drivers/net/usb/usbnet.c

   1 /*
   2  * USB Network driver infrastructure
   3  * Copyright (C) 2000-2005 by David Brownell
   4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * This is a generic "USB networking" framework that works with several
  22  * kinds of full and high speed networking devices:  host-to-host cables,
  23  * smart usb peripherals, and actual Ethernet adapters.
  24  *
  25  * These devices usually differ in terms of control protocols (if they
  26  * even have one!) and sometimes they define new framing to wrap or batch
  27  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  28  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  29  * issues can usefully be addressed by this framework.
  30  */
  31
  32 // #define      DEBUG                   // error path messages, extra info
  33 // #define      VERBOSE                 // more; success messages
  34
  35 #include <linux/module.h>
  36 #include <linux/init.h>
  37 #include <linux/netdevice.h>
  38 #include <linux/etherdevice.h>
  39 #include <linux/ctype.h>
  40 #include <linux/ethtool.h>
  41 #include <linux/workqueue.h>
  42 #include <linux/mii.h>
  43 #include <linux/usb.h>
  44 #include <linux/usb/usbnet.h>
  45 #include <linux/slab.h>
  46 #include <linux/kernel.h>
  47 #include <linux/pm_runtime.h>
  48
  49 #define DRIVER_VERSION          "22-Aug-2005"
  50
  51
  52 /*-------------------------------------------------------------------------*/
  53
  54 /*
  55  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  56  * Several dozen bytes of IPv4 data can fit in two such transactions.
  57  * One maximum size Ethernet packet takes twenty four of them.
  58  * For high speed, each frame comfortably fits almost 36 max size
  59  * Ethernet packets (so queues should be bigger).
  60  *
  61  * The goal is to let the USB host controller be busy for 5msec or
  62  * more before an irq is required, under load.  Jumbograms change
  63  * the equation.
  64  */
  65 #define MAX_QUEUE_MEMORY        (60 * 1518)
  66 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  67 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  68
  69 // reawaken network queue this soon after stopping; else watchdog barks
  70 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  71
  72 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  73  * us (it polls at HZ/4 usually) before we report too many false errors.
  74  */
  75 #define THROTTLE_JIFFIES        (HZ/8)
  76
  77 // between wakeups
  78 #define UNLINK_TIMEOUT_MS       3
  79
  80 /*-------------------------------------------------------------------------*/
  81
  82 // randomly generated ethernet address
  83 static u8       node_id [ETH_ALEN];
  84
  85 /* use ethtool to change the level for any given device */
  86 static int msg_level = -1;
  87 module_param (msg_level, int, 0);
  88 MODULE_PARM_DESC (msg_level, "Override default message level");
  89
  90 /*-------------------------------------------------------------------------*/
  91
  92 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  93 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  94 {
  95         int                             tmp;
  96         struct usb_host_interface       *alt = NULL;
  97         struct usb_host_endpoint        *in = NULL, *out = NULL;
  98         struct usb_host_endpoint        *status = NULL;
  99
 100         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 101                 unsigned        ep;
 102
 103                 in = out = status = NULL;
 104                 alt = intf->altsetting + tmp;
 105
 106                 /* take the first altsetting with in-bulk + out-bulk;
 107                  * remember any status endpoint, just in case;
 108                  * ignore other endpoints and altsettings.
 109                  */
 110                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 111                         struct usb_host_endpoint        *e;
 112                         int                             intr = 0;
 113
 114                         e = alt->endpoint + ep;
 115                         switch (e->desc.bmAttributes) {
 116                         case USB_ENDPOINT_XFER_INT:
 117                                 if (!usb_endpoint_dir_in(&e->desc))
 118                                         continue;
 119                                 intr = 1;
 120                                 /* FALLTHROUGH */
 121                         case USB_ENDPOINT_XFER_BULK:
 122                                 break;
 123                         default:
 124                                 continue;
 125                         }
 126                         if (usb_endpoint_dir_in(&e->desc)) {
 127                                 if (!intr && !in)
 128                                         in = e;
 129                                 else if (intr && !status)
 130                                         status = e;
 131                         } else {
 132                                 if (!out)
 133                                         out = e;
 134                         }
 135                 }
 136                 if (in && out)
 137                         break;
 138         }
 139         if (!alt || !in || !out)
 140                 return -EINVAL;
 141
 142         if (alt->desc.bAlternateSetting != 0 ||
 143             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 144                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 145                                 alt->desc.bAlternateSetting);
 146                 if (tmp < 0)
 147                         return tmp;
 148         }
 149
 150         dev->in = usb_rcvbulkpipe (dev->udev,
 151                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 152         dev->out = usb_sndbulkpipe (dev->udev,
 153                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 154         dev->status = status;
 155         return 0;
 156 }
 157 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 158
 159 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 160 {
 161         int             tmp = -1, ret;
 162         unsigned char   buf [13];
 163
 164         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 165         if (ret == 12)
 166                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 167         if (tmp < 0) {
 168                 dev_dbg(&dev->udev->dev,
 169                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 170                 if (ret >= 0)
 171                         ret = -EINVAL;
 172                 return ret;
 173         }
 174         return 0;
 175 }
 176 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 177
 178 static void intr_complete (struct urb *urb)
 179 {
 180         struct usbnet   *dev = urb->context;
 181         int             status = urb->status;
 182
 183         switch (status) {
 184         /* success */
 185         case 0:
 186                 dev->driver_info->status(dev, urb);
 187                 break;
 188
 189         /* software-driven interface shutdown */
 190         case -ENOENT:           /* urb killed */
 191         case -ESHUTDOWN:        /* hardware gone */
 192                 netif_dbg(dev, ifdown, dev->net,
 193                           "intr shutdown, code %d\n", status);
 194                 return;
 195
 196         /* NOTE:  not throttling like RX/TX, since this endpoint
 197          * already polls infrequently
 198          */
 199         default:
 200                 netdev_dbg(dev->net, "intr status %d\n", status);
 201                 break;
 202         }
 203
 204         status = usb_submit_urb (urb, GFP_ATOMIC);
 205         if (status != 0)
 206                 netif_err(dev, timer, dev->net,
 207                           "intr resubmit --> %d\n", status);
 208 }
 209
 210 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 211 {
 212         char            *buf = NULL;
 213         unsigned        pipe = 0;
 214         unsigned        maxp;
 215         unsigned        period;
 216
 217         if (!dev->driver_info->status)
 218                 return 0;
 219
 220         pipe = usb_rcvintpipe (dev->udev,
 221                         dev->status->desc.bEndpointAddress
 222                                 & USB_ENDPOINT_NUMBER_MASK);
 223         maxp = usb_maxpacket (dev->udev, pipe, 0);
 224
 225         /* avoid 1 msec chatter:  min 8 msec poll rate */
 226         period = max ((int) dev->status->desc.bInterval,
 227                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 228
 229         buf = kmalloc (maxp, GFP_KERNEL);
 230         if (buf) {
 231                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 232                 if (!dev->interrupt) {
 233                         kfree (buf);
 234                         return -ENOMEM;
 235                 } else {
 236                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 237                                 buf, maxp, intr_complete, dev, period);
 238                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 239                         dev_dbg(&intf->dev,
 240                                 "status ep%din, %d bytes period %d\n",
 241                                 usb_pipeendpoint(pipe), maxp, period);
 242                 }
 243         }
 244         return 0;
 245 }
 246
 247 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 248 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 249 {
 250         int ret = 0;
 251
 252         WARN_ON_ONCE(dev->interrupt == NULL);
 253         if (dev->interrupt) {
 254                 mutex_lock(&dev->interrupt_mutex);
 255
 256                 if (++dev->interrupt_count == 1)
 257                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 258
 259                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 260                         dev->interrupt_count);
 261                 mutex_unlock(&dev->interrupt_mutex);
 262         }
 263         return ret;
 264 }
 265 EXPORT_SYMBOL_GPL(usbnet_status_start);
 266
 267 /* For resume; submit interrupt URB if previously submitted */
 268 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 269 {
 270         int ret = 0;
 271
 272         mutex_lock(&dev->interrupt_mutex);
 273         if (dev->interrupt_count) {
 274                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 275                 dev_dbg(&dev->udev->dev,
 276                         "submitted interrupt URB for resume\n");
 277         }
 278         mutex_unlock(&dev->interrupt_mutex);
 279         return ret;
 280 }
 281
 282 /* Kill the interrupt URB if all submitters want it killed */
 283 void usbnet_status_stop(struct usbnet *dev)
 284 {
 285         if (dev->interrupt) {
 286                 mutex_lock(&dev->interrupt_mutex);
 287                 WARN_ON(dev->interrupt_count == 0);
 288
 289                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 290                         usb_kill_urb(dev->interrupt);
 291
 292                 dev_dbg(&dev->udev->dev,
 293                         "decremented interrupt URB count to %d\n",
 294                         dev->interrupt_count);
 295                 mutex_unlock(&dev->interrupt_mutex);
 296         }
 297 }
 298 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 299
 300 /* For suspend; always kill interrupt URB */
 301 static void __usbnet_status_stop_force(struct usbnet *dev)
 302 {
 303         if (dev->interrupt) {
 304                 mutex_lock(&dev->interrupt_mutex);
 305                 usb_kill_urb(dev->interrupt);
 306                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 307                 mutex_unlock(&dev->interrupt_mutex);
 308         }
 309 }
 310
 311 /* Passes this packet up the stack, updating its accounting.
