drivers/net/usb/usbnet.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * USB Network driver infrastructure
   4  * Copyright (C) 2000-2005 by David Brownell
   5  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   6  */
   7
   8 /*
   9  * This is a generic "USB networking" framework that works with several
  10  * kinds of full and high speed networking devices:  host-to-host cables,
  11  * smart usb peripherals, and actual Ethernet adapters.
  12  *
  13  * These devices usually differ in terms of control protocols (if they
  14  * even have one!) and sometimes they define new framing to wrap or batch
  15  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  16  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  17  * issues can usefully be addressed by this framework.
  18  */
  19
  20 // #define      DEBUG                   // error path messages, extra info
  21 // #define      VERBOSE                 // more; success messages
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/ctype.h>
  28 #include <linux/ethtool.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/mii.h>
  31 #include <linux/usb.h>
  32 #include <linux/usb/usbnet.h>
  33 #include <linux/slab.h>
  34 #include <linux/kernel.h>
  35 #include <linux/pm_runtime.h>
  36
  37 #define DRIVER_VERSION          "22-Aug-2005"
  38
  39
  40 /*-------------------------------------------------------------------------*/
  41
  42 /*
  43  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  44  * Several dozen bytes of IPv4 data can fit in two such transactions.
  45  * One maximum size Ethernet packet takes twenty four of them.
  46  * For high speed, each frame comfortably fits almost 36 max size
  47  * Ethernet packets (so queues should be bigger).
  48  *
  49  * The goal is to let the USB host controller be busy for 5msec or
  50  * more before an irq is required, under load.  Jumbograms change
  51  * the equation.
  52  */
  53 #define MAX_QUEUE_MEMORY        (60 * 1518)
  54 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  55 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  56
  57 // reawaken network queue this soon after stopping; else watchdog barks
  58 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  59
  60 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  61  * us (it polls at HZ/4 usually) before we report too many false errors.
  62  */
  63 #define THROTTLE_JIFFIES        (HZ/8)
  64
  65 // between wakeups
  66 #define UNLINK_TIMEOUT_MS       3
  67
  68 /*-------------------------------------------------------------------------*/
  69
  70 // randomly generated ethernet address
  71 static u8       node_id [ETH_ALEN];
  72
  73 /* use ethtool to change the level for any given device */
  74 static int msg_level = -1;
  75 module_param (msg_level, int, 0);
  76 MODULE_PARM_DESC (msg_level, "Override default message level");
  77
  78 /*-------------------------------------------------------------------------*/
  79
  80 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  81 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  82 {
  83         int                             tmp;
  84         struct usb_host_interface       *alt = NULL;
  85         struct usb_host_endpoint        *in = NULL, *out = NULL;
  86         struct usb_host_endpoint        *status = NULL;
  87
  88         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
  89                 unsigned        ep;
  90
  91                 in = out = status = NULL;
  92                 alt = intf->altsetting + tmp;
  93
  94                 /* take the first altsetting with in-bulk + out-bulk;
  95                  * remember any status endpoint, just in case;
  96                  * ignore other endpoints and altsettings.
  97                  */
  98                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
  99                         struct usb_host_endpoint        *e;
 100                         int                             intr = 0;
 101
 102                         e = alt->endpoint + ep;
 103                         switch (e->desc.bmAttributes) {
 104                         case USB_ENDPOINT_XFER_INT:
 105                                 if (!usb_endpoint_dir_in(&e->desc))
 106                                         continue;
 107                                 intr = 1;
 108                                 /* FALLTHROUGH */
 109                         case USB_ENDPOINT_XFER_BULK:
 110                                 break;
 111                         default:
 112                                 continue;
 113                         }
 114                         if (usb_endpoint_dir_in(&e->desc)) {
 115                                 if (!intr && !in)
 116                                         in = e;
 117                                 else if (intr && !status)
 118                                         status = e;
 119                         } else {
 120                                 if (!out)
 121                                         out = e;
 122                         }
 123                 }
 124                 if (in && out)
 125                         break;
 126         }
 127         if (!alt || !in || !out)
 128                 return -EINVAL;
 129
 130         if (alt->desc.bAlternateSetting != 0 ||
 131             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 132                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 133                                 alt->desc.bAlternateSetting);
 134                 if (tmp < 0)
 135                         return tmp;
 136         }
 137
 138         dev->in = usb_rcvbulkpipe (dev->udev,
 139                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 140         dev->out = usb_sndbulkpipe (dev->udev,
 141                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 142         dev->status = status;
 143         return 0;
 144 }
 145 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 146
 147 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 148 {
 149         int             tmp = -1, ret;
 150         unsigned char   buf [13];
 151
 152         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 153         if (ret == 12)
 154                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 155         if (tmp < 0) {
 156                 dev_dbg(&dev->udev->dev,
 157                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 158                 if (ret >= 0)
 159                         ret = -EINVAL;
 160                 return ret;
 161         }
 162         return 0;
 163 }
 164 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 165
 166 static void intr_complete (struct urb *urb)
 167 {
 168         struct usbnet   *dev = urb->context;
 169         int             status = urb->status;
 170
 171         switch (status) {
 172         /* success */
 173         case 0:
 174                 dev->driver_info->status(dev, urb);
 175                 break;
 176
 177         /* software-driven interface shutdown */
 178         case -ENOENT:           /* urb killed */
 179         case -ESHUTDOWN:        /* hardware gone */
 180                 netif_dbg(dev, ifdown, dev->net,
 181                           "intr shutdown, code %d\n", status);
 182                 return;
 183
 184         /* NOTE:  not throttling like RX/TX, since this endpoint
 185          * already polls infrequently
 186          */
 187         default:
 188                 netdev_dbg(dev->net, "intr status %d\n", status);
 189                 break;
 190         }
 191
 192         status = usb_submit_urb (urb, GFP_ATOMIC);
 193         if (status != 0)
 194                 netif_err(dev, timer, dev->net,
 195                           "intr resubmit --> %d\n", status);
 196 }
 197
 198 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 199 {
 200         char            *buf = NULL;
 201         unsigned        pipe = 0;
 202         unsigned        maxp;
 203         unsigned        period;
 204
 205         if (!dev->driver_info->status)
 206                 return 0;
 207
 208         pipe = usb_rcvintpipe (dev->udev,
 209                         dev->status->desc.bEndpointAddress
 210                                 & USB_ENDPOINT_NUMBER_MASK);
 211         maxp = usb_maxpacket (dev->udev, pipe, 0);
 212
 213         /* avoid 1 msec chatter:  min 8 msec poll rate */
 214         period = max ((int) dev->status->desc.bInterval,
 215                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 216
 217         buf = kmalloc (maxp, GFP_KERNEL);
 218         if (buf) {
 219                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 220                 if (!dev->interrupt) {
 221                         kfree (buf);
 222                         return -ENOMEM;
 223                 } else {
 224                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 225                                 buf, maxp, intr_complete, dev, period);
 226                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 227                         dev_dbg(&intf->dev,
 228                                 "status ep%din, %d bytes period %d\n",
 229                                 usb_pipeendpoint(pipe), maxp, period);
 230                 }
 231         }
 232         return 0;
 233 }
 234
 235 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 236 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 237 {
 238         int ret = 0;
 239
 240         WARN_ON_ONCE(dev->interrupt == NULL);
 241         if (dev->interrupt) {
 242                 mutex_lock(&dev->interrupt_mutex);
 243
 244                 if (++dev->interrupt_count == 1)
 245                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 246
 247                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 248                         dev->interrupt_count);
 249                 mutex_unlock(&dev->interrupt_mutex);
 250         }
 251         return ret;
 252 }
 253 EXPORT_SYMBOL_GPL(usbnet_status_start);
 254
 255 /* For resume; submit interrupt URB if previously submitted */
 256 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 257 {
 258         int ret = 0;
 259
 260         mutex_lock(&dev->interrupt_mutex);
 261         if (dev->interrupt_count) {
 262                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 263                 dev_dbg(&dev->udev->dev,
 264                         "submitted interrupt URB for resume\n");
 265         }
 266         mutex_unlock(&dev->interrupt_mutex);
 267         return ret;
 268 }
 269
 270 /* Kill the interrupt URB if all submitters want it killed */
 271 void usbnet_status_stop(struct usbnet *dev)
 272 {
 273         if (dev->interrupt) {
 274                 mutex_lock(&dev->interrupt_mutex);
 275                 WARN_ON(dev->interrupt_count == 0);
 276
 277                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 278                         usb_kill_urb(dev->interrupt);
 279
 280                 dev_dbg(&dev->udev->dev,
 281                         "decremented interrupt URB count to %d\n",
 282                         dev->interrupt_count);
 283                 mutex_unlock(&dev->interrupt_mutex);
 284         }
 285 }
 286 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 287
 288 /* For suspend; always kill interrupt URB */
 289 static void __usbnet_status_stop_force(struct usbnet *dev)
 290 {
 291         if (dev->interrupt) {
 292                 mutex_lock(&dev->interrupt_mutex);
 293                 usb_kill_urb(dev->interrupt);
 294                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 295                 mutex_unlock(&dev->interrupt_mutex);
 296         }
 297 }
 298
 299 /* Passes this packet up the stack, updating its accounting.
