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
  47 #define DRIVER_VERSION          "22-Aug-2005"
  48
  49
  50 /*-------------------------------------------------------------------------*/
  51
  52 /*
  53  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  54  * Several dozen bytes of IPv4 data can fit in two such transactions.
  55  * One maximum size Ethernet packet takes twenty four of them.
  56  * For high speed, each frame comfortably fits almost 36 max size
  57  * Ethernet packets (so queues should be bigger).
  58  *
  59  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
  60  * let the USB host controller be busy for 5msec or more before an irq
  61  * is required, under load.  Jumbograms change the equation.
  62  */
  63 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
  64 #define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  65                         (RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
  66 #define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  67                         (RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
  68
  69 // reawaken network queue this soon after stopping; else watchdog barks
  70 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  71
  72 // throttle rx/tx briefly after some faults, so khubd might disconnect()
  73 // us (it polls at HZ/4 usually) before we report too many false errors.
  74 #define THROTTLE_JIFFIES        (HZ/8)
  75
  76 // between wakeups
  77 #define UNLINK_TIMEOUT_MS       3
  78
  79 /*-------------------------------------------------------------------------*/
  80
  81 // randomly generated ethernet address
  82 static u8       node_id [ETH_ALEN];
  83
  84 static const char driver_name [] = "usbnet";
  85
  86 /* use ethtool to change the level for any given device */
  87 static int msg_level = -1;
  88 module_param (msg_level, int, 0);
  89 MODULE_PARM_DESC (msg_level, "Override default message level");
  90
  91 /*-------------------------------------------------------------------------*/
  92
  93 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  94 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  95 {
  96         int                             tmp;
  97         struct usb_host_interface       *alt = NULL;
  98         struct usb_host_endpoint        *in = NULL, *out = NULL;
  99         struct usb_host_endpoint        *status = NULL;
 100
 101         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 102                 unsigned        ep;
 103
 104                 in = out = status = NULL;
 105                 alt = intf->altsetting + tmp;
 106
 107                 /* take the first altsetting with in-bulk + out-bulk;
 108                  * remember any status endpoint, just in case;
 109                  * ignore other endpoints and altsetttings.
 110                  */
 111                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 112                         struct usb_host_endpoint        *e;
 113                         int                             intr = 0;
 114
 115                         e = alt->endpoint + ep;
 116                         switch (e->desc.bmAttributes) {
 117                         case USB_ENDPOINT_XFER_INT:
 118                                 if (!usb_endpoint_dir_in(&e->desc))
 119                                         continue;
 120                                 intr = 1;
 121                                 /* FALLTHROUGH */
 122                         case USB_ENDPOINT_XFER_BULK:
 123                                 break;
 124                         default:
 125                                 continue;
 126                         }
 127                         if (usb_endpoint_dir_in(&e->desc)) {
 128                                 if (!intr && !in)
 129                                         in = e;
 130                                 else if (intr && !status)
 131                                         status = e;
 132                         } else {
 133                                 if (!out)
 134                                         out = e;
 135                         }
 136                 }
 137                 if (in && out)
 138                         break;
 139         }
 140         if (!alt || !in || !out)
 141                 return -EINVAL;
 142
 143         if (alt->desc.bAlternateSetting != 0 ||
 144             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 145                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 146                                 alt->desc.bAlternateSetting);
 147                 if (tmp < 0)
 148                         return tmp;
 149         }
 150
 151         dev->in = usb_rcvbulkpipe (dev->udev,
 152                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 153         dev->out = usb_sndbulkpipe (dev->udev,
 154                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 155         dev->status = status;
 156         return 0;
 157 }
 158 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 159
 160 static u8 nibble(unsigned char c)
