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/ethtool.h>
  41 #include <linux/workqueue.h>
  42 #include <linux/mii.h>
  43 #include <linux/usb.h>
  44 #include <linux/usb/usbnet.h>
  45
  46 #define DRIVER_VERSION          "22-Aug-2005"
  47
  48
  49 /*-------------------------------------------------------------------------*/
  50
  51 /*
  52  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  53  * Several dozen bytes of IPv4 data can fit in two such transactions.
  54  * One maximum size Ethernet packet takes twenty four of them.
  55  * For high speed, each frame comfortably fits almost 36 max size
  56  * Ethernet packets (so queues should be bigger).
  57  *
  58  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
  59  * let the USB host controller be busy for 5msec or more before an irq
  60  * is required, under load.  Jumbograms change the equation.
  61  */
  62 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
  63 #define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  64                         (RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
  65 #define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  66                         (RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
  67
  68 // reawaken network queue this soon after stopping; else watchdog barks
  69 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  70
  71 // throttle rx/tx briefly after some faults, so khubd might disconnect()
  72 // us (it polls at HZ/4 usually) before we report too many false errors.
  73 #define THROTTLE_JIFFIES        (HZ/8)
  74
  75 // between wakeups
  76 #define UNLINK_TIMEOUT_MS       3
  77
  78 /*-------------------------------------------------------------------------*/
  79
  80 // randomly generated ethernet address
  81 static u8       node_id [ETH_ALEN];
  82
  83 static const char driver_name [] = "usbnet";
  84
  85 /* use ethtool to change the level for any given device */
  86 static int msg_level = -1;
  87 module_param (msg_level, int, 0);
  88 MODULE_PARM_DESC (msg_level, "Override default message level");
  89
  90 /*-------------------------------------------------------------------------*/
  91
  92 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  93 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  94 {
  95         int                             tmp;
  96         struct usb_host_interface       *alt = NULL;
  97         struct usb_host_endpoint        *in = NULL, *out = NULL;
  98         struct usb_host_endpoint        *status = NULL;
  99
 100         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 101                 unsigned        ep;
 102
 103                 in = out = status = NULL;
 104                 alt = intf->altsetting + tmp;
 105
 106                 /* take the first altsetting with in-bulk + out-bulk;
 107                  * remember any status endpoint, just in case;
 108                  * ignore other endpoints and altsetttings.
 109                  */
 110                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 111                         struct usb_host_endpoint        *e;
 112                         int                             intr = 0;
 113
 114                         e = alt->endpoint + ep;
 115                         switch (e->desc.bmAttributes) {
 116                         case USB_ENDPOINT_XFER_INT:
 117                                 if (!usb_endpoint_dir_in(&e->desc))
 118                                         continue;
 119                                 intr = 1;
 120                                 /* FALLTHROUGH */
 121                         case USB_ENDPOINT_XFER_BULK:
 122                                 break;
 123                         default:
 124                                 continue;
 125                         }
 126                         if (usb_endpoint_dir_in(&e->desc)) {
 127                                 if (!intr && !in)
 128                                         in = e;
 129                                 else if (intr && !status)
 130                                         status = e;
 131                         } else {
 132                                 if (!out)
 133                                         out = e;
 134                         }
 135                 }
 136                 if (in && out)
 137                         break;
 138         }
 139         if (!alt || !in || !out)
 140                 return -EINVAL;
 141
 142         if (alt->desc.bAlternateSetting != 0
 143                         || !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 144                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 145                                 alt->desc.bAlternateSetting);
 146                 if (tmp < 0)
 147                         return tmp;
 148         }
 149
 150         dev->in = usb_rcvbulkpipe (dev->udev,
 151                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 152         dev->out = usb_sndbulkpipe (dev->udev,
 153                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 154         dev->status = status;
 155         return 0;
 156 }
 157 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 158
 159 static void intr_complete (struct urb *urb);
 160
 161 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 162 {
 163         char            *buf = NULL;
 164         unsigned        pipe = 0;
 165         unsigned        maxp;
 166         unsigned        period;
 167
 168         if (!dev->driver_info->status)
 169                 return 0;
 170
 171         pipe = usb_rcvintpipe (dev->udev,
 172                         dev->status->desc.bEndpointAddress
 173                                 & USB_ENDPOINT_NUMBER_MASK);
 174         maxp = usb_maxpacket (dev->udev, pipe, 0);
 175
 176         /* avoid 1 msec chatter:  min 8 msec poll rate */
 177         period = max ((int) dev->status->desc.bInterval,
 178                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 179
 180         buf = kmalloc (maxp, GFP_KERNEL);
 181         if (buf) {
 182                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 183                 if (!dev->interrupt) {
 184                         kfree (buf);
 185                         return -ENOMEM;
 186                 } else {
 187                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 188                                 buf, maxp, intr_complete, dev, period);
 189                         dev_dbg(&intf->dev,
 190                                 "status ep%din, %d bytes period %d\n",
 191                                 usb_pipeendpoint(pipe), maxp, period);
 192                 }
 193         }
 194         return 0;
 195 }
 196
 197 /* Passes this packet up the stack, updating its accounting.
 198  * Some link protocols batch packets, so their rx_fixup paths
 199  * can return clones as well as just modify the original skb.