 300  * Some link protocols batch packets, so their rx_fixup paths
 301  * can return clones as well as just modify the original skb.
 302  */
 303 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 304 {
 305         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
 306         unsigned long flags;
 307         int     status;
 308
 309         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 310                 skb_queue_tail(&dev->rxq_pause, skb);
 311                 return;
 312         }
 313
 314         /* only update if unset to allow minidriver rx_fixup override */
 315         if (skb->protocol == 0)
 316                 skb->protocol = eth_type_trans (skb, dev->net);
 317
 318         flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 319         stats64->rx_packets++;
 320         stats64->rx_bytes += skb->len;
 321         u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 322
 323         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 324                   skb->len + sizeof (struct ethhdr), skb->protocol);
 325         memset (skb->cb, 0, sizeof (struct skb_data));
 326
 327         if (skb_defer_rx_timestamp(skb))
 328                 return;
 329
 330         status = netif_rx (skb);
 331         if (status != NET_RX_SUCCESS)
 332                 netif_dbg(dev, rx_err, dev->net,
 333                           "netif_rx status %d\n", status);
 334 }
 335 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 336
 337 /* must be called if hard_mtu or rx_urb_size changed */
 338 void usbnet_update_max_qlen(struct usbnet *dev)
 339 {
 340         enum usb_device_speed speed = dev->udev->speed;
 341
 342         switch (speed) {
 343         case USB_SPEED_HIGH:
 344                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 345                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 346                 break;
 347         case USB_SPEED_SUPER:
 348         case USB_SPEED_SUPER_PLUS:
 349                 /*
 350                  * Not take default 5ms qlen for super speed HC to
 351                  * save memory, and iperf tests show 2.5ms qlen can
 352                  * work well
 353                  */
 354                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 355                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 356                 break;
 357         default:
 358                 dev->rx_qlen = dev->tx_qlen = 4;
 359         }
 360 }
 361 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 362
 363 \f
 364 /*-------------------------------------------------------------------------
 365  *
 366  * Network Device Driver (peer link to "Host Device", from USB host)
 367  *
 368  *-------------------------------------------------------------------------*/
 369
 370 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 371 {
 372         struct usbnet   *dev = netdev_priv(net);
 373         int             ll_mtu = new_mtu + net->hard_header_len;
 374         int             old_hard_mtu = dev->hard_mtu;
 375         int             old_rx_urb_size = dev->rx_urb_size;
 376
 377         // no second zero-length packet read wanted after mtu-sized packets
 378         if ((ll_mtu % dev->maxpacket) == 0)
 379                 return -EDOM;
 380         net->mtu = new_mtu;
 381
 382         dev->hard_mtu = net->mtu + net->hard_header_len;
 383         if (dev->rx_urb_size == old_hard_mtu) {
 384                 dev->rx_urb_size = dev->hard_mtu;
 385                 if (dev->rx_urb_size > old_rx_urb_size) {
 386                         usbnet_pause_rx(dev);
 387                         usbnet_unlink_rx_urbs(dev);
 388                         usbnet_resume_rx(dev);
 389                 }
 390         }
 391
 392         /* max qlen depend on hard_mtu and rx_urb_size */
 393         usbnet_update_max_qlen(dev);
 394
 395         return 0;
 396 }
 397 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 398
 399 /* The caller must hold list->lock */
 400 static void __usbnet_queue_skb(struct sk_buff_head *list,
 401                         struct sk_buff *newsk, enum skb_state state)
 402 {
 403         struct skb_data *entry = (struct skb_data *) newsk->cb;
 404
 405         __skb_queue_tail(list, newsk);
 406         entry->state = state;
 407 }
 408
 409 /*-------------------------------------------------------------------------*/
 410
 411 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 412  * completion callbacks.  2.5 should have fixed those bugs...
 413  */
 414
 415 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 416                 struct sk_buff_head *list, enum skb_state state)
 417 {
 418         unsigned long           flags;
 419         enum skb_state          old_state;
 420         struct skb_data *entry = (struct skb_data *) skb->cb;
 421
 422         spin_lock_irqsave(&list->lock, flags);
 423         old_state = entry->state;
 424         entry->state = state;
 425         __skb_unlink(skb, list);
 426
 427         /* defer_bh() is never called with list == &dev->done.
 428          * spin_lock_nested() tells lockdep that it is OK to take
 429          * dev->done.lock here with list->lock held.
 430          */
 431         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 432
 433         __skb_queue_tail(&dev->done, skb);
 434         if (dev->done.qlen == 1)
 435                 tasklet_schedule(&dev->bh);
 436         spin_unlock(&dev->done.lock);
 437         spin_unlock_irqrestore(&list->lock, flags);
 438         return old_state;
 439 }
 440
 441 /* some work can't be done in tasklets, so we use keventd
 442  *
 443  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 444  * but tasklet_schedule() doesn't.  hope the failure is rare.
 445  */
 446 void usbnet_defer_kevent (struct usbnet *dev, int work)
 447 {
 448         set_bit (work, &dev->flags);
 449         if (!schedule_work (&dev->kevent))
 450                 netdev_dbg(dev->net, "kevent %d may have been dropped\n", work);
 451         else
 452                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 453 }
 454 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 455
 456 /*-------------------------------------------------------------------------*/
 457
 458 static void rx_complete (struct urb *urb);
 459
 460 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 461 {
 462         struct sk_buff          *skb;
 463         struct skb_data         *entry;
 464         int                     retval = 0;
 465         unsigned long           lockflags;
 466         size_t                  size = dev->rx_urb_size;
 467
 468         /* prevent rx skb allocation when error ratio is high */
 469         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 470                 usb_free_urb(urb);
 471                 return -ENOLINK;
 472         }
 473
 474         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 475                 skb = __netdev_alloc_skb(dev->net, size, flags);
 476         else
 477                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 478         if (!skb) {
 479                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 480                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 481                 usb_free_urb (urb);
 482                 return -ENOMEM;
 483         }
 484
 485         entry = (struct skb_data *) skb->cb;
 486         entry->urb = urb;
 487         entry->dev = dev;
 488         entry->length = 0;
 489
 490         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 491                 skb->data, size, rx_complete, skb);
 492
 493         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 494
 495         if (netif_running (dev->net) &&
 496             netif_device_present (dev->net) &&
 497             test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 498             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 499             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 500                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 501                 case -EPIPE:
 502                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 503                         break;
 504                 case -ENOMEM:
 505                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 506                         break;
 507                 case -ENODEV:
 508                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 509                         netif_device_detach (dev->net);
 510                         break;
 511                 case -EHOSTUNREACH:
 512                         retval = -ENOLINK;
 513                         break;
 514                 default:
 515                         netif_dbg(dev, rx_err, dev->net,
 516                                   "rx submit, %d\n", retval);
 517                         tasklet_schedule (&dev->bh);
 518                         break;
 519                 case 0:
 520                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 521                 }
 522         } else {
 523                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 524                 retval = -ENOLINK;
 525         }
 526         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 527         if (retval) {
 528                 dev_kfree_skb_any (skb);
 529                 usb_free_urb (urb);
 530         }
 531         return retval;
 532 }
 533
 534
 535 /*-------------------------------------------------------------------------*/
 536
 537 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 538 {
 539         if (dev->driver_info->rx_fixup &&
 540             !dev->driver_info->rx_fixup (dev, skb)) {
 541                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 542                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 543                         dev->net->stats.rx_errors++;
 544                 goto done;
 545         }
 546         // else network stack removes extra byte if we forced a short packet
 547
 548         /* all data was already cloned from skb inside the driver */
 549         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 550                 goto done;
 551
 552         if (skb->len < ETH_HLEN) {
 553                 dev->net->stats.rx_errors++;
 554                 dev->net->stats.rx_length_errors++;
 555                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 556         } else {
 557                 usbnet_skb_return(dev, skb);
 558                 return;
 559         }
 560
 561 done:
 562         skb_queue_tail(&dev->done, skb);
 563 }
 564
 565 /*-------------------------------------------------------------------------*/
 566
 567 static void rx_complete (struct urb *urb)
 568 {
 569         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 570         struct skb_data         *entry = (struct skb_data *) skb->cb;
 571         struct usbnet           *dev = entry->dev;
 572         int                     urb_status = urb->status;
 573         enum skb_state          state;
 574
 575         skb_put (skb, urb->actual_length);
 576         state = rx_done;
 577         entry->urb = NULL;
 578
 579         switch (urb_status) {
 580         /* success */
 581         case 0:
 582                 break;
 583
 584         /* stalls need manual reset. this is rare ... except that
 585          * when going through USB 2.0 TTs, unplug appears this way.
