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, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /*
  22  * This is a generic "USB networking" framework that works with several
  23  * kinds of full and high speed networking devices:  host-to-host cables,
  24  * smart usb peripherals, and actual Ethernet adapters.
  25  *
  26  * These devices usually differ in terms of control protocols (if they
  27  * even have one!) and sometimes they define new framing to wrap or batch
  28  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  29  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  30  * issues can usefully be addressed by this framework.
  31  */
  32
  33 // #define      DEBUG                   // error path messages, extra info
  34 // #define      VERBOSE                 // more; success messages
  35
  36 #include <linux/module.h>
  37 #include <linux/init.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/etherdevice.h>
  40 #include <linux/ctype.h>
  41 #include <linux/ethtool.h>
  42 #include <linux/workqueue.h>
  43 #include <linux/mii.h>
  44 #include <linux/usb.h>
  45 #include <linux/usb/usbnet.h>
  46 #include <linux/slab.h>
  47 #include <linux/kernel.h>
  48 #include <linux/pm_runtime.h>
  49
  50 #define DRIVER_VERSION          "22-Aug-2005"
  51
  52
  53 /*-------------------------------------------------------------------------*/
  54
  55 /*
  56  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  57  * Several dozen bytes of IPv4 data can fit in two such transactions.
  58  * One maximum size Ethernet packet takes twenty four of them.
  59  * For high speed, each frame comfortably fits almost 36 max size
  60  * Ethernet packets (so queues should be bigger).
  61  *
  62  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
  63  * let the USB host controller be busy for 5msec or more before an irq
  64  * is required, under load.  Jumbograms change the equation.
  65  */
  66 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
  67 #define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  68                         (RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
  69 #define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  70                         (RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
  71
  72 // reawaken network queue this soon after stopping; else watchdog barks
  73 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  74
  75 // throttle rx/tx briefly after some faults, so khubd might disconnect()
  76 // us (it polls at HZ/4 usually) before we report too many false errors.
  77 #define THROTTLE_JIFFIES        (HZ/8)
  78
  79 // between wakeups
  80 #define UNLINK_TIMEOUT_MS       3
  81
  82 /*-------------------------------------------------------------------------*/
  83
  84 // randomly generated ethernet address
  85 static u8       node_id [ETH_ALEN];
  86
  87 static const char driver_name [] = "usbnet";
  88
  89 /* use ethtool to change the level for any given device */
  90 static int msg_level = -1;
  91 module_param (msg_level, int, 0);
  92 MODULE_PARM_DESC (msg_level, "Override default message level");
  93
  94 /*-------------------------------------------------------------------------*/
  95
  96 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  97 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  98 {
  99         int                             tmp;
 100         struct usb_host_interface       *alt = NULL;
 101         struct usb_host_endpoint        *in = NULL, *out = NULL;
 102         struct usb_host_endpoint        *status = NULL;
 103
 104         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 105                 unsigned        ep;
 106
 107                 in = out = status = NULL;
 108                 alt = intf->altsetting + tmp;
 109
 110                 /* take the first altsetting with in-bulk + out-bulk;
 111                  * remember any status endpoint, just in case;
 112                  * ignore other endpoints and altsettings.
 113                  */
 114                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 115                         struct usb_host_endpoint        *e;
 116                         int                             intr = 0;
 117
 118                         e = alt->endpoint + ep;
 119                         switch (e->desc.bmAttributes) {
 120                         case USB_ENDPOINT_XFER_INT:
 121                                 if (!usb_endpoint_dir_in(&e->desc))
 122                                         continue;
 123                                 intr = 1;
 124                                 /* FALLTHROUGH */
 125                         case USB_ENDPOINT_XFER_BULK:
 126                                 break;
 127                         default:
 128                                 continue;
 129                         }
 130                         if (usb_endpoint_dir_in(&e->desc)) {
 131                                 if (!intr && !in)
 132                                         in = e;
 133                                 else if (intr && !status)
 134                                         status = e;
 135                         } else {
 136                                 if (!out)
 137                                         out = e;
 138                         }
 139                 }
 140                 if (in && out)
 141                         break;
 142         }
 143         if (!alt || !in || !out)
 144                 return -EINVAL;
 145
 146         if (alt->desc.bAlternateSetting != 0 ||
 147             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 148                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 149                                 alt->desc.bAlternateSetting);
 150                 if (tmp < 0)
 151                         return tmp;
 152         }
 153
 154         dev->in = usb_rcvbulkpipe (dev->udev,
 155                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156         dev->out = usb_sndbulkpipe (dev->udev,
 157                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 158         dev->status = status;
 159         return 0;
 160 }
 161 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 162
 163 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 164 {
 165         int             tmp, i;
 166         unsigned char   buf [13];
 167
 168         tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 169         if (tmp != 12) {
 170                 dev_dbg(&dev->udev->dev,
 171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172                 if (tmp >= 0)
 173                         tmp = -EINVAL;
 174                 return tmp;
 175         }
 176         for (i = tmp = 0; i < 6; i++, tmp += 2)
 177                 dev->net->dev_addr [i] =
 178                         (hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 179         return 0;
 180 }
 181 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 182
 183 static void intr_complete (struct urb *urb)
 184 {
 185         struct usbnet   *dev = urb->context;
 186         int             status = urb->status;
 187
 188         switch (status) {
 189         /* success */
 190         case 0:
 191                 dev->driver_info->status(dev, urb);
 192                 break;
 193
 194         /* software-driven interface shutdown */
 195         case -ENOENT:           /* urb killed */
 196         case -ESHUTDOWN:        /* hardware gone */
 197                 netif_dbg(dev, ifdown, dev->net,
 198                           "intr shutdown, code %d\n", status);
 199                 return;
 200
 201         /* NOTE:  not throttling like RX/TX, since this endpoint
 202          * already polls infrequently
 203          */
 204         default:
 205                 netdev_dbg(dev->net, "intr status %d\n", status);
 206                 break;
 207         }
 208
 209         status = usb_submit_urb (urb, GFP_ATOMIC);
 210         if (status != 0)
 211                 netif_err(dev, timer, dev->net,
 212                           "intr resubmit --> %d\n", status);
 213 }
 214
 215 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 216 {
 217         char            *buf = NULL;
 218         unsigned        pipe = 0;
 219         unsigned        maxp;
 220         unsigned        period;
 221
 222         if (!dev->driver_info->status)
 223                 return 0;
 224
 225         pipe = usb_rcvintpipe (dev->udev,
 226                         dev->status->desc.bEndpointAddress
 227                                 & USB_ENDPOINT_NUMBER_MASK);
 228         maxp = usb_maxpacket (dev->udev, pipe, 0);
 229
 230         /* avoid 1 msec chatter:  min 8 msec poll rate */
 231         period = max ((int) dev->status->desc.bInterval,
 232                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 233
 234         buf = kmalloc (maxp, GFP_KERNEL);
 235         if (buf) {
 236                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 237                 if (!dev->interrupt) {
 238                         kfree (buf);
 239                         return -ENOMEM;
 240                 } else {
 241                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 242                                 buf, maxp, intr_complete, dev, period);
 243                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 244                         dev_dbg(&intf->dev,
 245                                 "status ep%din, %d bytes period %d\n",
 246                                 usb_pipeendpoint(pipe), maxp, period);
 247                 }
 248         }
 249         return 0;
 250 }
 251
 252 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 253 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 254 {
 255         int ret = 0;
 256
 257         WARN_ON_ONCE(dev->interrupt == NULL);
 258         if (dev->interrupt) {
 259                 mutex_lock(&dev->interrupt_mutex);
 260
 261                 if (++dev->interrupt_count == 1)
 262                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 263
 264                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 265                         dev->interrupt_count);
 266                 mutex_unlock(&dev->interrupt_mutex);
 267         }
 268         return ret;
 269 }
 270 EXPORT_SYMBOL_GPL(usbnet_status_start);
 271
 272 /* For resume; submit interrupt URB if previously submitted */
 273 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 274 {
 275         int ret = 0;
 276
 277         mutex_lock(&dev->interrupt_mutex);
 278         if (dev->interrupt_count) {
 279                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 280                 dev_dbg(&dev->udev->dev,
 281                         "submitted interrupt URB for resume\n");
 282         }
 283         mutex_unlock(&dev->interrupt_mutex);
 284         return ret;
 285 }
 286
 287 /* Kill the interrupt URB if all submitters want it killed */
 288 void usbnet_status_stop(struct usbnet *dev)
 289 {
 290         if (dev->interrupt) {
 291                 mutex_lock(&dev->interrupt_mutex);
 292                 WARN_ON(dev->interrupt_count == 0);
 293
 294                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 295                         usb_kill_urb(dev->interrupt);
 296
 297                 dev_dbg(&dev->udev->dev,
 298                         "decremented interrupt URB count to %d\n",
 299                         dev->interrupt_count);
 300                 mutex_unlock(&dev->interrupt_mutex);
 301         }
 302 }
 303 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 304
 305 /* For suspend; always kill interrupt URB */
 306 static void __usbnet_status_stop_force(struct usbnet *dev)
 307 {
 308         if (dev->interrupt) {
 309                 mutex_lock(&dev->interrupt_mutex);
 310                 usb_kill_urb(dev->interrupt);
 311                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 312                 mutex_unlock(&dev->interrupt_mutex);
 313         }
 314 }
 315
 316 /* Passes this packet up the stack, updating its accounting.