 200  */
 201 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 202 {
 203         int     status;
 204
 205         skb->protocol = eth_type_trans (skb, dev->net);
 206         dev->stats.rx_packets++;
 207         dev->stats.rx_bytes += skb->len;
 208
 209         if (netif_msg_rx_status (dev))
 210                 devdbg (dev, "< rx, len %zu, type 0x%x",
 211                         skb->len + sizeof (struct ethhdr), skb->protocol);
 212         memset (skb->cb, 0, sizeof (struct skb_data));
 213         status = netif_rx (skb);
 214         if (status != NET_RX_SUCCESS && netif_msg_rx_err (dev))
 215                 devdbg (dev, "netif_rx status %d", status);
 216 }
 217 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 218
 219 \f
 220 /*-------------------------------------------------------------------------
 221  *
 222  * Network Device Driver (peer link to "Host Device", from USB host)
 223  *
 224  *-------------------------------------------------------------------------*/
 225
 226 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 227 {
 228         struct usbnet   *dev = netdev_priv(net);
 229         int             ll_mtu = new_mtu + net->hard_header_len;
 230         int             old_hard_mtu = dev->hard_mtu;
 231         int             old_rx_urb_size = dev->rx_urb_size;
 232
 233         if (new_mtu <= 0)
 234                 return -EINVAL;
 235         // no second zero-length packet read wanted after mtu-sized packets
 236         if ((ll_mtu % dev->maxpacket) == 0)
 237                 return -EDOM;
 238         net->mtu = new_mtu;
 239
 240         dev->hard_mtu = net->mtu + net->hard_header_len;
 241         if (dev->rx_urb_size == old_hard_mtu) {
 242                 dev->rx_urb_size = dev->hard_mtu;
 243                 if (dev->rx_urb_size > old_rx_urb_size)
 244                         usbnet_unlink_rx_urbs(dev);
 245         }
 246
 247         return 0;
 248 }
 249 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 250
 251 /*-------------------------------------------------------------------------*/
 252
 253 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 254  * completion callbacks.  2.5 should have fixed those bugs...
 255  */
 256
 257 static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
 258 {
 259         unsigned long           flags;
 260
 261         spin_lock_irqsave(&list->lock, flags);
 262         __skb_unlink(skb, list);
 263         spin_unlock(&list->lock);
 264         spin_lock(&dev->done.lock);
 265         __skb_queue_tail(&dev->done, skb);
 266         if (dev->done.qlen == 1)
 267                 tasklet_schedule(&dev->bh);
 268         spin_unlock_irqrestore(&dev->done.lock, flags);
 269 }
 270
 271 /* some work can't be done in tasklets, so we use keventd
 272  *
 273  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 274  * but tasklet_schedule() doesn't.  hope the failure is rare.
 275  */
 276 void usbnet_defer_kevent (struct usbnet *dev, int work)
 277 {
 278         set_bit (work, &dev->flags);
 279         if (!schedule_work (&dev->kevent))
 280                 deverr (dev, "kevent %d may have been dropped", work);
 281         else
 282                 devdbg (dev, "kevent %d scheduled", work);
 283 }
 284 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 285
 286 /*-------------------------------------------------------------------------*/
 287
 288 static void rx_complete (struct urb *urb);
 289
 290 static void rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 291 {
 292         struct sk_buff          *skb;
 293         struct skb_data         *entry;
 294         int                     retval = 0;
 295         unsigned long           lockflags;
 296         size_t                  size = dev->rx_urb_size;
 297
 298         if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
 299                 if (netif_msg_rx_err (dev))
 300                         devdbg (dev, "no rx skb");
 301                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 302                 usb_free_urb (urb);
 303                 return;
 304         }
 305         skb_reserve (skb, NET_IP_ALIGN);
 306
 307         entry = (struct skb_data *) skb->cb;
 308         entry->urb = urb;
 309         entry->dev = dev;
 310         entry->state = rx_start;
 311         entry->length = 0;
 312
 313         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 314                 skb->data, size, rx_complete, skb);
 315
 316         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 317
 318         if (netif_running (dev->net)
 319                         && netif_device_present (dev->net)
 320                         && !test_bit (EVENT_RX_HALT, &dev->flags)) {
 321                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 322                 case -EPIPE:
 323                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 324                         break;
 325                 case -ENOMEM:
 326                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 327                         break;
 328                 case -ENODEV:
 329                         if (netif_msg_ifdown (dev))
 330                                 devdbg (dev, "device gone");
 331                         netif_device_detach (dev->net);
 332                         break;
 333                 default:
 334                         if (netif_msg_rx_err (dev))
 335                                 devdbg (dev, "rx submit, %d", retval);
 336                         tasklet_schedule (&dev->bh);
 337                         break;
 338                 case 0:
 339                         __skb_queue_tail (&dev->rxq, skb);
 340                 }
 341         } else {
 342                 if (netif_msg_ifdown (dev))
 343                         devdbg (dev, "rx: stopped");
 344                 retval = -ENOLINK;
 345         }
 346         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 347         if (retval) {
 348                 dev_kfree_skb_any (skb);
 349                 usb_free_urb (urb);
 350         }
 351 }
 352
 353
 354 /*-------------------------------------------------------------------------*/
 355
 356 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 357 {
 358         if (dev->driver_info->rx_fixup
 359                         && !dev->driver_info->rx_fixup (dev, skb))
 360                 goto error;
 361         // else network stack removes extra byte if we forced a short packet
 362
 363         if (skb->len)
 364                 usbnet_skb_return (dev, skb);
 365         else {
 366                 if (netif_msg_rx_err (dev))
 367                         devdbg (dev, "drop");
 368 error:
 369                 dev->stats.rx_errors++;
 370                 skb_queue_tail (&dev->done, skb);
 371         }
 372 }
 373
 374 /*-------------------------------------------------------------------------*/
 375
 376 static void rx_complete (struct urb *urb)
 377 {
 378         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 379         struct skb_data         *entry = (struct skb_data *) skb->cb;
 380         struct usbnet           *dev = entry->dev;
 381         int                     urb_status = urb->status;
 382
 383         skb_put (skb, urb->actual_length);
 384         entry->state = rx_done;
 385         entry->urb = NULL;
 386
 387         switch (urb_status) {
 388         /* success */
 389         case 0:
 390                 if (skb->len < dev->net->hard_header_len) {
 391                         entry->state = rx_cleanup;
 392                         dev->stats.rx_errors++;
 393                         dev->stats.rx_length_errors++;
 394                         if (netif_msg_rx_err (dev))
 395                                 devdbg (dev, "rx length %d", skb->len);
 396                 }
 397                 break;
 398
 399         /* stalls need manual reset. this is rare ... except that
 400          * when going through USB 2.0 TTs, unplug appears this way.