 586          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 587          * storm, recovering as needed.
 588          */
 589         case -EPIPE:
 590                 dev->net->stats.rx_errors++;
 591                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 592                 // FALLTHROUGH
 593
 594         /* software-driven interface shutdown */
 595         case -ECONNRESET:               /* async unlink */
 596         case -ESHUTDOWN:                /* hardware gone */
 597                 netif_dbg(dev, ifdown, dev->net,
 598                           "rx shutdown, code %d\n", urb_status);
 599                 goto block;
 600
 601         /* we get controller i/o faults during hub_wq disconnect() delays.
 602          * throttle down resubmits, to avoid log floods; just temporarily,
 603          * so we still recover when the fault isn't a hub_wq delay.
 604          */
 605         case -EPROTO:
 606         case -ETIME:
 607         case -EILSEQ:
 608                 dev->net->stats.rx_errors++;
 609                 if (!timer_pending (&dev->delay)) {
 610                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 611                         netif_dbg(dev, link, dev->net,
 612                                   "rx throttle %d\n", urb_status);
 613                 }
 614 block:
 615                 state = rx_cleanup;
 616                 entry->urb = urb;
 617                 urb = NULL;
 618                 break;
 619
 620         /* data overrun ... flush fifo? */
 621         case -EOVERFLOW:
 622                 dev->net->stats.rx_over_errors++;
 623                 // FALLTHROUGH
 624
 625         default:
 626                 state = rx_cleanup;
 627                 dev->net->stats.rx_errors++;
 628                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 629                 break;
 630         }
 631
 632         /* stop rx if packet error rate is high */
 633         if (++dev->pkt_cnt > 30) {
 634                 dev->pkt_cnt = 0;
 635                 dev->pkt_err = 0;
 636         } else {
 637                 if (state == rx_cleanup)
 638                         dev->pkt_err++;
 639                 if (dev->pkt_err > 20)
 640                         set_bit(EVENT_RX_KILL, &dev->flags);
 641         }
 642
 643         state = defer_bh(dev, skb, &dev->rxq, state);
 644
 645         if (urb) {
 646                 if (netif_running (dev->net) &&
 647                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 648                     state != unlink_start) {
 649                         rx_submit (dev, urb, GFP_ATOMIC);
 650                         usb_mark_last_busy(dev->udev);
 651                         return;
 652                 }
 653                 usb_free_urb (urb);
 654         }
 655         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 656 }
 657
 658 /*-------------------------------------------------------------------------*/
 659 void usbnet_pause_rx(struct usbnet *dev)
 660 {
 661         set_bit(EVENT_RX_PAUSED, &dev->flags);
 662
 663         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 664 }
 665 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 666
 667 void usbnet_resume_rx(struct usbnet *dev)
 668 {
 669         struct sk_buff *skb;
 670         int num = 0;
 671
 672         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 673
 674         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 675                 usbnet_skb_return(dev, skb);
 676                 num++;
 677         }
 678
 679         tasklet_schedule(&dev->bh);
 680
 681         netif_dbg(dev, rx_status, dev->net,
 682                   "paused rx queue disabled, %d skbs requeued\n", num);
 683 }
 684 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 685
 686 void usbnet_purge_paused_rxq(struct usbnet *dev)
 687 {
 688         skb_queue_purge(&dev->rxq_pause);
 689 }
 690 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 691
 692 /*-------------------------------------------------------------------------*/
 693
 694 // unlink pending rx/tx; completion handlers do all other cleanup
 695
 696 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 697 {
 698         unsigned long           flags;
 699         struct sk_buff          *skb;
 700         int                     count = 0;
 701
 702         spin_lock_irqsave (&q->lock, flags);
 703         while (!skb_queue_empty(q)) {
 704                 struct skb_data         *entry;
 705                 struct urb              *urb;
 706                 int                     retval;
 707
 708                 skb_queue_walk(q, skb) {
 709                         entry = (struct skb_data *) skb->cb;
 710                         if (entry->state != unlink_start)
 711                                 goto found;
 712                 }
 713                 break;
 714 found:
 715                 entry->state = unlink_start;
 716                 urb = entry->urb;
 717
 718                 /*
 719                  * Get reference count of the URB to avoid it to be
 720                  * freed during usb_unlink_urb, which may trigger
 721                  * use-after-free problem inside usb_unlink_urb since
 722                  * usb_unlink_urb is always racing with .complete
 723                  * handler(include defer_bh).
 724                  */
 725                 usb_get_urb(urb);
 726                 spin_unlock_irqrestore(&q->lock, flags);
 727                 // during some PM-driven resume scenarios,
 728                 // these (async) unlinks complete immediately
 729                 retval = usb_unlink_urb (urb);
 730                 if (retval != -EINPROGRESS && retval != 0)
 731                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 732                 else
 733                         count++;
 734                 usb_put_urb(urb);
 735                 spin_lock_irqsave(&q->lock, flags);
 736         }
 737         spin_unlock_irqrestore (&q->lock, flags);
 738         return count;
 739 }
 740
 741 // Flush all pending rx urbs
 742 // minidrivers may need to do this when the MTU changes
 743
 744 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 745 {
 746         if (netif_running(dev->net)) {
 747                 (void) unlink_urbs (dev, &dev->rxq);
 748                 tasklet_schedule(&dev->bh);
 749         }
 750 }
 751 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 752
 753 /*-------------------------------------------------------------------------*/
 754
 755 static void wait_skb_queue_empty(struct sk_buff_head *q)
 756 {
 757         unsigned long flags;
 758
 759         spin_lock_irqsave(&q->lock, flags);
 760         while (!skb_queue_empty(q)) {
 761                 spin_unlock_irqrestore(&q->lock, flags);
 762                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 763                 set_current_state(TASK_UNINTERRUPTIBLE);
 764                 spin_lock_irqsave(&q->lock, flags);
 765         }
 766         spin_unlock_irqrestore(&q->lock, flags);
 767 }
 768
 769 // precondition: never called in_interrupt
 770 static void usbnet_terminate_urbs(struct usbnet *dev)
 771 {
 772         DECLARE_WAITQUEUE(wait, current);
 773         int temp;
 774
 775         /* ensure there are no more active urbs */
 776         add_wait_queue(&dev->wait, &wait);
 777         set_current_state(TASK_UNINTERRUPTIBLE);
 778         temp = unlink_urbs(dev, &dev->txq) +
 779                 unlink_urbs(dev, &dev->rxq);
 780
 781         /* maybe wait for deletions to finish. */
 782         wait_skb_queue_empty(&dev->rxq);
 783         wait_skb_queue_empty(&dev->txq);
 784         wait_skb_queue_empty(&dev->done);
 785         netif_dbg(dev, ifdown, dev->net,
 786                   "waited for %d urb completions\n", temp);
 787         set_current_state(TASK_RUNNING);
 788         remove_wait_queue(&dev->wait, &wait);
 789 }
 790
 791 int usbnet_stop (struct net_device *net)
 792 {
 793         struct usbnet           *dev = netdev_priv(net);
 794         const struct driver_info *info = dev->driver_info;
 795         int                     retval, pm, mpn;
 796
 797         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 798         netif_stop_queue (net);
 799
 800         netif_info(dev, ifdown, dev->net,
 801                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 802                    net->stats.rx_packets, net->stats.tx_packets,
 803                    net->stats.rx_errors, net->stats.tx_errors);
 804
 805         /* to not race resume */
 806         pm = usb_autopm_get_interface(dev->intf);
 807         /* allow minidriver to stop correctly (wireless devices to turn off
 808          * radio etc) */
 809         if (info->stop) {
 810                 retval = info->stop(dev);
 811                 if (retval < 0)
 812                         netif_info(dev, ifdown, dev->net,
 813                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 814                                    retval,
 815                                    dev->udev->bus->bus_name, dev->udev->devpath,
 816                                    info->description);
 817         }
 818
 819         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 820                 usbnet_terminate_urbs(dev);
 821
 822         usbnet_status_stop(dev);
 823
 824         usbnet_purge_paused_rxq(dev);
 825
 826         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 827
 828         /* deferred work (task, timer, softirq) must also stop.
