier not to.
1028                  */
1029                 if (type == HUB_INIT) {
1030                         delay = hub_power_on_good_delay(hub);
1031
1032                         hub_power_on(hub, false);
1033                         INIT_DELAYED_WORK(&hub->init_work, hub_init_func2);
1034                         queue_delayed_work(system_power_efficient_wq,
1035                                         &hub->init_work,
1036                                         msecs_to_jiffies(delay));
1037
1038                         /* Suppress autosuspend until init is done */
1039                         usb_autopm_get_interface_no_resume(
1040                                         to_usb_interface(hub->intfdev));
1041                         return;         /* Continues at init2: below */
1042                 } else if (type == HUB_RESET_RESUME) {
1043                         /* The internal host controller state for the hub device
1044                          * may be gone after a host power loss on system resume.
1045                          * Update the device's info so the HW knows it's a hub.
1046                          */
1047                         hcd = bus_to_hcd(hdev->bus);
1048                         if (hcd->driver->update_hub_device) {
1049                                 ret = hcd->driver->update_hub_device(hcd, hdev,
1050                                                 &hub->tt, GFP_NOIO);
1051                                 if (ret < 0) {
1052                                         dev_err(hub->intfdev, "Host not "
1053                                                         "accepting hub info "
1054                                                         "update.\n");
1055                                         dev_err(hub->intfdev, "LS/FS devices "
1056                                                         "and hubs may not work "
1057                                                         "under this hub\n.");
1058                                 }
1059                         }
1060                         hub_power_on(hub, true);
1061                 } else {
1062                         hub_power_on(hub, true);
1063                 }
1064         }
1065  init2:
1066
1067         /*
1068          * Check each port and set hub->change_bits to let hub_wq know
1069          * which ports need attention.
1070          */
1071         for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
1072                 struct usb_port *port_dev = hub->ports[port1 - 1];
1073                 struct usb_device *udev = port_dev->child;
1074                 u16 portstatus, portchange;
1075
1076                 portstatus = portchange = 0;
1077                 status = hub_port_status(hub, port1, &portstatus, &portchange);
1078                 if (status)
1079                         goto abort;
1080
1081                 if (udev || (portstatus & USB_PORT_STAT_CONNECTION))
1082                         dev_dbg(&port_dev->dev, "status %04x change %04x\n",
1083                                         portstatus, portchange);
1084
1085                 /*
1086                  * After anything other than HUB_RESUME (i.e., initialization
1087                  * or any sort of reset), every port should be disabled.
1088                  * Unconnected ports should likewise be disabled (paranoia),
1089                  * and so should ports for which we have no usb_device.
1090                  */
1091                 if ((portstatus & USB_PORT_STAT_ENABLE) && (
1092                                 type != HUB_RESUME ||
1093                                 !(portstatus & USB_PORT_STAT_CONNECTION) ||
1094                                 !udev ||
1095                                 udev->state == USB_STATE_NOTATTACHED)) {
1096                         /*
1097                          * USB3 protocol ports will automatically transition
1098                          * to Enabled state when detect an USB3.0 device attach.
1099                          * Do not disable USB3 protocol ports, just pretend
1100                          * power was lost
1101                          */
1102                         portstatus &= ~USB_PORT_STAT_ENABLE;
1103                         if (!hub_is_superspeed(hdev))
1104                                 usb_clear_port_feature(hdev, port1,
1105                                                    USB_PORT_FEAT_ENABLE);
1106                 }
1107
1108                 /* Clear status-change flags; we'll debounce later */
1109                 if (portchange & USB_PORT_STAT_C_CONNECTION) {
1110                         need_debounce_delay = true;
1111                         usb_clear_port_feature(hub->hdev, port1,
1112                                         USB_PORT_FEAT_C_CONNECTION);
1113                 }
1114                 if (portchange & USB_PORT_STAT_C_ENABLE) {
1115                         need_debounce_delay = true;
1116                         usb_clear_port_feature(hub->hdev, port1,
1117                                         USB_PORT_FEAT_C_ENABLE);
1118                 }
1119                 if (portchange & USB_PORT_STAT_C_RESET) {
1120                         need_debounce_delay = true;
1121                         usb_clear_port_feature(hub->hdev, port1,
1122                                         USB_PORT_FEAT_C_RESET);
1123                 }
1124                 if ((portchange & USB_PORT_STAT_C_BH_RESET) &&
1125                                 hub_is_superspeed(hub->hdev)) {
1126                         need_debounce_delay = true;
1127                         usb_clear_port_feature(hub->hdev, port1,
1128                                         USB_PORT_FEAT_C_BH_PORT_RESET);
1129                 }
1130                 /* We can forget about a "removed" device when there's a
1131                  * physical disconnect or the connect status changes.
1132                  */
1133                 if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
1134                                 (portchange & USB_PORT_STAT_C_CONNECTION))
1135                         clear_bit(port1, hub->removed_bits);
1136
1137                 if (!udev || udev->state == USB_STATE_NOTATTACHED) {
1138                         /* Tell hub_wq to disconnect the device or
1139                          * check for a new connection
1140                          */
1141                         if (udev || (portstatus & USB_PORT_STAT_CONNECTION) ||
1142                             (portstatus & USB_PORT_STAT_OVERCURRENT))
1143                                 set_bit(port1, hub->change_bits);
1144
1145                 } else if (portstatus & USB_PORT_STAT_ENABLE) {
1146                         bool port_resumed = (portstatus &
1147                                         USB_PORT_STAT_LINK_STATE) ==
1148                                 USB_SS_PORT_LS_U0;
1149                         /* The power session apparently survived the resume.
1150                          * If there was an overcurrent or suspend change
1151                          * (i.e., remote wakeup request), have hub_wq
1152                          * take care of it.  Look at the port link state
1153                          * for USB 3.0 hubs, since they don't have a suspend
1154                          * change bit, and they don't set the port link change
1155                          * bit on device-initiated resume.
1156                          */
1157                         if (portchange || (hub_is_superspeed(hub->hdev) &&
1158                                                 port_resumed))
1159                                 set_bit(port1, hub->change_bits);
1160
1161                 } else if (udev->persist_enabled) {
1162 #ifdef CONFIG_PM
1163                         udev->reset_resume = 1;
1164 #endif
1165                         /* Don't set the change_bits when the device
1166                          * was powered off.
1167                          */
1168                         if (test_bit(port1, hub->power_bits))
1169                                 set_bit(port1, hub->change_bits);
1170
1171                 } else {
1172                         /* The power session is gone; tell hub_wq */
1173                         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
1174                         set_bit(port1, hub->change_bits);
1175                 }
1176         }
1177
1178         /* If no port-status-change flags were set, we don't need any
1179          * debouncing.  If flags were set we can try to debounce the
1180          * ports all at once right now, instead of letting hub_wq do them
1181          * one at a time later on.
1182          *
1183          * If any port-status changes do occur during this delay, hub_wq
1184          * will see them later and handle them normally.
1185          */
1186         if (need_debounce_delay) {
1187                 delay = HUB_DEBOUNCE_STABLE;
1188
1189                 /* Don't do a long sleep inside a workqueue routine */
1190                 if (type == HUB_INIT2) {
1191                         INIT_DELAYED_WORK(&hub->init_work, hub_init_func3);
1192                         queue_delayed_work(system_power_efficient_wq,
1193                                         &hub->init_work,
1194                                         msecs_to_jiffies(delay));
1195                         device_unlock(&hdev->dev);
1196                         return;         /* Continues at init3: below */
1197                 } else {
1198                         msleep(delay);
1199                 }
1200         }
1201  init3:
1202         hub->quiescing = 0;
1203
1204         status = usb_submit_urb(hub->urb, GFP_NOIO);
1205         if (status < 0)
1206                 dev_err(hub->intfdev, "activate --> %d\n", status);
1207         if (hub->has_indicators && blinkenlights)
1208                 queue_delayed_work(system_power_efficient_wq,
1209                                 &hub->leds, LED_CYCLE_PERIOD);
1210
1211         /* Scan all ports that need attention */
1212         kick_hub_wq(hub);
1213  abort:
1214         if (type == HUB_INIT2 || type == HUB_INIT3) {
1215                 /* Allow autosuspend if it was suppressed */
1216  disconnected:
1217                 usb_autopm_put_interface_async(to_usb_interface(hub->intfdev));
1218                 device_unlock(&hdev->dev);
1219         }
1220
1221         kref_put(&hub->kref, hub_release);
1222 }
1223
1224 /* Implement the continuations for the delays above */
1225 static void hub_init_func2(struct work_struct *ws)
1226 {
1227         struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1228
1229         hub_activate(hub, HUB_INIT2);
1230 }
1231
1232 static void hub_init_func3(struct work_struct *ws)
1233 {
1234         struct usb_hub *hub = container_of(ws, struct usb_hub, init_work.work);
1235
1236         hub_activate(hub, HUB_INIT3);
1237 }
1238
1239 enum hub_quiescing_type {
1240         HUB_DISCONNECT, HUB_PRE_RESET, HUB_SUSPEND
1241 };
1242
1243 static void hub_quiesce(struct usb_hub *hub, enum hub_quiescing_type type)
1244 {
1245         struct usb_device *hdev = hub->hdev;
1246         int i;
1247
1248         /* hub_wq and related activity won't re-trigger */
1249         hub->quiescing = 1;
1250
1251         if (type != HUB_SUSPEND) {
1252                 /* Disconnect all the children */
1253                 for (i = 0; i < hdev->maxchild; ++i) {
1254                         if (hub->ports[i]->child)
1255                                 usb_disconnect(&hub->ports[i]->child);
1256                 }
1257         }
1258
1259         /* Stop hub_wq and related activity */
1260         usb_kill_urb(hub->urb);
1261         if (hub->has_indicators)
1262                 cancel_delayed_work_sync(&hub->leds);
1263         if (hub->tt.hub)
1264                 flush_work(&hub->tt.clear_work);
1265 }
1266
1267 static void hub_pm_barrier_for_all_ports(struct usb_hub *hub)
1268 {
1269         int i;
1270
1271         for (i = 0; i < hub->hdev->maxchild; ++i)
1272                 pm_runtime_barrier(&hub->ports[i]->dev);
1273 }
1274
1275 /* caller has locked the hub device */
1276 static int hub_pre_reset(struct usb_interface *intf)
1277 {
1278         struct usb_hub *hub = usb_get_intfdata(intf);
1279
1280         hub_quiesce(hub, HUB_PRE_RESET);
1281         hub->in_reset = 1;
1282         hub_pm_barrier_for_all_ports(hub);
1283         return 0;
1284 }
1285
1286 /* caller has locked the hub device */
1287 static int hub_post_reset(struct usb_interface *intf)
1288 {
1289         struct usb_hub *hub = usb_get_intfdata(intf);
1290
1291         hub->in_reset = 0;
1292         hub_pm_barrier_for_all_ports(hub);
1293         hub_activate(hub, HUB_POST_RESET);
1294         return 0;
1295 }
1296
1297 static int hub_configure(struct usb_hub *hub,
1298         struct usb_endpoint_descriptor *endpoint)
1299 {
1300         struct usb_hcd *hcd;
1301         struct usb_device *hdev = hub->hdev;
1302         struct device *hub_dev = hub->intfdev;
1303         u16 hubstatus, hubchange;
1304         u16 wHubCharacteristics;
1305         unsigned int pipe;
1306         int maxp, ret, i;
1307         char *message = "out of memory";
1308         unsigned unit_load;
1309         unsigned full_load;
1310         unsigned maxchild;
1311
1312         hub->buffer = kmalloc(sizeof(*hub->buffer), GFP_KERNEL);
1313         if (!hub->buffer) {
1314                 ret = -ENOMEM;
1315                 goto fail;
1316         }
1317
1318         hub->status = kmalloc(sizeof(*hub->status), GFP_KERNEL);
1319         if (!hub->status) {
1320                 ret = -ENOMEM;
1321                 goto fail;
1322         }
1323         mutex_init(&hub->status_mutex);
1324
1325         hub->descriptor = kzalloc(sizeof(*hub->descriptor), GFP_KERNEL);
1326         if (!hub->descriptor) {
1327                 ret = -ENOMEM;
1328                 goto fail;
1329         }
1330
1331         /* Request the entire hub descriptor.
1332          * hub->descriptor can handle USB_MAXCHILDREN ports,
1333          * but a (non-SS) hub can/will return fewer bytes here.
1334          */
1335         ret = get_hub_descriptor(hdev, hub->descriptor);
1336         if (ret < 0) {
1337                 message = "can't read hub descriptor";
1338                 goto fail;
1339         }
1340
1341         maxchild = USB_MAXCHILDREN;
1342         if (hub_is_superspeed(hdev))
1343                 maxchild = min_t(unsigned, maxchild, USB_SS_MAXPORTS);
1344
1345         if (hub->descriptor->bNbrPorts > maxchild) {
1346                 message = "hub has too many ports!";
1347                 ret = -ENODEV;
1348                 goto fail;
1349         } else if (hub->descriptor->bNbrPorts == 0) {
1350                 message = "hub doesn't have any ports!";
1351                 ret = -ENODEV;
1352                 goto fail;
1353         }
1354
1355         maxchild = hub->descriptor->bNbrPorts;
1356         dev_info(hub_dev, "%d port%s detected\n", maxchild,
1357                         (maxchild == 1) ? "" : "s");
1358
1359         hub->ports = kzalloc(maxchild * sizeof(struct usb_port *), GFP_KERNEL);
1360         if (!hub->ports) {
1361                 ret = -ENOMEM;
1362                 goto fail;
1363         }
1364
1365         wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
1366         if (hub_is_superspeed(hdev)) {
1367                 unit_load = 150;
1368                 full_load = 900;
1369         } else {
1370                 unit_load = 100;
1371                 full_load = 500;
1372         }
1373
1374         /* FIXME for USB 3.0, skip for now */
1375         if ((wHubCharacteristics & HUB_CHAR_COMPOUND) &&
1376                         !(hub_is_superspeed(hdev))) {
1377                 char    portstr[USB_MAXCHILDREN + 1];
1378
1379                 for (i = 0; i < maxchild; i++)
1380                         portstr[i] = hub->descriptor->u.hs.DeviceRemovable
1381                                     [((i + 1) / 8)] & (1 << ((i + 1) % 8))
1382                                 ? 'F' : 'R';
1383                 portstr[maxchild] = 0;
1384                 dev_dbg(hub_dev, "compound device; port removable status: %s\n", portstr);
1385         } else
1386                 dev_dbg(hub_dev, "standalone hub\n");
1387
1388         switch (wHubCharacteristics & HUB_CHAR_LPSM) {
1389         case HUB_CHAR_COMMON_LPSM:
1390                 dev_dbg(hub_dev, "ganged power switching\n");
1391                 break;
1392         case HUB_CHAR_INDV_PORT_LPSM:
1393                 dev_dbg(hub_dev, "individual port power switching\n");
1394                 break;
1395         case HUB_CHAR_NO_LPSM:
1396         case HUB_CHAR_LPSM:
1397                 dev_dbg(hub_dev, "no power switching (usb 1.0)\n");
1398                 break;
1399         }
1400
1401         switch (wHubCharacteristics & HUB_CHAR_OCPM) {
1402         case HUB_CHAR_COMMON_OCPM:
1403                 dev_dbg(hub_dev, "global over-current protection\n");
1404                 break;
1405         case HUB_CHAR_INDV_PORT_OCPM:
1406                 dev_dbg(hub_dev, "individual port over-current protection\n");
1407                 break;
1408         case HUB_CHAR_NO_OCPM:
1409         case HUB_CHAR_OCPM:
1410                 dev_dbg(hub_dev, "no over-current protection\n");
1411                 break;
1412         }
1413
1414         spin_lock_init(&hub->tt.lock);
1415         INIT_LIST_HEAD(&hub->tt.clear_list);
1416         INIT_WORK(&hub->tt.clear_work, hub_tt_work);
1417         switch (hdev->descriptor.bDeviceProtocol) {
1418         case USB_HUB_PR_FS:
1419                 break;
1420         case USB_HUB_PR_HS_SINGLE_TT:
1421                 dev_dbg(hub_dev, "Single TT\n");
1422                 hub->tt.hub = hdev;
1423                 break;
1424         case USB_HUB_PR_HS_MULTI_TT:
1425                 ret = usb_set_interface(hdev, 0, 1);
1426                 if (ret == 0) {
1427                         dev_dbg(hub_dev, "TT per port\n");
1428                         hub->tt.multi = 1;
1429                 } else
1430                         dev_err(hub_dev, "Using single TT (err %d)\n",
1431                                 ret);
1432                 hub->tt.hub = hdev;
1433                 break;
1434         case USB_HUB_PR_SS:
1435                 /* USB 3.0 hubs don't have a TT */
1436                 break;
1437         default:
1438                 dev_dbg(hub_dev, "Unrecognized hub protocol %d\n",
1439                         hdev->descriptor.bDeviceProtocol);
1440                 break;
1441         }
1442
1443         /* Note 8 FS bit times == (8 bits / 12000000 bps) ~= 666ns */
1444         switch (wHubCharacteristics & HUB_CHAR_TTTT) {
1445         case HUB_TTTT_8_BITS:
1446                 if (hdev->descriptor.bDeviceProtocol != 0) {
1447                         hub->tt.think_time = 666;
1448                         dev_dbg(hub_dev, "TT requires at most %d "
1449                                         "FS bit times (%d ns)\n",
1450                                 8, hub->tt.think_time);
1451                 }
1452                 break;
1453         case HUB_TTTT_16_BITS:
1454                 hub->tt.think_time = 666 * 2;
1455                 dev_dbg(hub_dev, "TT requires at most %d "
1456                                 "FS bit times (%d ns)\n",
1457                         16, hub->tt.think_time);
1458                 break;
1459         case HUB_TTTT_24_BITS:
1460                 hub->tt.think_time = 666 * 3;
1461                 dev_dbg(hub_dev, "TT requires at most %d "
1462                                 "FS bit times (%d ns)\n",
1463                         24, hub->tt.think_time);
1464                 break;
1465         case HUB_TTTT_32_BITS:
1466                 hub->tt.think_time = 666 * 4;
1467                 dev_dbg(hub_dev, "TT requires at most %d "
1468                                 "FS bit times (%d ns)\n",
1469                         32, hub->tt.think_time);
1470                 break;
1471         }
1472
1473         /* probe() zeroes hub->indicator[] */
1474         if (wHubCharacteristics & HUB_CHAR_PORTIND) {
1475                 hub->has_indicators = 1;
1476                 dev_dbg(hub_dev, "Port indicators are supported\n");
1477         }
1478
1479         dev_dbg(hub_dev, "power on to power good time: %dms\n",
1480                 hub->descriptor->bPwrOn2PwrGood * 2);
1481
1482         /* power budgeting mostly matters with bus-powered hubs,
1483          * and battery-powered root hubs (may provide just 8 mA).
1484          */
1485         ret = usb_get_status(hdev, USB_RECIP_DEVICE, 0, &hubstatus);
1486         if (ret) {
1487                 message = "can't get hub status";
1488                 goto fail;
1489         }
1490         hcd = bus_to_hcd(hdev->bus);
1491         if (hdev == hdev->bus->root_hub) {
1492                 if (hcd->power_budget > 0)
1493                         hdev->bus_mA = hcd->power_budget;
1494                 else
1495                         hdev->bus_mA = full_load * maxchild;
1496                 if (hdev->bus_mA >= full_load)
1497                         hub->mA_per_port = full_load;
1498                 else {
1499                         hub->mA_per_port = hdev->bus_mA;
1500                         hub->limited_power = 1;
1501                 }
1502         } else if ((hubstatus & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
1503                 int remaining = hdev->bus_mA -
1504                         hub->descriptor->bHubContrCurrent;
1505
1506                 dev_dbg(hub_dev, "hub controller current requirement: %dmA\n",
1507                         hub->descriptor->bHubContrCurrent);
1508                 hub->limited_power = 1;
1509
1510                 if (remaining < maxchild * unit_load)
1511                         dev_warn(hub_dev,
1512                                         "insufficient power available "
1513                                         "to use all downstream ports\n");
1514                 hub->mA_per_port = unit_load;   /* 7.2.1 */
1515
1516         } else {        /* Self-powered external hub */
1517                 /* FIXME: What about battery-powered external hubs that
1518                  * provide less current per port? */
1519                 hub->mA_per_port = full_load;
1520         }
1521         if (hub->mA_per_port < full_load)
1522                 dev_dbg(hub_dev, "%umA bus power budget for each child\n",
1523                                 hub->mA_per_port);
1524
1525         ret = hub_hub_status(hub, &hubstatus, &hubchange);
1526         if (ret < 0) {
1527                 message = "can't get hub status";
1528                 goto fail;
1529         }
1530
1531         /* local power status reports aren't always correct */
1532         if (hdev->actconfig->desc.bmAttributes & USB_CONFIG_ATT_SELFPOWER)
1533                 dev_dbg(hub_dev, "local power source is %s\n",
1534                         (hubstatus & HUB_STATUS_LOCAL_POWER)
1535                         ? "lost (inactive)" : "good");
1536
1537         if ((wHubCharacteristics & HUB_CHAR_OCPM) == 0)
1538                 dev_dbg(hub_dev, "%sover-current condition exists\n",
1539                         (hubstatus & HUB_STATUS_OVERCURRENT) ? "" : "no ");
1540
1541         /* set up the interrupt endpoint
1542          * We use the EP's maxpacket size instead of (PORTS+1+7)/8
1543          * bytes as USB2.0[11.12.3] says because some hubs are known
1544          * to send more data (and thus cause overflow). For root hubs,
1545          * maxpktsize is defined in hcd.c's fake endpoint descriptors
1546          * to be big enough for at least USB_MAXCHILDREN ports. */
1547         pipe = usb_rcvintpipe(hdev, endpoint->bEndpointAddress);
1548         maxp = usb_maxpacket(hdev, pipe, usb_pipeout(pipe));
1549
1550         if (maxp > sizeof(*hub->buffer))
1551                 maxp = sizeof(*hub->buffer);
1552
1553         hub->urb = usb_alloc_urb(0, GFP_KERNEL);
1554         if (!hub->urb) {
1555                 ret = -ENOMEM;
1556                 goto fail;
1557         }
1558
1559         usb_fill_int_urb(hub->urb, hdev, pipe, *hub->buffer, maxp, hub_irq,
1560                 hub, endpoint->bInterval);
1561
1562         /* maybe cycle the hub leds */
1563         if (hub->has_indicators && blinkenlights)
1564                 hub->indicator[0] = INDICATOR_CYCLE;
1565
1566         mutex_lock(&usb_port_peer_mutex);
1567         for (i = 0; i < maxchild; i++) {
1568                 ret = usb_hub_create_port_device(hub, i + 1);
1569                 if (ret < 0) {
1570                         dev_err(hub->intfdev,
1571                                 "couldn't create port%d device.\n", i + 1);
1572                         break;
1573                 }
1574         }
1575         hdev->maxchild = i;
1576         for (i = 0; i < hdev->maxchild; i++) {
1577                 struct usb_port *port_dev = hub->ports[i];
1578
1579                 pm_runtime_put(&port_dev->dev);
1580         }
1581
1582         mutex_unlock(&usb_port_peer_mutex);
1583         if (ret < 0)
1584                 goto fail;
1585
1586         /* Update the HCD's internal representation of this hub before hub_wq
1587          * starts getting port status changes for devices under the hub.