 317  * Some link protocols batch packets, so their rx_fixup paths
 318  * can return clones as well as just modify the original skb.
 319  */
 320 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 321 {
 322         int     status;
 323
 324         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 325                 skb_queue_tail(&dev->rxq_pause, skb);
 326                 return;
 327         }
 328
 329         skb->protocol = eth_type_trans (skb, dev->net);
 330         dev->net->stats.rx_packets++;
 331         dev->net->stats.rx_bytes += skb->len;
 332
 333         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 334                   skb->len + sizeof (struct ethhdr), skb->protocol);
 335         memset (skb->cb, 0, sizeof (struct skb_data));
 336
 337         if (skb_defer_rx_timestamp(skb))
 338                 return;
 339
 340         status = netif_rx (skb);
 341         if (status != NET_RX_SUCCESS)
 342                 netif_dbg(dev, rx_err, dev->net,
 343                           "netif_rx status %d\n", status);
 344 }
 345 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 346
 347 \f
 348 /*-------------------------------------------------------------------------
 349  *
 350  * Network Device Driver (peer link to "Host Device", from USB host)
 351  *
 352  *-------------------------------------------------------------------------*/
 353
 354 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 355 {
 356         struct usbnet   *dev = netdev_priv(net);
 357         int             ll_mtu = new_mtu + net->hard_header_len;
 358         int             old_hard_mtu = dev->hard_mtu;
 359         int             old_rx_urb_size = dev->rx_urb_size;
 360
 361         if (new_mtu <= 0)
 362                 return -EINVAL;
 363         // no second zero-length packet read wanted after mtu-sized packets
 364         if ((ll_mtu % dev->maxpacket) == 0)
 365                 return -EDOM;
 366         net->mtu = new_mtu;
 367
 368         dev->hard_mtu = net->mtu + net->hard_header_len;
 369         if (dev->rx_urb_size == old_hard_mtu) {
 370                 dev->rx_urb_size = dev->hard_mtu;
 371                 if (dev->rx_urb_size > old_rx_urb_size)
 372                         usbnet_unlink_rx_urbs(dev);
 373         }
 374
 375         return 0;
 376 }
 377 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 378
 379 /* The caller must hold list->lock */
 380 static void __usbnet_queue_skb(struct sk_buff_head *list,
 381                         struct sk_buff *newsk, enum skb_state state)
 382 {
 383         struct skb_data *entry = (struct skb_data *) newsk->cb;
 384
 385         __skb_queue_tail(list, newsk);
 386         entry->state = state;
 387 }
 388
 389 /*-------------------------------------------------------------------------*/
 390
 391 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 392  * completion callbacks.  2.5 should have fixed those bugs...
 393  */
 394
 395 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 396                 struct sk_buff_head *list, enum skb_state state)
 397 {
 398         unsigned long           flags;
 399         enum skb_state          old_state;
 400         struct skb_data *entry = (struct skb_data *) skb->cb;
 401
 402         spin_lock_irqsave(&list->lock, flags);
 403         old_state = entry->state;
 404         entry->state = state;
 405         __skb_unlink(skb, list);
 406         spin_unlock(&list->lock);
 407         spin_lock(&dev->done.lock);
 408         __skb_queue_tail(&dev->done, skb);
 409         if (dev->done.qlen == 1)
 410                 tasklet_schedule(&dev->bh);
 411         spin_unlock_irqrestore(&dev->done.lock, flags);
 412         return old_state;
 413 }
 414
 415 /* some work can't be done in tasklets, so we use keventd
 416  *
 417  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 418  * but tasklet_schedule() doesn't.  hope the failure is rare.
 419  */
 420 void usbnet_defer_kevent (struct usbnet *dev, int work)
 421 {
 422         set_bit (work, &dev->flags);
 423         if (!schedule_work (&dev->kevent)) {
 424                 if (net_ratelimit())
 425                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 426         } else {
 427                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 428         }
 429 }
 430 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 431
 432 /*-------------------------------------------------------------------------*/
 433
 434 static void rx_complete (struct urb *urb);
 435
 436 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 437 {
 438         struct sk_buff          *skb;
 439         struct skb_data         *entry;
 440         int                     retval = 0;
 441         unsigned long           lockflags;
 442         size_t                  size = dev->rx_urb_size;
 443
 444         /* prevent rx skb allocation when error ratio is high */
 445         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 446                 usb_free_urb(urb);
 447                 return -ENOLINK;
 448         }
 449
 450         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 451         if (!skb) {
 452                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 453                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 454                 usb_free_urb (urb);
 455                 return -ENOMEM;
 456         }
 457
 458         entry = (struct skb_data *) skb->cb;
 459         entry->urb = urb;
 460         entry->dev = dev;
 461         entry->length = 0;
 462
 463         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 464                 skb->data, size, rx_complete, skb);
 465
 466         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 467
 468         if (netif_running (dev->net) &&
 469             netif_device_present (dev->net) &&
 470             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 471             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 472                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 473                 case -EPIPE:
 474                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 475                         break;
 476                 case -ENOMEM:
 477                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 478                         break;
 479                 case -ENODEV:
 480                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 481                         netif_device_detach (dev->net);
 482                         break;
 483                 case -EHOSTUNREACH:
 484                         retval = -ENOLINK;
 485                         break;
 486                 default:
 487                         netif_dbg(dev, rx_err, dev->net,
 488                                   "rx submit, %d\n", retval);
 489                         tasklet_schedule (&dev->bh);
 490                         break;
 491                 case 0:
 492                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 493                 }
 494         } else {
 495                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 496                 retval = -ENOLINK;
 497         }
 498         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 499         if (retval) {
 500                 dev_kfree_skb_any (skb);
 501                 usb_free_urb (urb);
 502         }
 503         return retval;
 504 }
 505
 506
 507 /*-------------------------------------------------------------------------*/
 508
 509 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 510 {
 511         if (dev->driver_info->rx_fixup &&
 512             !dev->driver_info->rx_fixup (dev, skb)) {
 513                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 514                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 515                         dev->net->stats.rx_errors++;
 516                 goto done;
 517         }
 518         // else network stack removes extra byte if we forced a short packet
 519
 520         /* all data was already cloned from skb inside the driver */
 521         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 522                 goto done;
 523
 524         if (skb->len < ETH_HLEN) {
 525                 dev->net->stats.rx_errors++;
 526                 dev->net->stats.rx_length_errors++;
 527                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 528         } else {
 529                 usbnet_skb_return(dev, skb);
 530                 return;
 531         }
 532
 533 done:
 534         skb_queue_tail(&dev->done, skb);
 535 }
 536
 537 /*-------------------------------------------------------------------------*/
 538
 539 static void rx_complete (struct urb *urb)
 540 {
 541         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 542         struct skb_data         *entry = (struct skb_data *) skb->cb;
 543         struct usbnet           *dev = entry->dev;
 544         int                     urb_status = urb->status;
 545         enum skb_state          state;
 546
 547         skb_put (skb, urb->actual_length);
 548         state = rx_done;
 549         entry->urb = NULL;
 550
 551         switch (urb_status) {
 552         /* success */
 553         case 0:
 554                 break;
 555
 556         /* stalls need manual reset. this is rare ... except that
 557          * when going through USB 2.0 TTs, unplug appears this way.