 312  * Some link protocols batch packets, so their rx_fixup paths
 313  * can return clones as well as just modify the original skb.
 314  */
 315 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 316 {
 317         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
 318         int     status;
 319
 320         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 321                 skb_queue_tail(&dev->rxq_pause, skb);
 322                 return;
 323         }
 324
 325         /* only update if unset to allow minidriver rx_fixup override */
 326         if (skb->protocol == 0)
 327                 skb->protocol = eth_type_trans (skb, dev->net);
 328
 329         u64_stats_update_begin(&stats64->syncp);
 330         stats64->rx_packets++;
 331         stats64->rx_bytes += skb->len;
 332         u64_stats_update_end(&stats64->syncp);
 333
 334         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 335                   skb->len + sizeof (struct ethhdr), skb->protocol);
 336         memset (skb->cb, 0, sizeof (struct skb_data));
 337
 338         if (skb_defer_rx_timestamp(skb))
 339                 return;
 340
 341         status = netif_rx (skb);
 342         if (status != NET_RX_SUCCESS)
 343                 netif_dbg(dev, rx_err, dev->net,
 344                           "netif_rx status %d\n", status);
 345 }
 346 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 347
 348 /* must be called if hard_mtu or rx_urb_size changed */
 349 void usbnet_update_max_qlen(struct usbnet *dev)
 350 {
 351         enum usb_device_speed speed = dev->udev->speed;
 352
 353         switch (speed) {
 354         case USB_SPEED_HIGH:
 355                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 356                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 357                 break;
 358         case USB_SPEED_SUPER:
 359         case USB_SPEED_SUPER_PLUS:
 360                 /*
 361                  * Not take default 5ms qlen for super speed HC to
 362                  * save memory, and iperf tests show 2.5ms qlen can
 363                  * work well
 364                  */
 365                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 366                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 367                 break;
 368         default:
 369                 dev->rx_qlen = dev->tx_qlen = 4;
 370         }
 371 }
 372 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 373
 374 \f
 375 /*-------------------------------------------------------------------------
 376  *
 377  * Network Device Driver (peer link to "Host Device", from USB host)
 378  *
 379  *-------------------------------------------------------------------------*/
 380
 381 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 382 {
 383         struct usbnet   *dev = netdev_priv(net);
 384         int             ll_mtu = new_mtu + net->hard_header_len;
 385         int             old_hard_mtu = dev->hard_mtu;
 386         int             old_rx_urb_size = dev->rx_urb_size;
 387
 388         // no second zero-length packet read wanted after mtu-sized packets
 389         if ((ll_mtu % dev->maxpacket) == 0)
 390                 return -EDOM;
 391         net->mtu = new_mtu;
 392
 393         dev->hard_mtu = net->mtu + net->hard_header_len;
 394         if (dev->rx_urb_size == old_hard_mtu) {
 395                 dev->rx_urb_size = dev->hard_mtu;
 396                 if (dev->rx_urb_size > old_rx_urb_size) {
 397                         usbnet_pause_rx(dev);
 398                         usbnet_unlink_rx_urbs(dev);
 399                         usbnet_resume_rx(dev);
 400                 }
 401         }
 402
 403         /* max qlen depend on hard_mtu and rx_urb_size */
 404         usbnet_update_max_qlen(dev);
 405
 406         return 0;
 407 }
 408 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 409
 410 /* The caller must hold list->lock */
 411 static void __usbnet_queue_skb(struct sk_buff_head *list,
 412                         struct sk_buff *newsk, enum skb_state state)
 413 {
 414         struct skb_data *entry = (struct skb_data *) newsk->cb;
 415
 416         __skb_queue_tail(list, newsk);
 417         entry->state = state;
 418 }
 419
 420 /*-------------------------------------------------------------------------*/
 421
 422 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 423  * completion callbacks.  2.5 should have fixed those bugs...
 424  */
 425
 426 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 427                 struct sk_buff_head *list, enum skb_state state)
 428 {
 429         unsigned long           flags;
 430         enum skb_state          old_state;
 431         struct skb_data *entry = (struct skb_data *) skb->cb;
 432
 433         spin_lock_irqsave(&list->lock, flags);
 434         old_state = entry->state;
 435         entry->state = state;
 436         __skb_unlink(skb, list);
 437
 438         /* defer_bh() is never called with list == &dev->done.
 439          * spin_lock_nested() tells lockdep that it is OK to take
 440          * dev->done.lock here with list->lock held.
 441          */
 442         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 443
 444         __skb_queue_tail(&dev->done, skb);
 445         if (dev->done.qlen == 1)
 446                 tasklet_schedule(&dev->bh);
 447         spin_unlock(&dev->done.lock);
 448         spin_unlock_irqrestore(&list->lock, flags);
 449         return old_state;
 450 }
 451
 452 /* some work can't be done in tasklets, so we use keventd
 453  *
 454  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 455  * but tasklet_schedule() doesn't.  hope the failure is rare.
 456  */
 457 void usbnet_defer_kevent (struct usbnet *dev, int work)
 458 {
 459         set_bit (work, &dev->flags);
 460         if (!schedule_work (&dev->kevent))
 461                 netdev_dbg(dev->net, "kevent %d may have been dropped\n", work);
 462         else
 463                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 464 }
 465 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 466
 467 /*-------------------------------------------------------------------------*/
 468
 469 static void rx_complete (struct urb *urb);
 470
 471 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 472 {
 473         struct sk_buff          *skb;
 474         struct skb_data         *entry;
 475         int                     retval = 0;
 476         unsigned long           lockflags;
 477         size_t                  size = dev->rx_urb_size;
 478
 479         /* prevent rx skb allocation when error ratio is high */
 480         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 481                 usb_free_urb(urb);
 482                 return -ENOLINK;
 483         }
 484
 485         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 486                 skb = __netdev_alloc_skb(dev->net, size, flags);
 487         else
 488                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 489         if (!skb) {
 490                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 491                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 492                 usb_free_urb (urb);
 493                 return -ENOMEM;
 494         }
 495
 496         entry = (struct skb_data *) skb->cb;
 497         entry->urb = urb;
 498         entry->dev = dev;
 499         entry->length = 0;
 500
 501         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 502                 skb->data, size, rx_complete, skb);
 503
 504         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 505
 506         if (netif_running (dev->net) &&
 507             netif_device_present (dev->net) &&
 508             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 509             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 510                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 511                 case -EPIPE:
 512                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 513                         break;
 514                 case -ENOMEM:
 515                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 516                         break;
 517                 case -ENODEV:
 518                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 519                         netif_device_detach (dev->net);
 520                         break;
 521                 case -EHOSTUNREACH:
 522                         retval = -ENOLINK;
 523                         break;
 524                 default:
 525                         netif_dbg(dev, rx_err, dev->net,
 526                                   "rx submit, %d\n", retval);
 527                         tasklet_schedule (&dev->bh);
 528                         break;
 529                 case 0:
 530                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 531                 }
 532         } else {
 533                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 534                 retval = -ENOLINK;
 535         }
 536         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 537         if (retval) {
 538                 dev_kfree_skb_any (skb);
 539                 usb_free_urb (urb);
 540         }
 541         return retval;
 542 }
 543
 544
 545 /*-------------------------------------------------------------------------*/
 546
 547 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 548 {
 549         if (dev->driver_info->rx_fixup &&
 550             !dev->driver_info->rx_fixup (dev, skb)) {
 551                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 552                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 553                         dev->net->stats.rx_errors++;
 554                 goto done;
 555         }
 556         // else network stack removes extra byte if we forced a short packet
 557
 558         /* all data was already cloned from skb inside the driver */
 559         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 560                 goto done;
 561
 562         if (skb->len < ETH_HLEN) {
 563                 dev->net->stats.rx_errors++;
 564                 dev->net->stats.rx_length_errors++;
 565                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 566         } else {
 567                 usbnet_skb_return(dev, skb);
 568                 return;
 569         }
 570
 571 done:
 572         skb_queue_tail(&dev->done, skb);
 573 }
 574
 575 /*-------------------------------------------------------------------------*/
 576
 577 static void rx_complete (struct urb *urb)
 578 {
 579         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 580         struct skb_data         *entry = (struct skb_data *) skb->cb;
 581         struct usbnet           *dev = entry->dev;
 582         int                     urb_status = urb->status;
 583         enum skb_state          state;
 584
 585         skb_put (skb, urb->actual_length);
 586         state = rx_done;
 587         entry->urb = NULL;
 588
 589         switch (urb_status) {
 590         /* success */
 591         case 0:
 592                 break;
 593
 594         /* stalls need manual reset. this is rare ... except that
 595          * when going through USB 2.0 TTs, unplug appears this way.