1588          */
1589         if (hcd->driver->update_hub_device) {
1590                 ret = hcd->driver->update_hub_device(hcd, hdev,
1591                                 &hub->tt, GFP_KERNEL);
1592                 if (ret < 0) {
1593                         message = "can't update HCD hub info";
1594                         goto fail;
1595                 }
1596         }
1597
1598         usb_hub_adjust_deviceremovable(hdev, hub->descriptor);
1599
1600         hub_activate(hub, HUB_INIT);
1601         return 0;
1602
1603 fail:
1604         dev_err(hub_dev, "config failed, %s (err %d)\n",
1605                         message, ret);
1606         /* hub_disconnect() frees urb and descriptor */
1607         return ret;
1608 }
1609
1610 static void hub_release(struct kref *kref)
1611 {
1612         struct usb_hub *hub = container_of(kref, struct usb_hub, kref);
1613
1614         usb_put_dev(hub->hdev);
1615         usb_put_intf(to_usb_interface(hub->intfdev));
1616         kfree(hub);
1617 }
1618
1619 static unsigned highspeed_hubs;
1620
1621 static void hub_disconnect(struct usb_interface *intf)
1622 {
1623         struct usb_hub *hub = usb_get_intfdata(intf);
1624         struct usb_device *hdev = interface_to_usbdev(intf);
1625         int port1;
1626
1627         /*
1628          * Stop adding new hub events. We do not want to block here and thus
1629          * will not try to remove any pending work item.
1630          */
1631         hub->disconnected = 1;
1632
1633         /* Disconnect all children and quiesce the hub */
1634         hub->error = 0;
1635         hub_quiesce(hub, HUB_DISCONNECT);
1636
1637         mutex_lock(&usb_port_peer_mutex);
1638
1639         /* Avoid races with recursively_mark_NOTATTACHED() */
1640         spin_lock_irq(&device_state_lock);
1641         port1 = hdev->maxchild;
1642         hdev->maxchild = 0;
1643         usb_set_intfdata(intf, NULL);
1644         spin_unlock_irq(&device_state_lock);
1645
1646         for (; port1 > 0; --port1)
1647                 usb_hub_remove_port_device(hub, port1);
1648
1649         mutex_unlock(&usb_port_peer_mutex);
1650
1651         if (hub->hdev->speed == USB_SPEED_HIGH)
1652                 highspeed_hubs--;
1653
1654         usb_free_urb(hub->urb);
1655         kfree(hub->ports);
1656         kfree(hub->descriptor);
1657         kfree(hub->status);
1658         kfree(hub->buffer);
1659
1660         pm_suspend_ignore_children(&intf->dev, false);
1661         kref_put(&hub->kref, hub_release);
1662 }
1663
1664 static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
1665 {
1666         struct usb_host_interface *desc;
1667         struct usb_endpoint_descriptor *endpoint;
1668         struct usb_device *hdev;
1669         struct usb_hub *hub;
1670
1671         desc = intf->cur_altsetting;
1672         hdev = interface_to_usbdev(intf);
1673
1674         /*
1675          * Set default autosuspend delay as 0 to speedup bus suspend,
1676          * based on the below considerations:
1677          *
1678          * - Unlike other drivers, the hub driver does not rely on the
1679          *   autosuspend delay to provide enough time to handle a wakeup
1680          *   event, and the submitted status URB is just to check future
1681          *   change on hub downstream ports, so it is safe to do it.
1682          *
1683          * - The patch might cause one or more auto supend/resume for
1684          *   below very rare devices when they are plugged into hub
1685          *   first time:
1686          *
1687          *      devices having trouble initializing, and disconnect
1688          *      themselves from the bus and then reconnect a second
1689          *      or so later
1690          *
1691          *      devices just for downloading firmware, and disconnects
1692          *      themselves after completing it
1693          *
1694          *   For these quite rare devices, their drivers may change the
1695          *   autosuspend delay of their parent hub in the probe() to one
1696          *   appropriate value to avoid the subtle problem if someone
1697          *   does care it.
1698          *
1699          * - The patch may cause one or more auto suspend/resume on
1700          *   hub during running 'lsusb', but it is probably too
1701          *   infrequent to worry about.
1702          *
1703          * - Change autosuspend delay of hub can avoid unnecessary auto
1704          *   suspend timer for hub, also may decrease power consumption
1705          *   of USB bus.
1706          *
1707          * - If user has indicated to prevent autosuspend by passing
1708          *   usbcore.autosuspend = -1 then keep autosuspend disabled.
1709          */
1710 #ifdef CONFIG_PM
1711         if (hdev->dev.power.autosuspend_delay >= 0)
1712                 pm_runtime_set_autosuspend_delay(&hdev->dev, 0);
1713 #endif
1714
1715         /*
1716          * Hubs have proper suspend/resume support, except for root hubs
1717          * where the controller driver doesn't have bus_suspend and
1718          * bus_resume methods.
1719          */
1720         if (hdev->parent) {             /* normal device */
1721                 usb_enable_autosuspend(hdev);
1722         } else {                        /* root hub */
1723                 const struct hc_driver *drv = bus_to_hcd(hdev->bus)->driver;
1724
1725                 if (drv->bus_suspend && drv->bus_resume)
1726                         usb_enable_autosuspend(hdev);
1727         }
1728
1729         if (hdev->level == MAX_TOPO_LEVEL) {
1730                 dev_err(&intf->dev,
1731                         "Unsupported bus topology: hub nested too deep\n");
1732                 return -E2BIG;
1733         }
1734
1735 #ifdef  CONFIG_USB_OTG_BLACKLIST_HUB
1736         if (hdev->parent) {
1737                 dev_warn(&intf->dev, "ignoring external hub\n");
1738                 return -ENODEV;
1739         }
1740 #endif
1741
1742         /* Some hubs have a subclass of 1, which AFAICT according to the */
1743         /*  specs is not defined, but it works */
1744         if ((desc->desc.bInterfaceSubClass != 0) &&
1745             (desc->desc.bInterfaceSubClass != 1)) {
1746 descriptor_error:
1747                 dev_err(&intf->dev, "bad descriptor, ignoring hub\n");
1748                 return -EIO;
1749         }
1750
1751         /* Multiple endpoints? What kind of mutant ninja-hub is this? */
1752         if (desc->desc.bNumEndpoints != 1)
1753                 goto descriptor_error;
1754
1755         endpoint = &desc->endpoint[0].desc;
1756
1757         /* If it's not an interrupt in endpoint, we'd better punt! */
1758         if (!usb_endpoint_is_int_in(endpoint))
1759                 goto descriptor_error;
1760
1761         /* We found a hub */
1762         dev_info(&intf->dev, "USB hub found\n");
1763
1764         hub = kzalloc(sizeof(*hub), GFP_KERNEL);
1765         if (!hub)
1766                 return -ENOMEM;
1767
1768         kref_init(&hub->kref);
1769         hub->intfdev = &intf->dev;
1770         hub->hdev = hdev;
1771         INIT_DELAYED_WORK(&hub->leds, led_work);
1772         INIT_DELAYED_WORK(&hub->init_work, NULL);
1773         INIT_WORK(&hub->events, hub_event);
1774         usb_get_intf(intf);
1775         usb_get_dev(hdev);
1776
1777         usb_set_intfdata(intf, hub);
1778         intf->needs_remote_wakeup = 1;
1779         pm_suspend_ignore_children(&intf->dev, true);
1780
1781         if (hdev->speed == USB_SPEED_HIGH)
1782                 highspeed_hubs++;
1783
1784         if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
1785                 hub->quirk_check_port_auto_suspend = 1;
1786
1787         if (hub_configure(hub, endpoint) >= 0)
1788                 return 0;
1789
1790         hub_disconnect(intf);
1791         return -ENODEV;
1792 }
1793
1794 static int
1795 hub_ioctl(struct usb_interface *intf, unsigned int code, void *user_data)
1796 {
1797         struct usb_device *hdev = interface_to_usbdev(intf);
1798         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1799
1800         /* assert ifno == 0 (part of hub spec) */
1801         switch (code) {
1802         case USBDEVFS_HUB_PORTINFO: {
1803                 struct usbdevfs_hub_portinfo *info = user_data;
1804                 int i;
1805
1806                 spin_lock_irq(&device_state_lock);
1807                 if (hdev->devnum <= 0)
1808                         info->nports = 0;
1809                 else {
1810                         info->nports = hdev->maxchild;
1811                         for (i = 0; i < info->nports; i++) {
1812                                 if (hub->ports[i]->child == NULL)
1813                                         info->port[i] = 0;
1814                                 else
1815                                         info->port[i] =
1816                                                 hub->ports[i]->child->devnum;
1817                         }
1818                 }
1819                 spin_unlock_irq(&device_state_lock);
1820
1821                 return info->nports + 1;
1822                 }
1823
1824         default:
1825                 return -ENOSYS;
1826         }
1827 }
1828
1829 /*
1830  * Allow user programs to claim ports on a hub.  When a device is attached
1831  * to one of these "claimed" ports, the program will "own" the device.
1832  */
1833 static int find_port_owner(struct usb_device *hdev, unsigned port1,
1834                 struct usb_dev_state ***ppowner)
1835 {
1836         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1837
1838         if (hdev->state == USB_STATE_NOTATTACHED)
1839                 return -ENODEV;
1840         if (port1 == 0 || port1 > hdev->maxchild)
1841                 return -EINVAL;
1842
1843         /* Devices not managed by the hub driver
1844          * will always have maxchild equal to 0.
1845          */
1846         *ppowner = &(hub->ports[port1 - 1]->port_owner);
1847         return 0;
1848 }
1849
1850 /* In the following three functions, the caller must hold hdev's lock */
1851 int usb_hub_claim_port(struct usb_device *hdev, unsigned port1,
1852                        struct usb_dev_state *owner)
1853 {
1854         int rc;
1855         struct usb_dev_state **powner;
1856
1857         rc = find_port_owner(hdev, port1, &powner);
1858         if (rc)
1859                 return rc;
1860         if (*powner)
1861                 return -EBUSY;
1862         *powner = owner;
1863         return rc;
1864 }
1865 EXPORT_SYMBOL_GPL(usb_hub_claim_port);
1866
1867 int usb_hub_release_port(struct usb_device *hdev, unsigned port1,
1868                          struct usb_dev_state *owner)
1869 {
1870         int rc;
1871         struct usb_dev_state **powner;
1872
1873         rc = find_port_owner(hdev, port1, &powner);
1874         if (rc)
1875                 return rc;
1876         if (*powner != owner)
1877                 return -ENOENT;
1878         *powner = NULL;
1879         return rc;
1880 }
1881 EXPORT_SYMBOL_GPL(usb_hub_release_port);
1882
1883 void usb_hub_release_all_ports(struct usb_device *hdev, struct usb_dev_state *owner)
1884 {
1885         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
1886         int n;
1887
1888         for (n = 0; n < hdev->maxchild; n++) {
1889                 if (hub->ports[n]->port_owner == owner)
1890                         hub->ports[n]->port_owner = NULL;
1891         }
1892
1893 }
1894
1895 /* The caller must hold udev's lock */
1896 bool usb_device_is_owned(struct usb_device *udev)
1897 {
1898         struct usb_hub *hub;
1899
1900         if (udev->state == USB_STATE_NOTATTACHED || !udev->parent)
1901                 return false;
1902         hub = usb_hub_to_struct_hub(udev->parent);
1903         return !!hub->ports[udev->portnum - 1]->port_owner;
1904 }
1905
1906 static void recursively_mark_NOTATTACHED(struct usb_device *udev)
1907 {
1908         struct usb_hub *hub = usb_hub_to_struct_hub(udev);
1909         int i;
1910
1911         for (i = 0; i < udev->maxchild; ++i) {
1912                 if (hub->ports[i]->child)
1913                         recursively_mark_NOTATTACHED(hub->ports[i]->child);
1914         }
1915         if (udev->state == USB_STATE_SUSPENDED)
1916                 udev->active_duration -= jiffies;
1917         udev->state = USB_STATE_NOTATTACHED;
1918 }
1919
1920 /**
1921  * usb_set_device_state - change a device's current state (usbcore, hcds)
1922  * @udev: pointer to device whose state should be changed
1923  * @new_state: new state value to be stored
1924  *
1925  * udev->state is _not_ fully protected by the device lock.  Although
1926  * most transitions are made only while holding the lock, the state can
1927  * can change to USB_STATE_NOTATTACHED at almost any time.  This
1928  * is so that devices can be marked as disconnected as soon as possible,
1929  * without having to wait for any semaphores to be released.  As a result,
1930  * all changes to any device's state must be protected by the
1931  * device_state_lock spinlock.
1932  *
1933  * Once a device has been added to the device tree, all changes to its state
1934  * should be made using this routine.  The state should _not_ be set directly.
1935  *
1936  * If udev->state is already USB_STATE_NOTATTACHED then no change is made.
1937  * Otherwise udev->state is set to new_state, and if new_state is
1938  * USB_STATE_NOTATTACHED then all of udev's descendants' states are also set
1939  * to USB_STATE_NOTATTACHED.
1940  */
1941 void usb_set_device_state(struct usb_device *udev,
1942                 enum usb_device_state new_state)
1943 {
1944         unsigned long flags;
1945         int wakeup = -1;
1946
1947         spin_lock_irqsave(&device_state_lock, flags);
1948         if (udev->state == USB_STATE_NOTATTACHED)
1949                 ;       /* do nothing */
1950         else if (new_state != USB_STATE_NOTATTACHED) {
1951
1952                 /* root hub wakeup capabilities are managed out-of-band
1953                  * and may involve silicon errata ... ignore them here.
1954                  */
1955                 if (udev->parent) {
1956                         if (udev->state == USB_STATE_SUSPENDED
1957                                         || new_state == USB_STATE_SUSPENDED)
1958                                 ;       /* No change to wakeup settings */
1959                         else if (new_state == USB_STATE_CONFIGURED)
1960                                 wakeup = (udev->quirks &
1961                                         USB_QUIRK_IGNORE_REMOTE_WAKEUP) ? 0 :
1962                                         udev->actconfig->desc.bmAttributes &
1963                                         USB_CONFIG_ATT_WAKEUP;
1964                         else
1965                                 wakeup = 0;
1966                 }
1967                 if (udev->state == USB_STATE_SUSPENDED &&
1968                         new_state != USB_STATE_SUSPENDED)
1969                         udev->active_duration -= jiffies;
1970                 else if (new_state == USB_STATE_SUSPENDED &&
1971                                 udev->state != USB_STATE_SUSPENDED)
1972                         udev->active_duration += jiffies;
1973                 udev->state = new_state;
1974         } else
1975                 recursively_mark_NOTATTACHED(udev);
1976         spin_unlock_irqrestore(&device_state_lock, flags);
1977         if (wakeup >= 0)
1978                 device_set_wakeup_capable(&udev->dev, wakeup);
1979 }
1980 EXPORT_SYMBOL_GPL(usb_set_device_state);
1981
1982 /*
1983  * Choose a device number.
1984  *
1985  * Device numbers are used as filenames in usbfs.  On USB-1.1 and
1986  * USB-2.0 buses they are also used as device addresses, however on
1987  * USB-3.0 buses the address is assigned by the controller hardware
1988  * and it usually is not the same as the device number.
1989  *
1990  * WUSB devices are simple: they have no hubs behind, so the mapping
1991  * device <-> virtual port number becomes 1:1. Why? to simplify the
1992  * life of the device connection logic in
1993  * drivers/usb/wusbcore/devconnect.c. When we do the initial secret
1994  * handshake we need to assign a temporary address in the unauthorized
1995  * space. For simplicity we use the first virtual port number found to
1996  * be free [drivers/usb/wusbcore/devconnect.c:wusbhc_devconnect_ack()]
1997  * and that becomes it's address [X < 128] or its unauthorized address
1998  * [X | 0x80].
1999  *
2000  * We add 1 as an offset to the one-based USB-stack port number
2001  * (zero-based wusb virtual port index) for two reasons: (a) dev addr
2002  * 0 is reserved by USB for default address; (b) Linux's USB stack
2003  * uses always #1 for the root hub of the controller. So USB stack's
2004  * port #1, which is wusb virtual-port #0 has address #2.
2005  *
2006  * Devices connected under xHCI are not as simple.  The host controller
2007  * supports virtualization, so the hardware assigns device addresses and
2008  * the HCD must setup data structures before issuing a set address
2009  * command to the hardware.
2010  */
2011 static void choose_devnum(struct usb_device *udev)
2012 {
2013         int             devnum;
2014         struct usb_bus  *bus = udev->bus;
2015
2016         /* be safe when more hub events are proceed in parallel */
2017         mutex_lock(&bus->devnum_next_mutex);
2018         if (udev->wusb) {
2019                 devnum = udev->portnum + 1;
2020                 BUG_ON(test_bit(devnum, bus->devmap.devicemap));
2021         } else {
2022                 /* Try to allocate the next devnum beginning at
2023                  * bus->devnum_next. */
2024                 devnum = find_next_zero_bit(bus->devmap.devicemap, 128,
2025                                             bus->devnum_next);
2026                 if (devnum >= 128)
2027                         devnum = find_next_zero_bit(bus->devmap.devicemap,
2028                                                     128, 1);
2029                 bus->devnum_next = (devnum >= 127 ? 1 : devnum + 1);
2030         }
2031         if (devnum < 128) {
2032                 set_bit(devnum, bus->devmap.devicemap);
2033                 udev->devnum = devnum;
2034         }
2035         mutex_unlock(&bus->devnum_next_mutex);
2036 }
2037
2038 static void release_devnum(struct usb_device *udev)
2039 {
2040         if (udev->devnum > 0) {
2041                 clear_bit(udev->devnum, udev->bus->devmap.devicemap);
2042                 udev->devnum = -1;
2043         }
2044 }
2045
2046 static void update_devnum(struct usb_device *udev, int devnum)
2047 {
2048         /* The address for a WUSB device is managed by wusbcore. */
2049         if (!udev->wusb)
2050                 udev->devnum = devnum;
2051 }
2052
2053 static void hub_free_dev(struct usb_device *udev)
2054 {
2055         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2056
2057         /* Root hubs aren't real devices, so don't free HCD resources */
2058         if (hcd->driver->free_dev && udev->parent)
2059                 hcd->driver->free_dev(hcd, udev);
2060 }
2061
2062 static void hub_disconnect_children(struct usb_device *udev)
2063 {
2064         struct usb_hub *hub = usb_hub_to_struct_hub(udev);
2065         int i;
2066
2067         /* Free up all the children before we remove this device */
2068         for (i = 0; i < udev->maxchild; i++) {
2069                 if (hub->ports[i]->child)
2070                         usb_disconnect(&hub->ports[i]->child);
2071         }
2072 }
2073
2074 /**
2075  * usb_disconnect - disconnect a device (usbcore-internal)
2076  * @pdev: pointer to device being disconnected
2077  * Context: !in_interrupt ()
2078  *
2079  * Something got disconnected. Get rid of it and all of its children.
2080  *
2081  * If *pdev is a normal device then the parent hub must already be locked.
2082  * If *pdev is a root hub then the caller must hold the usb_bus_idr_lock,
2083  * which protects the set of root hubs as well as the list of buses.
2084  *
2085  * Only hub drivers (including virtual root hub drivers for host
2086  * controllers) should ever call this.
2087  *
2088  * This call is synchronous, and may not be used in an interrupt context.
2089  */
2090 void usb_disconnect(struct usb_device **pdev)
2091 {
2092         struct usb_port *port_dev = NULL;
2093         struct usb_device *udev = *pdev;
2094         struct usb_hub *hub = NULL;
2095         int port1 = 1;
2096
2097         /* mark the device as inactive, so any further urb submissions for
2098          * this device (and any of its children) will fail immediately.
2099          * this quiesces everything except pending urbs.
2100          */
2101         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2102         dev_info(&udev->dev, "USB disconnect, device number %d\n",
2103                         udev->devnum);
2104
2105         /*
2106          * Ensure that the pm runtime code knows that the USB device
2107          * is in the process of being disconnected.
2108          */
2109         pm_runtime_barrier(&udev->dev);
2110
2111         usb_lock_device(udev);
2112
2113         hub_disconnect_children(udev);
2114
2115         /* deallocate hcd/hardware state ... nuking all pending urbs and
2116          * cleaning up all state associated with the current configuration
2117          * so that the hardware is now fully quiesced.
2118          */
2119         dev_dbg(&udev->dev, "unregistering device\n");
2120         usb_disable_device(udev, 0);
2121         usb_hcd_synchronize_unlinks(udev);
2122
2123         if (udev->parent) {
2124                 port1 = udev->portnum;
2125                 hub = usb_hub_to_struct_hub(udev->parent);
2126                 port_dev = hub->ports[port1 - 1];
2127
2128                 sysfs_remove_link(&udev->dev.kobj, "port");
2129                 sysfs_remove_link(&port_dev->dev.kobj, "device");
2130
2131                 /*
2132                  * As usb_port_runtime_resume() de-references udev, make
2133                  * sure no resumes occur during removal
2134                  */
2135                 if (!test_and_set_bit(port1, hub->child_usage_bits))
2136                         pm_runtime_get_sync(&port_dev->dev);
2137         }
2138
2139         usb_remove_ep_devs(&udev->ep0);
2140         usb_unlock_device(udev);
2141
2142         /* Unregister the device.  The device driver is responsible
2143          * for de-configuring the device and invoking the remove-device
2144          * notifier chain (used by usbfs and possibly others).
2145          */
2146         device_del(&udev->dev);
2147
2148         /* Free the device number and delete the parent's children[]
2149          * (or root_hub) pointer.
2150          */
2151         release_devnum(udev);
2152
2153         /* Avoid races with recursively_mark_NOTATTACHED() */
2154         spin_lock_irq(&device_state_lock);
2155         *pdev = NULL;
2156         spin_unlock_irq(&device_state_lock);
2157
2158         if (port_dev && test_and_clear_bit(port1, hub->child_usage_bits))
2159                 pm_runtime_put(&port_dev->dev);
2160
2161         hub_free_dev(udev);
2162
2163         put_device(&udev->dev);
2164 }
2165
2166 #ifdef CONFIG_USB_ANNOUNCE_NEW_DEVICES
2167 static void show_string(struct usb_device *udev, char *id, char *string)
2168 {
2169         if (!string)
2170                 return;
2171         dev_info(&udev->dev, "%s: %s\n", id, string);
2172 }
2173
2174 static void announce_device(struct usb_device *udev)
2175 {
2176         dev_info(&udev->dev, "New USB device found, idVendor=%04x, idProduct=%04x\n",
2177                 le16_to_cpu(udev->descriptor.idVendor),
2178                 le16_to_cpu(udev->descriptor.idProduct));
2179         dev_info(&udev->dev,
2180                 "New USB device strings: Mfr=%d, Product=%d, SerialNumber=%d\n",
2181                 udev->descriptor.iManufacturer,
2182                 udev->descriptor.iProduct,
2183                 udev->descriptor.iSerialNumber);
2184         show_string(udev, "Product", udev->product);
2185         show_string(udev, "Manufacturer", udev->manufacturer);
2186         show_string(udev, "SerialNumber", udev->serial);
2187 }
2188 #else
2189 static inline void announce_device(struct usb_device *udev) { }
2190 #endif
2191
2192
2193 /**
2194  * usb_enumerate_device_otg - FIXME (usbcore-internal)
2195  * @udev: newly addressed device (in ADDRESS state)
2196  *
2197  * Finish enumeration for On-The-Go devices
2198  *
2199  * Return: 0 if successful. A negative error code otherwise.
2200  */
2201 static int usb_enumerate_device_otg(struct usb_device *udev)
2202 {
2203         int err = 0;
2204
2205 #ifdef  CONFIG_USB_OTG
2206         /*
2207          * OTG-aware devices on OTG-capable root hubs may be able to use SRP,
2208          * to wake us after we've powered off VBUS; and HNP, switching roles
2209          * "host" to "peripheral".  The OTG descriptor helps figure this out.