 558          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 559          * storm, recovering as needed.
 560          */
 561         case -EPIPE:
 562                 dev->net->stats.rx_errors++;
 563                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 564                 // FALLTHROUGH
 565
 566         /* software-driven interface shutdown */
 567         case -ECONNRESET:               /* async unlink */
 568         case -ESHUTDOWN:                /* hardware gone */
 569                 netif_dbg(dev, ifdown, dev->net,
 570                           "rx shutdown, code %d\n", urb_status);
 571                 goto block;
 572
 573         /* we get controller i/o faults during khubd disconnect() delays.
 574          * throttle down resubmits, to avoid log floods; just temporarily,
 575          * so we still recover when the fault isn't a khubd delay.
 576          */
 577         case -EPROTO:
 578         case -ETIME:
 579         case -EILSEQ:
 580                 dev->net->stats.rx_errors++;
 581                 if (!timer_pending (&dev->delay)) {
 582                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 583                         netif_dbg(dev, link, dev->net,
 584                                   "rx throttle %d\n", urb_status);
 585                 }
 586 block:
 587                 state = rx_cleanup;
 588                 entry->urb = urb;
 589                 urb = NULL;
 590                 break;
 591
 592         /* data overrun ... flush fifo? */
 593         case -EOVERFLOW:
 594                 dev->net->stats.rx_over_errors++;
 595                 // FALLTHROUGH
 596
 597         default:
 598                 state = rx_cleanup;
 599                 dev->net->stats.rx_errors++;
 600                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 601                 break;
 602         }
 603
 604         /* stop rx if packet error rate is high */
 605         if (++dev->pkt_cnt > 30) {
 606                 dev->pkt_cnt = 0;
 607                 dev->pkt_err = 0;
 608         } else {
 609                 if (state == rx_cleanup)
 610                         dev->pkt_err++;
 611                 if (dev->pkt_err > 20)
 612                         set_bit(EVENT_RX_KILL, &dev->flags);
 613         }
 614
 615         state = defer_bh(dev, skb, &dev->rxq, state);
 616
 617         if (urb) {
 618                 if (netif_running (dev->net) &&
 619                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 620                     state != unlink_start) {
 621                         rx_submit (dev, urb, GFP_ATOMIC);
 622                         usb_mark_last_busy(dev->udev);
 623                         return;
 624                 }
 625                 usb_free_urb (urb);
 626         }
 627         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 628 }
 629
 630 /*-------------------------------------------------------------------------*/
 631 void usbnet_pause_rx(struct usbnet *dev)
 632 {
 633         set_bit(EVENT_RX_PAUSED, &dev->flags);
 634
 635         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 636 }
 637 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 638
 639 void usbnet_resume_rx(struct usbnet *dev)
 640 {
 641         struct sk_buff *skb;
 642         int num = 0;
 643
 644         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 645
 646         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 647                 usbnet_skb_return(dev, skb);
 648                 num++;
 649         }
 650
 651         tasklet_schedule(&dev->bh);
 652
 653         netif_dbg(dev, rx_status, dev->net,
 654                   "paused rx queue disabled, %d skbs requeued\n", num);
 655 }
 656 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 657
 658 void usbnet_purge_paused_rxq(struct usbnet *dev)
 659 {
 660         skb_queue_purge(&dev->rxq_pause);
 661 }
 662 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 663
 664 /*-------------------------------------------------------------------------*/
 665
 666 // unlink pending rx/tx; completion handlers do all other cleanup
 667
 668 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 669 {
 670         unsigned long           flags;
 671         struct sk_buff          *skb;
 672         int                     count = 0;
 673
 674         spin_lock_irqsave (&q->lock, flags);
 675         while (!skb_queue_empty(q)) {
 676                 struct skb_data         *entry;
 677                 struct urb              *urb;
 678                 int                     retval;
 679
 680                 skb_queue_walk(q, skb) {
 681                         entry = (struct skb_data *) skb->cb;
 682                         if (entry->state != unlink_start)
 683                                 goto found;
 684                 }
 685                 break;
 686 found:
 687                 entry->state = unlink_start;
 688                 urb = entry->urb;
 689
 690                 /*
 691                  * Get reference count of the URB to avoid it to be
 692                  * freed during usb_unlink_urb, which may trigger
 693                  * use-after-free problem inside usb_unlink_urb since
 694                  * usb_unlink_urb is always racing with .complete
 695                  * handler(include defer_bh).
 696                  */
 697                 usb_get_urb(urb);
 698                 spin_unlock_irqrestore(&q->lock, flags);
 699                 // during some PM-driven resume scenarios,
 700                 // these (async) unlinks complete immediately
 701                 retval = usb_unlink_urb (urb);
 702                 if (retval != -EINPROGRESS && retval != 0)
 703                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 704                 else
 705                         count++;
 706                 usb_put_urb(urb);
 707                 spin_lock_irqsave(&q->lock, flags);
 708         }
 709         spin_unlock_irqrestore (&q->lock, flags);
 710         return count;
 711 }
 712
 713 // Flush all pending rx urbs
 714 // minidrivers may need to do this when the MTU changes
 715
 716 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 717 {
 718         if (netif_running(dev->net)) {
 719                 (void) unlink_urbs (dev, &dev->rxq);
 720                 tasklet_schedule(&dev->bh);
 721         }
 722 }
 723 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 724
 725 /*-------------------------------------------------------------------------*/
 726
 727 // precondition: never called in_interrupt
 728 static void usbnet_terminate_urbs(struct usbnet *dev)
 729 {
 730         DECLARE_WAITQUEUE(wait, current);
 731         int temp;
 732
 733         /* ensure there are no more active urbs */
 734         add_wait_queue(&dev->wait, &wait);
 735         set_current_state(TASK_UNINTERRUPTIBLE);
 736         temp = unlink_urbs(dev, &dev->txq) +
 737                 unlink_urbs(dev, &dev->rxq);
 738
 739         /* maybe wait for deletions to finish. */
 740         while (!skb_queue_empty(&dev->rxq)
 741                 && !skb_queue_empty(&dev->txq)
 742                 && !skb_queue_empty(&dev->done)) {
 743                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 744                         set_current_state(TASK_UNINTERRUPTIBLE);
 745                         netif_dbg(dev, ifdown, dev->net,
 746                                   "waited for %d urb completions\n", temp);
 747         }
 748         set_current_state(TASK_RUNNING);
 749         remove_wait_queue(&dev->wait, &wait);
 750 }
 751
 752 int usbnet_stop (struct net_device *net)
 753 {
 754         struct usbnet           *dev = netdev_priv(net);
 755         struct driver_info      *info = dev->driver_info;
 756         int                     retval, pm;
 757
 758         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 759         netif_stop_queue (net);
 760
 761         netif_info(dev, ifdown, dev->net,
 762                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 763                    net->stats.rx_packets, net->stats.tx_packets,
 764                    net->stats.rx_errors, net->stats.tx_errors);
 765
 766         /* to not race resume */
 767         pm = usb_autopm_get_interface(dev->intf);
 768         /* allow minidriver to stop correctly (wireless devices to turn off
 769          * radio etc) */
 770         if (info->stop) {
 771                 retval = info->stop(dev);
 772                 if (retval < 0)
 773                         netif_info(dev, ifdown, dev->net,
 774                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 775                                    retval,
 776                                    dev->udev->bus->bus_name, dev->udev->devpath,
 777                                    info->description);
 778         }
 779
 780         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 781                 usbnet_terminate_urbs(dev);
 782
 783         usbnet_status_stop(dev);
 784
 785         usbnet_purge_paused_rxq(dev);
 786
 787         /* deferred work (task, timer, softirq) must also stop.