 596          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 597          * storm, recovering as needed.
 598          */
 599         case -EPIPE:
 600                 dev->net->stats.rx_errors++;
 601                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 602                 // FALLTHROUGH
 603
 604         /* software-driven interface shutdown */
 605         case -ECONNRESET:               /* async unlink */
 606         case -ESHUTDOWN:                /* hardware gone */
 607                 netif_dbg(dev, ifdown, dev->net,
 608                           "rx shutdown, code %d\n", urb_status);
 609                 goto block;
 610
 611         /* we get controller i/o faults during hub_wq disconnect() delays.
 612          * throttle down resubmits, to avoid log floods; just temporarily,
 613          * so we still recover when the fault isn't a hub_wq delay.
 614          */
 615         case -EPROTO:
 616         case -ETIME:
 617         case -EILSEQ:
 618                 dev->net->stats.rx_errors++;
 619                 if (!timer_pending (&dev->delay)) {
 620                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 621                         netif_dbg(dev, link, dev->net,
 622                                   "rx throttle %d\n", urb_status);
 623                 }
 624 block:
 625                 state = rx_cleanup;
 626                 entry->urb = urb;
 627                 urb = NULL;
 628                 break;
 629
 630         /* data overrun ... flush fifo? */
 631         case -EOVERFLOW:
 632                 dev->net->stats.rx_over_errors++;
 633                 // FALLTHROUGH
 634
 635         default:
 636                 state = rx_cleanup;
 637                 dev->net->stats.rx_errors++;
 638                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 639                 break;
 640         }
 641
 642         /* stop rx if packet error rate is high */
 643         if (++dev->pkt_cnt > 30) {
 644                 dev->pkt_cnt = 0;
 645                 dev->pkt_err = 0;
 646         } else {
 647                 if (state == rx_cleanup)
 648                         dev->pkt_err++;
 649                 if (dev->pkt_err > 20)
 650                         set_bit(EVENT_RX_KILL, &dev->flags);
 651         }
 652
 653         state = defer_bh(dev, skb, &dev->rxq, state);
 654
 655         if (urb) {
 656                 if (netif_running (dev->net) &&
 657                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 658                     state != unlink_start) {
 659                         rx_submit (dev, urb, GFP_ATOMIC);
 660                         usb_mark_last_busy(dev->udev);
 661                         return;
 662                 }
 663                 usb_free_urb (urb);
 664         }
 665         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 666 }
 667
 668 /*-------------------------------------------------------------------------*/
 669 void usbnet_pause_rx(struct usbnet *dev)
 670 {
 671         set_bit(EVENT_RX_PAUSED, &dev->flags);
 672
 673         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 674 }
 675 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 676
 677 void usbnet_resume_rx(struct usbnet *dev)
 678 {
 679         struct sk_buff *skb;
 680         int num = 0;
 681
 682         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 683
 684         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 685                 usbnet_skb_return(dev, skb);
 686                 num++;
 687         }
 688
 689         tasklet_schedule(&dev->bh);
 690
 691         netif_dbg(dev, rx_status, dev->net,
 692                   "paused rx queue disabled, %d skbs requeued\n", num);
 693 }
 694 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 695
 696 void usbnet_purge_paused_rxq(struct usbnet *dev)
 697 {
 698         skb_queue_purge(&dev->rxq_pause);
 699 }
 700 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 701
 702 /*-------------------------------------------------------------------------*/
 703
 704 // unlink pending rx/tx; completion handlers do all other cleanup
 705
 706 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 707 {
 708         unsigned long           flags;
 709         struct sk_buff          *skb;
 710         int                     count = 0;
 711
 712         spin_lock_irqsave (&q->lock, flags);
 713         while (!skb_queue_empty(q)) {
 714                 struct skb_data         *entry;
 715                 struct urb              *urb;
 716                 int                     retval;
 717
 718                 skb_queue_walk(q, skb) {
 719                         entry = (struct skb_data *) skb->cb;
 720                         if (entry->state != unlink_start)
 721                                 goto found;
 722                 }
 723                 break;
 724 found:
 725                 entry->state = unlink_start;
 726                 urb = entry->urb;
 727
 728                 /*
 729                  * Get reference count of the URB to avoid it to be
 730                  * freed during usb_unlink_urb, which may trigger
 731                  * use-after-free problem inside usb_unlink_urb since
 732                  * usb_unlink_urb is always racing with .complete
 733                  * handler(include defer_bh).
 734                  */
 735                 usb_get_urb(urb);
 736                 spin_unlock_irqrestore(&q->lock, flags);
 737                 // during some PM-driven resume scenarios,
 738                 // these (async) unlinks complete immediately
 739                 retval = usb_unlink_urb (urb);
 740                 if (retval != -EINPROGRESS && retval != 0)
 741                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 742                 else
 743                         count++;
 744                 usb_put_urb(urb);
 745                 spin_lock_irqsave(&q->lock, flags);
 746         }
 747         spin_unlock_irqrestore (&q->lock, flags);
 748         return count;
 749 }
 750
 751 // Flush all pending rx urbs
 752 // minidrivers may need to do this when the MTU changes
 753
 754 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 755 {
 756         if (netif_running(dev->net)) {
 757                 (void) unlink_urbs (dev, &dev->rxq);
 758                 tasklet_schedule(&dev->bh);
 759         }
 760 }
 761 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 762
 763 /*-------------------------------------------------------------------------*/
 764
 765 static void wait_skb_queue_empty(struct sk_buff_head *q)
 766 {
 767         unsigned long flags;
 768
 769         spin_lock_irqsave(&q->lock, flags);
 770         while (!skb_queue_empty(q)) {
 771                 spin_unlock_irqrestore(&q->lock, flags);
 772                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 773                 set_current_state(TASK_UNINTERRUPTIBLE);
 774                 spin_lock_irqsave(&q->lock, flags);
 775         }
 776         spin_unlock_irqrestore(&q->lock, flags);
 777 }
 778
 779 // precondition: never called in_interrupt
 780 static void usbnet_terminate_urbs(struct usbnet *dev)
 781 {
 782         DECLARE_WAITQUEUE(wait, current);
 783         int temp;
 784
 785         /* ensure there are no more active urbs */
 786         add_wait_queue(&dev->wait, &wait);
 787         set_current_state(TASK_UNINTERRUPTIBLE);
 788         temp = unlink_urbs(dev, &dev->txq) +
 789                 unlink_urbs(dev, &dev->rxq);
 790
 791         /* maybe wait for deletions to finish. */
 792         wait_skb_queue_empty(&dev->rxq);
 793         wait_skb_queue_empty(&dev->txq);
 794         wait_skb_queue_empty(&dev->done);
 795         netif_dbg(dev, ifdown, dev->net,
 796                   "waited for %d urb completions\n", temp);
 797         set_current_state(TASK_RUNNING);
 798         remove_wait_queue(&dev->wait, &wait);
 799 }
 800
 801 int usbnet_stop (struct net_device *net)
 802 {
 803         struct usbnet           *dev = netdev_priv(net);
 804         struct driver_info      *info = dev->driver_info;
 805         int                     retval, pm, mpn;
 806
 807         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 808         netif_stop_queue (net);
 809
 810         netif_info(dev, ifdown, dev->net,
 811                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 812                    net->stats.rx_packets, net->stats.tx_packets,
 813                    net->stats.rx_errors, net->stats.tx_errors);
 814
 815         /* to not race resume */
 816         pm = usb_autopm_get_interface(dev->intf);
 817         /* allow minidriver to stop correctly (wireless devices to turn off
 818          * radio etc) */
 819         if (info->stop) {
 820                 retval = info->stop(dev);
 821                 if (retval < 0)
 822                         netif_info(dev, ifdown, dev->net,
 823                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 824                                    retval,
 825                                    dev->udev->bus->bus_name, dev->udev->devpath,
 826                                    info->description);
 827         }
 828
 829         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 830                 usbnet_terminate_urbs(dev);
 831
 832         usbnet_status_stop(dev);
 833
 834         usbnet_purge_paused_rxq(dev);
 835
 836         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 837
 838         /* deferred work (task, timer, softirq) must also stop.