2210          */
2211         if (!udev->bus->is_b_host
2212                         && udev->config
2213                         && udev->parent == udev->bus->root_hub) {
2214                 struct usb_otg_descriptor       *desc = NULL;
2215                 struct usb_bus                  *bus = udev->bus;
2216                 unsigned                        port1 = udev->portnum;
2217
2218                 /* descriptor may appear anywhere in config */
2219                 err = __usb_get_extra_descriptor(udev->rawdescriptors[0],
2220                                 le16_to_cpu(udev->config[0].desc.wTotalLength),
2221                                 USB_DT_OTG, (void **) &desc);
2222                 if (err || !(desc->bmAttributes & USB_OTG_HNP))
2223                         return 0;
2224
2225                 dev_info(&udev->dev, "Dual-Role OTG device on %sHNP port\n",
2226                                         (port1 == bus->otg_port) ? "" : "non-");
2227
2228                 /* enable HNP before suspend, it's simpler */
2229                 if (port1 == bus->otg_port) {
2230                         bus->b_hnp_enable = 1;
2231                         err = usb_control_msg(udev,
2232                                 usb_sndctrlpipe(udev, 0),
2233                                 USB_REQ_SET_FEATURE, 0,
2234                                 USB_DEVICE_B_HNP_ENABLE,
2235                                 0, NULL, 0,
2236                                 USB_CTRL_SET_TIMEOUT);
2237                         if (err < 0) {
2238                                 /*
2239                                  * OTG MESSAGE: report errors here,
2240                                  * customize to match your product.
2241                                  */
2242                                 dev_err(&udev->dev, "can't set HNP mode: %d\n",
2243                                                                         err);
2244                                 bus->b_hnp_enable = 0;
2245                         }
2246                 } else if (desc->bLength == sizeof
2247                                 (struct usb_otg_descriptor)) {
2248                         /* Set a_alt_hnp_support for legacy otg device */
2249                         err = usb_control_msg(udev,
2250                                 usb_sndctrlpipe(udev, 0),
2251                                 USB_REQ_SET_FEATURE, 0,
2252                                 USB_DEVICE_A_ALT_HNP_SUPPORT,
2253                                 0, NULL, 0,
2254                                 USB_CTRL_SET_TIMEOUT);
2255                         if (err < 0)
2256                                 dev_err(&udev->dev,
2257                                         "set a_alt_hnp_support failed: %d\n",
2258                                         err);
2259                 }
2260         }
2261 #endif
2262         return err;
2263 }
2264
2265
2266 /**
2267  * usb_enumerate_device - Read device configs/intfs/otg (usbcore-internal)
2268  * @udev: newly addressed device (in ADDRESS state)
2269  *
2270  * This is only called by usb_new_device() and usb_authorize_device()
2271  * and FIXME -- all comments that apply to them apply here wrt to
2272  * environment.
2273  *
2274  * If the device is WUSB and not authorized, we don't attempt to read
2275  * the string descriptors, as they will be errored out by the device
2276  * until it has been authorized.
2277  *
2278  * Return: 0 if successful. A negative error code otherwise.
2279  */
2280 static int usb_enumerate_device(struct usb_device *udev)
2281 {
2282         int err;
2283         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2284
2285         if (udev->config == NULL) {
2286                 err = usb_get_configuration(udev);
2287                 if (err < 0) {
2288                         if (err != -ENODEV)
2289                                 dev_err(&udev->dev, "can't read configurations, error %d\n",
2290                                                 err);
2291                         return err;
2292                 }
2293         }
2294
2295         /* read the standard strings and cache them if present */
2296         udev->product = usb_cache_string(udev, udev->descriptor.iProduct);
2297         udev->manufacturer = usb_cache_string(udev,
2298                                               udev->descriptor.iManufacturer);
2299         udev->serial = usb_cache_string(udev, udev->descriptor.iSerialNumber);
2300
2301         err = usb_enumerate_device_otg(udev);
2302         if (err < 0)
2303                 return err;
2304
2305         if (IS_ENABLED(CONFIG_USB_OTG_WHITELIST) && hcd->tpl_support &&
2306                 !is_targeted(udev)) {
2307                 /* Maybe it can talk to us, though we can't talk to it.
2308                  * (Includes HNP test device.)
2309                  */
2310                 if (IS_ENABLED(CONFIG_USB_OTG) && (udev->bus->b_hnp_enable
2311                         || udev->bus->is_b_host)) {
2312                         err = usb_port_suspend(udev, PMSG_AUTO_SUSPEND);
2313                         if (err < 0)
2314                                 dev_dbg(&udev->dev, "HNP fail, %d\n", err);
2315                 }
2316                 return -ENOTSUPP;
2317         }
2318
2319         usb_detect_interface_quirks(udev);
2320
2321         return 0;
2322 }
2323
2324 static void set_usb_port_removable(struct usb_device *udev)
2325 {
2326         struct usb_device *hdev = udev->parent;
2327         struct usb_hub *hub;
2328         u8 port = udev->portnum;
2329         u16 wHubCharacteristics;
2330         bool removable = true;
2331
2332         if (!hdev)
2333                 return;
2334
2335         hub = usb_hub_to_struct_hub(udev->parent);
2336
2337         /*
2338          * If the platform firmware has provided information about a port,
2339          * use that to determine whether it's removable.
2340          */
2341         switch (hub->ports[udev->portnum - 1]->connect_type) {
2342         case USB_PORT_CONNECT_TYPE_HOT_PLUG:
2343                 udev->removable = USB_DEVICE_REMOVABLE;
2344                 return;
2345         case USB_PORT_CONNECT_TYPE_HARD_WIRED:
2346         case USB_PORT_NOT_USED:
2347                 udev->removable = USB_DEVICE_FIXED;
2348                 return;
2349         default:
2350                 break;
2351         }
2352
2353         /*
2354          * Otherwise, check whether the hub knows whether a port is removable
2355          * or not
2356          */
2357         wHubCharacteristics = le16_to_cpu(hub->descriptor->wHubCharacteristics);
2358
2359         if (!(wHubCharacteristics & HUB_CHAR_COMPOUND))
2360                 return;
2361
2362         if (hub_is_superspeed(hdev)) {
2363                 if (le16_to_cpu(hub->descriptor->u.ss.DeviceRemovable)
2364                                 & (1 << port))
2365                         removable = false;
2366         } else {
2367                 if (hub->descriptor->u.hs.DeviceRemovable[port / 8] & (1 << (port % 8)))
2368                         removable = false;
2369         }
2370
2371         if (removable)
2372                 udev->removable = USB_DEVICE_REMOVABLE;
2373         else
2374                 udev->removable = USB_DEVICE_FIXED;
2375
2376 }
2377
2378 /**
2379  * usb_new_device - perform initial device setup (usbcore-internal)
2380  * @udev: newly addressed device (in ADDRESS state)
2381  *
2382  * This is called with devices which have been detected but not fully
2383  * enumerated.  The device descriptor is available, but not descriptors
2384  * for any device configuration.  The caller must have locked either
2385  * the parent hub (if udev is a normal device) or else the
2386  * usb_bus_idr_lock (if udev is a root hub).  The parent's pointer to
2387  * udev has already been installed, but udev is not yet visible through
2388  * sysfs or other filesystem code.
2389  *
2390  * This call is synchronous, and may not be used in an interrupt context.
2391  *
2392  * Only the hub driver or root-hub registrar should ever call this.
2393  *
2394  * Return: Whether the device is configured properly or not. Zero if the
2395  * interface was registered with the driver core; else a negative errno
2396  * value.
2397  *
2398  */
2399 int usb_new_device(struct usb_device *udev)
2400 {
2401         int err;
2402
2403         if (udev->parent) {
2404                 /* Initialize non-root-hub device wakeup to disabled;
2405                  * device (un)configuration controls wakeup capable
2406                  * sysfs power/wakeup controls wakeup enabled/disabled
2407                  */
2408                 device_init_wakeup(&udev->dev, 0);
2409         }
2410
2411         /* Tell the runtime-PM framework the device is active */
2412         pm_runtime_set_active(&udev->dev);
2413         pm_runtime_get_noresume(&udev->dev);
2414         pm_runtime_use_autosuspend(&udev->dev);
2415         pm_runtime_enable(&udev->dev);
2416
2417         /* By default, forbid autosuspend for all devices.  It will be
2418          * allowed for hubs during binding.
2419          */
2420         usb_disable_autosuspend(udev);
2421
2422         err = usb_enumerate_device(udev);       /* Read descriptors */
2423         if (err < 0)
2424                 goto fail;
2425         dev_dbg(&udev->dev, "udev %d, busnum %d, minor = %d\n",
2426                         udev->devnum, udev->bus->busnum,
2427                         (((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2428         /* export the usbdev device-node for libusb */
2429         udev->dev.devt = MKDEV(USB_DEVICE_MAJOR,
2430                         (((udev->bus->busnum-1) * 128) + (udev->devnum-1)));
2431
2432         /* Tell the world! */
2433         announce_device(udev);
2434
2435         if (udev->serial)
2436                 add_device_randomness(udev->serial, strlen(udev->serial));
2437         if (udev->product)
2438                 add_device_randomness(udev->product, strlen(udev->product));
2439         if (udev->manufacturer)
2440                 add_device_randomness(udev->manufacturer,
2441                                       strlen(udev->manufacturer));
2442
2443         device_enable_async_suspend(&udev->dev);
2444
2445         /* check whether the hub or firmware marks this port as non-removable */
2446         if (udev->parent)
2447                 set_usb_port_removable(udev);
2448
2449         /* Register the device.  The device driver is responsible
2450          * for configuring the device and invoking the add-device
2451          * notifier chain (used by usbfs and possibly others).
2452          */
2453         err = device_add(&udev->dev);
2454         if (err) {
2455                 dev_err(&udev->dev, "can't device_add, error %d\n", err);
2456                 goto fail;
2457         }
2458
2459         /* Create link files between child device and usb port device. */
2460         if (udev->parent) {
2461                 struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
2462                 int port1 = udev->portnum;
2463                 struct usb_port *port_dev = hub->ports[port1 - 1];
2464
2465                 err = sysfs_create_link(&udev->dev.kobj,
2466                                 &port_dev->dev.kobj, "port");
2467                 if (err)
2468                         goto fail;
2469
2470                 err = sysfs_create_link(&port_dev->dev.kobj,
2471                                 &udev->dev.kobj, "device");
2472                 if (err) {
2473                         sysfs_remove_link(&udev->dev.kobj, "port");
2474                         goto fail;
2475                 }
2476
2477                 if (!test_and_set_bit(port1, hub->child_usage_bits))
2478                         pm_runtime_get_sync(&port_dev->dev);
2479         }
2480
2481         (void) usb_create_ep_devs(&udev->dev, &udev->ep0, udev);
2482         usb_mark_last_busy(udev);
2483         pm_runtime_put_sync_autosuspend(&udev->dev);
2484         return err;
2485
2486 fail:
2487         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2488         pm_runtime_disable(&udev->dev);
2489         pm_runtime_set_suspended(&udev->dev);
2490         return err;
2491 }
2492
2493
2494 /**
2495  * usb_deauthorize_device - deauthorize a device (usbcore-internal)
2496  * @usb_dev: USB device
2497  *
2498  * Move the USB device to a very basic state where interfaces are disabled
2499  * and the device is in fact unconfigured and unusable.
2500  *
2501  * We share a lock (that we have) with device_del(), so we need to
2502  * defer its call.
2503  *
2504  * Return: 0.
2505  */
2506 int usb_deauthorize_device(struct usb_device *usb_dev)
2507 {
2508         usb_lock_device(usb_dev);
2509         if (usb_dev->authorized == 0)
2510                 goto out_unauthorized;
2511
2512         usb_dev->authorized = 0;
2513         usb_set_configuration(usb_dev, -1);
2514
2515 out_unauthorized:
2516         usb_unlock_device(usb_dev);
2517         return 0;
2518 }
2519
2520
2521 int usb_authorize_device(struct usb_device *usb_dev)
2522 {
2523         int result = 0, c;
2524
2525         usb_lock_device(usb_dev);
2526         if (usb_dev->authorized == 1)
2527                 goto out_authorized;
2528
2529         result = usb_autoresume_device(usb_dev);
2530         if (result < 0) {
2531                 dev_err(&usb_dev->dev,
2532                         "can't autoresume for authorization: %d\n", result);
2533                 goto error_autoresume;
2534         }
2535
2536         if (usb_dev->wusb) {
2537                 result = usb_get_device_descriptor(usb_dev, sizeof(usb_dev->descriptor));
2538                 if (result < 0) {
2539                         dev_err(&usb_dev->dev, "can't re-read device descriptor for "
2540                                 "authorization: %d\n", result);
2541                         goto error_device_descriptor;
2542                 }
2543         }
2544
2545         usb_dev->authorized = 1;
2546         /* Choose and set the configuration.  This registers the interfaces
2547          * with the driver core and lets interface drivers bind to them.
2548          */
2549         c = usb_choose_configuration(usb_dev);
2550         if (c >= 0) {
2551                 result = usb_set_configuration(usb_dev, c);
2552                 if (result) {
2553                         dev_err(&usb_dev->dev,
2554                                 "can't set config #%d, error %d\n", c, result);
2555                         /* This need not be fatal.  The user can try to
2556                          * set other configurations. */
2557                 }
2558         }
2559         dev_info(&usb_dev->dev, "authorized to connect\n");
2560
2561 error_device_descriptor:
2562         usb_autosuspend_device(usb_dev);
2563 error_autoresume:
2564 out_authorized:
2565         usb_unlock_device(usb_dev);     /* complements locktree */
2566         return result;
2567 }
2568
2569 /*
2570  * Return 1 if port speed is SuperSpeedPlus, 0 otherwise
2571  * check it from the link protocol field of the current speed ID attribute.
2572  * current speed ID is got from ext port status request. Sublink speed attribute
2573  * table is returned with the hub BOS SSP device capability descriptor
2574  */
2575 static int port_speed_is_ssp(struct usb_device *hdev, int speed_id)
2576 {
2577         int ssa_count;
2578         u32 ss_attr;
2579         int i;
2580         struct usb_ssp_cap_descriptor *ssp_cap = hdev->bos->ssp_cap;
2581
2582         if (!ssp_cap)
2583                 return 0;
2584
2585         ssa_count = le32_to_cpu(ssp_cap->bmAttributes) &
2586                 USB_SSP_SUBLINK_SPEED_ATTRIBS;
2587
2588         for (i = 0; i <= ssa_count; i++) {
2589                 ss_attr = le32_to_cpu(ssp_cap->bmSublinkSpeedAttr[i]);
2590                 if (speed_id == (ss_attr & USB_SSP_SUBLINK_SPEED_SSID))
2591                         return !!(ss_attr & USB_SSP_SUBLINK_SPEED_LP);
2592         }
2593         return 0;
2594 }
2595
2596 /* Returns 1 if @hub is a WUSB root hub, 0 otherwise */
2597 static unsigned hub_is_wusb(struct usb_hub *hub)
2598 {
2599         struct usb_hcd *hcd;
2600         if (hub->hdev->parent != NULL)  /* not a root hub? */
2601                 return 0;
2602         hcd = bus_to_hcd(hub->hdev->bus);
2603         return hcd->wireless;
2604 }
2605
2606
2607 #define PORT_RESET_TRIES        5
2608 #define SET_ADDRESS_TRIES       2
2609 #define GET_DESCRIPTOR_TRIES    2
2610 #define SET_CONFIG_TRIES        (2 * (use_both_schemes + 1))
2611 #define USE_NEW_SCHEME(i)       ((i) / 2 == (int)old_scheme_first)
2612
2613 #define HUB_ROOT_RESET_TIME     50      /* times are in msec */
2614 #define HUB_SHORT_RESET_TIME    10
2615 #define HUB_BH_RESET_TIME       50
2616 #define HUB_LONG_RESET_TIME     200
2617 #define HUB_RESET_TIMEOUT       800
2618
2619 /*
2620  * "New scheme" enumeration causes an extra state transition to be
2621  * exposed to an xhci host and causes USB3 devices to receive control
2622  * commands in the default state.  This has been seen to cause
2623  * enumeration failures, so disable this enumeration scheme for USB3
2624  * devices.
2625  */
2626 static bool use_new_scheme(struct usb_device *udev, int retry)
2627 {
2628         if (udev->speed >= USB_SPEED_SUPER)
2629                 return false;
2630
2631         return USE_NEW_SCHEME(retry);
2632 }
2633
2634 /* Is a USB 3.0 port in the Inactive or Compliance Mode state?
2635  * Port worm reset is required to recover
2636  */
2637 static bool hub_port_warm_reset_required(struct usb_hub *hub, int port1,
2638                 u16 portstatus)
2639 {
2640         u16 link_state;
2641
2642         if (!hub_is_superspeed(hub->hdev))
2643                 return false;
2644
2645         if (test_bit(port1, hub->warm_reset_bits))
2646                 return true;
2647
2648         link_state = portstatus & USB_PORT_STAT_LINK_STATE;
2649         return link_state == USB_SS_PORT_LS_SS_INACTIVE
2650                 || link_state == USB_SS_PORT_LS_COMP_MOD;
2651 }
2652
2653 static int hub_port_wait_reset(struct usb_hub *hub, int port1,
2654                         struct usb_device *udev, unsigned int delay, bool warm)
2655 {
2656         int delay_time, ret;
2657         u16 portstatus;
2658         u16 portchange;
2659         u32 ext_portstatus = 0;
2660
2661         for (delay_time = 0;
2662                         delay_time < HUB_RESET_TIMEOUT;
2663                         delay_time += delay) {
2664                 /* wait to give the device a chance to reset */
2665                 msleep(delay);
2666
2667                 /* read and decode port status */
2668                 if (hub_is_superspeedplus(hub->hdev))
2669                         ret = hub_ext_port_status(hub, port1,
2670                                                   HUB_EXT_PORT_STATUS,
2671                                                   &portstatus, &portchange,
2672                                                   &ext_portstatus);
2673                 else
2674                         ret = hub_port_status(hub, port1, &portstatus,
2675                                               &portchange);
2676                 if (ret < 0)
2677                         return ret;
2678
2679                 /*
2680                  * The port state is unknown until the reset completes.
2681                  *
2682                  * On top of that, some chips may require additional time
2683                  * to re-establish a connection after the reset is complete,
2684                  * so also wait for the connection to be re-established.
2685                  */
2686                 if (!(portstatus & USB_PORT_STAT_RESET) &&
2687                     (portstatus & USB_PORT_STAT_CONNECTION))
2688                         break;
2689
2690                 /* switch to the long delay after two short delay failures */
2691                 if (delay_time >= 2 * HUB_SHORT_RESET_TIME)
2692                         delay = HUB_LONG_RESET_TIME;
2693
2694                 dev_dbg(&hub->ports[port1 - 1]->dev,
2695                                 "not %sreset yet, waiting %dms\n",
2696                                 warm ? "warm " : "", delay);
2697         }
2698
2699         if ((portstatus & USB_PORT_STAT_RESET))
2700                 return -EBUSY;
2701
2702         if (hub_port_warm_reset_required(hub, port1, portstatus))
2703                 return -ENOTCONN;
2704
2705         /* Device went away? */
2706         if (!(portstatus & USB_PORT_STAT_CONNECTION))
2707                 return -ENOTCONN;
2708
2709         /* bomb out completely if the connection bounced.  A USB 3.0
2710          * connection may bounce if multiple warm resets were issued,
2711          * but the device may have successfully re-connected. Ignore it.
2712          */
2713         if (!hub_is_superspeed(hub->hdev) &&
2714                         (portchange & USB_PORT_STAT_C_CONNECTION))
2715                 return -ENOTCONN;
2716
2717         if (!(portstatus & USB_PORT_STAT_ENABLE))
2718                 return -EBUSY;
2719
2720         if (!udev)
2721                 return 0;
2722
2723         if (hub_is_wusb(hub))
2724                 udev->speed = USB_SPEED_WIRELESS;
2725         else if (hub_is_superspeedplus(hub->hdev) &&
2726                  port_speed_is_ssp(hub->hdev, ext_portstatus &
2727                                    USB_EXT_PORT_STAT_RX_SPEED_ID))
2728                 udev->speed = USB_SPEED_SUPER_PLUS;
2729         else if (hub_is_superspeed(hub->hdev))
2730                 udev->speed = USB_SPEED_SUPER;
2731         else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
2732                 udev->speed = USB_SPEED_HIGH;
2733         else if (portstatus & USB_PORT_STAT_LOW_SPEED)
2734                 udev->speed = USB_SPEED_LOW;
2735         else
2736                 udev->speed = USB_SPEED_FULL;
2737         return 0;
2738 }
2739
2740 /* Handle port reset and port warm(BH) reset (for USB3 protocol ports) */
2741 static int hub_port_reset(struct usb_hub *hub, int port1,
2742                         struct usb_device *udev, unsigned int delay, bool warm)
2743 {
2744         int i, status;
2745         u16 portchange, portstatus;
2746         struct usb_port *port_dev = hub->ports[port1 - 1];
2747
2748         if (!hub_is_superspeed(hub->hdev)) {
2749                 if (warm) {
2750                         dev_err(hub->intfdev, "only USB3 hub support "
2751                                                 "warm reset\n");
2752                         return -EINVAL;
2753                 }
2754                 /* Block EHCI CF initialization during the port reset.
2755                  * Some companion controllers don't like it when they mix.
2756                  */
2757                 down_read(&ehci_cf_port_reset_rwsem);
2758         } else if (!warm) {
2759                 /*
2760                  * If the caller hasn't explicitly requested a warm reset,
2761                  * double check and see if one is needed.
2762                  */
2763                 if (hub_port_status(hub, port1, &portstatus, &portchange) == 0)
2764                         if (hub_port_warm_reset_required(hub, port1,
2765                                                         portstatus))
2766                                 warm = true;
2767         }
2768         clear_bit(port1, hub->warm_reset_bits);
2769
2770         /* Reset the port */
2771         for (i = 0; i < PORT_RESET_TRIES; i++) {
2772                 status = set_port_feature(hub->hdev, port1, (warm ?
2773                                         USB_PORT_FEAT_BH_PORT_RESET :
2774                                         USB_PORT_FEAT_RESET));
2775                 if (status == -ENODEV) {
2776                         ;       /* The hub is gone */
2777                 } else if (status) {
2778                         dev_err(&port_dev->dev,
2779                                         "cannot %sreset (err = %d)\n",
2780                                         warm ? "warm " : "", status);
2781                 } else {
2782                         status = hub_port_wait_reset(hub, port1, udev, delay,
2783                                                                 warm);
2784                         if (status && status != -ENOTCONN && status != -ENODEV)
2785                                 dev_dbg(hub->intfdev,
2786                                                 "port_wait_reset: err = %d\n",
2787                                                 status);
2788                 }
2789
2790                 /* Check for disconnect or reset */
2791                 if (status == 0 || status == -ENOTCONN || status == -ENODEV) {
2792                         usb_clear_port_feature(hub->hdev, port1,
2793                                         USB_PORT_FEAT_C_RESET);
2794
2795                         if (!hub_is_superspeed(hub->hdev))
2796                                 goto done;
2797
2798                         usb_clear_port_feature(hub->hdev, port1,
2799                                         USB_PORT_FEAT_C_BH_PORT_RESET);
2800                         usb_clear_port_feature(hub->hdev, port1,
2801                                         USB_PORT_FEAT_C_PORT_LINK_STATE);
2802                         usb_clear_port_feature(hub->hdev, port1,
2803                                         USB_PORT_FEAT_C_CONNECTION);
2804
2805                         /*
2806                          * If a USB 3.0 device migrates from reset to an error
2807                          * state, re-issue the warm reset.
2808                          */
2809                         if (hub_port_status(hub, port1,
2810                                         &portstatus, &portchange) < 0)
2811                                 goto done;
2812
2813                         if (!hub_port_warm_reset_required(hub, port1,
2814                                         portstatus))
2815                                 goto done;
2816
2817                         /*
2818                          * If the port is in SS.Inactive or Compliance Mode, the
2819                          * hot or warm reset failed.  Try another warm reset.