 788          * can't flush_scheduled_work() until we drop rtnl (later),
 789          * else workers could deadlock; so make workers a NOP.
 790          */
 791         dev->flags = 0;
 792         del_timer_sync (&dev->delay);
 793         tasklet_kill (&dev->bh);
 794         if (!pm)
 795                 usb_autopm_put_interface(dev->intf);
 796
 797         if (info->manage_power &&
 798             !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
 799                 info->manage_power(dev, 0);
 800         else
 801                 usb_autopm_put_interface(dev->intf);
 802
 803         return 0;
 804 }
 805 EXPORT_SYMBOL_GPL(usbnet_stop);
 806
 807 /*-------------------------------------------------------------------------*/
 808
 809 // posts reads, and enables write queuing
 810
 811 // precondition: never called in_interrupt
 812
 813 int usbnet_open (struct net_device *net)
 814 {
 815         struct usbnet           *dev = netdev_priv(net);
 816         int                     retval;
 817         struct driver_info      *info = dev->driver_info;
 818
 819         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 820                 netif_info(dev, ifup, dev->net,
 821                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 822                            retval,
 823                            dev->udev->bus->bus_name,
 824                            dev->udev->devpath,
 825                            info->description);
 826                 goto done_nopm;
 827         }
 828
 829         // put into "known safe" state
 830         if (info->reset && (retval = info->reset (dev)) < 0) {
 831                 netif_info(dev, ifup, dev->net,
 832                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 833                            retval,
 834                            dev->udev->bus->bus_name,
 835                            dev->udev->devpath,
 836                            info->description);
 837                 goto done;
 838         }
 839
 840         // insist peer be connected
 841         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 842                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 843                 goto done;
 844         }
 845
 846         /* start any status interrupt transfer */
 847         if (dev->interrupt) {
 848                 retval = usbnet_status_start(dev, GFP_KERNEL);
 849                 if (retval < 0) {
 850                         netif_err(dev, ifup, dev->net,
 851                                   "intr submit %d\n", retval);
 852                         goto done;
 853                 }
 854         }
 855
 856         set_bit(EVENT_DEV_OPEN, &dev->flags);
 857         netif_start_queue (net);
 858         netif_info(dev, ifup, dev->net,
 859                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 860                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 861                    dev->net->mtu,
 862                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 863                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 864                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 865                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 866                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 867                    "simple");
 868
 869         /* reset rx error state */
 870         dev->pkt_cnt = 0;
 871         dev->pkt_err = 0;
 872         clear_bit(EVENT_RX_KILL, &dev->flags);
 873
 874         // delay posting reads until we're fully open
 875         tasklet_schedule (&dev->bh);
 876         if (info->manage_power) {
 877                 retval = info->manage_power(dev, 1);
 878                 if (retval < 0) {
 879                         retval = 0;
 880                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 881                 } else {
 882                         usb_autopm_put_interface(dev->intf);
 883                 }
 884         }
 885         return retval;
 886 done:
 887         usb_autopm_put_interface(dev->intf);
 888 done_nopm:
 889         return retval;
 890 }
 891 EXPORT_SYMBOL_GPL(usbnet_open);
 892
 893 /*-------------------------------------------------------------------------*/
 894
 895 /* ethtool methods; minidrivers may need to add some more, but
 896  * they'll probably want to use this base set.
 897  */
 898
 899 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 900 {
 901         struct usbnet *dev = netdev_priv(net);
 902
 903         if (!dev->mii.mdio_read)
 904                 return -EOPNOTSUPP;
 905
 906         return mii_ethtool_gset(&dev->mii, cmd);
 907 }
 908 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 909
 910 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 911 {
 912         struct usbnet *dev = netdev_priv(net);
 913         int retval;
 914
 915         if (!dev->mii.mdio_write)
 916                 return -EOPNOTSUPP;
 917
 918         retval = mii_ethtool_sset(&dev->mii, cmd);
 919
 920         /* link speed/duplex might have changed */
 921         if (dev->driver_info->link_reset)
 922                 dev->driver_info->link_reset(dev);
 923
 924         return retval;
 925
 926 }
 927 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 928
 929 u32 usbnet_get_link (struct net_device *net)
 930 {
 931         struct usbnet *dev = netdev_priv(net);
 932
 933         /* If a check_connect is defined, return its result */
 934         if (dev->driver_info->check_connect)
 935                 return dev->driver_info->check_connect (dev) == 0;
 936
 937         /* if the device has mii operations, use those */
 938         if (dev->mii.mdio_read)
 939                 return mii_link_ok(&dev->mii);
 940
 941         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 942         return ethtool_op_get_link(net);
 943 }
 944 EXPORT_SYMBOL_GPL(usbnet_get_link);
 945
 946 int usbnet_nway_reset(struct net_device *net)
 947 {
 948         struct usbnet *dev = netdev_priv(net);
 949
 950         if (!dev->mii.mdio_write)
 951                 return -EOPNOTSUPP;
 952
 953         return mii_nway_restart(&dev->mii);
 954 }
 955 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 956
 957 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 958 {
 959         struct usbnet *dev = netdev_priv(net);
 960
 961         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 962         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 963         strlcpy (info->fw_version, dev->driver_info->description,
 964                 sizeof info->fw_version);
 965         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 966 }
 967 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 968
 969 u32 usbnet_get_msglevel (struct net_device *net)
 970 {
 971         struct usbnet *dev = netdev_priv(net);
 972
 973         return dev->msg_enable;
 974 }
 975 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 976
 977 void usbnet_set_msglevel (struct net_device *net, u32 level)
 978 {
 979         struct usbnet *dev = netdev_priv(net);
 980
 981         dev->msg_enable = level;
 982 }
 983 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 984
 985 /* drivers may override default ethtool_ops in their bind() routine */
 986 static const struct ethtool_ops usbnet_ethtool_ops = {
 987         .get_settings           = usbnet_get_settings,
 988         .set_settings           = usbnet_set_settings,
 989         .get_link               = usbnet_get_link,
 990         .nway_reset             = usbnet_nway_reset,
 991         .get_drvinfo            = usbnet_get_drvinfo,
 992         .get_msglevel           = usbnet_get_msglevel,
 993         .set_msglevel           = usbnet_set_msglevel,
 994         .get_ts_info            = ethtool_op_get_ts_info,
 995 };
 996
 997 /*-------------------------------------------------------------------------*/
 998
 999 static void __handle_link_change(struct usbnet *dev)
1000 {
1001         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1002                 return;
1003
1004         if (!netif_carrier_ok(dev->net)) {
1005                 /* kill URBs for reading packets to save bus bandwidth */
1006                 unlink_urbs(dev, &dev->rxq);
1007
1008                 /*
1009                  * tx_timeout will unlink URBs for sending packets and
1010                  * tx queue is stopped by netcore after link becomes off
1011                  */
1012         } else {
1013                 /* submitting URBs for reading packets */
1014                 tasklet_schedule(&dev->bh);
1015         }
1016
1017         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1018 }
1019
1020 /* work that cannot be done in interrupt context uses keventd.