 401          * we avoid the highspeed version of the ETIMEOUT/EILSEQ
 402          * storm, recovering as needed.
 403          */
 404         case -EPIPE:
 405                 dev->stats.rx_errors++;
 406                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 407                 // FALLTHROUGH
 408
 409         /* software-driven interface shutdown */
 410         case -ECONNRESET:               /* async unlink */
 411         case -ESHUTDOWN:                /* hardware gone */
 412                 if (netif_msg_ifdown (dev))
 413                         devdbg (dev, "rx shutdown, code %d", urb_status);
 414                 goto block;
 415
 416         /* we get controller i/o faults during khubd disconnect() delays.
 417          * throttle down resubmits, to avoid log floods; just temporarily,
 418          * so we still recover when the fault isn't a khubd delay.
 419          */
 420         case -EPROTO:
 421         case -ETIME:
 422         case -EILSEQ:
 423                 dev->stats.rx_errors++;
 424                 if (!timer_pending (&dev->delay)) {
 425                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 426                         if (netif_msg_link (dev))
 427                                 devdbg (dev, "rx throttle %d", urb_status);
 428                 }
 429 block:
 430                 entry->state = rx_cleanup;
 431                 entry->urb = urb;
 432                 urb = NULL;
 433                 break;
 434
 435         /* data overrun ... flush fifo? */
 436         case -EOVERFLOW:
 437                 dev->stats.rx_over_errors++;
 438                 // FALLTHROUGH
 439
 440         default:
 441                 entry->state = rx_cleanup;
 442                 dev->stats.rx_errors++;
 443                 if (netif_msg_rx_err (dev))
 444                         devdbg (dev, "rx status %d", urb_status);
 445                 break;
 446         }
 447
 448         defer_bh(dev, skb, &dev->rxq);
 449
 450         if (urb) {
 451                 if (netif_running (dev->net)
 452                                 && !test_bit (EVENT_RX_HALT, &dev->flags)) {
 453                         rx_submit (dev, urb, GFP_ATOMIC);
 454                         return;
 455                 }
 456                 usb_free_urb (urb);
 457         }
 458         if (netif_msg_rx_err (dev))
 459                 devdbg (dev, "no read resubmitted");
 460 }
 461
 462 static void intr_complete (struct urb *urb)
 463 {
 464         struct usbnet   *dev = urb->context;
 465         int             status = urb->status;
 466
 467         switch (status) {
 468         /* success */
 469         case 0:
 470                 dev->driver_info->status(dev, urb);
 471                 break;
 472
 473         /* software-driven interface shutdown */
 474         case -ENOENT:           /* urb killed */
 475         case -ESHUTDOWN:        /* hardware gone */
 476                 if (netif_msg_ifdown (dev))
 477                         devdbg (dev, "intr shutdown, code %d", status);
 478                 return;
 479
 480         /* NOTE:  not throttling like RX/TX, since this endpoint
 481          * already polls infrequently
 482          */
 483         default:
 484                 devdbg (dev, "intr status %d", status);
 485                 break;
 486         }
 487
 488         if (!netif_running (dev->net))
 489                 return;
 490
 491         memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
 492         status = usb_submit_urb (urb, GFP_ATOMIC);
 493         if (status != 0 && netif_msg_timer (dev))
 494                 deverr(dev, "intr resubmit --> %d", status);
 495 }
 496
 497 /*-------------------------------------------------------------------------*/
 498
 499 // unlink pending rx/tx; completion handlers do all other cleanup
 500
 501 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 502 {
 503         unsigned long           flags;
 504         struct sk_buff          *skb, *skbnext;
 505         int                     count = 0;
 506
 507         spin_lock_irqsave (&q->lock, flags);
 508         skb_queue_walk_safe(q, skb, skbnext) {
 509                 struct skb_data         *entry;
 510                 struct urb              *urb;
 511                 int                     retval;
 512
 513                 entry = (struct skb_data *) skb->cb;
 514                 urb = entry->urb;
 515
 516                 // during some PM-driven resume scenarios,
 517                 // these (async) unlinks complete immediately
 518                 retval = usb_unlink_urb (urb);
 519                 if (retval != -EINPROGRESS && retval != 0)
 520                         devdbg (dev, "unlink urb err, %d", retval);
 521                 else
 522                         count++;
 523         }
 524         spin_unlock_irqrestore (&q->lock, flags);
 525         return count;
 526 }
 527
 528 // Flush all pending rx urbs
 529 // minidrivers may need to do this when the MTU changes
 530
 531 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 532 {
 533         if (netif_running(dev->net)) {
 534                 (void) unlink_urbs (dev, &dev->rxq);
 535                 tasklet_schedule(&dev->bh);
 536         }
 537 }
 538 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 539
 540 /*-------------------------------------------------------------------------*/
 541
 542 // precondition: never called in_interrupt
 543
 544 int usbnet_stop (struct net_device *net)
 545 {
 546         struct usbnet           *dev = netdev_priv(net);
 547         int                     temp;
 548         DECLARE_WAIT_QUEUE_HEAD_ONSTACK (unlink_wakeup);
 549         DECLARE_WAITQUEUE (wait, current);
 550
 551         netif_stop_queue (net);
 552
 553         if (netif_msg_ifdown (dev))
 554                 devinfo (dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld",
 555                         dev->stats.rx_packets, dev->stats.tx_packets,
 556                         dev->stats.rx_errors, dev->stats.tx_errors
 557                         );
 558
 559         // ensure there are no more active urbs
 560         add_wait_queue (&unlink_wakeup, &wait);
 561         dev->wait = &unlink_wakeup;
 562         temp = unlink_urbs (dev, &dev->txq) + unlink_urbs (dev, &dev->rxq);
 563
 564         // maybe wait for deletions to finish.