 829          * can't flush_scheduled_work() until we drop rtnl (later),
 830          * else workers could deadlock; so make workers a NOP.
 831          */
 832         dev->flags = 0;
 833         del_timer_sync (&dev->delay);
 834         tasklet_kill (&dev->bh);
 835         if (!pm)
 836                 usb_autopm_put_interface(dev->intf);
 837
 838         if (info->manage_power && mpn)
 839                 info->manage_power(dev, 0);
 840         else
 841                 usb_autopm_put_interface(dev->intf);
 842
 843         return 0;
 844 }
 845 EXPORT_SYMBOL_GPL(usbnet_stop);
 846
 847 /*-------------------------------------------------------------------------*/
 848
 849 // posts reads, and enables write queuing
 850
 851 // precondition: never called in_interrupt
 852
 853 int usbnet_open (struct net_device *net)
 854 {
 855         struct usbnet           *dev = netdev_priv(net);
 856         int                     retval;
 857         const struct driver_info *info = dev->driver_info;
 858
 859         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 860                 netif_info(dev, ifup, dev->net,
 861                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 862                            retval,
 863                            dev->udev->bus->bus_name,
 864                            dev->udev->devpath,
 865                            info->description);
 866                 goto done_nopm;
 867         }
 868
 869         // put into "known safe" state
 870         if (info->reset && (retval = info->reset (dev)) < 0) {
 871                 netif_info(dev, ifup, dev->net,
 872                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 873                            retval,
 874                            dev->udev->bus->bus_name,
 875                            dev->udev->devpath,
 876                            info->description);
 877                 goto done;
 878         }
 879
 880         /* hard_mtu or rx_urb_size may change in reset() */
 881         usbnet_update_max_qlen(dev);
 882
 883         // insist peer be connected
 884         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 885                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 886                 goto done;
 887         }
 888
 889         /* start any status interrupt transfer */
 890         if (dev->interrupt) {
 891                 retval = usbnet_status_start(dev, GFP_KERNEL);
 892                 if (retval < 0) {
 893                         netif_err(dev, ifup, dev->net,
 894                                   "intr submit %d\n", retval);
 895                         goto done;
 896                 }
 897         }
 898
 899         set_bit(EVENT_DEV_OPEN, &dev->flags);
 900         netif_start_queue (net);
 901         netif_info(dev, ifup, dev->net,
 902                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 903                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 904                    dev->net->mtu,
 905                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 906                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 907                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 908                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 909                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 910                    "simple");
 911
 912         /* reset rx error state */
 913         dev->pkt_cnt = 0;
 914         dev->pkt_err = 0;
 915         clear_bit(EVENT_RX_KILL, &dev->flags);
 916
 917         // delay posting reads until we're fully open
 918         tasklet_schedule (&dev->bh);
 919         if (info->manage_power) {
 920                 retval = info->manage_power(dev, 1);
 921                 if (retval < 0) {
 922                         retval = 0;
 923                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 924                 } else {
 925                         usb_autopm_put_interface(dev->intf);
 926                 }
 927         }
 928         return retval;
 929 done:
 930         usb_autopm_put_interface(dev->intf);
 931 done_nopm:
 932         return retval;
 933 }
 934 EXPORT_SYMBOL_GPL(usbnet_open);
 935
 936 /*-------------------------------------------------------------------------*/
 937
 938 /* ethtool methods; minidrivers may need to add some more, but
 939  * they'll probably want to use this base set.
 940  */
 941
 942 int usbnet_get_link_ksettings(struct net_device *net,
 943                               struct ethtool_link_ksettings *cmd)
 944 {
 945         struct usbnet *dev = netdev_priv(net);
 946
 947         if (!dev->mii.mdio_read)
 948                 return -EOPNOTSUPP;
 949
 950         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 951
 952         return 0;
 953 }
 954 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
 955
 956 int usbnet_set_link_ksettings(struct net_device *net,
 957                               const struct ethtool_link_ksettings *cmd)
 958 {
 959         struct usbnet *dev = netdev_priv(net);
 960         int retval;
 961
 962         if (!dev->mii.mdio_write)
 963                 return -EOPNOTSUPP;
 964
 965         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
 966
 967         /* link speed/duplex might have changed */
 968         if (dev->driver_info->link_reset)
 969                 dev->driver_info->link_reset(dev);
 970
 971         /* hard_mtu or rx_urb_size may change in link_reset() */
 972         usbnet_update_max_qlen(dev);
 973
 974         return retval;
 975 }
 976 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
 977
 978 void usbnet_get_stats64(struct net_device *net, struct rtnl_link_stats64 *stats)
 979 {
 980         struct usbnet *dev = netdev_priv(net);
 981         unsigned int start;
 982         int cpu;
 983
 984         netdev_stats_to_stats64(stats, &net->stats);
 985
 986         for_each_possible_cpu(cpu) {
 987                 struct pcpu_sw_netstats *stats64;
 988                 u64 rx_packets, rx_bytes;
 989                 u64 tx_packets, tx_bytes;
 990
 991                 stats64 = per_cpu_ptr(dev->stats64, cpu);
 992
 993                 do {
 994                         start = u64_stats_fetch_begin_irq(&stats64->syncp);
 995                         rx_packets = stats64->rx_packets;
 996                         rx_bytes = stats64->rx_bytes;
 997                         tx_packets = stats64->tx_packets;
 998                         tx_bytes = stats64->tx_bytes;
 999                 } while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
1000
1001                 stats->rx_packets += rx_packets;
1002                 stats->rx_bytes += rx_bytes;
1003                 stats->tx_packets += tx_packets;
1004                 stats->tx_bytes += tx_bytes;
1005         }
1006 }
1007 EXPORT_SYMBOL_GPL(usbnet_get_stats64);
1008
1009 u32 usbnet_get_link (struct net_device *net)
1010 {
1011         struct usbnet *dev = netdev_priv(net);
1012
1013         /* If a check_connect is defined, return its result */
1014         if (dev->driver_info->check_connect)
1015                 return dev->driver_info->check_connect (dev) == 0;
1016
1017         /* if the device has mii operations, use those */
1018         if (dev->mii.mdio_read)
1019                 return mii_link_ok(&dev->mii);
1020
1021         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1022         return ethtool_op_get_link(net);
1023 }
1024 EXPORT_SYMBOL_GPL(usbnet_get_link);
1025
1026 int usbnet_nway_reset(struct net_device *net)
1027 {
1028         struct usbnet *dev = netdev_priv(net);
1029
1030         if (!dev->mii.mdio_write)
1031                 return -EOPNOTSUPP;
1032
1033         return mii_nway_restart(&dev->mii);
1034 }
1035 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1036
1037 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1038 {
1039         struct usbnet *dev = netdev_priv(net);
1040
1041         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1042         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1043         strlcpy (info->fw_version, dev->driver_info->description,
1044                 sizeof info->fw_version);
1045         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1046 }
1047 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1048
1049 u32 usbnet_get_msglevel (struct net_device *net)
1050 {
1051         struct usbnet *dev = netdev_priv(net);
1052
1053         return dev->msg_enable;
1054 }
1055 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1056
1057 void usbnet_set_msglevel (struct net_device *net, u32 level)
1058 {
1059         struct usbnet *dev = netdev_priv(net);
1060
1061         dev->msg_enable = level;
1062 }
1063 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1064
1065 /* drivers may override default ethtool_ops in their bind() routine */
1066 static const struct ethtool_ops usbnet_ethtool_ops = {
1067         .get_link               = usbnet_get_link,
1068         .nway_reset             = usbnet_nway_reset,
1069         .get_drvinfo            = usbnet_get_drvinfo,
1070         .get_msglevel           = usbnet_get_msglevel,
1071         .set_msglevel           = usbnet_set_msglevel,
1072         .get_ts_info            = ethtool_op_get_ts_info,
1073         .get_link_ksettings     = usbnet_get_link_ksettings,
1074         .set_link_ksettings     = usbnet_set_link_ksettings,
1075 };
1076
1077 /*-------------------------------------------------------------------------*/
1078
1079 static void __handle_link_change(struct usbnet *dev)
1080 {
1081         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1082                 return;
1083
1084         if (!netif_carrier_ok(dev->net)) {
1085                 /* kill URBs for reading packets to save bus bandwidth */
1086                 unlink_urbs(dev, &dev->rxq);
1087
1088                 /*
1089                  * tx_timeout will unlink URBs for sending packets and
1090                  * tx queue is stopped by netcore after link becomes off
1091                  */
1092         } else {
1093                 /* submitting URBs for reading packets */
1094                 tasklet_schedule(&dev->bh);
1095         }
1096
1097         /* hard_mtu or rx_urb_size may change during link change */
1098         usbnet_update_max_qlen(dev);
1099
1100         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1101 }
1102
1103 static void usbnet_set_rx_mode(struct net_device *net)
1104 {
1105         struct usbnet           *dev = netdev_priv(net);
1106
1107         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1108 }
1109
1110 static void __handle_set_rx_mode(struct usbnet *dev)
1111 {
1112         if (dev->driver_info->set_rx_mode)
1113                 (dev->driver_info->set_rx_mode)(dev);
1114
1115         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1116 }
1117
1118 /* work that cannot be done in interrupt context uses keventd.