1021  *
1022  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1023  * especially now that control transfers can be queued.
1024  */
1025 static void
1026 kevent (struct work_struct *work)
1027 {
1028         struct usbnet           *dev =
1029                 container_of(work, struct usbnet, kevent);
1030         int                     status;
1031
1032         /* usb_clear_halt() needs a thread context */
1033         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1034                 unlink_urbs (dev, &dev->txq);
1035                 status = usb_autopm_get_interface(dev->intf);
1036                 if (status < 0)
1037                         goto fail_pipe;
1038                 status = usb_clear_halt (dev->udev, dev->out);
1039                 usb_autopm_put_interface(dev->intf);
1040                 if (status < 0 &&
1041                     status != -EPIPE &&
1042                     status != -ESHUTDOWN) {
1043                         if (netif_msg_tx_err (dev))
1044 fail_pipe:
1045                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1046                                            status);
1047                 } else {
1048                         clear_bit (EVENT_TX_HALT, &dev->flags);
1049                         if (status != -ESHUTDOWN)
1050                                 netif_wake_queue (dev->net);
1051                 }
1052         }
1053         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1054                 unlink_urbs (dev, &dev->rxq);
1055                 status = usb_autopm_get_interface(dev->intf);
1056                 if (status < 0)
1057                         goto fail_halt;
1058                 status = usb_clear_halt (dev->udev, dev->in);
1059                 usb_autopm_put_interface(dev->intf);
1060                 if (status < 0 &&
1061                     status != -EPIPE &&
1062                     status != -ESHUTDOWN) {
1063                         if (netif_msg_rx_err (dev))
1064 fail_halt:
1065                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1066                                            status);
1067                 } else {
1068                         clear_bit (EVENT_RX_HALT, &dev->flags);
1069                         tasklet_schedule (&dev->bh);
1070                 }
1071         }
1072
1073         /* tasklet could resubmit itself forever if memory is tight */
1074         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1075                 struct urb      *urb = NULL;
1076                 int resched = 1;
1077
1078                 if (netif_running (dev->net))
1079                         urb = usb_alloc_urb (0, GFP_KERNEL);
1080                 else
1081                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1082                 if (urb != NULL) {
1083                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1084                         status = usb_autopm_get_interface(dev->intf);
1085                         if (status < 0) {
1086                                 usb_free_urb(urb);
1087                                 goto fail_lowmem;
1088                         }
1089                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1090                                 resched = 0;
1091                         usb_autopm_put_interface(dev->intf);
1092 fail_lowmem:
1093                         if (resched)
1094                                 tasklet_schedule (&dev->bh);
1095                 }
1096         }
1097
1098         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1099                 struct driver_info      *info = dev->driver_info;
1100                 int                     retval = 0;
1101
1102                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1103                 status = usb_autopm_get_interface(dev->intf);
1104                 if (status < 0)
1105                         goto skip_reset;
1106                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1107                         usb_autopm_put_interface(dev->intf);
1108 skip_reset:
1109                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1110                                     retval,
1111                                     dev->udev->bus->bus_name,
1112                                     dev->udev->devpath,
1113                                     info->description);
1114                 } else {
1115                         usb_autopm_put_interface(dev->intf);
1116                 }
1117
1118                 /* handle link change from link resetting */
1119                 __handle_link_change(dev);
1120         }
1121
1122         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1123                 __handle_link_change(dev);
1124
1125         if (dev->flags)
1126                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1127 }
1128
1129 /*-------------------------------------------------------------------------*/
1130
1131 static void tx_complete (struct urb *urb)
1132 {
1133         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1134         struct skb_data         *entry = (struct skb_data *) skb->cb;
1135         struct usbnet           *dev = entry->dev;
1136
1137         if (urb->status == 0) {
1138                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1139                         dev->net->stats.tx_packets++;
1140                 dev->net->stats.tx_bytes += entry->length;
1141         } else {
1142                 dev->net->stats.tx_errors++;
1143
1144                 switch (urb->status) {
1145                 case -EPIPE:
1146                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1147                         break;
1148
1149                 /* software-driven interface shutdown */
1150                 case -ECONNRESET:               // async unlink
1151                 case -ESHUTDOWN:                // hardware gone
1152                         break;
1153
1154                 // like rx, tx gets controller i/o faults during khubd delays
1155                 // and so it uses the same throttling mechanism.
1156                 case -EPROTO:
1157                 case -ETIME:
1158                 case -EILSEQ:
1159                         usb_mark_last_busy(dev->udev);
1160                         if (!timer_pending (&dev->delay)) {
1161                                 mod_timer (&dev->delay,
1162                                         jiffies + THROTTLE_JIFFIES);
1163                                 netif_dbg(dev, link, dev->net,
1164                                           "tx throttle %d\n", urb->status);
1165                         }
1166                         netif_stop_queue (dev->net);
1167                         break;
1168                 default:
1169                         netif_dbg(dev, tx_err, dev->net,
1170                                   "tx err %d\n", entry->urb->status);
1171                         break;
1172                 }
1173         }
1174
1175         usb_autopm_put_interface_async(dev->intf);
1176         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1177 }
1178
1179 /*-------------------------------------------------------------------------*/
1180
1181 void usbnet_tx_timeout (struct net_device *net)
1182 {
1183         struct usbnet           *dev = netdev_priv(net);
1184
1185         unlink_urbs (dev, &dev->txq);
1186         tasklet_schedule (&dev->bh);
1187
1188         // FIXME: device recovery -- reset?
1189 }
1190 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1191
1192 /*-------------------------------------------------------------------------*/
1193
1194 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1195                                      struct net_device *net)
1196 {
1197         struct usbnet           *dev = netdev_priv(net);
1198         int                     length;
1199         struct urb              *urb = NULL;
1200         struct skb_data         *entry;
1201         struct driver_info      *info = dev->driver_info;
1202         unsigned long           flags;
1203         int retval;
1204
1205         if (skb)
1206                 skb_tx_timestamp(skb);
1207
1208         // some devices want funky USB-level framing, for
1209         // win32 driver (usually) and/or hardware quirks
1210         if (info->tx_fixup) {
1211                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1212                 if (!skb) {
1213                         /* packet collected; minidriver waiting for more */
1214                         if (info->flags & FLAG_MULTI_PACKET)
1215                                 goto not_drop;
1216                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1217                         goto drop;
1218                 }
1219         }
1220         length = skb->len;
1221
1222         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1223                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1224                 goto drop;
1225         }
1226
1227         entry = (struct skb_data *) skb->cb;
1228         entry->urb = urb;
1229         entry->dev = dev;
1230         entry->length = length;
1231
1232         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1233                         skb->data, skb->len, tx_complete, skb);
1234
1235         /* don't assume the hardware handles USB_ZERO_PACKET
1236          * NOTE:  strictly conforming cdc-ether devices should expect
1237          * the ZLP here, but ignore the one-byte packet.
1238          * NOTE2: CDC NCM specification is different from CDC ECM when
1239          * handling ZLP/short packets, so cdc_ncm driver will make short
1240          * packet itself if needed.