 565         while (!skb_queue_empty(&dev->rxq)
 566                         && !skb_queue_empty(&dev->txq)
 567                         && !skb_queue_empty(&dev->done)) {
 568                 msleep(UNLINK_TIMEOUT_MS);
 569                 if (netif_msg_ifdown (dev))
 570                         devdbg (dev, "waited for %d urb completions", temp);
 571         }
 572         dev->wait = NULL;
 573         remove_wait_queue (&unlink_wakeup, &wait);
 574
 575         usb_kill_urb(dev->interrupt);
 576
 577         /* deferred work (task, timer, softirq) must also stop.
 578          * can't flush_scheduled_work() until we drop rtnl (later),
 579          * else workers could deadlock; so make workers a NOP.
 580          */
 581         dev->flags = 0;
 582         del_timer_sync (&dev->delay);
 583         tasklet_kill (&dev->bh);
 584         usb_autopm_put_interface(dev->intf);
 585
 586         return 0;
 587 }
 588 EXPORT_SYMBOL_GPL(usbnet_stop);
 589
 590 /*-------------------------------------------------------------------------*/
 591
 592 // posts reads, and enables write queuing
 593
 594 // precondition: never called in_interrupt
 595
 596 int usbnet_open (struct net_device *net)
 597 {
 598         struct usbnet           *dev = netdev_priv(net);
 599         int                     retval;
 600         struct driver_info      *info = dev->driver_info;
 601
 602         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 603                 if (netif_msg_ifup (dev))
 604                         devinfo (dev,
 605                                 "resumption fail (%d) usbnet usb-%s-%s, %s",
 606                                 retval,
 607                                 dev->udev->bus->bus_name, dev->udev->devpath,
 608                         info->description);
 609                 goto done_nopm;
 610         }
 611
 612         // put into "known safe" state
 613         if (info->reset && (retval = info->reset (dev)) < 0) {
 614                 if (netif_msg_ifup (dev))
 615                         devinfo (dev,
 616                                 "open reset fail (%d) usbnet usb-%s-%s, %s",
 617                                 retval,
 618                                 dev->udev->bus->bus_name, dev->udev->devpath,
 619                         info->description);
 620                 goto done;
 621         }
 622
 623         // insist peer be connected
 624         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 625                 if (netif_msg_ifup (dev))
 626                         devdbg (dev, "can't open; %d", retval);
 627                 goto done;
 628         }
 629
 630         /* start any status interrupt transfer */
 631         if (dev->interrupt) {
 632                 retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 633                 if (retval < 0) {
 634                         if (netif_msg_ifup (dev))
 635                                 deverr (dev, "intr submit %d", retval);
 636                         goto done;
 637                 }
 638         }
 639
 640         netif_start_queue (net);
 641         if (netif_msg_ifup (dev)) {
 642                 char    *framing;
 643
 644                 if (dev->driver_info->flags & FLAG_FRAMING_NC)
 645                         framing = "NetChip";
 646                 else if (dev->driver_info->flags & FLAG_FRAMING_GL)
 647                         framing = "GeneSys";
 648                 else if (dev->driver_info->flags & FLAG_FRAMING_Z)
 649                         framing = "Zaurus";
 650                 else if (dev->driver_info->flags & FLAG_FRAMING_RN)
 651                         framing = "RNDIS";
 652                 else if (dev->driver_info->flags & FLAG_FRAMING_AX)
 653                         framing = "ASIX";
 654                 else
 655                         framing = "simple";
 656
 657                 devinfo (dev, "open: enable queueing "
 658                                 "(rx %d, tx %d) mtu %d %s framing",
 659                         (int)RX_QLEN (dev), (int)TX_QLEN (dev), dev->net->mtu,
 660                         framing);
 661         }
 662
 663         // delay posting reads until we're fully open
 664         tasklet_schedule (&dev->bh);
 665         return retval;
 666 done:
 667         usb_autopm_put_interface(dev->intf);
 668 done_nopm:
 669         return retval;
 670 }
 671 EXPORT_SYMBOL_GPL(usbnet_open);
 672
 673 /*-------------------------------------------------------------------------*/
 674
 675 /* ethtool methods; minidrivers may need to add some more, but
 676  * they'll probably want to use this base set.