1119  *
1120  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1121  * especially now that control transfers can be queued.
1122  */
1123 static void
1124 usbnet_deferred_kevent (struct work_struct *work)
1125 {
1126         struct usbnet           *dev =
1127                 container_of(work, struct usbnet, kevent);
1128         int                     status;
1129
1130         /* usb_clear_halt() needs a thread context */
1131         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1132                 unlink_urbs (dev, &dev->txq);
1133                 status = usb_autopm_get_interface(dev->intf);
1134                 if (status < 0)
1135                         goto fail_pipe;
1136                 status = usb_clear_halt (dev->udev, dev->out);
1137                 usb_autopm_put_interface(dev->intf);
1138                 if (status < 0 &&
1139                     status != -EPIPE &&
1140                     status != -ESHUTDOWN) {
1141                         if (netif_msg_tx_err (dev))
1142 fail_pipe:
1143                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1144                                            status);
1145                 } else {
1146                         clear_bit (EVENT_TX_HALT, &dev->flags);
1147                         if (status != -ESHUTDOWN)
1148                                 netif_wake_queue (dev->net);
1149                 }
1150         }
1151         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1152                 unlink_urbs (dev, &dev->rxq);
1153                 status = usb_autopm_get_interface(dev->intf);
1154                 if (status < 0)
1155                         goto fail_halt;
1156                 status = usb_clear_halt (dev->udev, dev->in);
1157                 usb_autopm_put_interface(dev->intf);
1158                 if (status < 0 &&
1159                     status != -EPIPE &&
1160                     status != -ESHUTDOWN) {
1161                         if (netif_msg_rx_err (dev))
1162 fail_halt:
1163                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1164                                            status);
1165                 } else {
1166                         clear_bit (EVENT_RX_HALT, &dev->flags);
1167                         tasklet_schedule (&dev->bh);
1168                 }
1169         }
1170
1171         /* tasklet could resubmit itself forever if memory is tight */
1172         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1173                 struct urb      *urb = NULL;
1174                 int resched = 1;
1175
1176                 if (netif_running (dev->net))
1177                         urb = usb_alloc_urb (0, GFP_KERNEL);
1178                 else
1179                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1180                 if (urb != NULL) {
1181                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1182                         status = usb_autopm_get_interface(dev->intf);
1183                         if (status < 0) {
1184                                 usb_free_urb(urb);
1185                                 goto fail_lowmem;
1186                         }
1187                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1188                                 resched = 0;
1189                         usb_autopm_put_interface(dev->intf);
1190 fail_lowmem:
1191                         if (resched)
1192                                 tasklet_schedule (&dev->bh);
1193                 }
1194         }
1195
1196         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1197                 const struct driver_info *info = dev->driver_info;
1198                 int                     retval = 0;
1199
1200                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1201                 status = usb_autopm_get_interface(dev->intf);
1202                 if (status < 0)
1203                         goto skip_reset;
1204                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1205                         usb_autopm_put_interface(dev->intf);
1206 skip_reset:
1207                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1208                                     retval,
1209                                     dev->udev->bus->bus_name,
1210                                     dev->udev->devpath,
1211                                     info->description);
1212                 } else {
1213                         usb_autopm_put_interface(dev->intf);
1214                 }
1215
1216                 /* handle link change from link resetting */
1217                 __handle_link_change(dev);
1218         }
1219
1220         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1221                 __handle_link_change(dev);
1222
1223         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1224                 __handle_set_rx_mode(dev);
1225
1226
1227         if (dev->flags)
1228                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1229 }
1230
1231 /*-------------------------------------------------------------------------*/
1232
1233 static void tx_complete (struct urb *urb)
1234 {
1235         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1236         struct skb_data         *entry = (struct skb_data *) skb->cb;
1237         struct usbnet           *dev = entry->dev;
1238
1239         if (urb->status == 0) {
1240                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1241                 unsigned long flags;
1242
1243                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1244                 stats64->tx_packets += entry->packets;
1245                 stats64->tx_bytes += entry->length;
1246                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1247         } else {
1248                 dev->net->stats.tx_errors++;
1249
1250                 switch (urb->status) {
1251                 case -EPIPE:
1252                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1253                         break;
1254
1255                 /* software-driven interface shutdown */
1256                 case -ECONNRESET:               // async unlink
1257                 case -ESHUTDOWN:                // hardware gone
1258                         break;
1259
1260                 /* like rx, tx gets controller i/o faults during hub_wq
1261                  * delays and so it uses the same throttling mechanism.
1262                  */
1263                 case -EPROTO:
1264                 case -ETIME:
1265                 case -EILSEQ:
1266                         usb_mark_last_busy(dev->udev);
1267                         if (!timer_pending (&dev->delay)) {
1268                                 mod_timer (&dev->delay,
1269                                         jiffies + THROTTLE_JIFFIES);
1270                                 netif_dbg(dev, link, dev->net,
1271                                           "tx throttle %d\n", urb->status);
1272                         }
1273                         netif_stop_queue (dev->net);
1274                         break;
1275                 default:
1276                         netif_dbg(dev, tx_err, dev->net,
1277                                   "tx err %d\n", entry->urb->status);
1278                         break;
1279                 }
1280         }
1281
1282         usb_autopm_put_interface_async(dev->intf);
1283         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1284 }
1285
1286 /*-------------------------------------------------------------------------*/
1287
1288 void usbnet_tx_timeout (struct net_device *net)
1289 {
1290         struct usbnet           *dev = netdev_priv(net);
1291
1292         unlink_urbs (dev, &dev->txq);
1293         tasklet_schedule (&dev->bh);
1294         /* this needs to be handled individually because the generic layer
1295          * doesn't know what is sufficient and could not restore private
1296          * information if a remedy of an unconditional reset were used.
1297          */
1298         if (dev->driver_info->recover)
1299                 (dev->driver_info->recover)(dev);
1300 }
1301 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1302
1303 /*-------------------------------------------------------------------------*/
1304
1305 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1306 {
1307         unsigned num_sgs, total_len = 0;
1308         int i, s = 0;
1309
1310         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1311         if (num_sgs == 1)
1312                 return 0;
1313
1314         /* reserve one for zero packet */
1315         urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1316                                 GFP_ATOMIC);
1317         if (!urb->sg)
1318                 return -ENOMEM;
1319
1320         urb->num_sgs = num_sgs;
1321         sg_init_table(urb->sg, urb->num_sgs + 1);
1322
1323         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1324         total_len += skb_headlen(skb);
1325
1326         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1327                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1328
1329                 total_len += skb_frag_size(f);
1330                 sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1331                             skb_frag_off(f));
1332         }
1333         urb->transfer_buffer_length = total_len;
1334
1335         return 1;
1336 }
1337
1338 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1339                                      struct net_device *net)
1340 {
1341         struct usbnet           *dev = netdev_priv(net);
1342         unsigned int                    length;
1343         struct urb              *urb = NULL;
1344         struct skb_data         *entry;
1345         const struct driver_info *info = dev->driver_info;
1346         unsigned long           flags;
1347         int retval;
1348
1349         if (skb)
1350                 skb_tx_timestamp(skb);
1351
1352         // some devices want funky USB-level framing, for
1353         // win32 driver (usually) and/or hardware quirks
1354         if (info->tx_fixup) {
1355                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1356                 if (!skb) {
1357                         /* packet collected; minidriver waiting for more */
1358                         if (info->flags & FLAG_MULTI_PACKET)
1359                                 goto not_drop;
1360                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1361                         goto drop;
1362                 }
1363         }
1364
1365         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1366                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1367                 goto drop;
1368         }
1369
1370         entry = (struct skb_data *) skb->cb;
1371         entry->urb = urb;
1372         entry->dev = dev;
1373
1374         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1375                         skb->data, skb->len, tx_complete, skb);
1376         if (dev->can_dma_sg) {
1377                 if (build_dma_sg(skb, urb) < 0)
1378                         goto drop;
1379         }
1380         length = urb->transfer_buffer_length;
1381
1382         /* don't assume the hardware handles USB_ZERO_PACKET
1383          * NOTE:  strictly conforming cdc-ether devices should expect
1384          * the ZLP here, but ignore the one-byte packet.