2820                          */
2821                         if (!warm) {
2822                                 dev_dbg(&port_dev->dev,
2823                                                 "hot reset failed, warm reset\n");
2824                                 warm = true;
2825                         }
2826                 }
2827
2828                 dev_dbg(&port_dev->dev,
2829                                 "not enabled, trying %sreset again...\n",
2830                                 warm ? "warm " : "");
2831                 delay = HUB_LONG_RESET_TIME;
2832         }
2833
2834         dev_err(&port_dev->dev, "Cannot enable. Maybe the USB cable is bad?\n");
2835
2836 done:
2837         if (status == 0) {
2838                 /* TRSTRCY = 10 ms; plus some extra */
2839                 msleep(10 + 40);
2840                 if (udev) {
2841                         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2842
2843                         update_devnum(udev, 0);
2844                         /* The xHC may think the device is already reset,
2845                          * so ignore the status.
2846                          */
2847                         if (hcd->driver->reset_device)
2848                                 hcd->driver->reset_device(hcd, udev);
2849
2850                         usb_set_device_state(udev, USB_STATE_DEFAULT);
2851                 }
2852         } else {
2853                 if (udev)
2854                         usb_set_device_state(udev, USB_STATE_NOTATTACHED);
2855         }
2856
2857         if (!hub_is_superspeed(hub->hdev))
2858                 up_read(&ehci_cf_port_reset_rwsem);
2859
2860         return status;
2861 }
2862
2863 /* Check if a port is power on */
2864 static int port_is_power_on(struct usb_hub *hub, unsigned portstatus)
2865 {
2866         int ret = 0;
2867
2868         if (hub_is_superspeed(hub->hdev)) {
2869                 if (portstatus & USB_SS_PORT_STAT_POWER)
2870                         ret = 1;
2871         } else {
2872                 if (portstatus & USB_PORT_STAT_POWER)
2873                         ret = 1;
2874         }
2875
2876         return ret;
2877 }
2878
2879 static void usb_lock_port(struct usb_port *port_dev)
2880                 __acquires(&port_dev->status_lock)
2881 {
2882         mutex_lock(&port_dev->status_lock);
2883         __acquire(&port_dev->status_lock);
2884 }
2885
2886 static void usb_unlock_port(struct usb_port *port_dev)
2887                 __releases(&port_dev->status_lock)
2888 {
2889         mutex_unlock(&port_dev->status_lock);
2890         __release(&port_dev->status_lock);
2891 }
2892
2893 #ifdef  CONFIG_PM
2894
2895 /* Check if a port is suspended(USB2.0 port) or in U3 state(USB3.0 port) */
2896 static int port_is_suspended(struct usb_hub *hub, unsigned portstatus)
2897 {
2898         int ret = 0;
2899
2900         if (hub_is_superspeed(hub->hdev)) {
2901                 if ((portstatus & USB_PORT_STAT_LINK_STATE)
2902                                 == USB_SS_PORT_LS_U3)
2903                         ret = 1;
2904         } else {
2905                 if (portstatus & USB_PORT_STAT_SUSPEND)
2906                         ret = 1;
2907         }
2908
2909         return ret;
2910 }
2911
2912 /* Determine whether the device on a port is ready for a normal resume,
2913  * is ready for a reset-resume, or should be disconnected.
2914  */
2915 static int check_port_resume_type(struct usb_device *udev,
2916                 struct usb_hub *hub, int port1,
2917                 int status, u16 portchange, u16 portstatus)
2918 {
2919         struct usb_port *port_dev = hub->ports[port1 - 1];
2920         int retries = 3;
2921
2922  retry:
2923         /* Is a warm reset needed to recover the connection? */
2924         if (status == 0 && udev->reset_resume
2925                 && hub_port_warm_reset_required(hub, port1, portstatus)) {
2926                 /* pass */;
2927         }
2928         /* Is the device still present? */
2929         else if (status || port_is_suspended(hub, portstatus) ||
2930                         !port_is_power_on(hub, portstatus)) {
2931                 if (status >= 0)
2932                         status = -ENODEV;
2933         } else if (!(portstatus & USB_PORT_STAT_CONNECTION)) {
2934                 if (retries--) {
2935                         usleep_range(200, 300);
2936                         status = hub_port_status(hub, port1, &portstatus,
2937                                                              &portchange);
2938                         goto retry;
2939                 }
2940                 status = -ENODEV;
2941         }
2942
2943         /* Can't do a normal resume if the port isn't enabled,
2944          * so try a reset-resume instead.
2945          */
2946         else if (!(portstatus & USB_PORT_STAT_ENABLE) && !udev->reset_resume) {
2947                 if (udev->persist_enabled)
2948                         udev->reset_resume = 1;
2949                 else
2950                         status = -ENODEV;
2951         }
2952
2953         if (status) {
2954                 dev_dbg(&port_dev->dev, "status %04x.%04x after resume, %d\n",
2955                                 portchange, portstatus, status);
2956         } else if (udev->reset_resume) {
2957
2958                 /* Late port handoff can set status-change bits */
2959                 if (portchange & USB_PORT_STAT_C_CONNECTION)
2960                         usb_clear_port_feature(hub->hdev, port1,
2961                                         USB_PORT_FEAT_C_CONNECTION);
2962                 if (portchange & USB_PORT_STAT_C_ENABLE)
2963                         usb_clear_port_feature(hub->hdev, port1,
2964                                         USB_PORT_FEAT_C_ENABLE);
2965         }
2966
2967         return status;
2968 }
2969
2970 int usb_disable_ltm(struct usb_device *udev)
2971 {
2972         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2973
2974         /* Check if the roothub and device supports LTM. */
2975         if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2976                         !usb_device_supports_ltm(udev))
2977                 return 0;
2978
2979         /* Clear Feature LTM Enable can only be sent if the device is
2980          * configured.
2981          */
2982         if (!udev->actconfig)
2983                 return 0;
2984
2985         return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
2986                         USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
2987                         USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
2988                         USB_CTRL_SET_TIMEOUT);
2989 }
2990 EXPORT_SYMBOL_GPL(usb_disable_ltm);
2991
2992 void usb_enable_ltm(struct usb_device *udev)
2993 {
2994         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
2995
2996         /* Check if the roothub and device supports LTM. */
2997         if (!usb_device_supports_ltm(hcd->self.root_hub) ||
2998                         !usb_device_supports_ltm(udev))
2999                 return;
3000
3001         /* Set Feature LTM Enable can only be sent if the device is
3002          * configured.
3003          */
3004         if (!udev->actconfig)
3005                 return;
3006
3007         usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3008                         USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
3009                         USB_DEVICE_LTM_ENABLE, 0, NULL, 0,
3010                         USB_CTRL_SET_TIMEOUT);
3011 }
3012 EXPORT_SYMBOL_GPL(usb_enable_ltm);
3013
3014 /*
3015  * usb_enable_remote_wakeup - enable remote wakeup for a device
3016  * @udev: target device
3017  *
3018  * For USB-2 devices: Set the device's remote wakeup feature.
3019  *
3020  * For USB-3 devices: Assume there's only one function on the device and
3021  * enable remote wake for the first interface.  FIXME if the interface
3022  * association descriptor shows there's more than one function.
3023  */
3024 static int usb_enable_remote_wakeup(struct usb_device *udev)
3025 {
3026         if (udev->speed < USB_SPEED_SUPER)
3027                 return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3028                                 USB_REQ_SET_FEATURE, USB_RECIP_DEVICE,
3029                                 USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
3030                                 USB_CTRL_SET_TIMEOUT);
3031         else
3032                 return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3033                                 USB_REQ_SET_FEATURE, USB_RECIP_INTERFACE,
3034                                 USB_INTRF_FUNC_SUSPEND,
3035                                 USB_INTRF_FUNC_SUSPEND_RW |
3036                                         USB_INTRF_FUNC_SUSPEND_LP,
3037                                 NULL, 0, USB_CTRL_SET_TIMEOUT);
3038 }
3039
3040 /*
3041  * usb_disable_remote_wakeup - disable remote wakeup for a device
3042  * @udev: target device
3043  *
3044  * For USB-2 devices: Clear the device's remote wakeup feature.
3045  *
3046  * For USB-3 devices: Assume there's only one function on the device and
3047  * disable remote wake for the first interface.  FIXME if the interface
3048  * association descriptor shows there's more than one function.
3049  */
3050 static int usb_disable_remote_wakeup(struct usb_device *udev)
3051 {
3052         if (udev->speed < USB_SPEED_SUPER)
3053                 return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3054                                 USB_REQ_CLEAR_FEATURE, USB_RECIP_DEVICE,
3055                                 USB_DEVICE_REMOTE_WAKEUP, 0, NULL, 0,
3056                                 USB_CTRL_SET_TIMEOUT);
3057         else
3058                 return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3059                                 USB_REQ_SET_FEATURE, USB_RECIP_INTERFACE,
3060                                 USB_INTRF_FUNC_SUSPEND, 0, NULL, 0,
3061                                 USB_CTRL_SET_TIMEOUT);
3062 }
3063
3064 /* Count of wakeup-enabled devices at or below udev */
3065 static unsigned wakeup_enabled_descendants(struct usb_device *udev)
3066 {
3067         struct usb_hub *hub = usb_hub_to_struct_hub(udev);
3068
3069         return udev->do_remote_wakeup +
3070                         (hub ? hub->wakeup_enabled_descendants : 0);
3071 }
3072
3073 /*
3074  * usb_port_suspend - suspend a usb device's upstream port
3075  * @udev: device that's no longer in active use, not a root hub
3076  * Context: must be able to sleep; device not locked; pm locks held
3077  *
3078  * Suspends a USB device that isn't in active use, conserving power.
3079  * Devices may wake out of a suspend, if anything important happens,
3080  * using the remote wakeup mechanism.  They may also be taken out of
3081  * suspend by the host, using usb_port_resume().  It's also routine
3082  * to disconnect devices while they are suspended.
3083  *
3084  * This only affects the USB hardware for a device; its interfaces
3085  * (and, for hubs, child devices) must already have been suspended.
3086  *
3087  * Selective port suspend reduces power; most suspended devices draw
3088  * less than 500 uA.  It's also used in OTG, along with remote wakeup.
3089  * All devices below the suspended port are also suspended.
3090  *
3091  * Devices leave suspend state when the host wakes them up.  Some devices
3092  * also support "remote wakeup", where the device can activate the USB
3093  * tree above them to deliver data, such as a keypress or packet.  In
3094  * some cases, this wakes the USB host.
3095  *
3096  * Suspending OTG devices may trigger HNP, if that's been enabled
3097  * between a pair of dual-role devices.  That will change roles, such
3098  * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral.
3099  *
3100  * Devices on USB hub ports have only one "suspend" state, corresponding
3101  * to ACPI D2, "may cause the device to lose some context".
3102  * State transitions include:
3103  *
3104  *   - suspend, resume ... when the VBUS power link stays live
3105  *   - suspend, disconnect ... VBUS lost
3106  *
3107  * Once VBUS drop breaks the circuit, the port it's using has to go through
3108  * normal re-enumeration procedures, starting with enabling VBUS power.
3109  * Other than re-initializing the hub (plug/unplug, except for root hubs),
3110  * Linux (2.6) currently has NO mechanisms to initiate that:  no hub_wq
3111  * timer, no SRP, no requests through sysfs.
3112  *
3113  * If Runtime PM isn't enabled or used, non-SuperSpeed devices may not get
3114  * suspended until their bus goes into global suspend (i.e., the root
3115  * hub is suspended).  Nevertheless, we change @udev->state to
3116  * USB_STATE_SUSPENDED as this is the device's "logical" state.  The actual
3117  * upstream port setting is stored in @udev->port_is_suspended.
3118  *
3119  * Returns 0 on success, else negative errno.
3120  */
3121 int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
3122 {
3123         struct usb_hub  *hub = usb_hub_to_struct_hub(udev->parent);
3124         struct usb_port *port_dev = hub->ports[udev->portnum - 1];
3125         int             port1 = udev->portnum;
3126         int             status;
3127         bool            really_suspend = true;
3128
3129         usb_lock_port(port_dev);
3130
3131         /* enable remote wakeup when appropriate; this lets the device
3132          * wake up the upstream hub (including maybe the root hub).
3133          *
3134          * NOTE:  OTG devices may issue remote wakeup (or SRP) even when
3135          * we don't explicitly enable it here.
3136          */
3137         if (udev->do_remote_wakeup) {
3138                 status = usb_enable_remote_wakeup(udev);
3139                 if (status) {
3140                         dev_dbg(&udev->dev, "won't remote wakeup, status %d\n",
3141                                         status);
3142                         /* bail if autosuspend is requested */
3143                         if (PMSG_IS_AUTO(msg))
3144                                 goto err_wakeup;
3145                 }
3146         }
3147
3148         /* disable USB2 hardware LPM */
3149         if (udev->usb2_hw_lpm_enabled == 1)
3150                 usb_set_usb2_hardware_lpm(udev, 0);
3151
3152         if (usb_disable_ltm(udev)) {
3153                 dev_err(&udev->dev, "Failed to disable LTM before suspend\n.");
3154                 status = -ENOMEM;
3155                 if (PMSG_IS_AUTO(msg))
3156                         goto err_ltm;
3157         }
3158         if (usb_unlocked_disable_lpm(udev)) {
3159                 dev_err(&udev->dev, "Failed to disable LPM before suspend\n.");
3160                 status = -ENOMEM;
3161                 if (PMSG_IS_AUTO(msg))
3162                         goto err_lpm3;
3163         }
3164
3165         /* see 7.1.7.6 */
3166         if (hub_is_superspeed(hub->hdev))
3167                 status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U3);
3168
3169         /*
3170          * For system suspend, we do not need to enable the suspend feature
3171          * on individual USB-2 ports.  The devices will automatically go
3172          * into suspend a few ms after the root hub stops sending packets.
3173          * The USB 2.0 spec calls this "global suspend".
3174          *
3175          * However, many USB hubs have a bug: They don't relay wakeup requests
3176          * from a downstream port if the port's suspend feature isn't on.
3177          * Therefore we will turn on the suspend feature if udev or any of its
3178          * descendants is enabled for remote wakeup.
3179          */
3180         else if (PMSG_IS_AUTO(msg) || wakeup_enabled_descendants(udev) > 0)
3181                 status = set_port_feature(hub->hdev, port1,
3182                                 USB_PORT_FEAT_SUSPEND);
3183         else {
3184                 really_suspend = false;
3185                 status = 0;
3186         }
3187         if (status) {
3188                 dev_dbg(&port_dev->dev, "can't suspend, status %d\n", status);
3189
3190                 /* Try to enable USB3 LPM and LTM again */
3191                 usb_unlocked_enable_lpm(udev);
3192  err_lpm3:
3193                 usb_enable_ltm(udev);
3194  err_ltm:
3195                 /* Try to enable USB2 hardware LPM again */
3196                 if (udev->usb2_hw_lpm_capable == 1)
3197                         usb_set_usb2_hardware_lpm(udev, 1);
3198
3199                 if (udev->do_remote_wakeup)
3200                         (void) usb_disable_remote_wakeup(udev);
3201  err_wakeup:
3202
3203                 /* System sleep transitions should never fail */
3204                 if (!PMSG_IS_AUTO(msg))
3205                         status = 0;
3206         } else {
3207                 dev_dbg(&udev->dev, "usb %ssuspend, wakeup %d\n",
3208                                 (PMSG_IS_AUTO(msg) ? "auto-" : ""),
3209                                 udev->do_remote_wakeup);
3210                 if (really_suspend) {
3211                         udev->port_is_suspended = 1;
3212
3213                         /* device has up to 10 msec to fully suspend */
3214                         msleep(10);
3215                 }
3216                 usb_set_device_state(udev, USB_STATE_SUSPENDED);
3217         }
3218
3219         if (status == 0 && !udev->do_remote_wakeup && udev->persist_enabled
3220                         && test_and_clear_bit(port1, hub->child_usage_bits))
3221                 pm_runtime_put_sync(&port_dev->dev);
3222
3223         usb_mark_last_busy(hub->hdev);
3224
3225         usb_unlock_port(port_dev);
3226         return status;
3227 }
3228
3229 /*
3230  * If the USB "suspend" state is in use (rather than "global suspend"),
3231  * many devices will be individually taken out of suspend state using
3232  * special "resume" signaling.  This routine kicks in shortly after
3233  * hardware resume signaling is finished, either because of selective
3234  * resume (by host) or remote wakeup (by device) ... now see what changed
3235  * in the tree that's rooted at this device.
3236  *
3237  * If @udev->reset_resume is set then the device is reset before the
3238  * status check is done.
3239  */
3240 static int finish_port_resume(struct usb_device *udev)
3241 {
3242         int     status = 0;
3243         u16     devstatus = 0;
3244
3245         /* caller owns the udev device lock */
3246         dev_dbg(&udev->dev, "%s\n",
3247                 udev->reset_resume ? "finish reset-resume" : "finish resume");
3248
3249         /* usb ch9 identifies four variants of SUSPENDED, based on what
3250          * state the device resumes to.  Linux currently won't see the
3251          * first two on the host side; they'd be inside hub_port_init()
3252          * during many timeouts, but hub_wq can't suspend until later.
3253          */
3254         usb_set_device_state(udev, udev->actconfig
3255                         ? USB_STATE_CONFIGURED
3256                         : USB_STATE_ADDRESS);
3257
3258         /* 10.5.4.5 says not to reset a suspended port if the attached
3259          * device is enabled for remote wakeup.  Hence the reset
3260          * operation is carried out here, after the port has been
3261          * resumed.
3262          */
3263         if (udev->reset_resume) {
3264                 /*
3265                  * If the device morphs or switches modes when it is reset,
3266                  * we don't want to perform a reset-resume.  We'll fail the
3267                  * resume, which will cause a logical disconnect, and then
3268                  * the device will be rediscovered.
3269                  */
3270  retry_reset_resume:
3271                 if (udev->quirks & USB_QUIRK_RESET)
3272                         status = -ENODEV;
3273                 else
3274                         status = usb_reset_and_verify_device(udev);
3275         }
3276
3277         /* 10.5.4.5 says be sure devices in the tree are still there.
3278          * For now let's assume the device didn't go crazy on resume,
3279          * and device drivers will know about any resume quirks.
3280          */
3281         if (status == 0) {
3282                 devstatus = 0;
3283                 status = usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus);
3284
3285                 /* If a normal resume failed, try doing a reset-resume */
3286                 if (status && !udev->reset_resume && udev->persist_enabled) {
3287                         dev_dbg(&udev->dev, "retry with reset-resume\n");
3288                         udev->reset_resume = 1;
3289                         goto retry_reset_resume;
3290                 }
3291         }
3292
3293         if (status) {
3294                 dev_dbg(&udev->dev, "gone after usb resume? status %d\n",
3295                                 status);
3296         /*
3297          * There are a few quirky devices which violate the standard
3298          * by claiming to have remote wakeup enabled after a reset,
3299          * which crash if the feature is cleared, hence check for
3300          * udev->reset_resume
3301          */
3302         } else if (udev->actconfig && !udev->reset_resume) {
3303                 if (udev->speed < USB_SPEED_SUPER) {
3304                         if (devstatus & (1 << USB_DEVICE_REMOTE_WAKEUP))
3305                                 status = usb_disable_remote_wakeup(udev);
3306                 } else {
3307                         status = usb_get_status(udev, USB_RECIP_INTERFACE, 0,
3308                                         &devstatus);
3309                         if (!status && devstatus & (USB_INTRF_STAT_FUNC_RW_CAP
3310                                         | USB_INTRF_STAT_FUNC_RW))
3311                                 status = usb_disable_remote_wakeup(udev);
3312                 }
3313
3314                 if (status)
3315                         dev_dbg(&udev->dev,
3316                                 "disable remote wakeup, status %d\n",
3317                                 status);
3318                 status = 0;
3319         }
3320         return status;
3321 }
3322
3323 /*
3324  * There are some SS USB devices which take longer time for link training.
3325  * XHCI specs 4.19.4 says that when Link training is successful, port
3326  * sets CCS bit to 1. So if SW reads port status before successful link
3327  * training, then it will not find device to be present.
3328  * USB Analyzer log with such buggy devices show that in some cases
3329  * device switch on the RX termination after long delay of host enabling
3330  * the VBUS. In few other cases it has been seen that device fails to
3331  * negotiate link training in first attempt. It has been
3332  * reported till now that few devices take as long as 2000 ms to train
3333  * the link after host enabling its VBUS and termination. Following
3334  * routine implements a 2000 ms timeout for link training. If in a case
3335  * link trains before timeout, loop will exit earlier.
3336  *
3337  * There are also some 2.0 hard drive based devices and 3.0 thumb
3338  * drives that, when plugged into a 2.0 only port, take a long
3339  * time to set CCS after VBUS enable.
3340  *
3341  * FIXME: If a device was connected before suspend, but was removed
3342  * while system was asleep, then the loop in the following routine will
3343  * only exit at timeout.
3344  *
3345  * This routine should only be called when persist is enabled.
3346  */
3347 static int wait_for_connected(struct usb_device *udev,
3348                 struct usb_hub *hub, int *port1,
3349                 u16 *portchange, u16 *portstatus)
3350 {
3351         int status = 0, delay_ms = 0;
3352
3353         while (delay_ms < 2000) {
3354                 if (status || *portstatus & USB_PORT_STAT_CONNECTION)
3355                         break;
3356                 msleep(20);
3357                 delay_ms += 20;
3358                 status = hub_port_status(hub, *port1, portstatus, portchange);
3359         }
3360         dev_dbg(&udev->dev, "Waited %dms for CONNECT\n", delay_ms);
3361         return status;
3362 }
3363
3364 /*
3365  * usb_port_resume - re-activate a suspended usb device's upstream port
3366  * @udev: device to re-activate, not a root hub
3367  * Context: must be able to sleep; device not locked; pm locks held
3368  *
3369  * This will re-activate the suspended device, increasing power usage
3370  * while letting drivers communicate again with its endpoints.
3371  * USB resume explicitly guarantees that the power session between
3372  * the host and the device is the same as it was when the device
3373  * suspended.
3374  *
3375  * If @udev->reset_resume is set then this routine won't check that the
3376  * port is still enabled.  Furthermore, finish_port_resume() above will
3377  * reset @udev.  The end result is that a broken power session can be
3378  * recovered and @udev will appear to persist across a loss of VBUS power.
3379  *
3380  * For example, if a host controller doesn't maintain VBUS suspend current
3381  * during a system sleep or is reset when the system wakes up, all the USB
3382  * power sessions below it will be broken.  This is especially troublesome
3383  * for mass-storage devices containing mounted filesystems, since the
3384  * device will appear to have disconnected and all the memory mappings
3385  * to it will be lost.  Using the USB_PERSIST facility, the device can be
3386  * made to appear as if it had not disconnected.
3387  *
3388  * This facility can be dangerous.  Although usb_reset_and_verify_device() makes
3389  * every effort to insure that the same device is present after the
3390  * reset as before, it cannot provide a 100% guarantee.  Furthermore it's
3391  * quite possible for a device to remain unaltered but its media to be
3392  * changed.  If the user replaces a flash memory card while the system is
3393  * asleep, he will have only himself to blame when the filesystem on the
3394  * new card is corrupted and the system crashes.
3395  *
3396  * Returns 0 on success, else negative errno.