1241          */
1242         if (length % dev->maxpacket == 0) {
1243                 if (!(info->flags & FLAG_SEND_ZLP)) {
1244                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1245                                 urb->transfer_buffer_length++;
1246                                 if (skb_tailroom(skb)) {
1247                                         skb->data[skb->len] = 0;
1248                                         __skb_put(skb, 1);
1249                                 }
1250                         }
1251                 } else
1252                         urb->transfer_flags |= URB_ZERO_PACKET;
1253         }
1254
1255         spin_lock_irqsave(&dev->txq.lock, flags);
1256         retval = usb_autopm_get_interface_async(dev->intf);
1257         if (retval < 0) {
1258                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1259                 goto drop;
1260         }
1261
1262 #ifdef CONFIG_PM
1263         /* if this triggers the device is still a sleep */
1264         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1265                 /* transmission will be done in resume */
1266                 usb_anchor_urb(urb, &dev->deferred);
1267                 /* no use to process more packets */
1268                 netif_stop_queue(net);
1269                 usb_put_urb(urb);
1270                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1271                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1272                 goto deferred;
1273         }
1274 #endif
1275
1276         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1277         case -EPIPE:
1278                 netif_stop_queue (net);
1279                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1280                 usb_autopm_put_interface_async(dev->intf);
1281                 break;
1282         default:
1283                 usb_autopm_put_interface_async(dev->intf);
1284                 netif_dbg(dev, tx_err, dev->net,
1285                           "tx: submit urb err %d\n", retval);
1286                 break;
1287         case 0:
1288                 net->trans_start = jiffies;
1289                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1290                 if (dev->txq.qlen >= TX_QLEN (dev))
1291                         netif_stop_queue (net);
1292         }
1293         spin_unlock_irqrestore (&dev->txq.lock, flags);
1294
1295         if (retval) {
1296                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1297 drop:
1298                 dev->net->stats.tx_dropped++;
1299 not_drop:
1300                 if (skb)
1301                         dev_kfree_skb_any (skb);
1302                 usb_free_urb (urb);
1303         } else
1304                 netif_dbg(dev, tx_queued, dev->net,
1305                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1306 #ifdef CONFIG_PM
1307 deferred:
1308 #endif
1309         return NETDEV_TX_OK;
1310 }
1311 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1312
1313 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1314 {
1315         struct urb      *urb;
1316         int             i;
1317         int             ret = 0;
1318
1319         /* don't refill the queue all at once */
1320         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1321                 urb = usb_alloc_urb(0, flags);
1322                 if (urb != NULL) {
1323                         ret = rx_submit(dev, urb, flags);
1324                         if (ret)
1325                                 goto err;
1326                 } else {
1327                         ret = -ENOMEM;
1328                         goto err;
1329                 }
1330         }
1331 err:
1332         return ret;
1333 }
1334
1335 /*-------------------------------------------------------------------------*/
1336
1337 // tasklet (work deferred from completions, in_irq) or timer
1338
1339 static void usbnet_bh (unsigned long param)
1340 {
1341         struct usbnet           *dev = (struct usbnet *) param;
1342         struct sk_buff          *skb;
1343         struct skb_data         *entry;
1344
1345         while ((skb = skb_dequeue (&dev->done))) {
1346                 entry = (struct skb_data *) skb->cb;
1347                 switch (entry->state) {
1348                 case rx_done:
1349                         entry->state = rx_cleanup;
1350                         rx_process (dev, skb);
1351                         continue;
1352                 case tx_done:
1353                 case rx_cleanup:
1354                         usb_free_urb (entry->urb);
1355                         dev_kfree_skb (skb);
1356                         continue;
1357                 default:
1358                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1359                 }
1360         }
1361
1362         /* restart RX again after disabling due to high error rate */
1363         clear_bit(EVENT_RX_KILL, &dev->flags);
1364
1365         /* waiting for all pending urbs to complete?
1366          * only then can we forgo submitting anew
1367          */
1368         if (waitqueue_active(&dev->wait)) {
1369                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1370                         wake_up_all(&dev->wait);
1371
1372         // or are we maybe short a few urbs?
1373         } else if (netif_running (dev->net) &&
1374                    netif_device_present (dev->net) &&
1375                    netif_carrier_ok(dev->net) &&
1376                    !timer_pending (&dev->delay) &&
1377                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1378                 int     temp = dev->rxq.qlen;
1379
1380                 if (temp < RX_QLEN(dev)) {
1381                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1382                                 return;
1383                         if (temp != dev->rxq.qlen)
1384                                 netif_dbg(dev, link, dev->net,
1385                                           "rxqlen %d --> %d\n",
1386                                           temp, dev->rxq.qlen);
1387                         if (dev->rxq.qlen < RX_QLEN(dev))
1388                                 tasklet_schedule (&dev->bh);
1389                 }
1390                 if (dev->txq.qlen < TX_QLEN (dev))
1391                         netif_wake_queue (dev->net);
1392         }
1393 }
1394
1395
1396 /*-------------------------------------------------------------------------
1397  *
1398  * USB Device Driver support
1399  *
1400  *-------------------------------------------------------------------------*/
1401
1402 // precondition: never called in_interrupt
1403
1404 void usbnet_disconnect (struct usb_interface *intf)
1405 {
1406         struct usbnet           *dev;
1407         struct usb_device       *xdev;
1408         struct net_device       *net;
1409
1410         dev = usb_get_intfdata(intf);
1411         usb_set_intfdata(intf, NULL);
1412         if (!dev)
1413                 return;
1414
1415         xdev = interface_to_usbdev (intf);
1416
1417         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1418                    intf->dev.driver->name,
1419                    xdev->bus->bus_name, xdev->devpath,
1420                    dev->driver_info->description);
1421
1422         net = dev->net;
1423         unregister_netdev (net);
1424
1425         cancel_work_sync(&dev->kevent);
1426
1427         usb_scuttle_anchored_urbs(&dev->deferred);
1428
1429         if (dev->driver_info->unbind)
1430                 dev->driver_info->unbind (dev, intf);
1431
1432         usb_kill_urb(dev->interrupt);
1433         usb_free_urb(dev->interrupt);
1434
1435         free_netdev(net);
1436 }
1437 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1438
1439 static const struct net_device_ops usbnet_netdev_ops = {
1440         .ndo_open               = usbnet_open,
1441         .ndo_stop               = usbnet_stop,
1442         .ndo_start_xmit         = usbnet_start_xmit,
1443         .ndo_tx_timeout         = usbnet_tx_timeout,
1444         .ndo_change_mtu         = usbnet_change_mtu,
1445         .ndo_set_mac_address    = eth_mac_addr,
1446         .ndo_validate_addr      = eth_validate_addr,
1447 };
1448
1449 /*-------------------------------------------------------------------------*/
1450
1451 // precondition: never called in_interrupt
1452
1453 static struct device_type wlan_type = {
1454         .name   = "wlan",
1455 };
1456
1457 static struct device_type wwan_type = {
1458         .name   = "wwan",
1459 };
1460
1461 int
1462 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1463 {
1464         struct usbnet                   *dev;
1465         struct net_device               *net;
1466         struct usb_host_interface       *interface;
1467         struct driver_info              *info;
1468         struct usb_device               *xdev;
1469         int                             status;
1470         const char                      *name;
1471         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1472
1473         /* usbnet already took usb runtime pm, so have to enable the feature
1474          * for usb interface, otherwise usb_autopm_get_interface may return
1475          * failure if RUNTIME_PM is enabled.