 839          * can't flush_scheduled_work() until we drop rtnl (later),
 840          * else workers could deadlock; so make workers a NOP.
 841          */
 842         dev->flags = 0;
 843         del_timer_sync (&dev->delay);
 844         tasklet_kill (&dev->bh);
 845         if (!pm)
 846                 usb_autopm_put_interface(dev->intf);
 847
 848         if (info->manage_power && mpn)
 849                 info->manage_power(dev, 0);
 850         else
 851                 usb_autopm_put_interface(dev->intf);
 852
 853         return 0;
 854 }
 855 EXPORT_SYMBOL_GPL(usbnet_stop);
 856
 857 /*-------------------------------------------------------------------------*/
 858
 859 // posts reads, and enables write queuing
 860
 861 // precondition: never called in_interrupt
 862
 863 int usbnet_open (struct net_device *net)
 864 {
 865         struct usbnet           *dev = netdev_priv(net);
 866         int                     retval;
 867         struct driver_info      *info = dev->driver_info;
 868
 869         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 870                 netif_info(dev, ifup, dev->net,
 871                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 872                            retval,
 873                            dev->udev->bus->bus_name,
 874                            dev->udev->devpath,
 875                            info->description);
 876                 goto done_nopm;
 877         }
 878
 879         // put into "known safe" state
 880         if (info->reset && (retval = info->reset (dev)) < 0) {
 881                 netif_info(dev, ifup, dev->net,
 882                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 883                            retval,
 884                            dev->udev->bus->bus_name,
 885                            dev->udev->devpath,
 886                            info->description);
 887                 goto done;
 888         }
 889
 890         /* hard_mtu or rx_urb_size may change in reset() */
 891         usbnet_update_max_qlen(dev);
 892
 893         // insist peer be connected
 894         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 895                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 896                 goto done;
 897         }
 898
 899         /* start any status interrupt transfer */
 900         if (dev->interrupt) {
 901                 retval = usbnet_status_start(dev, GFP_KERNEL);
 902                 if (retval < 0) {
 903                         netif_err(dev, ifup, dev->net,
 904                                   "intr submit %d\n", retval);
 905                         goto done;
 906                 }
 907         }
 908
 909         set_bit(EVENT_DEV_OPEN, &dev->flags);
 910         netif_start_queue (net);
 911         netif_info(dev, ifup, dev->net,
 912                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 913                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 914                    dev->net->mtu,
 915                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 916                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 917                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 918                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 919                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 920                    "simple");
 921
 922         /* reset rx error state */
 923         dev->pkt_cnt = 0;
 924         dev->pkt_err = 0;
 925         clear_bit(EVENT_RX_KILL, &dev->flags);
 926
 927         // delay posting reads until we're fully open
 928         tasklet_schedule (&dev->bh);
 929         if (info->manage_power) {
 930                 retval = info->manage_power(dev, 1);
 931                 if (retval < 0) {
 932                         retval = 0;
 933                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 934                 } else {
 935                         usb_autopm_put_interface(dev->intf);
 936                 }
 937         }
 938         return retval;
 939 done:
 940         usb_autopm_put_interface(dev->intf);
 941 done_nopm:
 942         return retval;
 943 }
 944 EXPORT_SYMBOL_GPL(usbnet_open);
 945
 946 /*-------------------------------------------------------------------------*/
 947
 948 /* ethtool methods; minidrivers may need to add some more, but
 949  * they'll probably want to use this base set.
 950  */
 951
 952 int usbnet_get_link_ksettings(struct net_device *net,
 953                               struct ethtool_link_ksettings *cmd)
 954 {
 955         struct usbnet *dev = netdev_priv(net);
 956
 957         if (!dev->mii.mdio_read)
 958                 return -EOPNOTSUPP;
 959
 960         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 961
 962         return 0;
 963 }
 964 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
 965
 966 int usbnet_set_link_ksettings(struct net_device *net,
 967                               const struct ethtool_link_ksettings *cmd)
 968 {
 969         struct usbnet *dev = netdev_priv(net);
 970         int retval;
 971
 972         if (!dev->mii.mdio_write)
 973                 return -EOPNOTSUPP;
 974
 975         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
 976
 977         /* link speed/duplex might have changed */
 978         if (dev->driver_info->link_reset)
 979                 dev->driver_info->link_reset(dev);
 980
 981         /* hard_mtu or rx_urb_size may change in link_reset() */
 982         usbnet_update_max_qlen(dev);
 983
 984         return retval;
 985 }
 986 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
 987
 988 void usbnet_get_stats64(struct net_device *net, struct rtnl_link_stats64 *stats)
 989 {
 990         struct usbnet *dev = netdev_priv(net);
 991         unsigned int start;
 992         int cpu;
 993
 994         netdev_stats_to_stats64(stats, &net->stats);
 995
 996         for_each_possible_cpu(cpu) {
 997                 struct pcpu_sw_netstats *stats64;
 998                 u64 rx_packets, rx_bytes;
 999                 u64 tx_packets, tx_bytes;
1000
1001                 stats64 = per_cpu_ptr(dev->stats64, cpu);
1002
1003                 do {
1004                         start = u64_stats_fetch_begin_irq(&stats64->syncp);
1005                         rx_packets = stats64->rx_packets;
1006                         rx_bytes = stats64->rx_bytes;
1007                         tx_packets = stats64->tx_packets;
1008                         tx_bytes = stats64->tx_bytes;
1009                 } while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
1010
1011                 stats->rx_packets += rx_packets;
1012                 stats->rx_bytes += rx_bytes;
1013                 stats->tx_packets += tx_packets;
1014                 stats->tx_bytes += tx_bytes;
1015         }
1016 }
1017 EXPORT_SYMBOL_GPL(usbnet_get_stats64);
1018
1019 u32 usbnet_get_link (struct net_device *net)
1020 {
1021         struct usbnet *dev = netdev_priv(net);
1022
1023         /* If a check_connect is defined, return its result */
1024         if (dev->driver_info->check_connect)
1025                 return dev->driver_info->check_connect (dev) == 0;
1026
1027         /* if the device has mii operations, use those */
1028         if (dev->mii.mdio_read)
1029                 return mii_link_ok(&dev->mii);
1030
1031         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1032         return ethtool_op_get_link(net);
1033 }
1034 EXPORT_SYMBOL_GPL(usbnet_get_link);
1035
1036 int usbnet_nway_reset(struct net_device *net)
1037 {
1038         struct usbnet *dev = netdev_priv(net);
1039
1040         if (!dev->mii.mdio_write)
1041                 return -EOPNOTSUPP;
1042
1043         return mii_nway_restart(&dev->mii);
1044 }
1045 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1046
1047 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1048 {
1049         struct usbnet *dev = netdev_priv(net);
1050
1051         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1052         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1053         strlcpy (info->fw_version, dev->driver_info->description,
1054                 sizeof info->fw_version);
1055         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1056 }
1057 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1058
1059 u32 usbnet_get_msglevel (struct net_device *net)
1060 {
1061         struct usbnet *dev = netdev_priv(net);
1062
1063         return dev->msg_enable;
1064 }
1065 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1066
1067 void usbnet_set_msglevel (struct net_device *net, u32 level)
1068 {
1069         struct usbnet *dev = netdev_priv(net);
1070
1071         dev->msg_enable = level;
1072 }
1073 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1074
1075 /* drivers may override default ethtool_ops in their bind() routine */
1076 static const struct ethtool_ops usbnet_ethtool_ops = {
1077         .get_link               = usbnet_get_link,
1078         .nway_reset             = usbnet_nway_reset,
1079         .get_drvinfo            = usbnet_get_drvinfo,
1080         .get_msglevel           = usbnet_get_msglevel,
1081         .set_msglevel           = usbnet_set_msglevel,
1082         .get_ts_info            = ethtool_op_get_ts_info,
1083         .get_link_ksettings     = usbnet_get_link_ksettings,
1084         .set_link_ksettings     = usbnet_set_link_ksettings,
1085 };
1086
1087 /*-------------------------------------------------------------------------*/
1088
1089 static void __handle_link_change(struct usbnet *dev)
1090 {
1091         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1092                 return;
1093
1094         if (!netif_carrier_ok(dev->net)) {
1095                 /* kill URBs for reading packets to save bus bandwidth */
1096                 unlink_urbs(dev, &dev->rxq);
1097
1098                 /*
1099                  * tx_timeout will unlink URBs for sending packets and
1100                  * tx queue is stopped by netcore after link becomes off
1101                  */
1102         } else {
1103                 /* submitting URBs for reading packets */
1104                 tasklet_schedule(&dev->bh);
1105         }
1106
1107         /* hard_mtu or rx_urb_size may change during link change */
1108         usbnet_update_max_qlen(dev);
1109
1110         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1111 }
1112
1113 static void usbnet_set_rx_mode(struct net_device *net)
1114 {
1115         struct usbnet           *dev = netdev_priv(net);
1116
1117         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1118 }
1119
1120 static void __handle_set_rx_mode(struct usbnet *dev)
1121 {
1122         if (dev->driver_info->set_rx_mode)
1123                 (dev->driver_info->set_rx_mode)(dev);
1124
1125         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1126 }
1127
1128 /* work that cannot be done in interrupt context uses keventd.