3397  */
3398 int usb_port_resume(struct usb_device *udev, pm_message_t msg)
3399 {
3400         struct usb_hub  *hub = usb_hub_to_struct_hub(udev->parent);
3401         struct usb_port *port_dev = hub->ports[udev->portnum  - 1];
3402         int             port1 = udev->portnum;
3403         int             status;
3404         u16             portchange, portstatus;
3405
3406         if (!test_and_set_bit(port1, hub->child_usage_bits)) {
3407                 status = pm_runtime_get_sync(&port_dev->dev);
3408                 if (status < 0) {
3409                         dev_dbg(&udev->dev, "can't resume usb port, status %d\n",
3410                                         status);
3411                         return status;
3412                 }
3413         }
3414
3415         usb_lock_port(port_dev);
3416
3417         /* Skip the initial Clear-Suspend step for a remote wakeup */
3418         status = hub_port_status(hub, port1, &portstatus, &portchange);
3419         if (status == 0 && !port_is_suspended(hub, portstatus))
3420                 goto SuspendCleared;
3421
3422         /* see 7.1.7.7; affects power usage, but not budgeting */
3423         if (hub_is_superspeed(hub->hdev))
3424                 status = hub_set_port_link_state(hub, port1, USB_SS_PORT_LS_U0);
3425         else
3426                 status = usb_clear_port_feature(hub->hdev,
3427                                 port1, USB_PORT_FEAT_SUSPEND);
3428         if (status) {
3429                 dev_dbg(&port_dev->dev, "can't resume, status %d\n", status);
3430         } else {
3431                 /* drive resume for USB_RESUME_TIMEOUT msec */
3432                 dev_dbg(&udev->dev, "usb %sresume\n",
3433                                 (PMSG_IS_AUTO(msg) ? "auto-" : ""));
3434                 msleep(USB_RESUME_TIMEOUT);
3435
3436                 /* Virtual root hubs can trigger on GET_PORT_STATUS to
3437                  * stop resume signaling.  Then finish the resume
3438                  * sequence.
3439                  */
3440                 status = hub_port_status(hub, port1, &portstatus, &portchange);
3441
3442                 /* TRSMRCY = 10 msec */
3443                 msleep(10);
3444         }
3445
3446  SuspendCleared:
3447         if (status == 0) {
3448                 udev->port_is_suspended = 0;
3449                 if (hub_is_superspeed(hub->hdev)) {
3450                         if (portchange & USB_PORT_STAT_C_LINK_STATE)
3451                                 usb_clear_port_feature(hub->hdev, port1,
3452                                         USB_PORT_FEAT_C_PORT_LINK_STATE);
3453                 } else {
3454                         if (portchange & USB_PORT_STAT_C_SUSPEND)
3455                                 usb_clear_port_feature(hub->hdev, port1,
3456                                                 USB_PORT_FEAT_C_SUSPEND);
3457                 }
3458         }
3459
3460         if (udev->persist_enabled)
3461                 status = wait_for_connected(udev, hub, &port1, &portchange,
3462                                 &portstatus);
3463
3464         status = check_port_resume_type(udev,
3465                         hub, port1, status, portchange, portstatus);
3466         if (status == 0)
3467                 status = finish_port_resume(udev);
3468         if (status < 0) {
3469                 dev_dbg(&udev->dev, "can't resume, status %d\n", status);
3470                 hub_port_logical_disconnect(hub, port1);
3471         } else  {
3472                 /* Try to enable USB2 hardware LPM */
3473                 if (udev->usb2_hw_lpm_capable == 1)
3474                         usb_set_usb2_hardware_lpm(udev, 1);
3475
3476                 /* Try to enable USB3 LTM and LPM */
3477                 usb_enable_ltm(udev);
3478                 usb_unlocked_enable_lpm(udev);
3479         }
3480
3481         usb_unlock_port(port_dev);
3482
3483         return status;
3484 }
3485
3486 int usb_remote_wakeup(struct usb_device *udev)
3487 {
3488         int     status = 0;
3489
3490         usb_lock_device(udev);
3491         if (udev->state == USB_STATE_SUSPENDED) {
3492                 dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
3493                 status = usb_autoresume_device(udev);
3494                 if (status == 0) {
3495                         /* Let the drivers do their thing, then... */
3496                         usb_autosuspend_device(udev);
3497                 }
3498         }
3499         usb_unlock_device(udev);
3500         return status;
3501 }
3502
3503 /* Returns 1 if there was a remote wakeup and a connect status change. */
3504 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
3505                 u16 portstatus, u16 portchange)
3506                 __must_hold(&port_dev->status_lock)
3507 {
3508         struct usb_port *port_dev = hub->ports[port - 1];
3509         struct usb_device *hdev;
3510         struct usb_device *udev;
3511         int connect_change = 0;
3512         int ret;
3513
3514         hdev = hub->hdev;
3515         udev = port_dev->child;
3516         if (!hub_is_superspeed(hdev)) {
3517                 if (!(portchange & USB_PORT_STAT_C_SUSPEND))
3518                         return 0;
3519                 usb_clear_port_feature(hdev, port, USB_PORT_FEAT_C_SUSPEND);
3520         } else {
3521                 if (!udev || udev->state != USB_STATE_SUSPENDED ||
3522                                  (portstatus & USB_PORT_STAT_LINK_STATE) !=
3523                                  USB_SS_PORT_LS_U0)
3524                         return 0;
3525         }
3526
3527         if (udev) {
3528                 /* TRSMRCY = 10 msec */
3529                 msleep(10);
3530
3531                 usb_unlock_port(port_dev);
3532                 ret = usb_remote_wakeup(udev);
3533                 usb_lock_port(port_dev);
3534                 if (ret < 0)
3535                         connect_change = 1;
3536         } else {
3537                 ret = -ENODEV;
3538                 hub_port_disable(hub, port, 1);
3539         }
3540         dev_dbg(&port_dev->dev, "resume, status %d\n", ret);
3541         return connect_change;
3542 }
3543
3544 static int check_ports_changed(struct usb_hub *hub)
3545 {
3546         int port1;
3547
3548         for (port1 = 1; port1 <= hub->hdev->maxchild; ++port1) {
3549                 u16 portstatus, portchange;
3550                 int status;
3551
3552                 status = hub_port_status(hub, port1, &portstatus, &portchange);
3553                 if (!status && portchange)
3554                         return 1;
3555         }
3556         return 0;
3557 }
3558
3559 static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
3560 {
3561         struct usb_hub          *hub = usb_get_intfdata(intf);
3562         struct usb_device       *hdev = hub->hdev;
3563         unsigned                port1;
3564         int                     status;
3565
3566         /*
3567          * Warn if children aren't already suspended.
3568          * Also, add up the number of wakeup-enabled descendants.
3569          */
3570         hub->wakeup_enabled_descendants = 0;
3571         for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3572                 struct usb_port *port_dev = hub->ports[port1 - 1];
3573                 struct usb_device *udev = port_dev->child;
3574
3575                 if (udev && udev->can_submit) {
3576                         dev_warn(&port_dev->dev, "device %s not suspended yet\n",
3577                                         dev_name(&udev->dev));
3578                         if (PMSG_IS_AUTO(msg))
3579                                 return -EBUSY;
3580                 }
3581                 if (udev)
3582                         hub->wakeup_enabled_descendants +=
3583                                         wakeup_enabled_descendants(udev);
3584         }
3585
3586         if (hdev->do_remote_wakeup && hub->quirk_check_port_auto_suspend) {
3587                 /* check if there are changes pending on hub ports */
3588                 if (check_ports_changed(hub)) {
3589                         if (PMSG_IS_AUTO(msg))
3590                                 return -EBUSY;
3591                         pm_wakeup_event(&hdev->dev, 2000);
3592                 }
3593         }
3594
3595         if (hub_is_superspeed(hdev) && hdev->do_remote_wakeup) {
3596                 /* Enable hub to send remote wakeup for all ports. */
3597                 for (port1 = 1; port1 <= hdev->maxchild; port1++) {
3598                         status = set_port_feature(hdev,
3599                                         port1 |
3600                                         USB_PORT_FEAT_REMOTE_WAKE_CONNECT |
3601                                         USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT |
3602                                         USB_PORT_FEAT_REMOTE_WAKE_OVER_CURRENT,
3603                                         USB_PORT_FEAT_REMOTE_WAKE_MASK);
3604                 }
3605         }
3606
3607         dev_dbg(&intf->dev, "%s\n", __func__);
3608
3609         /* stop hub_wq and related activity */
3610         hub_quiesce(hub, HUB_SUSPEND);
3611         return 0;
3612 }
3613
3614 static int hub_resume(struct usb_interface *intf)
3615 {
3616         struct usb_hub *hub = usb_get_intfdata(intf);
3617
3618         dev_dbg(&intf->dev, "%s\n", __func__);
3619         hub_activate(hub, HUB_RESUME);
3620         return 0;
3621 }
3622
3623 static int hub_reset_resume(struct usb_interface *intf)
3624 {
3625         struct usb_hub *hub = usb_get_intfdata(intf);
3626
3627         dev_dbg(&intf->dev, "%s\n", __func__);
3628         hub_activate(hub, HUB_RESET_RESUME);
3629         return 0;
3630 }
3631
3632 /**
3633  * usb_root_hub_lost_power - called by HCD if the root hub lost Vbus power
3634  * @rhdev: struct usb_device for the root hub
3635  *
3636  * The USB host controller driver calls this function when its root hub
3637  * is resumed and Vbus power has been interrupted or the controller
3638  * has been reset.  The routine marks @rhdev as having lost power.
3639  * When the hub driver is resumed it will take notice and carry out
3640  * power-session recovery for all the "USB-PERSIST"-enabled child devices;
3641  * the others will be disconnected.
3642  */
3643 void usb_root_hub_lost_power(struct usb_device *rhdev)
3644 {
3645         dev_warn(&rhdev->dev, "root hub lost power or was reset\n");
3646         rhdev->reset_resume = 1;
3647 }
3648 EXPORT_SYMBOL_GPL(usb_root_hub_lost_power);
3649
3650 static const char * const usb3_lpm_names[]  = {
3651         "U0",
3652         "U1",
3653         "U2",
3654         "U3",
3655 };
3656
3657 /*
3658  * Send a Set SEL control transfer to the device, prior to enabling
3659  * device-initiated U1 or U2.  This lets the device know the exit latencies from
3660  * the time the device initiates a U1 or U2 exit, to the time it will receive a
3661  * packet from the host.
3662  *
3663  * This function will fail if the SEL or PEL values for udev are greater than
3664  * the maximum allowed values for the link state to be enabled.
3665  */
3666 static int usb_req_set_sel(struct usb_device *udev, enum usb3_link_state state)
3667 {
3668         struct usb_set_sel_req *sel_values;
3669         unsigned long long u1_sel;
3670         unsigned long long u1_pel;
3671         unsigned long long u2_sel;
3672         unsigned long long u2_pel;
3673         int ret;
3674
3675         if (udev->state != USB_STATE_CONFIGURED)
3676                 return 0;
3677
3678         /* Convert SEL and PEL stored in ns to us */
3679         u1_sel = DIV_ROUND_UP(udev->u1_params.sel, 1000);
3680         u1_pel = DIV_ROUND_UP(udev->u1_params.pel, 1000);
3681         u2_sel = DIV_ROUND_UP(udev->u2_params.sel, 1000);
3682         u2_pel = DIV_ROUND_UP(udev->u2_params.pel, 1000);
3683
3684         /*
3685          * Make sure that the calculated SEL and PEL values for the link
3686          * state we're enabling aren't bigger than the max SEL/PEL
3687          * value that will fit in the SET SEL control transfer.
3688          * Otherwise the device would get an incorrect idea of the exit
3689          * latency for the link state, and could start a device-initiated
3690          * U1/U2 when the exit latencies are too high.
3691          */
3692         if ((state == USB3_LPM_U1 &&
3693                                 (u1_sel > USB3_LPM_MAX_U1_SEL_PEL ||
3694                                  u1_pel > USB3_LPM_MAX_U1_SEL_PEL)) ||
3695                         (state == USB3_LPM_U2 &&
3696                          (u2_sel > USB3_LPM_MAX_U2_SEL_PEL ||
3697                           u2_pel > USB3_LPM_MAX_U2_SEL_PEL))) {
3698                 dev_dbg(&udev->dev, "Device-initiated %s disabled due to long SEL %llu us or PEL %llu us\n",
3699                                 usb3_lpm_names[state], u1_sel, u1_pel);
3700                 return -EINVAL;
3701         }
3702
3703         /*
3704          * If we're enabling device-initiated LPM for one link state,
3705          * but the other link state has a too high SEL or PEL value,
3706          * just set those values to the max in the Set SEL request.
3707          */
3708         if (u1_sel > USB3_LPM_MAX_U1_SEL_PEL)
3709                 u1_sel = USB3_LPM_MAX_U1_SEL_PEL;
3710
3711         if (u1_pel > USB3_LPM_MAX_U1_SEL_PEL)
3712                 u1_pel = USB3_LPM_MAX_U1_SEL_PEL;
3713
3714         if (u2_sel > USB3_LPM_MAX_U2_SEL_PEL)
3715                 u2_sel = USB3_LPM_MAX_U2_SEL_PEL;
3716
3717         if (u2_pel > USB3_LPM_MAX_U2_SEL_PEL)
3718                 u2_pel = USB3_LPM_MAX_U2_SEL_PEL;
3719
3720         /*
3721          * usb_enable_lpm() can be called as part of a failed device reset,
3722          * which may be initiated by an error path of a mass storage driver.
3723          * Therefore, use GFP_NOIO.
3724          */
3725         sel_values = kmalloc(sizeof *(sel_values), GFP_NOIO);
3726         if (!sel_values)
3727                 return -ENOMEM;
3728
3729         sel_values->u1_sel = u1_sel;
3730         sel_values->u1_pel = u1_pel;
3731         sel_values->u2_sel = cpu_to_le16(u2_sel);
3732         sel_values->u2_pel = cpu_to_le16(u2_pel);
3733
3734         ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3735                         USB_REQ_SET_SEL,
3736                         USB_RECIP_DEVICE,
3737                         0, 0,
3738                         sel_values, sizeof *(sel_values),
3739                         USB_CTRL_SET_TIMEOUT);
3740         kfree(sel_values);
3741         return ret;
3742 }
3743
3744 /*
3745  * Enable or disable device-initiated U1 or U2 transitions.
3746  */
3747 static int usb_set_device_initiated_lpm(struct usb_device *udev,
3748                 enum usb3_link_state state, bool enable)
3749 {
3750         int ret;
3751         int feature;
3752
3753         switch (state) {
3754         case USB3_LPM_U1:
3755                 feature = USB_DEVICE_U1_ENABLE;
3756                 break;
3757         case USB3_LPM_U2:
3758                 feature = USB_DEVICE_U2_ENABLE;
3759                 break;
3760         default:
3761                 dev_warn(&udev->dev, "%s: Can't %s non-U1 or U2 state.\n",
3762                                 __func__, enable ? "enable" : "disable");
3763                 return -EINVAL;
3764         }
3765
3766         if (udev->state != USB_STATE_CONFIGURED) {
3767                 dev_dbg(&udev->dev, "%s: Can't %s %s state "
3768                                 "for unconfigured device.\n",
3769                                 __func__, enable ? "enable" : "disable",
3770                                 usb3_lpm_names[state]);
3771                 return 0;
3772         }
3773
3774         if (enable) {
3775                 /*
3776                  * Now send the control transfer to enable device-initiated LPM
3777                  * for either U1 or U2.
3778                  */
3779                 ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3780                                 USB_REQ_SET_FEATURE,
3781                                 USB_RECIP_DEVICE,
3782                                 feature,
3783                                 0, NULL, 0,
3784                                 USB_CTRL_SET_TIMEOUT);
3785         } else {
3786                 ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
3787                                 USB_REQ_CLEAR_FEATURE,
3788                                 USB_RECIP_DEVICE,
3789                                 feature,
3790                                 0, NULL, 0,
3791                                 USB_CTRL_SET_TIMEOUT);
3792         }
3793         if (ret < 0) {
3794                 dev_warn(&udev->dev, "%s of device-initiated %s failed.\n",
3795                                 enable ? "Enable" : "Disable",
3796                                 usb3_lpm_names[state]);
3797                 return -EBUSY;
3798         }
3799         return 0;
3800 }
3801
3802 static int usb_set_lpm_timeout(struct usb_device *udev,
3803                 enum usb3_link_state state, int timeout)
3804 {
3805         int ret;
3806         int feature;
3807
3808         switch (state) {
3809         case USB3_LPM_U1:
3810                 feature = USB_PORT_FEAT_U1_TIMEOUT;
3811                 break;
3812         case USB3_LPM_U2:
3813                 feature = USB_PORT_FEAT_U2_TIMEOUT;
3814                 break;
3815         default:
3816                 dev_warn(&udev->dev, "%s: Can't set timeout for non-U1 or U2 state.\n",
3817                                 __func__);
3818                 return -EINVAL;
3819         }
3820
3821         if (state == USB3_LPM_U1 && timeout > USB3_LPM_U1_MAX_TIMEOUT &&
3822                         timeout != USB3_LPM_DEVICE_INITIATED) {
3823                 dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x, "
3824                                 "which is a reserved value.\n",
3825                                 usb3_lpm_names[state], timeout);
3826                 return -EINVAL;
3827         }
3828
3829         ret = set_port_feature(udev->parent,
3830                         USB_PORT_LPM_TIMEOUT(timeout) | udev->portnum,
3831                         feature);
3832         if (ret < 0) {
3833                 dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x,"
3834                                 "error code %i\n", usb3_lpm_names[state],
3835                                 timeout, ret);
3836                 return -EBUSY;
3837         }
3838         if (state == USB3_LPM_U1)
3839                 udev->u1_params.timeout = timeout;
3840         else
3841                 udev->u2_params.timeout = timeout;
3842         return 0;
3843 }
3844
3845 /*
3846  * Enable the hub-initiated U1/U2 idle timeouts, and enable device-initiated
3847  * U1/U2 entry.
3848  *
3849  * We will attempt to enable U1 or U2, but there are no guarantees that the
3850  * control transfers to set the hub timeout or enable device-initiated U1/U2
3851  * will be successful.
3852  *
3853  * If we cannot set the parent hub U1/U2 timeout, we attempt to let the xHCI
3854  * driver know about it.  If that call fails, it should be harmless, and just
3855  * take up more slightly more bus bandwidth for unnecessary U1/U2 exit latency.
3856  */
3857 static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
3858                 enum usb3_link_state state)
3859 {
3860         int timeout, ret;
3861         __u8 u1_mel = udev->bos->ss_cap->bU1devExitLat;
3862         __le16 u2_mel = udev->bos->ss_cap->bU2DevExitLat;
3863
3864         /* If the device says it doesn't have *any* exit latency to come out of
3865          * U1 or U2, it's probably lying.  Assume it doesn't implement that link
3866          * state.
3867          */
3868         if ((state == USB3_LPM_U1 && u1_mel == 0) ||
3869                         (state == USB3_LPM_U2 && u2_mel == 0))
3870                 return;
3871
3872         /*
3873          * First, let the device know about the exit latencies
3874          * associated with the link state we're about to enable.
3875          */
3876         ret = usb_req_set_sel(udev, state);
3877         if (ret < 0) {
3878                 dev_warn(&udev->dev, "Set SEL for device-initiated %s failed.\n",
3879                                 usb3_lpm_names[state]);
3880                 return;
3881         }
3882
3883         /* We allow the host controller to set the U1/U2 timeout internally
3884          * first, so that it can change its schedule to account for the
3885          * additional latency to send data to a device in a lower power
3886          * link state.
3887          */
3888         timeout = hcd->driver->enable_usb3_lpm_timeout(hcd, udev, state);
3889
3890         /* xHCI host controller doesn't want to enable this LPM state. */
3891         if (timeout == 0)
3892                 return;
3893
3894         if (timeout < 0) {
3895                 dev_warn(&udev->dev, "Could not enable %s link state, "
3896                                 "xHCI error %i.\n", usb3_lpm_names[state],
3897                                 timeout);
3898                 return;
3899         }
3900
3901         if (usb_set_lpm_timeout(udev, state, timeout)) {
3902                 /* If we can't set the parent hub U1/U2 timeout,
3903                  * device-initiated LPM won't be allowed either, so let the xHCI
3904                  * host know that this link state won't be enabled.
3905                  */
3906                 hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state);
3907         } else {
3908                 /* Only a configured device will accept the Set Feature
3909                  * U1/U2_ENABLE
3910                  */
3911                 if (udev->actconfig)
3912                         usb_set_device_initiated_lpm(udev, state, true);
3913
3914                 /* As soon as usb_set_lpm_timeout(timeout) returns 0, the
3915                  * hub-initiated LPM is enabled. Thus, LPM is enabled no
3916                  * matter the result of usb_set_device_initiated_lpm().
3917                  * The only difference is whether device is able to initiate
3918                  * LPM.
3919                  */
3920                 if (state == USB3_LPM_U1)
3921                         udev->usb3_lpm_u1_enabled = 1;
3922                 else if (state == USB3_LPM_U2)
3923                         udev->usb3_lpm_u2_enabled = 1;
3924         }
3925 }
3926
3927 /*
3928  * Disable the hub-initiated U1/U2 idle timeouts, and disable device-initiated
3929  * U1/U2 entry.
3930  *
3931  * If this function returns -EBUSY, the parent hub will still allow U1/U2 entry.
3932  * If zero is returned, the parent will not allow the link to go into U1/U2.
3933  *
3934  * If zero is returned, device-initiated U1/U2 entry may still be enabled, but
3935  * it won't have an effect on the bus link state because the parent hub will
3936  * still disallow device-initiated U1/U2 entry.
3937  *
3938  * If zero is returned, the xHCI host controller may still think U1/U2 entry is
3939  * possible.  The result will be slightly more bus bandwidth will be taken up
3940  * (to account for U1/U2 exit latency), but it should be harmless.
3941  */
3942 static int usb_disable_link_state(struct usb_hcd *hcd, struct usb_device *udev,
3943                 enum usb3_link_state state)
3944 {
3945         switch (state) {
3946         case USB3_LPM_U1:
3947         case USB3_LPM_U2:
3948                 break;
3949         default:
3950                 dev_warn(&udev->dev, "%s: Can't disable non-U1 or U2 state.\n",
3951                                 __func__);
3952                 return -EINVAL;
3953         }
3954
3955         if (usb_set_lpm_timeout(udev, state, 0))
3956                 return -EBUSY;
3957
3958         usb_set_device_initiated_lpm(udev, state, false);
3959
3960         if (hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state))
3961                 dev_warn(&udev->dev, "Could not disable xHCI %s timeout, "
3962                                 "bus schedule bandwidth may be impacted.\n",
3963                                 usb3_lpm_names[state]);
3964
3965         /* As soon as usb_set_lpm_timeout(0) return 0, hub initiated LPM
3966          * is disabled. Hub will disallows link to enter U1/U2 as well,
3967          * even device is initiating LPM. Hence LPM is disabled if hub LPM
3968          * timeout set to 0, no matter device-initiated LPM is disabled or
3969          * not.
3970          */
3971         if (state == USB3_LPM_U1)
3972                 udev->usb3_lpm_u1_enabled = 0;
3973         else if (state == USB3_LPM_U2)
3974                 udev->usb3_lpm_u2_enabled = 0;
3975
3976         return 0;
3977 }
3978
3979 /*
3980  * Disable hub-initiated and device-initiated U1 and U2 entry.
3981  * Caller must own the bandwidth_mutex.
3982  *
3983  * This will call usb_enable_lpm() on failure, which will decrement
3984  * lpm_disable_count, and will re-enable LPM if lpm_disable_count reaches zero.