1476          */
1477         if (!driver->supports_autosuspend) {
1478                 driver->supports_autosuspend = 1;
1479                 pm_runtime_enable(&udev->dev);
1480         }
1481
1482         name = udev->dev.driver->name;
1483         info = (struct driver_info *) prod->driver_info;
1484         if (!info) {
1485                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1486                 return -ENODEV;
1487         }
1488         xdev = interface_to_usbdev (udev);
1489         interface = udev->cur_altsetting;
1490
1491         status = -ENOMEM;
1492
1493         // set up our own records
1494         net = alloc_etherdev(sizeof(*dev));
1495         if (!net)
1496                 goto out;
1497
1498         /* netdev_printk() needs this so do it as early as possible */
1499         SET_NETDEV_DEV(net, &udev->dev);
1500
1501         dev = netdev_priv(net);
1502         dev->udev = xdev;
1503         dev->intf = udev;
1504         dev->driver_info = info;
1505         dev->driver_name = name;
1506         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1507                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1508         init_waitqueue_head(&dev->wait);
1509         skb_queue_head_init (&dev->rxq);
1510         skb_queue_head_init (&dev->txq);
1511         skb_queue_head_init (&dev->done);
1512         skb_queue_head_init(&dev->rxq_pause);
1513         dev->bh.func = usbnet_bh;
1514         dev->bh.data = (unsigned long) dev;
1515         INIT_WORK (&dev->kevent, kevent);
1516         init_usb_anchor(&dev->deferred);
1517         dev->delay.function = usbnet_bh;
1518         dev->delay.data = (unsigned long) dev;
1519         init_timer (&dev->delay);
1520         mutex_init (&dev->phy_mutex);
1521         mutex_init(&dev->interrupt_mutex);
1522         dev->interrupt_count = 0;
1523
1524         dev->net = net;
1525         strcpy (net->name, "usb%d");
1526         memcpy (net->dev_addr, node_id, sizeof node_id);
1527
1528         /* rx and tx sides can use different message sizes;
1529          * bind() should set rx_urb_size in that case.
1530          */
1531         dev->hard_mtu = net->mtu + net->hard_header_len;
1532 #if 0
1533 // dma_supported() is deeply broken on almost all architectures
1534         // possible with some EHCI controllers
1535         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1536                 net->features |= NETIF_F_HIGHDMA;
1537 #endif
1538
1539         net->netdev_ops = &usbnet_netdev_ops;
1540         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1541         net->ethtool_ops = &usbnet_ethtool_ops;
1542
1543         // allow device-specific bind/init procedures
1544         // NOTE net->name still not usable ...
1545         if (info->bind) {
1546                 status = info->bind (dev, udev);
1547                 if (status < 0)
1548                         goto out1;
1549
1550                 // heuristic:  "usb%d" for links we know are two-host,
1551                 // else "eth%d" when there's reasonable doubt.  userspace
1552                 // can rename the link if it knows better.
1553                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1554                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1555                      (net->dev_addr [0] & 0x02) == 0))
1556                         strcpy (net->name, "eth%d");
1557                 /* WLAN devices should always be named "wlan%d" */
1558                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1559                         strcpy(net->name, "wlan%d");
1560                 /* WWAN devices should always be named "wwan%d" */
1561                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1562                         strcpy(net->name, "wwan%d");
1563
1564                 /* devices that cannot do ARP */
1565                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1566                         net->flags |= IFF_NOARP;
1567
1568                 /* maybe the remote can't receive an Ethernet MTU */
1569                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1570                         net->mtu = dev->hard_mtu - net->hard_header_len;
1571         } else if (!info->in || !info->out)
1572                 status = usbnet_get_endpoints (dev, udev);
1573         else {
1574                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1575                 dev->out = usb_sndbulkpipe (xdev, info->out);
1576                 if (!(info->flags & FLAG_NO_SETINT))
1577                         status = usb_set_interface (xdev,
1578                                 interface->desc.bInterfaceNumber,
1579                                 interface->desc.bAlternateSetting);
1580                 else
1581                         status = 0;
1582
1583         }
1584         if (status >= 0 && dev->status)
1585                 status = init_status (dev, udev);
1586         if (status < 0)
1587                 goto out3;
1588
1589         if (!dev->rx_urb_size)
1590                 dev->rx_urb_size = dev->hard_mtu;
1591         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1592
1593         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1594                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1595         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1596                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1597
1598         status = register_netdev (net);
1599         if (status)
1600                 goto out4;
1601         netif_info(dev, probe, dev->net,
1602                    "register '%s' at usb-%s-%s, %s, %pM\n",
1603                    udev->dev.driver->name,
1604                    xdev->bus->bus_name, xdev->devpath,
1605                    dev->driver_info->description,
1606                    net->dev_addr);
1607
1608         // ok, it's ready to go.
1609         usb_set_intfdata (udev, dev);
1610
1611         netif_device_attach (net);
1612
1613         if (dev->driver_info->flags & FLAG_LINK_INTR)
1614                 usbnet_link_change(dev, 0, 0);
1615
1616         return 0;
1617
1618 out4:
1619         usb_free_urb(dev->interrupt);
1620 out3:
1621         if (info->unbind)
1622                 info->unbind (dev, udev);
1623 out1:
1624         free_netdev(net);
1625 out:
1626         return status;
1627 }
1628 EXPORT_SYMBOL_GPL(usbnet_probe);
1629
1630 /*-------------------------------------------------------------------------*/
1631
1632 /*
1633  * suspend the whole driver as soon as the first interface is suspended
1634  * resume only when the last interface is resumed
1635  */
1636
1637 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1638 {
1639         struct usbnet           *dev = usb_get_intfdata(intf);
1640
1641         if (!dev->suspend_count++) {
1642                 spin_lock_irq(&dev->txq.lock);
1643                 /* don't autosuspend while transmitting */
1644                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1645                         dev->suspend_count--;
1646                         spin_unlock_irq(&dev->txq.lock);
1647                         return -EBUSY;
1648                 } else {
1649                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1650                         spin_unlock_irq(&dev->txq.lock);
1651                 }
1652                 /*
1653                  * accelerate emptying of the rx and queues, to avoid
1654                  * having everything error out.