 161 {
 162         if (likely(isdigit(c)))
 163                 return c - '0';
 164         c = toupper(c);
 165         if (likely(isxdigit(c)))
 166                 return 10 + c - 'A';
 167         return 0;
 168 }
 169
 170 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 171 {
 172         int             tmp, i;
 173         unsigned char   buf [13];
 174
 175         tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 176         if (tmp != 12) {
 177                 dev_dbg(&dev->udev->dev,
 178                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 179                 if (tmp >= 0)
 180                         tmp = -EINVAL;
 181                 return tmp;
 182         }
 183         for (i = tmp = 0; i < 6; i++, tmp += 2)
 184                 dev->net->dev_addr [i] =
 185                         (nibble(buf [tmp]) << 4) + nibble(buf [tmp + 1]);
 186         return 0;
 187 }
 188 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 189
 190 static void intr_complete (struct urb *urb);
 191
 192 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 193 {
 194         char            *buf = NULL;
 195         unsigned        pipe = 0;
 196         unsigned        maxp;
 197         unsigned        period;
 198
 199         if (!dev->driver_info->status)
 200                 return 0;
 201
 202         pipe = usb_rcvintpipe (dev->udev,
 203                         dev->status->desc.bEndpointAddress
 204                                 & USB_ENDPOINT_NUMBER_MASK);
 205         maxp = usb_maxpacket (dev->udev, pipe, 0);
 206
 207         /* avoid 1 msec chatter:  min 8 msec poll rate */
 208         period = max ((int) dev->status->desc.bInterval,
 209                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 210
 211         buf = kmalloc (maxp, GFP_KERNEL);
 212         if (buf) {
 213                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 214                 if (!dev->interrupt) {
 215                         kfree (buf);
 216                         return -ENOMEM;
 217                 } else {
 218                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 219                                 buf, maxp, intr_complete, dev, period);
 220                         dev_dbg(&intf->dev,
 221                                 "status ep%din, %d bytes period %d\n",
 222                                 usb_pipeendpoint(pipe), maxp, period);
 223                 }
 224         }
 225         return 0;
 226 }
 227
 228 /* Passes this packet up the stack, updating its accounting.
 229  * Some link protocols batch packets, so their rx_fixup paths
 230  * can return clones as well as just modify the original skb.
 231  */
 232 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 233 {
 234         int     status;
 235
 236         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 237                 skb_queue_tail(&dev->rxq_pause, skb);
 238                 return;
 239         }
 240
 241         skb->protocol = eth_type_trans (skb, dev->net);
 242         dev->net->stats.rx_packets++;
 243         dev->net->stats.rx_bytes += skb->len;
 244
 245         if (netif_msg_rx_status (dev))
 246                 devdbg (dev, "< rx, len %zu, type 0x%x",
 247                         skb->len + sizeof (struct ethhdr), skb->protocol);
 248         memset (skb->cb, 0, sizeof (struct skb_data));
 249         status = netif_rx (skb);
 250         if (status != NET_RX_SUCCESS && netif_msg_rx_err (dev))
 251                 devdbg (dev, "netif_rx status %d", status);
 252 }
 253 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 254
 255 \f
 256 /*-------------------------------------------------------------------------
 257  *
 258  * Network Device Driver (peer link to "Host Device", from USB host)
 259  *
 260  *-------------------------------------------------------------------------*/
 261
 262 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 263 {
 264         struct usbnet   *dev = netdev_priv(net);
 265         int             ll_mtu = new_mtu + net->hard_header_len;
 266         int             old_hard_mtu = dev->hard_mtu;
 267         int             old_rx_urb_size = dev->rx_urb_size;
 268
 269         if (new_mtu <= 0)
 270                 return -EINVAL;
 271         // no second zero-length packet read wanted after mtu-sized packets
 272         if ((ll_mtu % dev->maxpacket) == 0)
 273                 return -EDOM;
 274         net->mtu = new_mtu;
 275
 276         dev->hard_mtu = net->mtu + net->hard_header_len;
 277         if (dev->rx_urb_size == old_hard_mtu) {
 278                 dev->rx_urb_size = dev->hard_mtu;
 279                 if (dev->rx_urb_size > old_rx_urb_size)
 280                         usbnet_unlink_rx_urbs(dev);
 281         }
 282
 283         return 0;
 284 }
 285 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 286
 287 /*-------------------------------------------------------------------------*/
 288
 289 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 290  * completion callbacks.  2.5 should have fixed those bugs...