3985  */
3986 int usb_disable_lpm(struct usb_device *udev)
3987 {
3988         struct usb_hcd *hcd;
3989
3990         if (!udev || !udev->parent ||
3991                         udev->speed < USB_SPEED_SUPER ||
3992                         !udev->lpm_capable ||
3993                         udev->state < USB_STATE_DEFAULT)
3994                 return 0;
3995
3996         hcd = bus_to_hcd(udev->bus);
3997         if (!hcd || !hcd->driver->disable_usb3_lpm_timeout)
3998                 return 0;
3999
4000         udev->lpm_disable_count++;
4001         if ((udev->u1_params.timeout == 0 && udev->u2_params.timeout == 0))
4002                 return 0;
4003
4004         /* If LPM is enabled, attempt to disable it. */
4005         if (usb_disable_link_state(hcd, udev, USB3_LPM_U1))
4006                 goto enable_lpm;
4007         if (usb_disable_link_state(hcd, udev, USB3_LPM_U2))
4008                 goto enable_lpm;
4009
4010         return 0;
4011
4012 enable_lpm:
4013         usb_enable_lpm(udev);
4014         return -EBUSY;
4015 }
4016 EXPORT_SYMBOL_GPL(usb_disable_lpm);
4017
4018 /* Grab the bandwidth_mutex before calling usb_disable_lpm() */
4019 int usb_unlocked_disable_lpm(struct usb_device *udev)
4020 {
4021         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4022         int ret;
4023
4024         if (!hcd)
4025                 return -EINVAL;
4026
4027         mutex_lock(hcd->bandwidth_mutex);
4028         ret = usb_disable_lpm(udev);
4029         mutex_unlock(hcd->bandwidth_mutex);
4030
4031         return ret;
4032 }
4033 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
4034
4035 /*
4036  * Attempt to enable device-initiated and hub-initiated U1 and U2 entry.  The
4037  * xHCI host policy may prevent U1 or U2 from being enabled.
4038  *
4039  * Other callers may have disabled link PM, so U1 and U2 entry will be disabled
4040  * until the lpm_disable_count drops to zero.  Caller must own the
4041  * bandwidth_mutex.
4042  */
4043 void usb_enable_lpm(struct usb_device *udev)
4044 {
4045         struct usb_hcd *hcd;
4046         struct usb_hub *hub;
4047         struct usb_port *port_dev;
4048
4049         if (!udev || !udev->parent ||
4050                         udev->speed < USB_SPEED_SUPER ||
4051                         !udev->lpm_capable ||
4052                         udev->state < USB_STATE_DEFAULT)
4053                 return;
4054
4055         udev->lpm_disable_count--;
4056         hcd = bus_to_hcd(udev->bus);
4057         /* Double check that we can both enable and disable LPM.
4058          * Device must be configured to accept set feature U1/U2 timeout.
4059          */
4060         if (!hcd || !hcd->driver->enable_usb3_lpm_timeout ||
4061                         !hcd->driver->disable_usb3_lpm_timeout)
4062                 return;
4063
4064         if (udev->lpm_disable_count > 0)
4065                 return;
4066
4067         hub = usb_hub_to_struct_hub(udev->parent);
4068         if (!hub)
4069                 return;
4070
4071         port_dev = hub->ports[udev->portnum - 1];
4072
4073         if (port_dev->usb3_lpm_u1_permit)
4074                 usb_enable_link_state(hcd, udev, USB3_LPM_U1);
4075
4076         if (port_dev->usb3_lpm_u2_permit)
4077                 usb_enable_link_state(hcd, udev, USB3_LPM_U2);
4078 }
4079 EXPORT_SYMBOL_GPL(usb_enable_lpm);
4080
4081 /* Grab the bandwidth_mutex before calling usb_enable_lpm() */
4082 void usb_unlocked_enable_lpm(struct usb_device *udev)
4083 {
4084         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4085
4086         if (!hcd)
4087                 return;
4088
4089         mutex_lock(hcd->bandwidth_mutex);
4090         usb_enable_lpm(udev);
4091         mutex_unlock(hcd->bandwidth_mutex);
4092 }
4093 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
4094
4095 /* usb3 devices use U3 for disabled, make sure remote wakeup is disabled */
4096 static void hub_usb3_port_prepare_disable(struct usb_hub *hub,
4097                                           struct usb_port *port_dev)
4098 {
4099         struct usb_device *udev = port_dev->child;
4100         int ret;
4101
4102         if (udev && udev->port_is_suspended && udev->do_remote_wakeup) {
4103                 ret = hub_set_port_link_state(hub, port_dev->portnum,
4104                                               USB_SS_PORT_LS_U0);
4105                 if (!ret) {
4106                         msleep(USB_RESUME_TIMEOUT);
4107                         ret = usb_disable_remote_wakeup(udev);
4108                 }
4109                 if (ret)
4110                         dev_warn(&udev->dev,
4111                                  "Port disable: can't disable remote wake\n");
4112                 udev->do_remote_wakeup = 0;
4113         }
4114 }
4115
4116 #else   /* CONFIG_PM */
4117
4118 #define hub_suspend             NULL
4119 #define hub_resume              NULL
4120 #define hub_reset_resume        NULL
4121
4122 static inline void hub_usb3_port_prepare_disable(struct usb_hub *hub,
4123                                                  struct usb_port *port_dev) { }
4124
4125 int usb_disable_lpm(struct usb_device *udev)
4126 {
4127         return 0;
4128 }
4129 EXPORT_SYMBOL_GPL(usb_disable_lpm);
4130
4131 void usb_enable_lpm(struct usb_device *udev) { }
4132 EXPORT_SYMBOL_GPL(usb_enable_lpm);
4133
4134 int usb_unlocked_disable_lpm(struct usb_device *udev)
4135 {
4136         return 0;
4137 }
4138 EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm);
4139
4140 void usb_unlocked_enable_lpm(struct usb_device *udev) { }
4141 EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm);
4142
4143 int usb_disable_ltm(struct usb_device *udev)
4144 {
4145         return 0;
4146 }
4147 EXPORT_SYMBOL_GPL(usb_disable_ltm);
4148
4149 void usb_enable_ltm(struct usb_device *udev) { }
4150 EXPORT_SYMBOL_GPL(usb_enable_ltm);
4151
4152 static int hub_handle_remote_wakeup(struct usb_hub *hub, unsigned int port,
4153                 u16 portstatus, u16 portchange)
4154 {
4155         return 0;
4156 }
4157
4158 #endif  /* CONFIG_PM */
4159
4160 /*
4161  * USB-3 does not have a similar link state as USB-2 that will avoid negotiating
4162  * a connection with a plugged-in cable but will signal the host when the cable
4163  * is unplugged. Disable remote wake and set link state to U3 for USB-3 devices
4164  */
4165 static int hub_port_disable(struct usb_hub *hub, int port1, int set_state)
4166 {
4167         struct usb_port *port_dev = hub->ports[port1 - 1];
4168         struct usb_device *hdev = hub->hdev;
4169         int ret = 0;
4170
4171         if (!hub->error) {
4172                 if (hub_is_superspeed(hub->hdev)) {
4173                         hub_usb3_port_prepare_disable(hub, port_dev);
4174                         ret = hub_set_port_link_state(hub, port_dev->portnum,
4175                                                       USB_SS_PORT_LS_U3);
4176                 } else {
4177                         ret = usb_clear_port_feature(hdev, port1,
4178                                         USB_PORT_FEAT_ENABLE);
4179                 }
4180         }
4181         if (port_dev->child && set_state)
4182                 usb_set_device_state(port_dev->child, USB_STATE_NOTATTACHED);
4183         if (ret && ret != -ENODEV)
4184                 dev_err(&port_dev->dev, "cannot disable (err = %d)\n", ret);
4185         return ret;
4186 }
4187
4188
4189 /* USB 2.0 spec, 7.1.7.3 / fig 7-29:
4190  *
4191  * Between connect detection and reset signaling there must be a delay
4192  * of 100ms at least for debounce and power-settling.  The corresponding
4193  * timer shall restart whenever the downstream port detects a disconnect.
4194  *
4195  * Apparently there are some bluetooth and irda-dongles and a number of
4196  * low-speed devices for which this debounce period may last over a second.
4197  * Not covered by the spec - but easy to deal with.
4198  *
4199  * This implementation uses a 1500ms total debounce timeout; if the
4200  * connection isn't stable by then it returns -ETIMEDOUT.  It checks
4201  * every 25ms for transient disconnects.  When the port status has been
4202  * unchanged for 100ms it returns the port status.
4203  */
4204 int hub_port_debounce(struct usb_hub *hub, int port1, bool must_be_connected)
4205 {
4206         int ret;
4207         u16 portchange, portstatus;
4208         unsigned connection = 0xffff;
4209         int total_time, stable_time = 0;
4210         struct usb_port *port_dev = hub->ports[port1 - 1];
4211
4212         for (total_time = 0; ; total_time += HUB_DEBOUNCE_STEP) {
4213                 ret = hub_port_status(hub, port1, &portstatus, &portchange);
4214                 if (ret < 0)
4215                         return ret;
4216
4217                 if (!(portchange & USB_PORT_STAT_C_CONNECTION) &&
4218                      (portstatus & USB_PORT_STAT_CONNECTION) == connection) {
4219                         if (!must_be_connected ||
4220                              (connection == USB_PORT_STAT_CONNECTION))
4221                                 stable_time += HUB_DEBOUNCE_STEP;
4222                         if (stable_time >= HUB_DEBOUNCE_STABLE)
4223                                 break;
4224                 } else {
4225                         stable_time = 0;
4226                         connection = portstatus & USB_PORT_STAT_CONNECTION;
4227                 }
4228
4229                 if (portchange & USB_PORT_STAT_C_CONNECTION) {
4230                         usb_clear_port_feature(hub->hdev, port1,
4231                                         USB_PORT_FEAT_C_CONNECTION);
4232                 }
4233
4234                 if (total_time >= HUB_DEBOUNCE_TIMEOUT)
4235                         break;
4236                 msleep(HUB_DEBOUNCE_STEP);
4237         }
4238
4239         dev_dbg(&port_dev->dev, "debounce total %dms stable %dms status 0x%x\n",
4240                         total_time, stable_time, portstatus);
4241
4242         if (stable_time < HUB_DEBOUNCE_STABLE)
4243                 return -ETIMEDOUT;
4244         return portstatus;
4245 }
4246
4247 void usb_ep0_reinit(struct usb_device *udev)
4248 {
4249         usb_disable_endpoint(udev, 0 + USB_DIR_IN, true);
4250         usb_disable_endpoint(udev, 0 + USB_DIR_OUT, true);
4251         usb_enable_endpoint(udev, &udev->ep0, true);
4252 }
4253 EXPORT_SYMBOL_GPL(usb_ep0_reinit);
4254
4255 #define usb_sndaddr0pipe()      (PIPE_CONTROL << 30)
4256 #define usb_rcvaddr0pipe()      ((PIPE_CONTROL << 30) | USB_DIR_IN)
4257
4258 static int hub_set_address(struct usb_device *udev, int devnum)
4259 {
4260         int retval;
4261         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4262
4263         /*
4264          * The host controller will choose the device address,
4265          * instead of the core having chosen it earlier
4266          */
4267         if (!hcd->driver->address_device && devnum <= 1)
4268                 return -EINVAL;
4269         if (udev->state == USB_STATE_ADDRESS)
4270                 return 0;
4271         if (udev->state != USB_STATE_DEFAULT)
4272                 return -EINVAL;
4273         if (hcd->driver->address_device)
4274                 retval = hcd->driver->address_device(hcd, udev);
4275         else
4276                 retval = usb_control_msg(udev, usb_sndaddr0pipe(),
4277                                 USB_REQ_SET_ADDRESS, 0, devnum, 0,
4278                                 NULL, 0, USB_CTRL_SET_TIMEOUT);
4279         if (retval == 0) {
4280                 update_devnum(udev, devnum);
4281                 /* Device now using proper address. */
4282                 usb_set_device_state(udev, USB_STATE_ADDRESS);
4283                 usb_ep0_reinit(udev);
4284         }
4285         return retval;
4286 }
4287
4288 /*
4289  * There are reports of USB 3.0 devices that say they support USB 2.0 Link PM
4290  * when they're plugged into a USB 2.0 port, but they don't work when LPM is
4291  * enabled.
4292  *
4293  * Only enable USB 2.0 Link PM if the port is internal (hardwired), or the
4294  * device says it supports the new USB 2.0 Link PM errata by setting the BESL
4295  * support bit in the BOS descriptor.
4296  */
4297 static void hub_set_initial_usb2_lpm_policy(struct usb_device *udev)
4298 {
4299         struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
4300         int connect_type = USB_PORT_CONNECT_TYPE_UNKNOWN;
4301
4302         if (!udev->usb2_hw_lpm_capable || !udev->bos)
4303                 return;
4304
4305         if (hub)
4306                 connect_type = hub->ports[udev->portnum - 1]->connect_type;
4307
4308         if ((udev->bos->ext_cap->bmAttributes & cpu_to_le32(USB_BESL_SUPPORT)) ||
4309                         connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
4310                 udev->usb2_hw_lpm_allowed = 1;
4311                 usb_set_usb2_hardware_lpm(udev, 1);
4312         }
4313 }
4314
4315 static int hub_enable_device(struct usb_device *udev)
4316 {
4317         struct usb_hcd *hcd = bus_to_hcd(udev->bus);
4318
4319         if (!hcd->driver->enable_device)
4320                 return 0;
4321         if (udev->state == USB_STATE_ADDRESS)
4322                 return 0;
4323         if (udev->state != USB_STATE_DEFAULT)
4324                 return -EINVAL;
4325
4326         return hcd->driver->enable_device(hcd, udev);
4327 }
4328
4329 /* Reset device, (re)assign address, get device descriptor.
4330  * Device connection must be stable, no more debouncing needed.
4331  * Returns device in USB_STATE_ADDRESS, except on error.
4332  *
4333  * If this is called for an already-existing device (as part of
4334  * usb_reset_and_verify_device), the caller must own the device lock and
4335  * the port lock.  For a newly detected device that is not accessible
4336  * through any global pointers, it's not necessary to lock the device,
4337  * but it is still necessary to lock the port.
4338  */
4339 static int
4340 hub_port_init(struct usb_hub *hub, struct usb_device *udev, int port1,
4341                 int retry_counter)
4342 {
4343         struct usb_device       *hdev = hub->hdev;
4344         struct usb_hcd          *hcd = bus_to_hcd(hdev->bus);
4345         int                     retries, operations, retval, i;
4346         unsigned                delay = HUB_SHORT_RESET_TIME;
4347         enum usb_device_speed   oldspeed = udev->speed;
4348         const char              *speed;
4349         int                     devnum = udev->devnum;
4350
4351         /* root hub ports have a slightly longer reset period
4352          * (from USB 2.0 spec, section 7.1.7.5)
4353          */
4354         if (!hdev->parent) {
4355                 delay = HUB_ROOT_RESET_TIME;
4356                 if (port1 == hdev->bus->otg_port)
4357                         hdev->bus->b_hnp_enable = 0;
4358         }
4359
4360         /* Some low speed devices have problems with the quick delay, so */
4361         /*  be a bit pessimistic with those devices. RHbug #23670 */
4362         if (oldspeed == USB_SPEED_LOW)
4363                 delay = HUB_LONG_RESET_TIME;
4364
4365         mutex_lock(hcd->address0_mutex);
4366
4367         /* Reset the device; full speed may morph to high speed */
4368         /* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
4369         retval = hub_port_reset(hub, port1, udev, delay, false);
4370         if (retval < 0)         /* error or disconnect */
4371                 goto fail;
4372         /* success, speed is known */
4373
4374         retval = -ENODEV;
4375
4376         /* Don't allow speed changes at reset, except usb 3.0 to faster */
4377         if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed &&
4378             !(oldspeed == USB_SPEED_SUPER && udev->speed > oldspeed)) {
4379                 dev_dbg(&udev->dev, "device reset changed speed!\n");
4380                 goto fail;
4381         }
4382         oldspeed = udev->speed;
4383
4384         /* USB 2.0 section 5.5.3 talks about ep0 maxpacket ...
4385          * it's fixed size except for full speed devices.
4386          * For Wireless USB devices, ep0 max packet is always 512 (tho
4387          * reported as 0xff in the device descriptor). WUSB1.0[4.8.1].
4388          */
4389         switch (udev->speed) {
4390         case USB_SPEED_SUPER_PLUS:
4391         case USB_SPEED_SUPER:
4392         case USB_SPEED_WIRELESS:        /* fixed at 512 */
4393                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(512);
4394                 break;
4395         case USB_SPEED_HIGH:            /* fixed at 64 */
4396                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4397                 break;
4398         case USB_SPEED_FULL:            /* 8, 16, 32, or 64 */
4399                 /* to determine the ep0 maxpacket size, try to read
4400                  * the device descriptor to get bMaxPacketSize0 and
4401                  * then correct our initial guess.
4402                  */
4403                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
4404                 break;
4405         case USB_SPEED_LOW:             /* fixed at 8 */
4406                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(8);
4407                 break;
4408         default:
4409                 goto fail;
4410         }
4411
4412         if (udev->speed == USB_SPEED_WIRELESS)
4413                 speed = "variable speed Wireless";
4414         else
4415                 speed = usb_speed_string(udev->speed);
4416
4417         if (udev->speed < USB_SPEED_SUPER)
4418                 dev_info(&udev->dev,
4419                                 "%s %s USB device number %d using %s\n",
4420                                 (udev->config) ? "reset" : "new", speed,
4421                                 devnum, udev->bus->controller->driver->name);
4422
4423         /* Set up TT records, if needed  */
4424         if (hdev->tt) {
4425                 udev->tt = hdev->tt;
4426                 udev->ttport = hdev->ttport;
4427         } else if (udev->speed != USB_SPEED_HIGH
4428                         && hdev->speed == USB_SPEED_HIGH) {
4429                 if (!hub->tt.hub) {
4430                         dev_err(&udev->dev, "parent hub has no TT\n");
4431                         retval = -EINVAL;
4432                         goto fail;
4433                 }
4434                 udev->tt = &hub->tt;
4435                 udev->ttport = port1;
4436         }
4437
4438         /* Why interleave GET_DESCRIPTOR and SET_ADDRESS this way?
4439          * Because device hardware and firmware is sometimes buggy in
4440          * this area, and this is how Linux has done it for ages.
4441          * Change it cautiously.
4442          *
4443          * NOTE:  If use_new_scheme() is true we will start by issuing
4444          * a 64-byte GET_DESCRIPTOR request.  This is what Windows does,
4445          * so it may help with some non-standards-compliant devices.
4446          * Otherwise we start with SET_ADDRESS and then try to read the
4447          * first 8 bytes of the device descriptor to get the ep0 maxpacket
4448          * value.
4449          */
4450         for (retries = 0; retries < GET_DESCRIPTOR_TRIES; (++retries, msleep(100))) {
4451                 bool did_new_scheme = false;
4452
4453                 if (use_new_scheme(udev, retry_counter)) {
4454                         struct usb_device_descriptor *buf;
4455                         int r = 0;
4456
4457                         did_new_scheme = true;
4458                         retval = hub_enable_device(udev);
4459                         if (retval < 0) {
4460                                 dev_err(&udev->dev,
4461                                         "hub failed to enable device, error %d\n",
4462                                         retval);
4463                                 goto fail;
4464                         }
4465
4466 #define GET_DESCRIPTOR_BUFSIZE  64
4467                         buf = kmalloc(GET_DESCRIPTOR_BUFSIZE, GFP_NOIO);
4468                         if (!buf) {
4469                                 retval = -ENOMEM;
4470                                 continue;
4471                         }
4472
4473                         /* Retry on all errors; some devices are flakey.
4474                          * 255 is for WUSB devices, we actually need to use
4475                          * 512 (WUSB1.0[4.8.1]).
4476                          */
4477                         for (operations = 0; operations < 3; ++operations) {
4478                                 buf->bMaxPacketSize0 = 0;
4479                                 r = usb_control_msg(udev, usb_rcvaddr0pipe(),
4480                                         USB_REQ_GET_DESCRIPTOR, USB_DIR_IN,
4481                                         USB_DT_DEVICE << 8, 0,
4482                                         buf, GET_DESCRIPTOR_BUFSIZE,
4483                                         initial_descriptor_timeout);
4484                                 switch (buf->bMaxPacketSize0) {
4485                                 case 8: case 16: case 32: case 64: case 255:
4486                                         if (buf->bDescriptorType ==
4487                                                         USB_DT_DEVICE) {
4488                                                 r = 0;
4489                                                 break;
4490                                         }
4491                                         /* FALL THROUGH */
4492                                 default:
4493                                         if (r == 0)
4494                                                 r = -EPROTO;
4495                                         break;
4496                                 }
4497                                 /*
4498                                  * Some devices time out if they are powered on
4499                                  * when already connected. They need a second
4500                                  * reset. But only on the first attempt,
4501                                  * lest we get into a time out/reset loop
4502                                  */
4503                                 if (r == 0  || (r == -ETIMEDOUT && retries == 0))
4504                                         break;
4505                         }
4506                         udev->descriptor.bMaxPacketSize0 =
4507                                         buf->bMaxPacketSize0;
4508                         kfree(buf);
4509
4510                         retval = hub_port_reset(hub, port1, udev, delay, false);
4511                         if (retval < 0)         /* error or disconnect */
4512                                 goto fail;
4513                         if (oldspeed != udev->speed) {
4514                                 dev_dbg(&udev->dev,
4515                                         "device reset changed speed!\n");
4516                                 retval = -ENODEV;
4517                                 goto fail;
4518                         }
4519                         if (r) {
4520                                 if (r != -ENODEV)
4521                                         dev_err(&udev->dev, "device descriptor read/64, error %d\n",
4522                                                         r);
4523                                 retval = -EMSGSIZE;
4524                                 continue;
4525                         }
4526 #undef GET_DESCRIPTOR_BUFSIZE
4527                 }
4528
4529                 /*
4530                  * If device is WUSB, we already assigned an
4531                  * unauthorized address in the Connect Ack sequence;
4532                  * authorization will assign the final address.
4533                  */
4534                 if (udev->wusb == 0) {
4535                         for (operations = 0; operations < SET_ADDRESS_TRIES; ++operations) {
4536                                 retval = hub_set_address(udev, devnum);
4537                                 if (retval >= 0)
4538                                         break;
4539                                 msleep(200);
4540                         }
4541                         if (retval < 0) {
4542                                 if (retval != -ENODEV)
4543                                         dev_err(&udev->dev, "device not accepting address %d, error %d\n",
4544                                                         devnum, retval);
4545                                 goto fail;
4546                         }
4547                         if (udev->speed >= USB_SPEED_SUPER) {
4548                                 devnum = udev->devnum;
4549                                 dev_info(&udev->dev,
4550                                                 "%s SuperSpeed%s USB device number %d using %s\n",
4551                                                 (udev->config) ? "reset" : "new",
4552                                          (udev->speed == USB_SPEED_SUPER_PLUS) ? "Plus" : "",
4553                                                 devnum, udev->bus->controller->driver->name);
4554                         }
4555
4556                         /* cope with hardware quirkiness:
4557                          *  - let SET_ADDRESS settle, some device hardware wants it
4558                          *  - read ep0 maxpacket even for high and low speed,
4559                          */
4560                         msleep(10);
4561                         /* use_new_scheme() checks the speed which may have
4562                          * changed since the initial look so we cache the result
4563                          * in did_new_scheme
4564                          */
4565                         if (did_new_scheme)
4566                                 break;
4567                 }
4568
4569                 retval = usb_get_device_descriptor(udev, 8);
4570                 if (retval < 8) {
4571                         if (retval != -ENODEV)
4572                                 dev_err(&udev->dev,
4573                                         "device descriptor read/8, error %d\n",
4574                                         retval);
4575                         if (retval >= 0)
4576                                 retval = -EMSGSIZE;
4577                 } else {
4578                         retval = 0;
4579                         break;
4580                 }
4581         }
4582         if (retval)
4583                 goto fail;
4584
4585         /*
4586          * Some superspeed devices have finished the link training process
4587          * and attached to a superspeed hub port, but the device descriptor
4588          * got from those devices show they aren't superspeed devices. Warm
4589          * reset the port attached by the devices can fix them.