1129  *
1130  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1131  * especially now that control transfers can be queued.
1132  */
1133 static void
1134 usbnet_deferred_kevent (struct work_struct *work)
1135 {
1136         struct usbnet           *dev =
1137                 container_of(work, struct usbnet, kevent);
1138         int                     status;
1139
1140         /* usb_clear_halt() needs a thread context */
1141         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1142                 unlink_urbs (dev, &dev->txq);
1143                 status = usb_autopm_get_interface(dev->intf);
1144                 if (status < 0)
1145                         goto fail_pipe;
1146                 status = usb_clear_halt (dev->udev, dev->out);
1147                 usb_autopm_put_interface(dev->intf);
1148                 if (status < 0 &&
1149                     status != -EPIPE &&
1150                     status != -ESHUTDOWN) {
1151                         if (netif_msg_tx_err (dev))
1152 fail_pipe:
1153                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1154                                            status);
1155                 } else {
1156                         clear_bit (EVENT_TX_HALT, &dev->flags);
1157                         if (status != -ESHUTDOWN)
1158                                 netif_wake_queue (dev->net);
1159                 }
1160         }
1161         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1162                 unlink_urbs (dev, &dev->rxq);
1163                 status = usb_autopm_get_interface(dev->intf);
1164                 if (status < 0)
1165                         goto fail_halt;
1166                 status = usb_clear_halt (dev->udev, dev->in);
1167                 usb_autopm_put_interface(dev->intf);
1168                 if (status < 0 &&
1169                     status != -EPIPE &&
1170                     status != -ESHUTDOWN) {
1171                         if (netif_msg_rx_err (dev))
1172 fail_halt:
1173                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1174                                            status);
1175                 } else {
1176                         clear_bit (EVENT_RX_HALT, &dev->flags);
1177                         tasklet_schedule (&dev->bh);
1178                 }
1179         }
1180
1181         /* tasklet could resubmit itself forever if memory is tight */
1182         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1183                 struct urb      *urb = NULL;
1184                 int resched = 1;
1185
1186                 if (netif_running (dev->net))
1187                         urb = usb_alloc_urb (0, GFP_KERNEL);
1188                 else
1189                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1190                 if (urb != NULL) {
1191                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1192                         status = usb_autopm_get_interface(dev->intf);
1193                         if (status < 0) {
1194                                 usb_free_urb(urb);
1195                                 goto fail_lowmem;
1196                         }
1197                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1198                                 resched = 0;
1199                         usb_autopm_put_interface(dev->intf);
1200 fail_lowmem:
1201                         if (resched)
1202                                 tasklet_schedule (&dev->bh);
1203                 }
1204         }
1205
1206         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1207                 struct driver_info      *info = dev->driver_info;
1208                 int                     retval = 0;
1209
1210                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1211                 status = usb_autopm_get_interface(dev->intf);
1212                 if (status < 0)
1213                         goto skip_reset;
1214                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1215                         usb_autopm_put_interface(dev->intf);
1216 skip_reset:
1217                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1218                                     retval,
1219                                     dev->udev->bus->bus_name,
1220                                     dev->udev->devpath,
1221                                     info->description);
1222                 } else {
1223                         usb_autopm_put_interface(dev->intf);
1224                 }
1225
1226                 /* handle link change from link resetting */
1227                 __handle_link_change(dev);
1228         }
1229
1230         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1231                 __handle_link_change(dev);
1232
1233         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1234                 __handle_set_rx_mode(dev);
1235
1236
1237         if (dev->flags)
1238                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1239 }
1240
1241 /*-------------------------------------------------------------------------*/
1242
1243 static void tx_complete (struct urb *urb)
1244 {
1245         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1246         struct skb_data         *entry = (struct skb_data *) skb->cb;
1247         struct usbnet           *dev = entry->dev;
1248
1249         if (urb->status == 0) {
1250                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1251
1252                 u64_stats_update_begin(&stats64->syncp);
1253                 stats64->tx_packets += entry->packets;
1254                 stats64->tx_bytes += entry->length;
1255                 u64_stats_update_end(&stats64->syncp);
1256         } else {
1257                 dev->net->stats.tx_errors++;
1258
1259                 switch (urb->status) {
1260                 case -EPIPE:
1261                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1262                         break;
1263
1264                 /* software-driven interface shutdown */
1265                 case -ECONNRESET:               // async unlink
1266                 case -ESHUTDOWN:                // hardware gone
1267                         break;
1268
1269                 /* like rx, tx gets controller i/o faults during hub_wq
1270                  * delays and so it uses the same throttling mechanism.
1271                  */
1272                 case -EPROTO:
1273                 case -ETIME:
1274                 case -EILSEQ:
1275                         usb_mark_last_busy(dev->udev);
1276                         if (!timer_pending (&dev->delay)) {
1277                                 mod_timer (&dev->delay,
1278                                         jiffies + THROTTLE_JIFFIES);
1279                                 netif_dbg(dev, link, dev->net,
1280                                           "tx throttle %d\n", urb->status);
1281                         }
1282                         netif_stop_queue (dev->net);
1283                         break;
1284                 default:
1285                         netif_dbg(dev, tx_err, dev->net,
1286                                   "tx err %d\n", entry->urb->status);
1287                         break;
1288                 }
1289         }
1290
1291         usb_autopm_put_interface_async(dev->intf);
1292         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1293 }
1294
1295 /*-------------------------------------------------------------------------*/
1296
1297 void usbnet_tx_timeout (struct net_device *net)
1298 {
1299         struct usbnet           *dev = netdev_priv(net);
1300
1301         unlink_urbs (dev, &dev->txq);
1302         tasklet_schedule (&dev->bh);
1303         /* this needs to be handled individually because the generic layer
1304          * doesn't know what is sufficient and could not restore private
1305          * information if a remedy of an unconditional reset were used.
1306          */
1307         if (dev->driver_info->recover)
1308                 (dev->driver_info->recover)(dev);
1309 }
1310 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1311
1312 /*-------------------------------------------------------------------------*/
1313
1314 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1315 {
1316         unsigned num_sgs, total_len = 0;
1317         int i, s = 0;
1318
1319         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1320         if (num_sgs == 1)
1321                 return 0;
1322
1323         /* reserve one for zero packet */
1324         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1325                           GFP_ATOMIC);
1326         if (!urb->sg)
1327                 return -ENOMEM;
1328
1329         urb->num_sgs = num_sgs;
1330         sg_init_table(urb->sg, urb->num_sgs + 1);
1331
1332         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1333         total_len += skb_headlen(skb);
1334
1335         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1336                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1337
1338                 total_len += skb_frag_size(f);
1339                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1340                                 f->page_offset);
1341         }
1342         urb->transfer_buffer_length = total_len;
1343
1344         return 1;
1345 }
1346
1347 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1348                                      struct net_device *net)
1349 {
1350         struct usbnet           *dev = netdev_priv(net);
1351         unsigned int                    length;
1352         struct urb              *urb = NULL;
1353         struct skb_data         *entry;
1354         struct driver_info      *info = dev->driver_info;
1355         unsigned long           flags;
1356         int retval;
1357
1358         if (skb)
1359                 skb_tx_timestamp(skb);
1360
1361         // some devices want funky USB-level framing, for
1362         // win32 driver (usually) and/or hardware quirks
1363         if (info->tx_fixup) {
1364                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1365                 if (!skb) {
1366                         /* packet collected; minidriver waiting for more */
1367                         if (info->flags & FLAG_MULTI_PACKET)
1368                                 goto not_drop;
1369                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1370                         goto drop;
1371                 }
1372         }
1373
1374         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1375                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1376                 goto drop;
1377         }
1378
1379         entry = (struct skb_data *) skb->cb;
1380         entry->urb = urb;
1381         entry->dev = dev;
1382
1383         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1384                         skb->data, skb->len, tx_complete, skb);
1385         if (dev->can_dma_sg) {
1386                 if (build_dma_sg(skb, urb) < 0)
1387                         goto drop;
1388         }
1389         length = urb->transfer_buffer_length;
1390
1391         /* don't assume the hardware handles USB_ZERO_PACKET
1392          * NOTE:  strictly conforming cdc-ether devices should expect
1393          * the ZLP here, but ignore the one-byte packet.