1385          * NOTE2: CDC NCM specification is different from CDC ECM when
1386          * handling ZLP/short packets, so cdc_ncm driver will make short
1387          * packet itself if needed.
1388          */
1389         if (length % dev->maxpacket == 0) {
1390                 if (!(info->flags & FLAG_SEND_ZLP)) {
1391                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1392                                 length++;
1393                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1394                                         skb->data[skb->len] = 0;
1395                                         __skb_put(skb, 1);
1396                                 } else if (urb->num_sgs)
1397                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1398                                                         dev->padding_pkt, 1);
1399                         }
1400                 } else
1401                         urb->transfer_flags |= URB_ZERO_PACKET;
1402         }
1403         urb->transfer_buffer_length = length;
1404
1405         if (info->flags & FLAG_MULTI_PACKET) {
1406                 /* Driver has set number of packets and a length delta.
1407                  * Calculate the complete length and ensure that it's
1408                  * positive.
1409                  */
1410                 entry->length += length;
1411                 if (WARN_ON_ONCE(entry->length <= 0))
1412                         entry->length = length;
1413         } else {
1414                 usbnet_set_skb_tx_stats(skb, 1, length);
1415         }
1416
1417         spin_lock_irqsave(&dev->txq.lock, flags);
1418         retval = usb_autopm_get_interface_async(dev->intf);
1419         if (retval < 0) {
1420                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1421                 goto drop;
1422         }
1423         if (netif_queue_stopped(net)) {
1424                 usb_autopm_put_interface_async(dev->intf);
1425                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1426                 goto drop;
1427         }
1428
1429 #ifdef CONFIG_PM
1430         /* if this triggers the device is still a sleep */
1431         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1432                 /* transmission will be done in resume */
1433                 usb_anchor_urb(urb, &dev->deferred);
1434                 /* no use to process more packets */
1435                 netif_stop_queue(net);
1436                 usb_put_urb(urb);
1437                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1438                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1439                 goto deferred;
1440         }
1441 #endif
1442
1443         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1444         case -EPIPE:
1445                 netif_stop_queue (net);
1446                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1447                 usb_autopm_put_interface_async(dev->intf);
1448                 break;
1449         default:
1450                 usb_autopm_put_interface_async(dev->intf);
1451                 netif_dbg(dev, tx_err, dev->net,
1452                           "tx: submit urb err %d\n", retval);
1453                 break;
1454         case 0:
1455                 netif_trans_update(net);
1456                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1457                 if (dev->txq.qlen >= TX_QLEN (dev))
1458                         netif_stop_queue (net);
1459         }
1460         spin_unlock_irqrestore (&dev->txq.lock, flags);
1461
1462         if (retval) {
1463                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1464 drop:
1465                 dev->net->stats.tx_dropped++;
1466 not_drop:
1467                 if (skb)
1468                         dev_kfree_skb_any (skb);
1469                 if (urb) {
1470                         kfree(urb->sg);
1471                         usb_free_urb(urb);
1472                 }
1473         } else
1474                 netif_dbg(dev, tx_queued, dev->net,
1475                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1476 #ifdef CONFIG_PM
1477 deferred:
1478 #endif
1479         return NETDEV_TX_OK;
1480 }
1481 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1482
1483 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1484 {
1485         struct urb      *urb;
1486         int             i;
1487         int             ret = 0;
1488
1489         /* don't refill the queue all at once */
1490         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1491                 urb = usb_alloc_urb(0, flags);
1492                 if (urb != NULL) {
1493                         ret = rx_submit(dev, urb, flags);
1494                         if (ret)
1495                                 goto err;
1496                 } else {
1497                         ret = -ENOMEM;
1498                         goto err;
1499                 }
1500         }
1501 err:
1502         return ret;
1503 }
1504
1505 /*-------------------------------------------------------------------------*/
1506
1507 // tasklet (work deferred from completions, in_irq) or timer
1508
1509 static void usbnet_bh (struct timer_list *t)
1510 {
1511         struct usbnet           *dev = from_timer(dev, t, delay);
1512         struct sk_buff          *skb;
1513         struct skb_data         *entry;
1514
1515         while ((skb = skb_dequeue (&dev->done))) {
1516                 entry = (struct skb_data *) skb->cb;
1517                 switch (entry->state) {
1518                 case rx_done:
1519                         entry->state = rx_cleanup;
1520                         rx_process (dev, skb);
1521                         continue;
1522                 case tx_done:
1523                         kfree(entry->urb->sg);
1524                         /* fall through */
1525                 case rx_cleanup:
1526                         usb_free_urb (entry->urb);
1527                         dev_kfree_skb (skb);
1528                         continue;
1529                 default:
1530                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1531                 }
1532         }
1533
1534         /* restart RX again after disabling due to high error rate */
1535         clear_bit(EVENT_RX_KILL, &dev->flags);
1536
1537         /* waiting for all pending urbs to complete?
1538          * only then can we forgo submitting anew
1539          */
1540         if (waitqueue_active(&dev->wait)) {
1541                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1542                         wake_up_all(&dev->wait);
1543
1544         // or are we maybe short a few urbs?
1545         } else if (netif_running (dev->net) &&
1546                    netif_device_present (dev->net) &&
1547                    netif_carrier_ok(dev->net) &&
1548                    !timer_pending(&dev->delay) &&
1549                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1550                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1551                 int     temp = dev->rxq.qlen;
1552
1553                 if (temp < RX_QLEN(dev)) {
1554                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1555                                 return;
1556                         if (temp != dev->rxq.qlen)
1557                                 netif_dbg(dev, link, dev->net,
1558                                           "rxqlen %d --> %d\n",
1559                                           temp, dev->rxq.qlen);
1560                         if (dev->rxq.qlen < RX_QLEN(dev))
1561                                 tasklet_schedule (&dev->bh);
1562                 }
1563                 if (dev->txq.qlen < TX_QLEN (dev))
1564                         netif_wake_queue (dev->net);
1565         }
1566 }
1567
1568
1569 /*-------------------------------------------------------------------------
1570  *
1571  * USB Device Driver support
1572  *
1573  *-------------------------------------------------------------------------*/
1574
1575 // precondition: never called in_interrupt
1576
1577 void usbnet_disconnect (struct usb_interface *intf)
1578 {
1579         struct usbnet           *dev;
1580         struct usb_device       *xdev;
1581         struct net_device       *net;
1582
1583         dev = usb_get_intfdata(intf);
1584         usb_set_intfdata(intf, NULL);
1585         if (!dev)
1586                 return;
1587
1588         xdev = interface_to_usbdev (intf);
1589
1590         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1591                    intf->dev.driver->name,
1592                    xdev->bus->bus_name, xdev->devpath,
1593                    dev->driver_info->description);
1594
1595         net = dev->net;
1596         unregister_netdev (net);
1597
1598         cancel_work_sync(&dev->kevent);
1599
1600         usb_scuttle_anchored_urbs(&dev->deferred);
1601
1602         if (dev->driver_info->unbind)
1603                 dev->driver_info->unbind (dev, intf);
1604
1605         usb_kill_urb(dev->interrupt);
1606         usb_free_urb(dev->interrupt);
1607         kfree(dev->padding_pkt);
1608
1609         free_percpu(dev->stats64);
1610         free_netdev(net);
1611 }
1612 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1613
1614 static const struct net_device_ops usbnet_netdev_ops = {
1615         .ndo_open               = usbnet_open,
1616         .ndo_stop               = usbnet_stop,
1617         .ndo_start_xmit         = usbnet_start_xmit,
1618         .ndo_tx_timeout         = usbnet_tx_timeout,
1619         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1620         .ndo_change_mtu         = usbnet_change_mtu,
1621         .ndo_get_stats64        = usbnet_get_stats64,
1622         .ndo_set_mac_address    = eth_mac_addr,
1623         .ndo_validate_addr      = eth_validate_addr,
1624 };
1625
1626 /*-------------------------------------------------------------------------*/
1627
1628 // precondition: never called in_interrupt
1629
1630 static struct device_type wlan_type = {
1631         .name   = "wlan",
1632 };
1633
1634 static struct device_type wwan_type = {
1635         .name   = "wwan",
1636 };
1637
1638 int
1639 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1640 {
1641         struct usbnet                   *dev;
1642         struct net_device               *net;
1643         struct usb_host_interface       *interface;
1644         const struct driver_info        *info;
1645         struct usb_device               *xdev;
1646         int                             status;
1647         const char                      *name;
1648         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1649
1650         /* usbnet already took usb runtime pm, so have to enable the feature
1651          * for usb interface, otherwise usb_autopm_get_interface may return
1652          * failure if RUNTIME_PM is enabled.