1655                  */
1656                 netif_device_detach (dev->net);
1657                 usbnet_terminate_urbs(dev);
1658                 __usbnet_status_stop_force(dev);
1659
1660                 /*
1661                  * reattach so runtime management can use and
1662                  * wake the device
1663                  */
1664                 netif_device_attach (dev->net);
1665         }
1666         return 0;
1667 }
1668 EXPORT_SYMBOL_GPL(usbnet_suspend);
1669
1670 int usbnet_resume (struct usb_interface *intf)
1671 {
1672         struct usbnet           *dev = usb_get_intfdata(intf);
1673         struct sk_buff          *skb;
1674         struct urb              *res;
1675         int                     retval;
1676
1677         if (!--dev->suspend_count) {
1678                 /* resume interrupt URB if it was previously submitted */
1679                 __usbnet_status_start_force(dev, GFP_NOIO);
1680
1681                 spin_lock_irq(&dev->txq.lock);
1682                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1683
1684                         skb = (struct sk_buff *)res->context;
1685                         retval = usb_submit_urb(res, GFP_ATOMIC);
1686                         if (retval < 0) {
1687                                 dev_kfree_skb_any(skb);
1688                                 usb_free_urb(res);
1689                                 usb_autopm_put_interface_async(dev->intf);
1690                         } else {
1691                                 dev->net->trans_start = jiffies;
1692                                 __skb_queue_tail(&dev->txq, skb);
1693                         }
1694                 }
1695
1696                 smp_mb();
1697                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1698                 spin_unlock_irq(&dev->txq.lock);
1699
1700                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1701                         /* handle remote wakeup ASAP
1702                          * we cannot race against stop
1703                          */
1704                         if (netif_device_present(dev->net) &&
1705                                 !timer_pending(&dev->delay) &&
1706                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1707                                         rx_alloc_submit(dev, GFP_NOIO);
1708
1709                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1710                                 netif_tx_wake_all_queues(dev->net);
1711                         tasklet_schedule (&dev->bh);
1712                 }
1713         }
1714
1715         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1716                 usb_autopm_get_interface_no_resume(intf);
1717
1718         return 0;
1719 }
1720 EXPORT_SYMBOL_GPL(usbnet_resume);
1721
1722 /*
1723  * Either a subdriver implements manage_power, then it is assumed to always
1724  * be ready to be suspended or it reports the readiness to be suspended
1725  * explicitly
1726  */
1727 void usbnet_device_suggests_idle(struct usbnet *dev)
1728 {
1729         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1730                 dev->intf->needs_remote_wakeup = 1;
1731                 usb_autopm_put_interface_async(dev->intf);
1732         }
1733 }
1734 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1735
1736 /*
1737  * For devices that can do without special commands
1738  */
1739 int usbnet_manage_power(struct usbnet *dev, int on)
1740 {
1741         dev->intf->needs_remote_wakeup = on;
1742         return 0;
1743 }
1744 EXPORT_SYMBOL(usbnet_manage_power);
1745
1746 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1747 {
1748         /* update link after link is reseted */
1749         if (link && !need_reset)
1750                 netif_carrier_on(dev->net);
1751         else
1752                 netif_carrier_off(dev->net);
1753
1754         if (need_reset && link)
1755                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1756         else
1757                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1758 }
1759 EXPORT_SYMBOL(usbnet_link_change);
1760
1761 /*-------------------------------------------------------------------------*/
1762 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1763                              u16 value, u16 index, void *data, u16 size)
1764 {
1765         void *buf = NULL;
1766         int err = -ENOMEM;
1767
1768         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1769                    " value=0x%04x index=0x%04x size=%d\n",
1770                    cmd, reqtype, value, index, size);
1771
1772         if (data) {
1773                 buf = kmalloc(size, GFP_KERNEL);
1774                 if (!buf)
1775                         goto out;
1776         }
1777
1778         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1779                               cmd, reqtype, value, index, buf, size,
1780                               USB_CTRL_GET_TIMEOUT);
1781         if (err > 0 && err <= size)
1782                 memcpy(data, buf, err);
1783         kfree(buf);
1784 out:
1785         return err;
1786 }
1787
1788 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1789                               u16 value, u16 index, const void *data,
1790                               u16 size)
1791 {
1792         void *buf = NULL;
1793         int err = -ENOMEM;
1794
1795         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1796                    " value=0x%04x index=0x%04x size=%d\n",
1797                    cmd, reqtype, value, index, size);
1798
1799         if (data) {
1800                 buf = kmemdup(data, size, GFP_KERNEL);
1801                 if (!buf)
1802                         goto out;
1803         }
1804
1805         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1806                               cmd, reqtype, value, index, buf, size,
1807                               USB_CTRL_SET_TIMEOUT);
1808         kfree(buf);
1809
1810 out:
1811         return err;
1812 }
1813
1814 /*
1815  * The function can't be called inside suspend/resume callback,
1816  * otherwise deadlock will be caused.
1817  */
1818 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1819                     u16 value, u16 index, void *data, u16 size)
1820 {
1821         int ret;
1822
1823         if (usb_autopm_get_interface(dev->intf) < 0)
1824                 return -ENODEV;
1825         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1826                                 data, size);
1827         usb_autopm_put_interface(dev->intf);
1828         return ret;
1829 }
1830 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1831
1832 /*
1833  * The function can't be called inside suspend/resume callback,
1834  * otherwise deadlock will be caused.
1835  */
1836 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1837                      u16 value, u16 index, const void *data, u16 size)
1838 {
1839         int ret;
1840
1841         if (usb_autopm_get_interface(dev->intf) < 0)
1842                 return -ENODEV;
1843         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1844                                  data, size);
1845         usb_autopm_put_interface(dev->intf);
1846         return ret;
1847 }
1848 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1849
1850 /*
1851  * The function can be called inside suspend/resume callback safely
1852  * and should only be called by suspend/resume callback generally.
1853  */
1854 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1855                           u16 value, u16 index, void *data, u16 size)
1856 {
1857         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1858                                  data, size);
1859 }
1860 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1861
1862 /*
1863  * The function can be called inside suspend/resume callback safely
1864  * and should only be called by suspend/resume callback generally.
1865  */
1866 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1867                           u16 value, u16 index, const void *data,
1868                           u16 size)
1869 {
1870         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1871                                   data, size);
1872 }
1873 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1874
1875 static void usbnet_async_cmd_cb(struct urb *urb)
1876 {
1877         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
1878         int status = urb->status;
1879
1880         if (status < 0)
1881                 dev_dbg(&urb->dev->dev, "%s failed with %d",
1882                         __func__, status);
1883
1884         kfree(req);
1885         usb_free_urb(urb);
1886 }
1887
1888 /*
1889  * The caller must make sure that device can't be put into suspend
1890  * state until the control URB completes.
1891  */
1892 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
1893                            u16 value, u16 index, const void *data, u16 size)
1894 {
1895         struct usb_ctrlrequest *req = NULL;
1896         struct urb *urb;
1897         int err = -ENOMEM;
1898         void *buf = NULL;
1899
1900         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1901                    " value=0x%04x index=0x%04x size=%d\n",
1902                    cmd, reqtype, value, index, size);
1903
1904         urb = usb_alloc_urb(0, GFP_ATOMIC);
1905         if (!urb) {
1906                 netdev_err(dev->net, "Error allocating URB in"
1907                            " %s!\n", __func__);
1908                 goto fail;
1909         }
1910
1911         if (data) {
1912                 buf = kmemdup(data, size, GFP_ATOMIC);
1913                 if (!buf) {
1914                         netdev_err(dev->net, "Error allocating buffer"
1915                                    " in %s!\n", __func__);
1916                         goto fail_free;
1917                 }
1918         }
1919
1920         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
1921         if (!req)
1922                 goto fail_free_buf;
1923
1924         req->bRequestType = reqtype;
1925         req->bRequest = cmd;
1926         req->wValue = cpu_to_le16(value);
1927         req->wIndex = cpu_to_le16(index);
1928         req->wLength = cpu_to_le16(size);
1929
1930         usb_fill_control_urb(urb, dev->udev,
1931                              usb_sndctrlpipe(dev->udev, 0),
1932                              (void *)req, buf, size,
1933                              usbnet_async_cmd_cb, req);
1934         urb->transfer_flags |= URB_FREE_BUFFER;
1935
1936         err = usb_submit_urb(urb, GFP_ATOMIC);
1937         if (err < 0) {
1938                 netdev_err(dev->net, "Error submitting the control"
1939                            " message: status=%d\n", err);
1940                 goto fail_free;
1941         }
1942         return 0;
1943
1944 fail_free_buf:
1945         kfree(buf);
1946 fail_free:
1947         kfree(req);
1948         usb_free_urb(urb);
1949 fail:
1950         return err;
1951
1952 }
1953 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
1954 /*-------------------------------------------------------------------------*/
1955
1956 static int __init usbnet_init(void)
1957 {
1958         /* Compiler should optimize this out. */
1959         BUILD_BUG_ON(
1960                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
1961
1962         eth_random_addr(node_id);
1963         return 0;
1964 }
1965 module_init(usbnet_init);
1966
1967 static void __exit usbnet_exit(void)
1968 {
1969 }
1970 module_exit(usbnet_exit);
1971
1972 MODULE_AUTHOR("David Brownell");
1973 MODULE_DESCRIPTION("USB network driver framework");
1974 MODULE_LICENSE("GPL");