4590          */
4591         if ((udev->speed >= USB_SPEED_SUPER) &&
4592                         (le16_to_cpu(udev->descriptor.bcdUSB) < 0x0300)) {
4593                 dev_err(&udev->dev, "got a wrong device descriptor, "
4594                                 "warm reset device\n");
4595                 hub_port_reset(hub, port1, udev,
4596                                 HUB_BH_RESET_TIME, true);
4597                 retval = -EINVAL;
4598                 goto fail;
4599         }
4600
4601         if (udev->descriptor.bMaxPacketSize0 == 0xff ||
4602                         udev->speed >= USB_SPEED_SUPER)
4603                 i = 512;
4604         else
4605                 i = udev->descriptor.bMaxPacketSize0;
4606         if (usb_endpoint_maxp(&udev->ep0.desc) != i) {
4607                 if (udev->speed == USB_SPEED_LOW ||
4608                                 !(i == 8 || i == 16 || i == 32 || i == 64)) {
4609                         dev_err(&udev->dev, "Invalid ep0 maxpacket: %d\n", i);
4610                         retval = -EMSGSIZE;
4611                         goto fail;
4612                 }
4613                 if (udev->speed == USB_SPEED_FULL)
4614                         dev_dbg(&udev->dev, "ep0 maxpacket = %d\n", i);
4615                 else
4616                         dev_warn(&udev->dev, "Using ep0 maxpacket: %d\n", i);
4617                 udev->ep0.desc.wMaxPacketSize = cpu_to_le16(i);
4618                 usb_ep0_reinit(udev);
4619         }
4620
4621         retval = usb_get_device_descriptor(udev, USB_DT_DEVICE_SIZE);
4622         if (retval < (signed)sizeof(udev->descriptor)) {
4623                 if (retval != -ENODEV)
4624                         dev_err(&udev->dev, "device descriptor read/all, error %d\n",
4625                                         retval);
4626                 if (retval >= 0)
4627                         retval = -ENOMSG;
4628                 goto fail;
4629         }
4630
4631         usb_detect_quirks(udev);
4632
4633         if (udev->wusb == 0 && le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0201) {
4634                 retval = usb_get_bos_descriptor(udev);
4635                 if (!retval) {
4636                         udev->lpm_capable = usb_device_supports_lpm(udev);
4637                         usb_set_lpm_parameters(udev);
4638                 }
4639         }
4640
4641         retval = 0;
4642         /* notify HCD that we have a device connected and addressed */
4643         if (hcd->driver->update_device)
4644                 hcd->driver->update_device(hcd, udev);
4645         hub_set_initial_usb2_lpm_policy(udev);
4646 fail:
4647         if (retval) {
4648                 hub_port_disable(hub, port1, 0);
4649                 update_devnum(udev, devnum);    /* for disconnect processing */
4650         }
4651         mutex_unlock(hcd->address0_mutex);
4652         return retval;
4653 }
4654
4655 static void
4656 check_highspeed(struct usb_hub *hub, struct usb_device *udev, int port1)
4657 {
4658         struct usb_qualifier_descriptor *qual;
4659         int                             status;
4660
4661         if (udev->quirks & USB_QUIRK_DEVICE_QUALIFIER)
4662                 return;
4663
4664         qual = kmalloc(sizeof *qual, GFP_KERNEL);
4665         if (qual == NULL)
4666                 return;
4667
4668         status = usb_get_descriptor(udev, USB_DT_DEVICE_QUALIFIER, 0,
4669                         qual, sizeof *qual);
4670         if (status == sizeof *qual) {
4671                 dev_info(&udev->dev, "not running at top speed; "
4672                         "connect to a high speed hub\n");
4673                 /* hub LEDs are probably harder to miss than syslog */
4674                 if (hub->has_indicators) {
4675                         hub->indicator[port1-1] = INDICATOR_GREEN_BLINK;
4676                         queue_delayed_work(system_power_efficient_wq,
4677                                         &hub->leds, 0);
4678                 }
4679         }
4680         kfree(qual);
4681 }
4682
4683 static unsigned
4684 hub_power_remaining(struct usb_hub *hub)
4685 {
4686         struct usb_device *hdev = hub->hdev;
4687         int remaining;
4688         int port1;
4689
4690         if (!hub->limited_power)
4691                 return 0;
4692
4693         remaining = hdev->bus_mA - hub->descriptor->bHubContrCurrent;
4694         for (port1 = 1; port1 <= hdev->maxchild; ++port1) {
4695                 struct usb_port *port_dev = hub->ports[port1 - 1];
4696                 struct usb_device *udev = port_dev->child;
4697                 unsigned unit_load;
4698                 int delta;
4699
4700                 if (!udev)
4701                         continue;
4702                 if (hub_is_superspeed(udev))
4703                         unit_load = 150;
4704                 else
4705                         unit_load = 100;
4706
4707                 /*
4708                  * Unconfigured devices may not use more than one unit load,
4709                  * or 8mA for OTG ports
4710                  */
4711                 if (udev->actconfig)
4712                         delta = usb_get_max_power(udev, udev->actconfig);
4713                 else if (port1 != udev->bus->otg_port || hdev->parent)
4714                         delta = unit_load;
4715                 else
4716                         delta = 8;
4717                 if (delta > hub->mA_per_port)
4718                         dev_warn(&port_dev->dev, "%dmA is over %umA budget!\n",
4719                                         delta, hub->mA_per_port);
4720                 remaining -= delta;
4721         }
4722         if (remaining < 0) {
4723                 dev_warn(hub->intfdev, "%dmA over power budget!\n",
4724                         -remaining);
4725                 remaining = 0;
4726         }
4727         return remaining;
4728 }
4729
4730 static void hub_port_connect(struct usb_hub *hub, int port1, u16 portstatus,
4731                 u16 portchange)
4732 {
4733         int status, i;
4734         unsigned unit_load;
4735         struct usb_device *hdev = hub->hdev;
4736         struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
4737         struct usb_port *port_dev = hub->ports[port1 - 1];
4738         struct usb_device *udev = port_dev->child;
4739         static int unreliable_port = -1;
4740
4741         /* Disconnect any existing devices under this port */
4742         if (udev) {
4743                 if (hcd->usb_phy && !hdev->parent)
4744                         usb_phy_notify_disconnect(hcd->usb_phy, udev->speed);
4745                 usb_disconnect(&port_dev->child);
4746         }
4747
4748         /* We can forget about a "removed" device when there's a physical
4749          * disconnect or the connect status changes.
4750          */
4751         if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
4752                         (portchange & USB_PORT_STAT_C_CONNECTION))
4753                 clear_bit(port1, hub->removed_bits);
4754
4755         if (portchange & (USB_PORT_STAT_C_CONNECTION |
4756                                 USB_PORT_STAT_C_ENABLE)) {
4757                 status = hub_port_debounce_be_stable(hub, port1);
4758                 if (status < 0) {
4759                         if (status != -ENODEV &&
4760                                 port1 != unreliable_port &&
4761                                 printk_ratelimit())
4762                                 dev_err(&port_dev->dev, "connect-debounce failed\n");
4763                         portstatus &= ~USB_PORT_STAT_CONNECTION;
4764                         unreliable_port = port1;
4765                 } else {
4766                         portstatus = status;
4767                 }
4768         }
4769
4770         /* Return now if debouncing failed or nothing is connected or
4771          * the device was "removed".
4772          */
4773         if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
4774                         test_bit(port1, hub->removed_bits)) {
4775
4776                 /*
4777                  * maybe switch power back on (e.g. root hub was reset)
4778                  * but only if the port isn't owned by someone else.
4779                  */
4780                 if (hub_is_port_power_switchable(hub)
4781                                 && !port_is_power_on(hub, portstatus)
4782                                 && !port_dev->port_owner)
4783                         set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
4784
4785                 if (portstatus & USB_PORT_STAT_ENABLE)
4786                         goto done;
4787                 return;
4788         }
4789         if (hub_is_superspeed(hub->hdev))
4790                 unit_load = 150;
4791         else
4792                 unit_load = 100;
4793
4794         status = 0;
4795         for (i = 0; i < SET_CONFIG_TRIES; i++) {
4796
4797                 /* reallocate for each attempt, since references
4798                  * to the previous one can escape in various ways
4799                  */
4800                 udev = usb_alloc_dev(hdev, hdev->bus, port1);
4801                 if (!udev) {
4802                         dev_err(&port_dev->dev,
4803                                         "couldn't allocate usb_device\n");
4804                         goto done;
4805                 }
4806
4807                 usb_set_device_state(udev, USB_STATE_POWERED);
4808                 udev->bus_mA = hub->mA_per_port;
4809                 udev->level = hdev->level + 1;
4810                 udev->wusb = hub_is_wusb(hub);
4811
4812                 /* Devices connected to SuperSpeed hubs are USB 3.0 or later */
4813                 if (hub_is_superspeed(hub->hdev))
4814                         udev->speed = USB_SPEED_SUPER;
4815                 else
4816                         udev->speed = USB_SPEED_UNKNOWN;
4817
4818                 choose_devnum(udev);
4819                 if (udev->devnum <= 0) {
4820                         status = -ENOTCONN;     /* Don't retry */
4821                         goto loop;
4822                 }
4823
4824                 /* reset (non-USB 3.0 devices) and get descriptor */
4825                 usb_lock_port(port_dev);
4826                 status = hub_port_init(hub, udev, port1, i);
4827                 usb_unlock_port(port_dev);
4828                 if (status < 0)
4829                         goto loop;
4830
4831                 if (udev->quirks & USB_QUIRK_DELAY_INIT)
4832                         msleep(1000);
4833
4834                 /* consecutive bus-powered hubs aren't reliable; they can
4835                  * violate the voltage drop budget.  if the new child has
4836                  * a "powered" LED, users should notice we didn't enable it
4837                  * (without reading syslog), even without per-port LEDs
4838                  * on the parent.
4839                  */
4840                 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB
4841                                 && udev->bus_mA <= unit_load) {
4842                         u16     devstat;
4843
4844                         status = usb_get_status(udev, USB_RECIP_DEVICE, 0,
4845                                         &devstat);
4846                         if (status) {
4847                                 dev_dbg(&udev->dev, "get status %d ?\n", status);
4848                                 goto loop_disable;
4849                         }
4850                         if ((devstat & (1 << USB_DEVICE_SELF_POWERED)) == 0) {
4851                                 dev_err(&udev->dev,
4852                                         "can't connect bus-powered hub "
4853                                         "to this port\n");
4854                                 if (hub->has_indicators) {
4855                                         hub->indicator[port1-1] =
4856                                                 INDICATOR_AMBER_BLINK;
4857                                         queue_delayed_work(
4858                                                 system_power_efficient_wq,
4859                                                 &hub->leds, 0);
4860                                 }
4861                                 status = -ENOTCONN;     /* Don't retry */
4862                                 goto loop_disable;
4863                         }
4864                 }
4865
4866                 /* check for devices running slower than they could */
4867                 if (le16_to_cpu(udev->descriptor.bcdUSB) >= 0x0200
4868                                 && udev->speed == USB_SPEED_FULL
4869                                 && highspeed_hubs != 0)
4870                         check_highspeed(hub, udev, port1);
4871
4872                 /* Store the parent's children[] pointer.  At this point
4873                  * udev becomes globally accessible, although presumably
4874                  * no one will look at it until hdev is unlocked.
4875                  */
4876                 status = 0;
4877
4878                 mutex_lock(&usb_port_peer_mutex);
4879
4880                 /* We mustn't add new devices if the parent hub has
4881                  * been disconnected; we would race with the
4882                  * recursively_mark_NOTATTACHED() routine.
4883                  */
4884                 spin_lock_irq(&device_state_lock);
4885                 if (hdev->state == USB_STATE_NOTATTACHED)
4886                         status = -ENOTCONN;
4887                 else
4888                         port_dev->child = udev;
4889                 spin_unlock_irq(&device_state_lock);
4890                 mutex_unlock(&usb_port_peer_mutex);
4891
4892                 /* Run it through the hoops (find a driver, etc) */
4893                 if (!status) {
4894                         status = usb_new_device(udev);
4895                         if (status) {
4896                                 mutex_lock(&usb_port_peer_mutex);
4897                                 spin_lock_irq(&device_state_lock);
4898                                 port_dev->child = NULL;
4899                                 spin_unlock_irq(&device_state_lock);
4900                                 mutex_unlock(&usb_port_peer_mutex);
4901                         } else {
4902                                 if (hcd->usb_phy && !hdev->parent)
4903                                         usb_phy_notify_connect(hcd->usb_phy,
4904                                                         udev->speed);
4905                         }
4906                 }
4907
4908                 if (status)
4909                         goto loop_disable;
4910
4911                 status = hub_power_remaining(hub);
4912                 if (status)
4913                         dev_dbg(hub->intfdev, "%dmA power budget left\n", status);
4914
4915                 return;
4916
4917 loop_disable:
4918                 hub_port_disable(hub, port1, 1);
4919 loop:
4920                 usb_ep0_reinit(udev);
4921                 release_devnum(udev);
4922                 hub_free_dev(udev);
4923                 usb_put_dev(udev);
4924                 if ((status == -ENOTCONN) || (status == -ENOTSUPP))
4925                         break;
4926         }
4927         if (hub->hdev->parent ||
4928                         !hcd->driver->port_handed_over ||
4929                         !(hcd->driver->port_handed_over)(hcd, port1)) {
4930                 if (status != -ENOTCONN && status != -ENODEV)
4931                         dev_err(&port_dev->dev,
4932                                         "unable to enumerate USB device\n");
4933         }
4934
4935 done:
4936         hub_port_disable(hub, port1, 1);
4937         if (hcd->driver->relinquish_port && !hub->hdev->parent)
4938                 hcd->driver->relinquish_port(hcd, port1);
4939
4940 }
4941
4942 /* Handle physical or logical connection change events.
4943  * This routine is called when:
4944  *      a port connection-change occurs;
4945  *      a port enable-change occurs (often caused by EMI);
4946  *      usb_reset_and_verify_device() encounters changed descriptors (as from
4947  *              a firmware download)
4948  * caller already locked the hub
4949  */
4950 static void hub_port_connect_change(struct usb_hub *hub, int port1,
4951                                         u16 portstatus, u16 portchange)
4952                 __must_hold(&port_dev->status_lock)
4953 {
4954         struct usb_port *port_dev = hub->ports[port1 - 1];
4955         struct usb_device *udev = port_dev->child;
4956         int status = -ENODEV;
4957
4958         dev_dbg(&port_dev->dev, "status %04x, change %04x, %s\n", portstatus,
4959                         portchange, portspeed(hub, portstatus));
4960
4961         if (hub->has_indicators) {
4962                 set_port_led(hub, port1, HUB_LED_AUTO);
4963                 hub->indicator[port1-1] = INDICATOR_AUTO;
4964         }
4965
4966 #ifdef  CONFIG_USB_OTG
4967         /* during HNP, don't repeat the debounce */
4968         if (hub->hdev->bus->is_b_host)
4969                 portchange &= ~(USB_PORT_STAT_C_CONNECTION |
4970                                 USB_PORT_STAT_C_ENABLE);
4971 #endif
4972
4973         /* Try to resuscitate an existing device */
4974         if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
4975                         udev->state != USB_STATE_NOTATTACHED) {
4976                 if (portstatus & USB_PORT_STAT_ENABLE) {
4977                         status = 0;             /* Nothing to do */
4978 #ifdef CONFIG_PM
4979                 } else if (udev->state == USB_STATE_SUSPENDED &&
4980                                 udev->persist_enabled) {
4981                         /* For a suspended device, treat this as a
4982                          * remote wakeup event.
4983                          */
4984                         usb_unlock_port(port_dev);
4985                         status = usb_remote_wakeup(udev);
4986                         usb_lock_port(port_dev);
4987 #endif
4988                 } else {
4989                         /* Don't resuscitate */;
4990                 }
4991         }
4992         clear_bit(port1, hub->change_bits);
4993
4994         /* successfully revalidated the connection */
4995         if (status == 0)
4996                 return;
4997
4998         usb_unlock_port(port_dev);
4999         hub_port_connect(hub, port1, portstatus, portchange);
5000         usb_lock_port(port_dev);
5001 }
5002
5003 static void port_event(struct usb_hub *hub, int port1)
5004                 __must_hold(&port_dev->status_lock)
5005 {
5006         int connect_change;
5007         struct usb_port *port_dev = hub->ports[port1 - 1];
5008         struct usb_device *udev = port_dev->child;
5009         struct usb_device *hdev = hub->hdev;
5010         u16 portstatus, portchange;
5011
5012         connect_change = test_bit(port1, hub->change_bits);
5013         clear_bit(port1, hub->event_bits);
5014         clear_bit(port1, hub->wakeup_bits);
5015
5016         if (hub_port_status(hub, port1, &portstatus, &portchange) < 0)
5017                 return;
5018
5019         if (portchange & USB_PORT_STAT_C_CONNECTION) {
5020                 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
5021                 connect_change = 1;
5022         }
5023
5024         if (portchange & USB_PORT_STAT_C_ENABLE) {
5025                 if (!connect_change)
5026                         dev_dbg(&port_dev->dev, "enable change, status %08x\n",
5027                                         portstatus);
5028                 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
5029
5030                 /*
5031                  * EM interference sometimes causes badly shielded USB devices
5032                  * to be shutdown by the hub, this hack enables them again.
5033                  * Works at least with mouse driver.
5034                  */
5035                 if (!(portstatus & USB_PORT_STAT_ENABLE)
5036                     && !connect_change && udev) {
5037                         dev_err(&port_dev->dev, "disabled by hub (EMI?), re-enabling...\n");
5038                         connect_change = 1;
5039                 }
5040         }
5041
5042         if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
5043                 u16 status = 0, unused;
5044
5045                 dev_dbg(&port_dev->dev, "over-current change\n");
5046                 usb_clear_port_feature(hdev, port1,
5047                                 USB_PORT_FEAT_C_OVER_CURRENT);
5048                 msleep(100);    /* Cool down */
5049                 hub_power_on(hub, true);
5050                 hub_port_status(hub, port1, &status, &unused);
5051                 if (status & USB_PORT_STAT_OVERCURRENT)
5052                         dev_err(&port_dev->dev, "over-current condition\n");
5053         }
5054
5055         if (portchange & USB_PORT_STAT_C_RESET) {
5056                 dev_dbg(&port_dev->dev, "reset change\n");
5057                 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_RESET);
5058         }
5059         if ((portchange & USB_PORT_STAT_C_BH_RESET)
5060             && hub_is_superspeed(hdev)) {
5061                 dev_dbg(&port_dev->dev, "warm reset change\n");
5062                 usb_clear_port_feature(hdev, port1,
5063                                 USB_PORT_FEAT_C_BH_PORT_RESET);
5064         }
5065         if (portchange & USB_PORT_STAT_C_LINK_STATE) {
5066                 dev_dbg(&port_dev->dev, "link state change\n");
5067                 usb_clear_port_feature(hdev, port1,
5068                                 USB_PORT_FEAT_C_PORT_LINK_STATE);
5069         }
5070         if (portchange & USB_PORT_STAT_C_CONFIG_ERROR) {
5071                 dev_warn(&port_dev->dev, "config error\n");
5072                 usb_clear_port_feature(hdev, port1,
5073                                 USB_PORT_FEAT_C_PORT_CONFIG_ERROR);
5074         }
5075
5076         /* skip port actions that require the port to be powered on */
5077         if (!pm_runtime_active(&port_dev->dev))
5078                 return;
5079
5080         if (hub_handle_remote_wakeup(hub, port1, portstatus, portchange))
5081                 connect_change = 1;
5082
5083         /*
5084          * Warm reset a USB3 protocol port if it's in
5085          * SS.Inactive state.
5086          */
5087         if (hub_port_warm_reset_required(hub, port1, portstatus)) {
5088                 dev_dbg(&port_dev->dev, "do warm reset\n");
5089                 if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
5090                                 || udev->state == USB_STATE_NOTATTACHED) {
5091                         if (hub_port_reset(hub, port1, NULL,
5092                                         HUB_BH_RESET_TIME, true) < 0)
5093                                 hub_port_disable(hub, port1, 1);
5094                 } else {
5095                         usb_unlock_port(port_dev);
5096                         usb_lock_device(udev);
5097                         usb_reset_device(udev);
5098                         usb_unlock_device(udev);
5099                         usb_lock_port(port_dev);
5100                         connect_change = 0;
5101                 }
5102         }
5103
5104         if (connect_change)
5105                 hub_port_connect_change(hub, port1, portstatus, portchange);
5106 }
5107
5108 static void hub_event(struct work_struct *work)
5109 {
5110         struct usb_device *hdev;
5111         struct usb_interface *intf;
5112         struct usb_hub *hub;
5113         struct device *hub_dev;
5114         u16 hubstatus;
5115         u16 hubchange;
5116         int i, ret;
5117
5118         hub = container_of(work, struct usb_hub, events);
5119         hdev = hub->hdev;
5120         hub_dev = hub->intfdev;
5121         intf = to_usb_interface(hub_dev);
5122
5123         dev_dbg(hub_dev, "state %d ports %d chg %04x evt %04x\n",
5124                         hdev->state, hdev->maxchild,
5125                         /* NOTE: expects max 15 ports... */
5126                         (u16) hub->change_bits[0],
5127                         (u16) hub->event_bits[0]);
5128
5129         /* Lock the device, then check to see if we were
5130          * disconnected while waiting for the lock to succeed. */
5131         usb_lock_device(hdev);
5132         if (unlikely(hub->disconnected))
5133                 goto out_hdev_lock;
5134
5135         /* If the hub has died, clean up after it */
5136         if (hdev->state == USB_STATE_NOTATTACHED) {
5137                 hub->error = -ENODEV;
5138                 hub_quiesce(hub, HUB_DISCONNECT);
5139                 goto out_hdev_lock;
5140         }
5141
5142         /* Autoresume */
5143         ret = usb_autopm_get_interface(intf);
5144         if (ret) {
5145                 dev_dbg(hub_dev, "Can't autoresume: %d\n", ret);
5146                 goto out_hdev_lock;
5147         }
5148
5149         /* If this is an inactive hub, do nothing */
5150         if (hub->quiescing)
5151                 goto out_autopm;
5152
5153         if (hub->error) {
5154                 dev_dbg(hub_dev, "resetting for error %d\n", hub->error);
5155
5156                 ret = usb_reset_device(hdev);
5157                 if (ret) {
5158                         dev_dbg(hub_dev, "error resetting hub: %d\n", ret);
5159                         goto out_autopm;
5160                 }
5161
5162                 hub->nerrors = 0;
5163                 hub->error = 0;
5164         }
5165
5166         /* deal with port status changes */
5167         for (i = 1; i <= hdev->maxchild; i++) {
5168                 struct usb_port *port_dev = hub->ports[i - 1];
5169
5170                 if (test_bit(i, hub->event_bits)
5171                                 || test_bit(i, hub->change_bits)
5172                                 || test_bit(i, hub->wakeup_bits)) {
5173                         /*
5174                          * The get_noresume and barrier ensure that if
5175                          * the port was in the process of resuming, we
5176                          * flush that work and keep the port active for
5177                          * the duration of the port_event().  However,
5178                          * if the port is runtime pm suspended
5179                          * (powered-off), we leave it in that state, run
5180                          * an abbreviated port_event(), and move on.