 677  */
 678
 679 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 680 {
 681         struct usbnet *dev = netdev_priv(net);
 682
 683         if (!dev->mii.mdio_read)
 684                 return -EOPNOTSUPP;
 685
 686         return mii_ethtool_gset(&dev->mii, cmd);
 687 }
 688 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 689
 690 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 691 {
 692         struct usbnet *dev = netdev_priv(net);
 693         int retval;
 694
 695         if (!dev->mii.mdio_write)
 696                 return -EOPNOTSUPP;
 697
 698         retval = mii_ethtool_sset(&dev->mii, cmd);
 699
 700         /* link speed/duplex might have changed */
 701         if (dev->driver_info->link_reset)
 702                 dev->driver_info->link_reset(dev);
 703
 704         return retval;
 705
 706 }
 707 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 708
 709 u32 usbnet_get_link (struct net_device *net)
 710 {
 711         struct usbnet *dev = netdev_priv(net);
 712
 713         /* If a check_connect is defined, return its result */
 714         if (dev->driver_info->check_connect)
 715                 return dev->driver_info->check_connect (dev) == 0;
 716
 717         /* if the device has mii operations, use those */
 718         if (dev->mii.mdio_read)
 719                 return mii_link_ok(&dev->mii);
 720
 721         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 722         return ethtool_op_get_link(net);
 723 }
 724 EXPORT_SYMBOL_GPL(usbnet_get_link);
 725
 726 int usbnet_nway_reset(struct net_device *net)
 727 {
 728         struct usbnet *dev = netdev_priv(net);
 729
 730         if (!dev->mii.mdio_write)
 731                 return -EOPNOTSUPP;
 732
 733         return mii_nway_restart(&dev->mii);
 734 }
 735 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 736
 737 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 738 {
 739         struct usbnet *dev = netdev_priv(net);
 740
 741         strncpy (info->driver, dev->driver_name, sizeof info->driver);
 742         strncpy (info->version, DRIVER_VERSION, sizeof info->version);
 743         strncpy (info->fw_version, dev->driver_info->description,
 744                 sizeof info->fw_version);
 745         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 746 }
 747 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 748
 749 u32 usbnet_get_msglevel (struct net_device *net)
 750 {
 751         struct usbnet *dev = netdev_priv(net);
 752
 753         return dev->msg_enable;
 754 }
 755 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 756
 757 void usbnet_set_msglevel (struct net_device *net, u32 level)
 758 {
 759         struct usbnet *dev = netdev_priv(net);
 760
 761         dev->msg_enable = level;
 762 }
 763 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 764
 765 /* drivers may override default ethtool_ops in their bind() routine */
 766 static struct ethtool_ops usbnet_ethtool_ops = {
 767         .get_settings           = usbnet_get_settings,
 768         .set_settings           = usbnet_set_settings,
 769         .get_link               = usbnet_get_link,
 770         .nway_reset             = usbnet_nway_reset,
 771         .get_drvinfo            = usbnet_get_drvinfo,
 772         .get_msglevel           = usbnet_get_msglevel,
 773         .set_msglevel           = usbnet_set_msglevel,
 774 };
 775
 776 /*-------------------------------------------------------------------------*/
 777
 778 /* work that cannot be done in interrupt context uses keventd.
 779  *
 780  * NOTE:  with 2.5 we could do more of this using completion callbacks,
 781  * especially now that control transfers can be queued.
 782  */
 783 static void
 784 kevent (struct work_struct *work)
 785 {
 786         struct usbnet           *dev =
 787                 container_of(work, struct usbnet, kevent);
 788         int                     status;
 789
 790         /* usb_clear_halt() needs a thread context */
 791         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 792                 unlink_urbs (dev, &dev->txq);
 793                 status = usb_clear_halt (dev->udev, dev->out);
 794                 if (status < 0
 795                                 && status != -EPIPE
 796                                 && status != -ESHUTDOWN) {
 797                         if (netif_msg_tx_err (dev))
 798                                 deverr (dev, "can't clear tx halt, status %d",
 799                                         status);
 800                 } else {
 801                         clear_bit (EVENT_TX_HALT, &dev->flags);
 802                         if (status != -ESHUTDOWN)
 803                                 netif_wake_queue (dev->net);
 804                 }
 805         }
 806         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 807                 unlink_urbs (dev, &dev->rxq);
 808                 status = usb_clear_halt (dev->udev, dev->in);
 809                 if (status < 0
 810                                 && status != -EPIPE
 811                                 && status != -ESHUTDOWN) {
 812                         if (netif_msg_rx_err (dev))
 813                                 deverr (dev, "can't clear rx halt, status %d",
 814                                         status);
 815                 } else {
 816                         clear_bit (EVENT_RX_HALT, &dev->flags);
 817                         tasklet_schedule (&dev->bh);
 818                 }
 819         }
 820
 821         /* tasklet could resubmit itself forever if memory is tight */
 822         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 823                 struct urb      *urb = NULL;
 824
 825                 if (netif_running (dev->net))
 826                         urb = usb_alloc_urb (0, GFP_KERNEL);
 827                 else
 828                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 829                 if (urb != NULL) {
 830                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 831                         rx_submit (dev, urb, GFP_KERNEL);
 832                         tasklet_schedule (&dev->bh);
 833                 }
 834         }
 835
 836         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
 837                 struct driver_info      *info = dev->driver_info;
 838                 int                     retval = 0;
 839
 840                 clear_bit (EVENT_LINK_RESET, &dev->flags);
 841                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
 842                         devinfo(dev, "link reset failed (%d) usbnet usb-%s-%s, %s",
 843                                 retval,
 844                                 dev->udev->bus->bus_name, dev->udev->devpath,
 845                                 info->description);
 846                 }
 847         }
 848
 849         if (dev->flags)
 850                 devdbg (dev, "kevent done, flags = 0x%lx",
 851                         dev->flags);
 852 }
 853
 854 /*-------------------------------------------------------------------------*/
 855
 856 static void tx_complete (struct urb *urb)
 857 {
 858         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 859         struct skb_data         *entry = (struct skb_data *) skb->cb;
 860         struct usbnet           *dev = entry->dev;
 861
 862         if (urb->status == 0) {
 863                 dev->stats.tx_packets++;
 864                 dev->stats.tx_bytes += entry->length;
 865         } else {
 866                 dev->stats.tx_errors++;
 867
 868                 switch (urb->status) {
 869                 case -EPIPE:
 870                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
 871                         break;
 872
 873                 /* software-driven interface shutdown */
 874                 case -ECONNRESET:               // async unlink
 875                 case -ESHUTDOWN:                // hardware gone
 876                         break;
 877
 878                 // like rx, tx gets controller i/o faults during khubd delays
 879                 // and so it uses the same throttling mechanism.