 291  */
 292
 293 static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
 294 {
 295         unsigned long           flags;
 296
 297         spin_lock_irqsave(&list->lock, flags);
 298         __skb_unlink(skb, list);
 299         spin_unlock(&list->lock);
 300         spin_lock(&dev->done.lock);
 301         __skb_queue_tail(&dev->done, skb);
 302         if (dev->done.qlen == 1)
 303                 tasklet_schedule(&dev->bh);
 304         spin_unlock_irqrestore(&dev->done.lock, flags);
 305 }
 306
 307 /* some work can't be done in tasklets, so we use keventd
 308  *
 309  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 310  * but tasklet_schedule() doesn't.  hope the failure is rare.
 311  */
 312 void usbnet_defer_kevent (struct usbnet *dev, int work)
 313 {
 314         set_bit (work, &dev->flags);
 315         if (!schedule_work (&dev->kevent))
 316                 deverr (dev, "kevent %d may have been dropped", work);
 317         else
 318                 devdbg (dev, "kevent %d scheduled", work);
 319 }
 320 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 321
 322 /*-------------------------------------------------------------------------*/
 323
 324 static void rx_complete (struct urb *urb);
 325
 326 static void rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 327 {
 328         struct sk_buff          *skb;
 329         struct skb_data         *entry;
 330         int                     retval = 0;
 331         unsigned long           lockflags;
 332         size_t                  size = dev->rx_urb_size;
 333
 334         if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
 335                 if (netif_msg_rx_err (dev))
 336                         devdbg (dev, "no rx skb");
 337                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 338                 usb_free_urb (urb);
 339                 return;
 340         }
 341         skb_reserve (skb, NET_IP_ALIGN);
 342
 343         entry = (struct skb_data *) skb->cb;
 344         entry->urb = urb;
 345         entry->dev = dev;
 346         entry->state = rx_start;
 347         entry->length = 0;
 348
 349         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 350                 skb->data, size, rx_complete, skb);
 351
 352         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 353
 354         if (netif_running (dev->net) &&
 355             netif_device_present (dev->net) &&
 356             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 357             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 358                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 359                 case -EPIPE:
 360                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 361                         break;
 362                 case -ENOMEM:
 363                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 364                         break;
 365                 case -ENODEV:
 366                         if (netif_msg_ifdown (dev))
 367                                 devdbg (dev, "device gone");
 368                         netif_device_detach (dev->net);
 369                         break;
 370                 default:
 371                         if (netif_msg_rx_err (dev))
 372                                 devdbg (dev, "rx submit, %d", retval);
 373                         tasklet_schedule (&dev->bh);
 374                         break;
 375                 case 0:
 376                         __skb_queue_tail (&dev->rxq, skb);
 377                 }
 378         } else {
 379                 if (netif_msg_ifdown (dev))
 380                         devdbg (dev, "rx: stopped");
 381                 retval = -ENOLINK;
 382         }
 383         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 384         if (retval) {
 385                 dev_kfree_skb_any (skb);
 386                 usb_free_urb (urb);
 387         }
 388 }
 389
 390
 391 /*-------------------------------------------------------------------------*/
 392
 393 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 394 {
 395         if (dev->driver_info->rx_fixup &&
 396             !dev->driver_info->rx_fixup (dev, skb))
 397                 goto error;
 398         // else network stack removes extra byte if we forced a short packet
 399
 400         if (skb->len)
 401                 usbnet_skb_return (dev, skb);
 402         else {
 403                 if (netif_msg_rx_err (dev))
 404                         devdbg (dev, "drop");
 405 error:
 406                 dev->net->stats.rx_errors++;
 407                 skb_queue_tail (&dev->done, skb);
 408         }
 409 }
 410
 411 /*-------------------------------------------------------------------------*/
 412
 413 static void rx_complete (struct urb *urb)
 414 {
 415         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 416         struct skb_data         *entry = (struct skb_data *) skb->cb;
 417         struct usbnet           *dev = entry->dev;
 418         int                     urb_status = urb->status;
 419
 420         skb_put (skb, urb->actual_length);
 421         entry->state = rx_done;
 422         entry->urb = NULL;
 423
 424         switch (urb_status) {
 425         /* success */
 426         case 0:
 427                 if (skb->len < dev->net->hard_header_len) {
 428                         entry->state = rx_cleanup;
 429                         dev->net->stats.rx_errors++;
 430                         dev->net->stats.rx_length_errors++;
 431                         if (netif_msg_rx_err (dev))
 432                                 devdbg (dev, "rx length %d", skb->len);
 433                 }
 434                 break;
 435
 436         /* stalls need manual reset. this is rare ... except that
 437          * when going through USB 2.0 TTs, unplug appears this way.