1653          */
1654         if (!driver->supports_autosuspend) {
1655                 driver->supports_autosuspend = 1;
1656                 pm_runtime_enable(&udev->dev);
1657         }
1658
1659         name = udev->dev.driver->name;
1660         info = (const struct driver_info *) prod->driver_info;
1661         if (!info) {
1662                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1663                 return -ENODEV;
1664         }
1665         xdev = interface_to_usbdev (udev);
1666         interface = udev->cur_altsetting;
1667
1668         status = -ENOMEM;
1669
1670         // set up our own records
1671         net = alloc_etherdev(sizeof(*dev));
1672         if (!net)
1673                 goto out;
1674
1675         /* netdev_printk() needs this so do it as early as possible */
1676         SET_NETDEV_DEV(net, &udev->dev);
1677
1678         dev = netdev_priv(net);
1679         dev->udev = xdev;
1680         dev->intf = udev;
1681         dev->driver_info = info;
1682         dev->driver_name = name;
1683
1684         dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1685         if (!dev->stats64)
1686                 goto out0;
1687
1688         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1689                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1690         init_waitqueue_head(&dev->wait);
1691         skb_queue_head_init (&dev->rxq);
1692         skb_queue_head_init (&dev->txq);
1693         skb_queue_head_init (&dev->done);
1694         skb_queue_head_init(&dev->rxq_pause);
1695         dev->bh.func = (void (*)(unsigned long))usbnet_bh;
1696         dev->bh.data = (unsigned long)&dev->delay;
1697         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1698         init_usb_anchor(&dev->deferred);
1699         timer_setup(&dev->delay, usbnet_bh, 0);
1700         mutex_init (&dev->phy_mutex);
1701         mutex_init(&dev->interrupt_mutex);
1702         dev->interrupt_count = 0;
1703
1704         dev->net = net;
1705         strcpy (net->name, "usb%d");
1706         memcpy (net->dev_addr, node_id, sizeof node_id);
1707
1708         /* rx and tx sides can use different message sizes;
1709          * bind() should set rx_urb_size in that case.
1710          */
1711         dev->hard_mtu = net->mtu + net->hard_header_len;
1712         net->min_mtu = 0;
1713         net->max_mtu = ETH_MAX_MTU;
1714
1715         net->netdev_ops = &usbnet_netdev_ops;
1716         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1717         net->ethtool_ops = &usbnet_ethtool_ops;
1718
1719         // allow device-specific bind/init procedures
1720         // NOTE net->name still not usable ...
1721         if (info->bind) {
1722                 status = info->bind (dev, udev);
1723                 if (status < 0)
1724                         goto out1;
1725
1726                 // heuristic:  "usb%d" for links we know are two-host,
1727                 // else "eth%d" when there's reasonable doubt.  userspace
1728                 // can rename the link if it knows better.
1729                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1730                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1731                      (net->dev_addr [0] & 0x02) == 0))
1732                         strcpy (net->name, "eth%d");
1733                 /* WLAN devices should always be named "wlan%d" */
1734                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1735                         strcpy(net->name, "wlan%d");
1736                 /* WWAN devices should always be named "wwan%d" */
1737                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1738                         strcpy(net->name, "wwan%d");
1739
1740                 /* devices that cannot do ARP */
1741                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1742                         net->flags |= IFF_NOARP;
1743
1744                 /* maybe the remote can't receive an Ethernet MTU */
1745                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1746                         net->mtu = dev->hard_mtu - net->hard_header_len;
1747         } else if (!info->in || !info->out)
1748                 status = usbnet_get_endpoints (dev, udev);
1749         else {
1750                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1751                 dev->out = usb_sndbulkpipe (xdev, info->out);
1752                 if (!(info->flags & FLAG_NO_SETINT))
1753                         status = usb_set_interface (xdev,
1754                                 interface->desc.bInterfaceNumber,
1755                                 interface->desc.bAlternateSetting);
1756                 else
1757                         status = 0;
1758
1759         }
1760         if (status >= 0 && dev->status)
1761                 status = init_status (dev, udev);
1762         if (status < 0)
1763                 goto out3;
1764
1765         if (!dev->rx_urb_size)
1766                 dev->rx_urb_size = dev->hard_mtu;
1767         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1768
1769         /* let userspace know we have a random address */
1770         if (ether_addr_equal(net->dev_addr, node_id))
1771                 net->addr_assign_type = NET_ADDR_RANDOM;
1772
1773         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1774                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1775         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1776                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1777
1778         /* initialize max rx_qlen and tx_qlen */
1779         usbnet_update_max_qlen(dev);
1780
1781         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1782                 !(info->flags & FLAG_MULTI_PACKET)) {
1783                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1784                 if (!dev->padding_pkt) {
1785                         status = -ENOMEM;
1786                         goto out4;
1787                 }
1788         }
1789
1790         status = register_netdev (net);
1791         if (status)
1792                 goto out5;
1793         netif_info(dev, probe, dev->net,
1794                    "register '%s' at usb-%s-%s, %s, %pM\n",
1795                    udev->dev.driver->name,
1796                    xdev->bus->bus_name, xdev->devpath,
1797                    dev->driver_info->description,
1798                    net->dev_addr);
1799
1800         // ok, it's ready to go.
1801         usb_set_intfdata (udev, dev);
1802
1803         netif_device_attach (net);
1804
1805         if (dev->driver_info->flags & FLAG_LINK_INTR)
1806                 usbnet_link_change(dev, 0, 0);
1807
1808         return 0;
1809
1810 out5:
1811         kfree(dev->padding_pkt);
1812 out4:
1813         usb_free_urb(dev->interrupt);
1814 out3:
1815         if (info->unbind)
1816                 info->unbind (dev, udev);
1817 out1:
1818         /* subdrivers must undo all they did in bind() if they
1819          * fail it, but we may fail later and a deferred kevent
1820          * may trigger an error resubmitting itself and, worse,
1821          * schedule a timer. So we kill it all just in case.
1822          */
1823         cancel_work_sync(&dev->kevent);
1824         del_timer_sync(&dev->delay);
1825         free_percpu(dev->stats64);
1826 out0:
1827         free_netdev(net);
1828 out:
1829         return status;
1830 }
1831 EXPORT_SYMBOL_GPL(usbnet_probe);
1832
1833 /*-------------------------------------------------------------------------*/
1834
1835 /*
1836  * suspend the whole driver as soon as the first interface is suspended
1837  * resume only when the last interface is resumed
1838  */
1839
1840 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1841 {
1842         struct usbnet           *dev = usb_get_intfdata(intf);
1843
1844         if (!dev->suspend_count++) {
1845                 spin_lock_irq(&dev->txq.lock);
1846                 /* don't autosuspend while transmitting */
1847                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1848                         dev->suspend_count--;
1849                         spin_unlock_irq(&dev->txq.lock);
1850                         return -EBUSY;
1851                 } else {
1852                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1853                         spin_unlock_irq(&dev->txq.lock);
1854                 }
1855                 /*
1856                  * accelerate emptying of the rx and queues, to avoid
1857                  * having everything error out.