 880                 case -EPROTO:
 881                 case -ETIME:
 882                 case -EILSEQ:
 883                         if (!timer_pending (&dev->delay)) {
 884                                 mod_timer (&dev->delay,
 885                                         jiffies + THROTTLE_JIFFIES);
 886                                 if (netif_msg_link (dev))
 887                                         devdbg (dev, "tx throttle %d",
 888                                                         urb->status);
 889                         }
 890                         netif_stop_queue (dev->net);
 891                         break;
 892                 default:
 893                         if (netif_msg_tx_err (dev))
 894                                 devdbg (dev, "tx err %d", entry->urb->status);
 895                         break;
 896                 }
 897         }
 898
 899         urb->dev = NULL;
 900         entry->state = tx_done;
 901         defer_bh(dev, skb, &dev->txq);
 902 }
 903
 904 /*-------------------------------------------------------------------------*/
 905
 906 void usbnet_tx_timeout (struct net_device *net)
 907 {
 908         struct usbnet           *dev = netdev_priv(net);
 909
 910         unlink_urbs (dev, &dev->txq);
 911         tasklet_schedule (&dev->bh);
 912
 913         // FIXME: device recovery -- reset?
 914 }
 915 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
 916
 917 /*-------------------------------------------------------------------------*/
 918
 919 int usbnet_start_xmit (struct sk_buff *skb, struct net_device *net)
 920 {
 921         struct usbnet           *dev = netdev_priv(net);
 922         int                     length;
 923         int                     retval = NET_XMIT_SUCCESS;
 924         struct urb              *urb = NULL;
 925         struct skb_data         *entry;
 926         struct driver_info      *info = dev->driver_info;
 927         unsigned long           flags;
 928
 929         // some devices want funky USB-level framing, for
 930         // win32 driver (usually) and/or hardware quirks
 931         if (info->tx_fixup) {
 932                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
 933                 if (!skb) {
 934                         if (netif_msg_tx_err (dev))
 935                                 devdbg (dev, "can't tx_fixup skb");
 936                         goto drop;
 937                 }
 938         }
 939         length = skb->len;
 940
 941         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
 942                 if (netif_msg_tx_err (dev))
 943                         devdbg (dev, "no urb");
 944                 goto drop;
 945         }
 946
 947         entry = (struct skb_data *) skb->cb;
 948         entry->urb = urb;
 949         entry->dev = dev;
 950         entry->state = tx_start;
 951         entry->length = length;
 952
 953         usb_fill_bulk_urb (urb, dev->udev, dev->out,
 954                         skb->data, skb->len, tx_complete, skb);
 955
 956         /* don't assume the hardware handles USB_ZERO_PACKET
 957          * NOTE:  strictly conforming cdc-ether devices should expect
 958          * the ZLP here, but ignore the one-byte packet.
 959          */
 960         if ((length % dev->maxpacket) == 0) {
 961                 urb->transfer_buffer_length++;
 962                 if (skb_tailroom(skb)) {
 963                         skb->data[skb->len] = 0;
 964                         __skb_put(skb, 1);
 965                 }
 966         }
 967
 968         spin_lock_irqsave (&dev->txq.lock, flags);
 969
 970         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
 971         case -EPIPE:
 972                 netif_stop_queue (net);
 973                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
 974                 break;
 975         default:
 976                 if (netif_msg_tx_err (dev))
 977                         devdbg (dev, "tx: submit urb err %d", retval);
 978                 break;
 979         case 0:
 980                 net->trans_start = jiffies;
 981                 __skb_queue_tail (&dev->txq, skb);
 982                 if (dev->txq.qlen >= TX_QLEN (dev))
 983                         netif_stop_queue (net);
 984         }
 985         spin_unlock_irqrestore (&dev->txq.lock, flags);
 986
 987         if (retval) {
 988                 if (netif_msg_tx_err (dev))
 989                         devdbg (dev, "drop, code %d", retval);
 990 drop:
 991                 retval = NET_XMIT_SUCCESS;
 992                 dev->stats.tx_dropped++;
 993                 if (skb)
 994                         dev_kfree_skb_any (skb);
 995                 usb_free_urb (urb);
 996         } else if (netif_msg_tx_queued (dev)) {
 997                 devdbg (dev, "> tx, len %d, type 0x%x",
 998                         length, skb->protocol);
 999         }
1000         return retval;
1001 }
1002 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1003
1004 /*-------------------------------------------------------------------------*/
1005
1006 // tasklet (work deferred from completions, in_irq) or timer
1007
1008 static void usbnet_bh (unsigned long param)
1009 {
1010         struct usbnet           *dev = (struct usbnet *) param;
1011         struct sk_buff          *skb;
1012         struct skb_data         *entry;
1013
1014         while ((skb = skb_dequeue (&dev->done))) {
1015                 entry = (struct skb_data *) skb->cb;
1016                 switch (entry->state) {
1017                 case rx_done:
1018                         entry->state = rx_cleanup;
1019                         rx_process (dev, skb);
1020                         continue;
1021                 case tx_done:
1022                 case rx_cleanup:
1023                         usb_free_urb (entry->urb);
1024                         dev_kfree_skb (skb);
1025                         continue;
1026                 default:
1027                         devdbg (dev, "bogus skb state %d", entry->state);
1028                 }
1029         }
1030
1031         // waiting for all pending urbs to complete?