1394          * NOTE2: CDC NCM specification is different from CDC ECM when
1395          * handling ZLP/short packets, so cdc_ncm driver will make short
1396          * packet itself if needed.
1397          */
1398         if (length % dev->maxpacket == 0) {
1399                 if (!(info->flags & FLAG_SEND_ZLP)) {
1400                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1401                                 length++;
1402                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1403                                         skb->data[skb->len] = 0;
1404                                         __skb_put(skb, 1);
1405                                 } else if (urb->num_sgs)
1406                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1407                                                         dev->padding_pkt, 1);
1408                         }
1409                 } else
1410                         urb->transfer_flags |= URB_ZERO_PACKET;
1411         }
1412         urb->transfer_buffer_length = length;
1413
1414         if (info->flags & FLAG_MULTI_PACKET) {
1415                 /* Driver has set number of packets and a length delta.
1416                  * Calculate the complete length and ensure that it's
1417                  * positive.
1418                  */
1419                 entry->length += length;
1420                 if (WARN_ON_ONCE(entry->length <= 0))
1421                         entry->length = length;
1422         } else {
1423                 usbnet_set_skb_tx_stats(skb, 1, length);
1424         }
1425
1426         spin_lock_irqsave(&dev->txq.lock, flags);
1427         retval = usb_autopm_get_interface_async(dev->intf);
1428         if (retval < 0) {
1429                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1430                 goto drop;
1431         }
1432
1433 #ifdef CONFIG_PM
1434         /* if this triggers the device is still a sleep */
1435         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1436                 /* transmission will be done in resume */
1437                 usb_anchor_urb(urb, &dev->deferred);
1438                 /* no use to process more packets */
1439                 netif_stop_queue(net);
1440                 usb_put_urb(urb);
1441                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1442                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1443                 goto deferred;
1444         }
1445 #endif
1446
1447         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1448         case -EPIPE:
1449                 netif_stop_queue (net);
1450                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1451                 usb_autopm_put_interface_async(dev->intf);
1452                 break;
1453         default:
1454                 usb_autopm_put_interface_async(dev->intf);
1455                 netif_dbg(dev, tx_err, dev->net,
1456                           "tx: submit urb err %d\n", retval);
1457                 break;
1458         case 0:
1459                 netif_trans_update(net);
1460                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1461                 if (dev->txq.qlen >= TX_QLEN (dev))
1462                         netif_stop_queue (net);
1463         }
1464         spin_unlock_irqrestore (&dev->txq.lock, flags);
1465
1466         if (retval) {
1467                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1468 drop:
1469                 dev->net->stats.tx_dropped++;
1470 not_drop:
1471                 if (skb)
1472                         dev_kfree_skb_any (skb);
1473                 if (urb) {
1474                         kfree(urb->sg);
1475                         usb_free_urb(urb);
1476                 }
1477         } else
1478                 netif_dbg(dev, tx_queued, dev->net,
1479                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1480 #ifdef CONFIG_PM
1481 deferred:
1482 #endif
1483         return NETDEV_TX_OK;
1484 }
1485 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1486
1487 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1488 {
1489         struct urb      *urb;
1490         int             i;
1491         int             ret = 0;
1492
1493         /* don't refill the queue all at once */
1494         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1495                 urb = usb_alloc_urb(0, flags);
1496                 if (urb != NULL) {
1497                         ret = rx_submit(dev, urb, flags);
1498                         if (ret)
1499                                 goto err;
1500                 } else {
1501                         ret = -ENOMEM;
1502                         goto err;
1503                 }
1504         }
1505 err:
1506         return ret;
1507 }
1508
1509 /*-------------------------------------------------------------------------*/
1510
1511 // tasklet (work deferred from completions, in_irq) or timer
1512
1513 static void usbnet_bh (struct timer_list *t)
1514 {
1515         struct usbnet           *dev = from_timer(dev, t, delay);
1516         struct sk_buff          *skb;
1517         struct skb_data         *entry;
1518
1519         while ((skb = skb_dequeue (&dev->done))) {
1520                 entry = (struct skb_data *) skb->cb;
1521                 switch (entry->state) {
1522                 case rx_done:
1523                         entry->state = rx_cleanup;
1524                         rx_process (dev, skb);
1525                         continue;
1526                 case tx_done:
1527                         kfree(entry->urb->sg);
1528                 case rx_cleanup:
1529                         usb_free_urb (entry->urb);
1530                         dev_kfree_skb (skb);
1531                         continue;
1532                 default:
1533                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1534                 }
1535         }
1536
1537         /* restart RX again after disabling due to high error rate */
1538         clear_bit(EVENT_RX_KILL, &dev->flags);
1539
1540         /* waiting for all pending urbs to complete?
1541          * only then can we forgo submitting anew
1542          */
1543         if (waitqueue_active(&dev->wait)) {
1544                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1545                         wake_up_all(&dev->wait);
1546
1547         // or are we maybe short a few urbs?
1548         } else if (netif_running (dev->net) &&
1549                    netif_device_present (dev->net) &&
1550                    netif_carrier_ok(dev->net) &&
1551                    !timer_pending(&dev->delay) &&
1552                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1553                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1554                 int     temp = dev->rxq.qlen;
1555
1556                 if (temp < RX_QLEN(dev)) {
1557                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1558                                 return;
1559                         if (temp != dev->rxq.qlen)
1560                                 netif_dbg(dev, link, dev->net,
1561                                           "rxqlen %d --> %d\n",
1562                                           temp, dev->rxq.qlen);
1563                         if (dev->rxq.qlen < RX_QLEN(dev))
1564                                 tasklet_schedule (&dev->bh);
1565                 }
1566                 if (dev->txq.qlen < TX_QLEN (dev))
1567                         netif_wake_queue (dev->net);
1568         }
1569 }
1570
1571
1572 /*-------------------------------------------------------------------------
1573  *
1574  * USB Device Driver support
1575  *
1576  *-------------------------------------------------------------------------*/
1577
1578 // precondition: never called in_interrupt
1579
1580 void usbnet_disconnect (struct usb_interface *intf)
1581 {
1582         struct usbnet           *dev;
1583         struct usb_device       *xdev;
1584         struct net_device       *net;
1585
1586         dev = usb_get_intfdata(intf);
1587         usb_set_intfdata(intf, NULL);
1588         if (!dev)
1589                 return;
1590
1591         xdev = interface_to_usbdev (intf);
1592
1593         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1594                    intf->dev.driver->name,
1595                    xdev->bus->bus_name, xdev->devpath,
1596                    dev->driver_info->description);
1597
1598         net = dev->net;
1599         unregister_netdev (net);
1600
1601         cancel_work_sync(&dev->kevent);
1602
1603         usb_scuttle_anchored_urbs(&dev->deferred);
1604
1605         if (dev->driver_info->unbind)
1606                 dev->driver_info->unbind (dev, intf);
1607
1608         usb_kill_urb(dev->interrupt);
1609         usb_free_urb(dev->interrupt);
1610         kfree(dev->padding_pkt);
1611
1612         free_percpu(dev->stats64);
1613         free_netdev(net);
1614 }
1615 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1616
1617 static const struct net_device_ops usbnet_netdev_ops = {
1618         .ndo_open               = usbnet_open,
1619         .ndo_stop               = usbnet_stop,
1620         .ndo_start_xmit         = usbnet_start_xmit,
1621         .ndo_tx_timeout         = usbnet_tx_timeout,
1622         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1623         .ndo_change_mtu         = usbnet_change_mtu,
1624         .ndo_get_stats64        = usbnet_get_stats64,
1625         .ndo_set_mac_address    = eth_mac_addr,
1626         .ndo_validate_addr      = eth_validate_addr,
1627 };
1628
1629 /*-------------------------------------------------------------------------*/
1630
1631 // precondition: never called in_interrupt
1632
1633 static struct device_type wlan_type = {
1634         .name   = "wlan",
1635 };
1636
1637 static struct device_type wwan_type = {
1638         .name   = "wwan",
1639 };
1640
1641 int
1642 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1643 {
1644         struct usbnet                   *dev;
1645         struct net_device               *net;
1646         struct usb_host_interface       *interface;
1647         struct driver_info              *info;
1648         struct usb_device               *xdev;
1649         int                             status;
1650         const char                      *name;
1651         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1652
1653         /* usbnet already took usb runtime pm, so have to enable the feature
1654          * for usb interface, otherwise usb_autopm_get_interface may return
1655          * failure if RUNTIME_PM is enabled.