1858                  */
1859                 netif_device_detach (dev->net);
1860                 usbnet_terminate_urbs(dev);
1861                 __usbnet_status_stop_force(dev);
1862
1863                 /*
1864                  * reattach so runtime management can use and
1865                  * wake the device
1866                  */
1867                 netif_device_attach (dev->net);
1868         }
1869         return 0;
1870 }
1871 EXPORT_SYMBOL_GPL(usbnet_suspend);
1872
1873 int usbnet_resume (struct usb_interface *intf)
1874 {
1875         struct usbnet           *dev = usb_get_intfdata(intf);
1876         struct sk_buff          *skb;
1877         struct urb              *res;
1878         int                     retval;
1879
1880         if (!--dev->suspend_count) {
1881                 /* resume interrupt URB if it was previously submitted */
1882                 __usbnet_status_start_force(dev, GFP_NOIO);
1883
1884                 spin_lock_irq(&dev->txq.lock);
1885                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1886
1887                         skb = (struct sk_buff *)res->context;
1888                         retval = usb_submit_urb(res, GFP_ATOMIC);
1889                         if (retval < 0) {
1890                                 dev_kfree_skb_any(skb);
1891                                 kfree(res->sg);
1892                                 usb_free_urb(res);
1893                                 usb_autopm_put_interface_async(dev->intf);
1894                         } else {
1895                                 netif_trans_update(dev->net);
1896                                 __skb_queue_tail(&dev->txq, skb);
1897                         }
1898                 }
1899
1900                 smp_mb();
1901                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1902                 spin_unlock_irq(&dev->txq.lock);
1903
1904                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1905                         /* handle remote wakeup ASAP
1906                          * we cannot race against stop
1907                          */
1908                         if (netif_device_present(dev->net) &&
1909                                 !timer_pending(&dev->delay) &&
1910                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1911                                         rx_alloc_submit(dev, GFP_NOIO);
1912
1913                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1914                                 netif_tx_wake_all_queues(dev->net);
1915                         tasklet_schedule (&dev->bh);
1916                 }
1917         }
1918
1919         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1920                 usb_autopm_get_interface_no_resume(intf);
1921
1922         return 0;
1923 }
1924 EXPORT_SYMBOL_GPL(usbnet_resume);
1925
1926 /*
1927  * Either a subdriver implements manage_power, then it is assumed to always
1928  * be ready to be suspended or it reports the readiness to be suspended
1929  * explicitly
1930  */
1931 void usbnet_device_suggests_idle(struct usbnet *dev)
1932 {
1933         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1934                 dev->intf->needs_remote_wakeup = 1;
1935                 usb_autopm_put_interface_async(dev->intf);
1936         }
1937 }
1938 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1939
1940 /*
1941  * For devices that can do without special commands
1942  */
1943 int usbnet_manage_power(struct usbnet *dev, int on)
1944 {
1945         dev->intf->needs_remote_wakeup = on;
1946         return 0;
1947 }
1948 EXPORT_SYMBOL(usbnet_manage_power);
1949
1950 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1951 {
1952         /* update link after link is reseted */
1953         if (link && !need_reset)
1954                 netif_carrier_on(dev->net);
1955         else
1956                 netif_carrier_off(dev->net);
1957
1958         if (need_reset && link)
1959                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1960         else
1961                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1962 }
1963 EXPORT_SYMBOL(usbnet_link_change);
1964
1965 /*-------------------------------------------------------------------------*/
1966 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1967                              u16 value, u16 index, void *data, u16 size)
1968 {
1969         void *buf = NULL;
1970         int err = -ENOMEM;
1971
1972         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1973                    " value=0x%04x index=0x%04x size=%d\n",
1974                    cmd, reqtype, value, index, size);
1975
1976         if (size) {
1977                 buf = kmalloc(size, GFP_KERNEL);
1978                 if (!buf)
1979                         goto out;
1980         }
1981
1982         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1983                               cmd, reqtype, value, index, buf, size,
1984                               USB_CTRL_GET_TIMEOUT);
1985         if (err > 0 && err <= size) {
1986         if (data)
1987             memcpy(data, buf, err);
1988         else
1989             netdev_dbg(dev->net,
1990                 "Huh? Data requested but thrown away.\n");
1991     }
1992         kfree(buf);
1993 out:
1994         return err;
1995 }
1996
1997 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1998                               u16 value, u16 index, const void *data,
1999                               u16 size)
2000 {
2001         void *buf = NULL;
2002         int err = -ENOMEM;
2003
2004         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2005                    " value=0x%04x index=0x%04x size=%d\n",
2006                    cmd, reqtype, value, index, size);
2007
2008         if (data) {
2009                 buf = kmemdup(data, size, GFP_KERNEL);
2010                 if (!buf)
2011                         goto out;
2012         } else {
2013         if (size) {
2014             WARN_ON_ONCE(1);
2015             err = -EINVAL;
2016             goto out;
2017         }
2018     }
2019
2020         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2021                               cmd, reqtype, value, index, buf, size,
2022                               USB_CTRL_SET_TIMEOUT);
2023         kfree(buf);
2024
2025 out:
2026         return err;
2027 }
2028
2029 /*
2030  * The function can't be called inside suspend/resume callback,
2031  * otherwise deadlock will be caused.
2032  */
2033 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2034                     u16 value, u16 index, void *data, u16 size)
2035 {
2036         int ret;
2037
2038         if (usb_autopm_get_interface(dev->intf) < 0)
2039                 return -ENODEV;
2040         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2041                                 data, size);
2042         usb_autopm_put_interface(dev->intf);
2043         return ret;
2044 }
2045 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2046
2047 /*
2048  * The function can't be called inside suspend/resume callback,
2049  * otherwise deadlock will be caused.
2050  */
2051 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2052                      u16 value, u16 index, const void *data, u16 size)
2053 {
2054         int ret;
2055
2056         if (usb_autopm_get_interface(dev->intf) < 0)
2057                 return -ENODEV;
2058         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2059                                  data, size);
2060         usb_autopm_put_interface(dev->intf);
2061         return ret;
2062 }
2063 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2064
2065 /*
2066  * The function can be called inside suspend/resume callback safely
2067  * and should only be called by suspend/resume callback generally.
2068  */
2069 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2070                           u16 value, u16 index, void *data, u16 size)
2071 {
2072         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2073                                  data, size);
2074 }
2075 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2076
2077 /*
2078  * The function can be called inside suspend/resume callback safely
2079  * and should only be called by suspend/resume callback generally.
2080  */
2081 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2082                           u16 value, u16 index, const void *data,
2083                           u16 size)
2084 {
2085         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2086                                   data, size);
2087 }
2088 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2089
2090 static void usbnet_async_cmd_cb(struct urb *urb)
2091 {
2092         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2093         int status = urb->status;
2094
2095         if (status < 0)
2096                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2097                         __func__, status);
2098
2099         kfree(req);
2100         usb_free_urb(urb);
2101 }
2102
2103 /*
2104  * The caller must make sure that device can't be put into suspend
2105  * state until the control URB completes.
2106  */
2107 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2108                            u16 value, u16 index, const void *data, u16 size)
2109 {
2110         struct usb_ctrlrequest *req = NULL;
2111         struct urb *urb;
2112         int err = -ENOMEM;
2113         void *buf = NULL;
2114
2115         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2116                    " value=0x%04x index=0x%04x size=%d\n",
2117                    cmd, reqtype, value, index, size);
2118
2119         urb = usb_alloc_urb(0, GFP_ATOMIC);
2120         if (!urb)
2121                 goto fail;
2122
2123         if (data) {
2124                 buf = kmemdup(data, size, GFP_ATOMIC);
2125                 if (!buf) {
2126                         netdev_err(dev->net, "Error allocating buffer"
2127                                    " in %s!\n", __func__);
2128                         goto fail_free;
2129                 }
2130         }
2131
2132         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2133         if (!req)
2134                 goto fail_free_buf;
2135
2136         req->bRequestType = reqtype;
2137         req->bRequest = cmd;
2138         req->wValue = cpu_to_le16(value);
2139         req->wIndex = cpu_to_le16(index);
2140         req->wLength = cpu_to_le16(size);
2141
2142         usb_fill_control_urb(urb, dev->udev,
2143                              usb_sndctrlpipe(dev->udev, 0),
2144                              (void *)req, buf, size,
2145                              usbnet_async_cmd_cb, req);
2146         urb->transfer_flags |= URB_FREE_BUFFER;
2147
2148         err = usb_submit_urb(urb, GFP_ATOMIC);
2149         if (err < 0) {
2150                 netdev_err(dev->net, "Error submitting the control"
2151                            " message: status=%d\n", err);
2152                 goto fail_free;
2153         }
2154         return 0;
2155
2156 fail_free_buf:
2157         kfree(buf);
2158 fail_free:
2159         kfree(req);
2160         usb_free_urb(urb);
2161 fail:
2162         return err;
2163
2164 }
2165 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2166 /*-------------------------------------------------------------------------*/
2167
2168 static int __init usbnet_init(void)
2169 {
2170         /* Compiler should optimize this out. */
2171         BUILD_BUG_ON(
2172                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2173
2174         eth_random_addr(node_id);
2175         return 0;
2176 }
2177 module_init(usbnet_init);
2178
2179 static void __exit usbnet_exit(void)
2180 {
2181 }
2182 module_exit(usbnet_exit);
2183
2184 MODULE_AUTHOR("David Brownell");
2185 MODULE_DESCRIPTION("USB network driver framework");
2186 MODULE_LICENSE("GPL");