1032         if (dev->wait) {
1033                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1034                         wake_up (dev->wait);
1035                 }
1036
1037         // or are we maybe short a few urbs?
1038         } else if (netif_running (dev->net)
1039                         && netif_device_present (dev->net)
1040                         && !timer_pending (&dev->delay)
1041                         && !test_bit (EVENT_RX_HALT, &dev->flags)) {
1042                 int     temp = dev->rxq.qlen;
1043                 int     qlen = RX_QLEN (dev);
1044
1045                 if (temp < qlen) {
1046                         struct urb      *urb;
1047                         int             i;
1048
1049                         // don't refill the queue all at once
1050                         for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1051                                 urb = usb_alloc_urb (0, GFP_ATOMIC);
1052                                 if (urb != NULL)
1053                                         rx_submit (dev, urb, GFP_ATOMIC);
1054                         }
1055                         if (temp != dev->rxq.qlen && netif_msg_link (dev))
1056                                 devdbg (dev, "rxqlen %d --> %d",
1057                                                 temp, dev->rxq.qlen);
1058                         if (dev->rxq.qlen < qlen)
1059                                 tasklet_schedule (&dev->bh);
1060                 }
1061                 if (dev->txq.qlen < TX_QLEN (dev))
1062                         netif_wake_queue (dev->net);
1063         }
1064 }
1065
1066
1067 \f
1068 /*-------------------------------------------------------------------------
1069  *
1070  * USB Device Driver support
1071  *
1072  *-------------------------------------------------------------------------*/
1073
1074 // precondition: never called in_interrupt
1075
1076 void usbnet_disconnect (struct usb_interface *intf)
1077 {
1078         struct usbnet           *dev;
1079         struct usb_device       *xdev;
1080         struct net_device       *net;
1081
1082         dev = usb_get_intfdata(intf);
1083         usb_set_intfdata(intf, NULL);
1084         if (!dev)
1085                 return;
1086
1087         xdev = interface_to_usbdev (intf);
1088
1089         if (netif_msg_probe (dev))
1090                 devinfo (dev, "unregister '%s' usb-%s-%s, %s",
1091                         intf->dev.driver->name,
1092                         xdev->bus->bus_name, xdev->devpath,
1093                         dev->driver_info->description);
1094
1095         net = dev->net;
1096         unregister_netdev (net);
1097
1098         /* we don't hold rtnl here ... */
1099         flush_scheduled_work ();
1100
1101         if (dev->driver_info->unbind)
1102                 dev->driver_info->unbind (dev, intf);
1103
1104         free_netdev(net);
1105         usb_put_dev (xdev);
1106 }
1107 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1108
1109 static const struct net_device_ops usbnet_netdev_ops = {
1110         .ndo_open               = usbnet_open,
1111         .ndo_stop               = usbnet_stop,
1112         .ndo_start_xmit         = usbnet_start_xmit,
1113         .ndo_tx_timeout         = usbnet_tx_timeout,
1114         .ndo_change_mtu         = usbnet_change_mtu,
1115         .ndo_set_mac_address    = eth_mac_addr,
1116         .ndo_validate_addr      = eth_validate_addr,
1117 };
1118
1119 /*-------------------------------------------------------------------------*/
1120
1121 // precondition: never called in_interrupt
1122
1123 int
1124 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1125 {
1126         struct usbnet                   *dev;
1127         struct net_device               *net;
1128         struct usb_host_interface       *interface;
1129         struct driver_info              *info;
1130         struct usb_device               *xdev;
1131         int                             status;
1132         const char                      *name;
1133
1134         name = udev->dev.driver->name;
1135         info = (struct driver_info *) prod->driver_info;
1136         if (!info) {
1137                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1138                 return -ENODEV;
1139         }
1140         xdev = interface_to_usbdev (udev);
1141         interface = udev->cur_altsetting;
1142
1143         usb_get_dev (xdev);
1144
1145         status = -ENOMEM;
1146
1147         // set up our own records
1148         net = alloc_etherdev(sizeof(*dev));
1149         if (!net) {
1150                 dbg ("can't kmalloc dev");
1151                 goto out;
1152         }
1153
1154         dev = netdev_priv(net);
1155         dev->udev = xdev;
1156         dev->intf = udev;
1157         dev->driver_info = info;
1158         dev->driver_name = name;
1159         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1160                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1161         skb_queue_head_init (&dev->rxq);
1162         skb_queue_head_init (&dev->txq);
1163         skb_queue_head_init (&dev->done);
1164         dev->bh.func = usbnet_bh;
1165         dev->bh.data = (unsigned long) dev;
1166         INIT_WORK (&dev->kevent, kevent);
1167         dev->delay.function = usbnet_bh;
1168         dev->delay.data = (unsigned long) dev;
1169         init_timer (&dev->delay);
1170         mutex_init (&dev->phy_mutex);
1171
1172         dev->net = net;
1173         strcpy (net->name, "usb%d");
1174         memcpy (net->dev_addr, node_id, sizeof node_id);
1175
1176         /* rx and tx sides can use different message sizes;
1177          * bind() should set rx_urb_size in that case.