1656          */
1657         if (!driver->supports_autosuspend) {
1658                 driver->supports_autosuspend = 1;
1659                 pm_runtime_enable(&udev->dev);
1660         }
1661
1662         name = udev->dev.driver->name;
1663         info = (struct driver_info *) prod->driver_info;
1664         if (!info) {
1665                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1666                 return -ENODEV;
1667         }
1668         xdev = interface_to_usbdev (udev);
1669         interface = udev->cur_altsetting;
1670
1671         status = -ENOMEM;
1672
1673         // set up our own records
1674         net = alloc_etherdev(sizeof(*dev));
1675         if (!net)
1676                 goto out;
1677
1678         /* netdev_printk() needs this so do it as early as possible */
1679         SET_NETDEV_DEV(net, &udev->dev);
1680
1681         dev = netdev_priv(net);
1682         dev->udev = xdev;
1683         dev->intf = udev;
1684         dev->driver_info = info;
1685         dev->driver_name = name;
1686
1687         dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1688         if (!dev->stats64)
1689                 goto out0;
1690
1691         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1692                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1693         init_waitqueue_head(&dev->wait);
1694         skb_queue_head_init (&dev->rxq);
1695         skb_queue_head_init (&dev->txq);
1696         skb_queue_head_init (&dev->done);
1697         skb_queue_head_init(&dev->rxq_pause);
1698         dev->bh.func = (void (*)(unsigned long))usbnet_bh;
1699         dev->bh.data = (unsigned long)&dev->delay;
1700         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1701         init_usb_anchor(&dev->deferred);
1702         timer_setup(&dev->delay, usbnet_bh, 0);
1703         mutex_init (&dev->phy_mutex);
1704         mutex_init(&dev->interrupt_mutex);
1705         dev->interrupt_count = 0;
1706
1707         dev->net = net;
1708         strcpy (net->name, "usb%d");
1709         memcpy (net->dev_addr, node_id, sizeof node_id);
1710
1711         /* rx and tx sides can use different message sizes;
1712          * bind() should set rx_urb_size in that case.
1713          */
1714         dev->hard_mtu = net->mtu + net->hard_header_len;
1715         net->min_mtu = 0;
1716         net->max_mtu = ETH_MAX_MTU;
1717
1718         net->netdev_ops = &usbnet_netdev_ops;
1719         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1720         net->ethtool_ops = &usbnet_ethtool_ops;
1721
1722         // allow device-specific bind/init procedures
1723         // NOTE net->name still not usable ...
1724         if (info->bind) {
1725                 status = info->bind (dev, udev);
1726                 if (status < 0)
1727                         goto out1;
1728
1729                 // heuristic:  "usb%d" for links we know are two-host,
1730                 // else "eth%d" when there's reasonable doubt.  userspace
1731                 // can rename the link if it knows better.
1732                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1733                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1734                      (net->dev_addr [0] & 0x02) == 0))
1735                         strcpy (net->name, "eth%d");
1736                 /* WLAN devices should always be named "wlan%d" */
1737                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1738                         strcpy(net->name, "wlan%d");
1739                 /* WWAN devices should always be named "wwan%d" */
1740                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1741                         strcpy(net->name, "wwan%d");
1742
1743                 /* devices that cannot do ARP */
1744                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1745                         net->flags |= IFF_NOARP;
1746
1747                 /* maybe the remote can't receive an Ethernet MTU */
1748                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1749                         net->mtu = dev->hard_mtu - net->hard_header_len;
1750         } else if (!info->in || !info->out)
1751                 status = usbnet_get_endpoints (dev, udev);
1752         else {
1753                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1754                 dev->out = usb_sndbulkpipe (xdev, info->out);
1755                 if (!(info->flags & FLAG_NO_SETINT))
1756                         status = usb_set_interface (xdev,
1757                                 interface->desc.bInterfaceNumber,
1758                                 interface->desc.bAlternateSetting);
1759                 else
1760                         status = 0;
1761
1762         }
1763         if (status >= 0 && dev->status)
1764                 status = init_status (dev, udev);
1765         if (status < 0)
1766                 goto out3;
1767
1768         if (!dev->rx_urb_size)
1769                 dev->rx_urb_size = dev->hard_mtu;
1770         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1771
1772         /* let userspace know we have a random address */
1773         if (ether_addr_equal(net->dev_addr, node_id))
1774                 net->addr_assign_type = NET_ADDR_RANDOM;
1775
1776         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1777                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1778         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1779                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1780
1781         /* initialize max rx_qlen and tx_qlen */
1782         usbnet_update_max_qlen(dev);
1783
1784         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1785                 !(info->flags & FLAG_MULTI_PACKET)) {
1786                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1787                 if (!dev->padding_pkt) {
1788                         status = -ENOMEM;
1789                         goto out4;
1790                 }
1791         }
1792
1793         status = register_netdev (net);
1794         if (status)
1795                 goto out5;
1796         netif_info(dev, probe, dev->net,
1797                    "register '%s' at usb-%s-%s, %s, %pM\n",
1798                    udev->dev.driver->name,
1799                    xdev->bus->bus_name, xdev->devpath,
1800                    dev->driver_info->description,
1801                    net->dev_addr);
1802
1803         // ok, it's ready to go.
1804         usb_set_intfdata (udev, dev);
1805
1806         netif_device_attach (net);
1807
1808         if (dev->driver_info->flags & FLAG_LINK_INTR)
1809                 usbnet_link_change(dev, 0, 0);
1810
1811         return 0;
1812
1813 out5:
1814         kfree(dev->padding_pkt);
1815 out4:
1816         usb_free_urb(dev->interrupt);
1817 out3:
1818         if (info->unbind)
1819                 info->unbind (dev, udev);
1820 out1:
1821         /* subdrivers must undo all they did in bind() if they
1822          * fail it, but we may fail later and a deferred kevent
1823          * may trigger an error resubmitting itself and, worse,
1824          * schedule a timer. So we kill it all just in case.
1825          */
1826         cancel_work_sync(&dev->kevent);
1827         del_timer_sync(&dev->delay);
1828         free_percpu(dev->stats64);
1829 out0:
1830         free_netdev(net);
1831 out:
1832         return status;
1833 }
1834 EXPORT_SYMBOL_GPL(usbnet_probe);
1835
1836 /*-------------------------------------------------------------------------*/
1837
1838 /*
1839  * suspend the whole driver as soon as the first interface is suspended
1840  * resume only when the last interface is resumed
1841  */
1842
1843 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1844 {
1845         struct usbnet           *dev = usb_get_intfdata(intf);
1846
1847         if (!dev->suspend_count++) {
1848                 spin_lock_irq(&dev->txq.lock);
1849                 /* don't autosuspend while transmitting */
1850                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1851                         dev->suspend_count--;
1852                         spin_unlock_irq(&dev->txq.lock);
1853                         return -EBUSY;
1854                 } else {
1855                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1856                         spin_unlock_irq(&dev->txq.lock);
1857                 }
1858                 /*
1859                  * accelerate emptying of the rx and queues, to avoid
1860                  * having everything error out.