5181                          */
5182                         pm_runtime_get_noresume(&port_dev->dev);
5183                         pm_runtime_barrier(&port_dev->dev);
5184                         usb_lock_port(port_dev);
5185                         port_event(hub, i);
5186                         usb_unlock_port(port_dev);
5187                         pm_runtime_put_sync(&port_dev->dev);
5188                 }
5189         }
5190
5191         /* deal with hub status changes */
5192         if (test_and_clear_bit(0, hub->event_bits) == 0)
5193                 ;       /* do nothing */
5194         else if (hub_hub_status(hub, &hubstatus, &hubchange) < 0)
5195                 dev_err(hub_dev, "get_hub_status failed\n");
5196         else {
5197                 if (hubchange & HUB_CHANGE_LOCAL_POWER) {
5198                         dev_dbg(hub_dev, "power change\n");
5199                         clear_hub_feature(hdev, C_HUB_LOCAL_POWER);
5200                         if (hubstatus & HUB_STATUS_LOCAL_POWER)
5201                                 /* FIXME: Is this always true? */
5202                                 hub->limited_power = 1;
5203                         else
5204                                 hub->limited_power = 0;
5205                 }
5206                 if (hubchange & HUB_CHANGE_OVERCURRENT) {
5207                         u16 status = 0;
5208                         u16 unused;
5209
5210                         dev_dbg(hub_dev, "over-current change\n");
5211                         clear_hub_feature(hdev, C_HUB_OVER_CURRENT);
5212                         msleep(500);    /* Cool down */
5213                         hub_power_on(hub, true);
5214                         hub_hub_status(hub, &status, &unused);
5215                         if (status & HUB_STATUS_OVERCURRENT)
5216                                 dev_err(hub_dev, "over-current condition\n");
5217                 }
5218         }
5219
5220 out_autopm:
5221         /* Balance the usb_autopm_get_interface() above */
5222         usb_autopm_put_interface_no_suspend(intf);
5223 out_hdev_lock:
5224         usb_unlock_device(hdev);
5225
5226         /* Balance the stuff in kick_hub_wq() and allow autosuspend */
5227         usb_autopm_put_interface(intf);
5228         kref_put(&hub->kref, hub_release);
5229 }
5230
5231 static const struct usb_device_id hub_id_table[] = {
5232     { .match_flags = USB_DEVICE_ID_MATCH_VENDOR
5233                         | USB_DEVICE_ID_MATCH_INT_CLASS,
5234       .idVendor = USB_VENDOR_GENESYS_LOGIC,
5235       .bInterfaceClass = USB_CLASS_HUB,
5236       .driver_info = HUB_QUIRK_CHECK_PORT_AUTOSUSPEND},
5237     { .match_flags = USB_DEVICE_ID_MATCH_DEV_CLASS,
5238       .bDeviceClass = USB_CLASS_HUB},
5239     { .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS,
5240       .bInterfaceClass = USB_CLASS_HUB},
5241     { }                                         /* Terminating entry */
5242 };
5243
5244 MODULE_DEVICE_TABLE(usb, hub_id_table);
5245
5246 static struct usb_driver hub_driver = {
5247         .name =         "hub",
5248         .probe =        hub_probe,
5249         .disconnect =   hub_disconnect,
5250         .suspend =      hub_suspend,
5251         .resume =       hub_resume,
5252         .reset_resume = hub_reset_resume,
5253         .pre_reset =    hub_pre_reset,
5254         .post_reset =   hub_post_reset,
5255         .unlocked_ioctl = hub_ioctl,
5256         .id_table =     hub_id_table,
5257         .supports_autosuspend = 1,
5258 };
5259
5260 int usb_hub_init(void)
5261 {
5262         if (usb_register(&hub_driver) < 0) {
5263                 printk(KERN_ERR "%s: can't register hub driver\n",
5264                         usbcore_name);
5265                 return -1;
5266         }
5267
5268         /*
5269          * The workqueue needs to be freezable to avoid interfering with
5270          * USB-PERSIST port handover. Otherwise it might see that a full-speed
5271          * device was gone before the EHCI controller had handed its port
5272          * over to the companion full-speed controller.
5273          */
5274         hub_wq = alloc_workqueue("usb_hub_wq", WQ_FREEZABLE, 0);
5275         if (hub_wq)
5276                 return 0;
5277
5278         /* Fall through if kernel_thread failed */
5279         usb_deregister(&hub_driver);
5280         pr_err("%s: can't allocate workqueue for usb hub\n", usbcore_name);
5281
5282         return -1;
5283 }
5284
5285 void usb_hub_cleanup(void)
5286 {
5287         destroy_workqueue(hub_wq);
5288
5289         /*
5290          * Hub resources are freed for us by usb_deregister. It calls
5291          * usb_driver_purge on every device which in turn calls that
5292          * devices disconnect function if it is using this driver.
5293          * The hub_disconnect function takes care of releasing the
5294          * individual hub resources. -greg
5295          */
5296         usb_deregister(&hub_driver);
5297 } /* usb_hub_cleanup() */
5298
5299 static int descriptors_changed(struct usb_device *udev,
5300                 struct usb_device_descriptor *old_device_descriptor,
5301                 struct usb_host_bos *old_bos)
5302 {
5303         int             changed = 0;
5304         unsigned        index;
5305         unsigned        serial_len = 0;
5306         unsigned        len;
5307         unsigned        old_length;
5308         int             length;
5309         char            *buf;
5310
5311         if (memcmp(&udev->descriptor, old_device_descriptor,
5312                         sizeof(*old_device_descriptor)) != 0)
5313                 return 1;
5314
5315         if ((old_bos && !udev->bos) || (!old_bos && udev->bos))
5316                 return 1;
5317         if (udev->bos) {
5318                 len = le16_to_cpu(udev->bos->desc->wTotalLength);
5319                 if (len != le16_to_cpu(old_bos->desc->wTotalLength))
5320                         return 1;
5321                 if (memcmp(udev->bos->desc, old_bos->desc, len))
5322                         return 1;
5323         }
5324
5325         /* Since the idVendor, idProduct, and bcdDevice values in the
5326          * device descriptor haven't changed, we will assume the
5327          * Manufacturer and Product strings haven't changed either.
5328          * But the SerialNumber string could be different (e.g., a
5329          * different flash card of the same brand).
5330          */
5331         if (udev->serial)
5332                 serial_len = strlen(udev->serial) + 1;
5333
5334         len = serial_len;
5335         for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5336                 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5337                 len = max(len, old_length);
5338         }
5339
5340         buf = kmalloc(len, GFP_NOIO);
5341         if (!buf)
5342                 /* assume the worst */
5343                 return 1;
5344
5345         for (index = 0; index < udev->descriptor.bNumConfigurations; index++) {
5346                 old_length = le16_to_cpu(udev->config[index].desc.wTotalLength);
5347                 length = usb_get_descriptor(udev, USB_DT_CONFIG, index, buf,
5348                                 old_length);
5349                 if (length != old_length) {
5350                         dev_dbg(&udev->dev, "config index %d, error %d\n",
5351                                         index, length);
5352                         changed = 1;
5353                         break;
5354                 }
5355                 if (memcmp(buf, udev->rawdescriptors[index], old_length)
5356                                 != 0) {
5357                         dev_dbg(&udev->dev, "config index %d changed (#%d)\n",
5358                                 index,
5359                                 ((struct usb_config_descriptor *) buf)->
5360                                         bConfigurationValue);
5361                         changed = 1;
5362                         break;
5363                 }
5364         }
5365
5366         if (!changed && serial_len) {
5367                 length = usb_string(udev, udev->descriptor.iSerialNumber,
5368                                 buf, serial_len);
5369                 if (length + 1 != serial_len) {
5370                         dev_dbg(&udev->dev, "serial string error %d\n",
5371                                         length);
5372                         changed = 1;
5373                 } else if (memcmp(buf, udev->serial, length) != 0) {
5374                         dev_dbg(&udev->dev, "serial string changed\n");
5375                         changed = 1;
5376                 }
5377         }
5378
5379         kfree(buf);
5380         return changed;
5381 }
5382
5383 /**
5384  * usb_reset_and_verify_device - perform a USB port reset to reinitialize a device
5385  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
5386  *
5387  * WARNING - don't use this routine to reset a composite device
5388  * (one with multiple interfaces owned by separate drivers)!
5389  * Use usb_reset_device() instead.
5390  *
5391  * Do a port reset, reassign the device's address, and establish its
5392  * former operating configuration.  If the reset fails, or the device's
5393  * descriptors change from their values before the reset, or the original
5394  * configuration and altsettings cannot be restored, a flag will be set
5395  * telling hub_wq to pretend the device has been disconnected and then
5396  * re-connected.  All drivers will be unbound, and the device will be
5397  * re-enumerated and probed all over again.
5398  *
5399  * Return: 0 if the reset succeeded, -ENODEV if the device has been
5400  * flagged for logical disconnection, or some other negative error code
5401  * if the reset wasn't even attempted.
5402  *
5403  * Note:
5404  * The caller must own the device lock and the port lock, the latter is
5405  * taken by usb_reset_device().  For example, it's safe to use
5406  * usb_reset_device() from a driver probe() routine after downloading
5407  * new firmware.  For calls that might not occur during probe(), drivers
5408  * should lock the device using usb_lock_device_for_reset().
5409  *
5410  * Locking exception: This routine may also be called from within an
5411  * autoresume handler.  Such usage won't conflict with other tasks
5412  * holding the device lock because these tasks should always call
5413  * usb_autopm_resume_device(), thereby preventing any unwanted
5414  * autoresume.  The autoresume handler is expected to have already
5415  * acquired the port lock before calling this routine.
5416  */
5417 static int usb_reset_and_verify_device(struct usb_device *udev)
5418 {
5419         struct usb_device               *parent_hdev = udev->parent;
5420         struct usb_hub                  *parent_hub;
5421         struct usb_hcd                  *hcd = bus_to_hcd(udev->bus);
5422         struct usb_device_descriptor    descriptor = udev->descriptor;
5423         struct usb_host_bos             *bos;
5424         int                             i, j, ret = 0;
5425         int                             port1 = udev->portnum;
5426
5427         if (udev->state == USB_STATE_NOTATTACHED ||
5428                         udev->state == USB_STATE_SUSPENDED) {
5429                 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
5430                                 udev->state);
5431                 return -EINVAL;
5432         }
5433
5434         if (!parent_hdev)
5435                 return -EISDIR;
5436
5437         parent_hub = usb_hub_to_struct_hub(parent_hdev);
5438
5439         /* Disable USB2 hardware LPM.
5440          * It will be re-enabled by the enumeration process.
5441          */
5442         if (udev->usb2_hw_lpm_enabled == 1)
5443                 usb_set_usb2_hardware_lpm(udev, 0);
5444
5445         /* Disable LPM and LTM while we reset the device and reinstall the alt
5446          * settings.  Device-initiated LPM settings, and system exit latency
5447          * settings are cleared when the device is reset, so we have to set
5448          * them up again.
5449          */
5450         ret = usb_unlocked_disable_lpm(udev);
5451         if (ret) {
5452                 dev_err(&udev->dev, "%s Failed to disable LPM\n.", __func__);
5453                 goto re_enumerate_no_bos;
5454         }
5455         ret = usb_disable_ltm(udev);
5456         if (ret) {
5457                 dev_err(&udev->dev, "%s Failed to disable LTM\n.",
5458                                 __func__);
5459                 goto re_enumerate_no_bos;
5460         }
5461
5462         bos = udev->bos;
5463         udev->bos = NULL;
5464
5465         for (i = 0; i < SET_CONFIG_TRIES; ++i) {
5466
5467                 /* ep0 maxpacket size may change; let the HCD know about it.
5468                  * Other endpoints will be handled by re-enumeration. */
5469                 usb_ep0_reinit(udev);
5470                 ret = hub_port_init(parent_hub, udev, port1, i);
5471                 if (ret >= 0 || ret == -ENOTCONN || ret == -ENODEV)
5472                         break;
5473         }
5474
5475         if (ret < 0)
5476                 goto re_enumerate;
5477
5478         /* Device might have changed firmware (DFU or similar) */
5479         if (descriptors_changed(udev, &descriptor, bos)) {
5480                 dev_info(&udev->dev, "device firmware changed\n");
5481                 udev->descriptor = descriptor;  /* for disconnect() calls */
5482                 goto re_enumerate;
5483         }
5484
5485         /* Restore the device's previous configuration */
5486         if (!udev->actconfig)
5487                 goto done;
5488
5489         mutex_lock(hcd->bandwidth_mutex);
5490         ret = usb_hcd_alloc_bandwidth(udev, udev->actconfig, NULL, NULL);
5491         if (ret < 0) {
5492                 dev_warn(&udev->dev,
5493                                 "Busted HC?  Not enough HCD resources for "
5494                                 "old configuration.\n");
5495                 mutex_unlock(hcd->bandwidth_mutex);
5496                 goto re_enumerate;
5497         }
5498         ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
5499                         USB_REQ_SET_CONFIGURATION, 0,
5500                         udev->actconfig->desc.bConfigurationValue, 0,
5501                         NULL, 0, USB_CTRL_SET_TIMEOUT);
5502         if (ret < 0) {
5503                 dev_err(&udev->dev,
5504                         "can't restore configuration #%d (error=%d)\n",
5505                         udev->actconfig->desc.bConfigurationValue, ret);
5506                 mutex_unlock(hcd->bandwidth_mutex);
5507                 goto re_enumerate;
5508         }
5509         mutex_unlock(hcd->bandwidth_mutex);
5510         usb_set_device_state(udev, USB_STATE_CONFIGURED);
5511
5512         /* Put interfaces back into the same altsettings as before.
5513          * Don't bother to send the Set-Interface request for interfaces
5514          * that were already in altsetting 0; besides being unnecessary,
5515          * many devices can't handle it.  Instead just reset the host-side
5516          * endpoint state.
5517          */
5518         for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
5519                 struct usb_host_config *config = udev->actconfig;
5520                 struct usb_interface *intf = config->interface[i];
5521                 struct usb_interface_descriptor *desc;
5522
5523                 desc = &intf->cur_altsetting->desc;
5524                 if (desc->bAlternateSetting == 0) {
5525                         usb_disable_interface(udev, intf, true);
5526                         usb_enable_interface(udev, intf, true);
5527                         ret = 0;
5528                 } else {
5529                         /* Let the bandwidth allocation function know that this
5530                          * device has been reset, and it will have to use
5531                          * alternate setting 0 as the current alternate setting.
5532                          */
5533                         intf->resetting_device = 1;
5534                         ret = usb_set_interface(udev, desc->bInterfaceNumber,
5535                                         desc->bAlternateSetting);
5536                         intf->resetting_device = 0;
5537                 }
5538                 if (ret < 0) {
5539                         dev_err(&udev->dev, "failed to restore interface %d "
5540                                 "altsetting %d (error=%d)\n",
5541                                 desc->bInterfaceNumber,
5542                                 desc->bAlternateSetting,
5543                                 ret);
5544                         goto re_enumerate;
5545                 }
5546                 /* Resetting also frees any allocated streams */
5547                 for (j = 0; j < intf->cur_altsetting->desc.bNumEndpoints; j++)
5548                         intf->cur_altsetting->endpoint[j].streams = 0;
5549         }
5550
5551 done:
5552         /* Now that the alt settings are re-installed, enable LTM and LPM. */
5553         usb_set_usb2_hardware_lpm(udev, 1);
5554         usb_unlocked_enable_lpm(udev);
5555         usb_enable_ltm(udev);
5556         usb_release_bos_descriptor(udev);
5557         udev->bos = bos;
5558         return 0;
5559
5560 re_enumerate:
5561         usb_release_bos_descriptor(udev);
5562         udev->bos = bos;
5563 re_enumerate_no_bos:
5564         /* LPM state doesn't matter when we're about to destroy the device. */
5565         hub_port_logical_disconnect(parent_hub, port1);
5566         return -ENODEV;
5567 }
5568
5569 /**
5570  * usb_reset_device - warn interface drivers and perform a USB port reset
5571  * @udev: device to reset (not in SUSPENDED or NOTATTACHED state)
5572  *
5573  * Warns all drivers bound to registered interfaces (using their pre_reset
5574  * method), performs the port reset, and then lets the drivers know that
5575  * the reset is over (using their post_reset method).
5576  *
5577  * Return: The same as for usb_reset_and_verify_device().
5578  *
5579  * Note:
5580  * The caller must own the device lock.  For example, it's safe to use
5581  * this from a driver probe() routine after downloading new firmware.
5582  * For calls that might not occur during probe(), drivers should lock
5583  * the device using usb_lock_device_for_reset().
5584  *
5585  * If an interface is currently being probed or disconnected, we assume
5586  * its driver knows how to handle resets.  For all other interfaces,
5587  * if the driver doesn't have pre_reset and post_reset methods then
5588  * we attempt to unbind it and rebind afterward.
5589  */
5590 int usb_reset_device(struct usb_device *udev)
5591 {
5592         int ret;
5593         int i;
5594         unsigned int noio_flag;
5595         struct usb_port *port_dev;
5596         struct usb_host_config *config = udev->actconfig;
5597         struct usb_hub *hub = usb_hub_to_struct_hub(udev->parent);
5598
5599         if (udev->state == USB_STATE_NOTATTACHED ||
5600                         udev->state == USB_STATE_SUSPENDED) {
5601                 dev_dbg(&udev->dev, "device reset not allowed in state %d\n",
5602                                 udev->state);
5603                 return -EINVAL;
5604         }
5605
5606         if (!udev->parent) {
5607                 /* this requires hcd-specific logic; see ohci_restart() */
5608                 dev_dbg(&udev->dev, "%s for root hub!\n", __func__);
5609                 return -EISDIR;
5610         }
5611
5612         port_dev = hub->ports[udev->portnum - 1];
5613
5614         /*
5615          * Don't allocate memory with GFP_KERNEL in current
5616          * context to avoid possible deadlock if usb mass
5617          * storage interface or usbnet interface(iSCSI case)
5618          * is included in current configuration. The easist
5619          * approach is to do it for every device reset,
5620          * because the device 'memalloc_noio' flag may have
5621          * not been set before reseting the usb device.
5622          */
5623         noio_flag = memalloc_noio_save();
5624
5625         /* Prevent autosuspend during the reset */
5626         usb_autoresume_device(udev);
5627
5628         if (config) {
5629                 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
5630                         struct usb_interface *cintf = config->interface[i];
5631                         struct usb_driver *drv;
5632                         int unbind = 0;
5633
5634                         if (cintf->dev.driver) {
5635                                 drv = to_usb_driver(cintf->dev.driver);
5636                                 if (drv->pre_reset && drv->post_reset)
5637                                         unbind = (drv->pre_reset)(cintf);
5638                                 else if (cintf->condition ==
5639                                                 USB_INTERFACE_BOUND)
5640                                         unbind = 1;
5641                                 if (unbind)
5642                                         usb_forced_unbind_intf(cintf);
5643                         }
5644                 }
5645         }
5646
5647         usb_lock_port(port_dev);
5648         ret = usb_reset_and_verify_device(udev);
5649         usb_unlock_port(port_dev);
5650
5651         if (config) {
5652                 for (i = config->desc.bNumInterfaces - 1; i >= 0; --i) {
5653                         struct usb_interface *cintf = config->interface[i];
5654                         struct usb_driver *drv;
5655                         int rebind = cintf->needs_binding;
5656
5657                         if (!rebind && cintf->dev.driver) {
5658                                 drv = to_usb_driver(cintf->dev.driver);
5659                                 if (drv->post_reset)
5660                                         rebind = (drv->post_reset)(cintf);
5661                                 else if (cintf->condition ==
5662                                                 USB_INTERFACE_BOUND)
5663                                         rebind = 1;
5664                                 if (rebind)
5665                                         cintf->needs_binding = 1;
5666                         }
5667                 }
5668                 usb_unbind_and_rebind_marked_interfaces(udev);
5669         }
5670
5671         usb_autosuspend_device(udev);
5672         memalloc_noio_restore(noio_flag);
5673         return ret;
5674 }
5675 EXPORT_SYMBOL_GPL(usb_reset_device);
5676
5677
5678 /**
5679  * usb_queue_reset_device - Reset a USB device from an atomic context
5680  * @iface: USB interface belonging to the device to reset
5681  *
5682  * This function can be used to reset a USB device from an atomic
5683  * context, where usb_reset_device() won't work (as it blocks).
5684  *
5685  * Doing a reset via this method is functionally equivalent to calling
5686  * usb_reset_device(), except for the fact that it is delayed to a
5687  * workqueue. This means that any drivers bound to other interfaces
5688  * might be unbound, as well as users from usbfs in user space.
5689  *
5690  * Corner cases:
5691  *
5692  * - Scheduling two resets at the same time from two different drivers
5693  *   attached to two different interfaces of the same device is
5694  *   possible; depending on how the driver attached to each interface
5695  *   handles ->pre_reset(), the second reset might happen or not.
5696  *
5697  * - If the reset is delayed so long that the interface is unbound from
5698  *   its driver, the reset will be skipped.
5699  *
5700  * - This function can be called during .probe().  It can also be called
5701  *   during .disconnect(), but doing so is pointless because the reset
5702  *   will not occur.  If you really want to reset the device during
5703  *   .disconnect(), call usb_reset_device() directly -- but watch out
5704  *   for nested unbinding issues!
5705  */
5706 void usb_queue_reset_device(struct usb_interface *iface)
5707 {
5708         if (schedule_work(&iface->reset_ws))
5709                 usb_get_intf(iface);
5710 }
5711 EXPORT_SYMBOL_GPL(usb_queue_reset_device);
5712
5713 /**
5714  * usb_hub_find_child - Get the pointer of child device
5715  * attached to the port which is specified by @port1.
5716  * @hdev: USB device belonging to the usb hub
5717  * @port1: port num to indicate which port the child device
5718  *      is attached to.
5719  *
5720  * USB drivers call this function to get hub's child device
5721  * pointer.
5722  *
5723  * Return: %NULL if input param is invalid and
5724  * child's usb_device pointer if non-NULL.
5725  */
5726 struct usb_device *usb_hub_find_child(struct usb_device *hdev,
5727                 int port1)
5728 {
5729         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5730
5731         if (port1 < 1 || port1 > hdev->maxchild)
5732                 return NULL;
5733         return hub->ports[port1 - 1]->child;
5734 }
5735 EXPORT_SYMBOL_GPL(usb_hub_find_child);
5736
5737 void usb_hub_adjust_deviceremovable(struct usb_device *hdev,
5738                 struct usb_hub_descriptor *desc)
5739 {
5740         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5741         enum usb_port_connect_type connect_type;
5742         int i;
5743
5744         if (!hub)
5745                 return;
5746
5747         if (!hub_is_superspeed(hdev)) {
5748                 for (i = 1; i <= hdev->maxchild; i++) {
5749                         struct usb_port *port_dev = hub->ports[i - 1];
5750
5751                         connect_type = port_dev->connect_type;
5752                         if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
5753                                 u8 mask = 1 << (i%8);
5754
5755                                 if (!(desc->u.hs.DeviceRemovable[i/8] & mask)) {
5756                                         dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
5757                                         desc->u.hs.DeviceRemovable[i/8] |= mask;
5758                                 }
5759                         }
5760                 }
5761         } else {
5762                 u16 port_removable = le16_to_cpu(desc->u.ss.DeviceRemovable);
5763
5764                 for (i = 1; i <= hdev->maxchild; i++) {
5765                         struct usb_port *port_dev = hub->ports[i - 1];
5766
5767                         connect_type = port_dev->connect_type;
5768                         if (connect_type == USB_PORT_CONNECT_TYPE_HARD_WIRED) {
5769                                 u16 mask = 1 << i;
5770
5771                                 if (!(port_removable & mask)) {
5772                                         dev_dbg(&port_dev->dev, "DeviceRemovable is changed to 1 according to platform information.\n");
5773                                         port_removable |= mask;
5774                                 }
5775                         }
5776                 }
5777
5778                 desc->u.ss.DeviceRemovable = cpu_to_le16(port_removable);
5779         }
5780 }
5781
5782 #ifdef CONFIG_ACPI
5783 /**
5784  * usb_get_hub_port_acpi_handle - Get the usb port's acpi handle
5785  * @hdev: USB device belonging to the usb hub
5786  * @port1: port num of the port
5787  *
5788  * Return: Port's acpi handle if successful, %NULL if params are
5789  * invalid.
5790  */
5791 acpi_handle usb_get_hub_port_acpi_handle(struct usb_device *hdev,
5792         int port1)
5793 {
5794         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
5795
5796         if (!hub)
5797                 return NULL;
5798
5799         return ACPI_HANDLE(&hub->ports[port1 - 1]->dev);
5800 }
5801 #endif