1178          */
1179         dev->hard_mtu = net->mtu + net->hard_header_len;
1180 #if 0
1181 // dma_supported() is deeply broken on almost all architectures
1182         // possible with some EHCI controllers
1183         if (dma_supported (&udev->dev, DMA_64BIT_MASK))
1184                 net->features |= NETIF_F_HIGHDMA;
1185 #endif
1186
1187         net->netdev_ops = &usbnet_netdev_ops;
1188 #ifdef CONFIG_COMPAT_NET_DEV_OPS
1189         net->hard_start_xmit = usbnet_start_xmit;
1190         net->open = usbnet_open;
1191         net->stop = usbnet_stop;
1192         net->tx_timeout = usbnet_tx_timeout;
1193 #endif
1194         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1195         net->ethtool_ops = &usbnet_ethtool_ops;
1196
1197         // allow device-specific bind/init procedures
1198         // NOTE net->name still not usable ...
1199         if (info->bind) {
1200                 status = info->bind (dev, udev);
1201                 if (status < 0)
1202                         goto out1;
1203
1204                 // heuristic:  "usb%d" for links we know are two-host,
1205                 // else "eth%d" when there's reasonable doubt.  userspace
1206                 // can rename the link if it knows better.
1207                 if ((dev->driver_info->flags & FLAG_ETHER) != 0
1208                                 && (net->dev_addr [0] & 0x02) == 0)
1209                         strcpy (net->name, "eth%d");
1210                 /* WLAN devices should always be named "wlan%d" */
1211                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1212                         strcpy(net->name, "wlan%d");
1213
1214                 /* maybe the remote can't receive an Ethernet MTU */
1215                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1216                         net->mtu = dev->hard_mtu - net->hard_header_len;
1217         } else if (!info->in || !info->out)
1218                 status = usbnet_get_endpoints (dev, udev);
1219         else {
1220                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1221                 dev->out = usb_sndbulkpipe (xdev, info->out);
1222                 if (!(info->flags & FLAG_NO_SETINT))
1223                         status = usb_set_interface (xdev,
1224                                 interface->desc.bInterfaceNumber,
1225                                 interface->desc.bAlternateSetting);
1226                 else
1227                         status = 0;
1228
1229         }
1230         if (status >= 0 && dev->status)
1231                 status = init_status (dev, udev);
1232         if (status < 0)
1233                 goto out3;
1234
1235         if (!dev->rx_urb_size)
1236                 dev->rx_urb_size = dev->hard_mtu;
1237         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1238
1239         SET_NETDEV_DEV(net, &udev->dev);
1240         status = register_netdev (net);
1241         if (status)
1242                 goto out3;
1243         if (netif_msg_probe (dev))
1244                 devinfo (dev, "register '%s' at usb-%s-%s, %s, %pM",
1245                         udev->dev.driver->name,
1246                         xdev->bus->bus_name, xdev->devpath,
1247                         dev->driver_info->description,
1248                         net->dev_addr);
1249
1250         // ok, it's ready to go.
1251         usb_set_intfdata (udev, dev);
1252
1253         // start as if the link is up
1254         netif_device_attach (net);
1255
1256         return 0;
1257
1258 out3:
1259         if (info->unbind)
1260                 info->unbind (dev, udev);
1261 out1:
1262         free_netdev(net);
1263 out:
1264         usb_put_dev(xdev);
1265         return status;
1266 }
1267 EXPORT_SYMBOL_GPL(usbnet_probe);
1268
1269 /*-------------------------------------------------------------------------*/
1270
1271 /*
1272  * suspend the whole driver as soon as the first interface is suspended
1273  * resume only when the last interface is resumed
1274  */
1275
1276 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1277 {
1278         struct usbnet           *dev = usb_get_intfdata(intf);
1279
1280         if (!dev->suspend_count++) {
1281                 /*
1282                  * accelerate emptying of the rx and queues, to avoid
1283                  * having everything error out.
1284                  */
1285                 netif_device_detach (dev->net);
1286                 (void) unlink_urbs (dev, &dev->rxq);
1287                 (void) unlink_urbs (dev, &dev->txq);
1288                 /*
1289                  * reattach so runtime management can use and
1290                  * wake the device
1291                  */
1292                 netif_device_attach (dev->net);
1293         }
1294         return 0;
1295 }
1296 EXPORT_SYMBOL_GPL(usbnet_suspend);
1297
1298 int usbnet_resume (struct usb_interface *intf)
1299 {
1300         struct usbnet           *dev = usb_get_intfdata(intf);
1301
1302         if (!--dev->suspend_count)
1303                 tasklet_schedule (&dev->bh);
1304
1305         return 0;
1306 }
1307 EXPORT_SYMBOL_GPL(usbnet_resume);
1308
1309
1310 /*-------------------------------------------------------------------------*/
1311
1312 static int __init usbnet_init(void)
1313 {
1314         /* compiler should optimize this out */
1315         BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
1316                         < sizeof (struct skb_data));
1317
1318         random_ether_addr(node_id);
1319         return 0;
1320 }
1321 module_init(usbnet_init);
1322
1323 static void __exit usbnet_exit(void)
1324 {
1325 }
1326 module_exit(usbnet_exit);
1327
1328 MODULE_AUTHOR("David Brownell");
1329 MODULE_DESCRIPTION("USB network driver framework");
1330 MODULE_LICENSE("GPL");