1861                  */
1862                 netif_device_detach (dev->net);
1863                 usbnet_terminate_urbs(dev);
1864                 __usbnet_status_stop_force(dev);
1865
1866                 /*
1867                  * reattach so runtime management can use and
1868                  * wake the device
1869                  */
1870                 netif_device_attach (dev->net);
1871         }
1872         return 0;
1873 }
1874 EXPORT_SYMBOL_GPL(usbnet_suspend);
1875
1876 int usbnet_resume (struct usb_interface *intf)
1877 {
1878         struct usbnet           *dev = usb_get_intfdata(intf);
1879         struct sk_buff          *skb;
1880         struct urb              *res;
1881         int                     retval;
1882
1883         if (!--dev->suspend_count) {
1884                 /* resume interrupt URB if it was previously submitted */
1885                 __usbnet_status_start_force(dev, GFP_NOIO);
1886
1887                 spin_lock_irq(&dev->txq.lock);
1888                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1889
1890                         skb = (struct sk_buff *)res->context;
1891                         retval = usb_submit_urb(res, GFP_ATOMIC);
1892                         if (retval < 0) {
1893                                 dev_kfree_skb_any(skb);
1894                                 kfree(res->sg);
1895                                 usb_free_urb(res);
1896                                 usb_autopm_put_interface_async(dev->intf);
1897                         } else {
1898                                 netif_trans_update(dev->net);
1899                                 __skb_queue_tail(&dev->txq, skb);
1900                         }
1901                 }
1902
1903                 smp_mb();
1904                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1905                 spin_unlock_irq(&dev->txq.lock);
1906
1907                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1908                         /* handle remote wakeup ASAP
1909                          * we cannot race against stop
1910                          */
1911                         if (netif_device_present(dev->net) &&
1912                                 !timer_pending(&dev->delay) &&
1913                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1914                                         rx_alloc_submit(dev, GFP_NOIO);
1915
1916                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1917                                 netif_tx_wake_all_queues(dev->net);
1918                         tasklet_schedule (&dev->bh);
1919                 }
1920         }
1921
1922         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1923                 usb_autopm_get_interface_no_resume(intf);
1924
1925         return 0;
1926 }
1927 EXPORT_SYMBOL_GPL(usbnet_resume);
1928
1929 /*
1930  * Either a subdriver implements manage_power, then it is assumed to always
1931  * be ready to be suspended or it reports the readiness to be suspended
1932  * explicitly
1933  */
1934 void usbnet_device_suggests_idle(struct usbnet *dev)
1935 {
1936         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1937                 dev->intf->needs_remote_wakeup = 1;
1938                 usb_autopm_put_interface_async(dev->intf);
1939         }
1940 }
1941 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1942
1943 /*
1944  * For devices that can do without special commands
1945  */
1946 int usbnet_manage_power(struct usbnet *dev, int on)
1947 {
1948         dev->intf->needs_remote_wakeup = on;
1949         return 0;
1950 }
1951 EXPORT_SYMBOL(usbnet_manage_power);
1952
1953 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1954 {
1955         /* update link after link is reseted */
1956         if (link && !need_reset)
1957                 netif_carrier_on(dev->net);
1958         else
1959                 netif_carrier_off(dev->net);
1960
1961         if (need_reset && link)
1962                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1963         else
1964                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1965 }
1966 EXPORT_SYMBOL(usbnet_link_change);
1967
1968 /*-------------------------------------------------------------------------*/
1969 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1970                              u16 value, u16 index, void *data, u16 size)
1971 {
1972         void *buf = NULL;
1973         int err = -ENOMEM;
1974
1975         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1976                    " value=0x%04x index=0x%04x size=%d\n",
1977                    cmd, reqtype, value, index, size);
1978
1979         if (size) {
1980                 buf = kmalloc(size, GFP_KERNEL);
1981                 if (!buf)
1982                         goto out;
1983         }
1984
1985         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1986                               cmd, reqtype, value, index, buf, size,
1987                               USB_CTRL_GET_TIMEOUT);
1988         if (err > 0 && err <= size) {
1989         if (data)
1990             memcpy(data, buf, err);
1991         else
1992             netdev_dbg(dev->net,
1993                 "Huh? Data requested but thrown away.\n");
1994     }
1995         kfree(buf);
1996 out:
1997         return err;
1998 }
1999
2000 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2001                               u16 value, u16 index, const void *data,
2002                               u16 size)
2003 {
2004         void *buf = NULL;
2005         int err = -ENOMEM;
2006
2007         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2008                    " value=0x%04x index=0x%04x size=%d\n",
2009                    cmd, reqtype, value, index, size);
2010
2011         if (data) {
2012                 buf = kmemdup(data, size, GFP_KERNEL);
2013                 if (!buf)
2014                         goto out;
2015         } else {
2016         if (size) {
2017             WARN_ON_ONCE(1);
2018             err = -EINVAL;
2019             goto out;
2020         }
2021     }
2022
2023         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2024                               cmd, reqtype, value, index, buf, size,
2025                               USB_CTRL_SET_TIMEOUT);
2026         kfree(buf);
2027
2028 out:
2029         return err;
2030 }
2031
2032 /*
2033  * The function can't be called inside suspend/resume callback,
2034  * otherwise deadlock will be caused.
2035  */
2036 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2037                     u16 value, u16 index, void *data, u16 size)
2038 {
2039         int ret;
2040
2041         if (usb_autopm_get_interface(dev->intf) < 0)
2042                 return -ENODEV;
2043         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2044                                 data, size);
2045         usb_autopm_put_interface(dev->intf);
2046         return ret;
2047 }
2048 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2049
2050 /*
2051  * The function can't be called inside suspend/resume callback,
2052  * otherwise deadlock will be caused.
2053  */
2054 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2055                      u16 value, u16 index, const void *data, u16 size)
2056 {
2057         int ret;
2058
2059         if (usb_autopm_get_interface(dev->intf) < 0)
2060                 return -ENODEV;
2061         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2062                                  data, size);
2063         usb_autopm_put_interface(dev->intf);
2064         return ret;
2065 }
2066 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2067
2068 /*
2069  * The function can be called inside suspend/resume callback safely
2070  * and should only be called by suspend/resume callback generally.
2071  */
2072 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2073                           u16 value, u16 index, void *data, u16 size)
2074 {
2075         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2076                                  data, size);
2077 }
2078 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2079
2080 /*
2081  * The function can be called inside suspend/resume callback safely
2082  * and should only be called by suspend/resume callback generally.
2083  */
2084 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2085                           u16 value, u16 index, const void *data,
2086                           u16 size)
2087 {
2088         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2089                                   data, size);
2090 }
2091 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2092
2093 static void usbnet_async_cmd_cb(struct urb *urb)
2094 {
2095         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2096         int status = urb->status;
2097
2098         if (status < 0)
2099                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2100                         __func__, status);
2101
2102         kfree(req);
2103         usb_free_urb(urb);
2104 }
2105
2106 /*
2107  * The caller must make sure that device can't be put into suspend
2108  * state until the control URB completes.
2109  */
2110 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2111                            u16 value, u16 index, const void *data, u16 size)
2112 {
2113         struct usb_ctrlrequest *req = NULL;
2114         struct urb *urb;
2115         int err = -ENOMEM;
2116         void *buf = NULL;
2117
2118         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2119                    " value=0x%04x index=0x%04x size=%d\n",
2120                    cmd, reqtype, value, index, size);
2121
2122         urb = usb_alloc_urb(0, GFP_ATOMIC);
2123         if (!urb)
2124                 goto fail;
2125
2126         if (data) {
2127                 buf = kmemdup(data, size, GFP_ATOMIC);
2128                 if (!buf) {
2129                         netdev_err(dev->net, "Error allocating buffer"
2130                                    " in %s!\n", __func__);
2131                         goto fail_free;
2132                 }
2133         }
2134
2135         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2136         if (!req)
2137                 goto fail_free_buf;
2138
2139         req->bRequestType = reqtype;
2140         req->bRequest = cmd;
2141         req->wValue = cpu_to_le16(value);
2142         req->wIndex = cpu_to_le16(index);
2143         req->wLength = cpu_to_le16(size);
2144
2145         usb_fill_control_urb(urb, dev->udev,
2146                              usb_sndctrlpipe(dev->udev, 0),
2147                              (void *)req, buf, size,
2148                              usbnet_async_cmd_cb, req);
2149         urb->transfer_flags |= URB_FREE_BUFFER;
2150
2151         err = usb_submit_urb(urb, GFP_ATOMIC);
2152         if (err < 0) {
2153                 netdev_err(dev->net, "Error submitting the control"
2154                            " message: status=%d\n", err);
2155                 goto fail_free;
2156         }
2157         return 0;
2158
2159 fail_free_buf:
2160         kfree(buf);
2161 fail_free:
2162         kfree(req);
2163         usb_free_urb(urb);
2164 fail:
2165         return err;
2166
2167 }
2168 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2169 /*-------------------------------------------------------------------------*/
2170
2171 static int __init usbnet_init(void)
2172 {
2173         /* Compiler should optimize this out. */
2174         BUILD_BUG_ON(
2175                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2176
2177         eth_random_addr(node_id);
2178         return 0;
2179 }
2180 module_init(usbnet_init);
2181
2182 static void __exit usbnet_exit(void)
2183 {
2184 }
2185 module_exit(usbnet_exit);
2186
2187 MODULE_AUTHOR("David Brownell");
2188 MODULE_DESCRIPTION("USB network driver framework");
2189 MODULE_LICENSE("GPL");