 438          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 439          * storm, recovering as needed.
 440          */
 441         case -EPIPE:
 442                 dev->net->stats.rx_errors++;
 443                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 444                 // FALLTHROUGH
 445
 446         /* software-driven interface shutdown */
 447         case -ECONNRESET:               /* async unlink */
 448         case -ESHUTDOWN:                /* hardware gone */
 449                 if (netif_msg_ifdown (dev))
 450                         devdbg (dev, "rx shutdown, code %d", urb_status);
 451                 goto block;
 452
 453         /* we get controller i/o faults during khubd disconnect() delays.
 454          * throttle down resubmits, to avoid log floods; just temporarily,
 455          * so we still recover when the fault isn't a khubd delay.
 456          */
 457         case -EPROTO:
 458         case -ETIME:
 459         case -EILSEQ:
 460                 dev->net->stats.rx_errors++;
 461                 if (!timer_pending (&dev->delay)) {
 462                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 463                         if (netif_msg_link (dev))
 464                                 devdbg (dev, "rx throttle %d", urb_status);
 465                 }
 466 block:
 467                 entry->state = rx_cleanup;
 468                 entry->urb = urb;
 469                 urb = NULL;
 470                 break;
 471
 472         /* data overrun ... flush fifo? */
 473         case -EOVERFLOW:
 474                 dev->net->stats.rx_over_errors++;
 475                 // FALLTHROUGH
 476
 477         default:
 478                 entry->state = rx_cleanup;
 479                 dev->net->stats.rx_errors++;
 480                 if (netif_msg_rx_err (dev))
 481                         devdbg (dev, "rx status %d", urb_status);
 482                 break;
 483         }
 484
 485         defer_bh(dev, skb, &dev->rxq);
 486
 487         if (urb) {
 488                 if (netif_running (dev->net) &&
 489                     !test_bit (EVENT_RX_HALT, &dev->flags)) {
 490                         rx_submit (dev, urb, GFP_ATOMIC);
 491                         return;
 492                 }
 493                 usb_free_urb (urb);
 494         }
 495         if (netif_msg_rx_err (dev))
 496                 devdbg (dev, "no read resubmitted");
 497 }
 498
 499 static void intr_complete (struct urb *urb)
 500 {
 501         struct usbnet   *dev = urb->context;
 502         int             status = urb->status;
 503
 504         switch (status) {
 505         /* success */
 506         case 0:
 507                 dev->driver_info->status(dev, urb);
 508                 break;
 509
 510         /* software-driven interface shutdown */
 511         case -ENOENT:           /* urb killed */
 512         case -ESHUTDOWN:        /* hardware gone */
 513                 if (netif_msg_ifdown (dev))
 514                         devdbg (dev, "intr shutdown, code %d", status);
 515                 return;
 516
 517         /* NOTE:  not throttling like RX/TX, since this endpoint
 518          * already polls infrequently
 519          */
 520         default:
 521                 devdbg (dev, "intr status %d", status);
 522                 break;
 523         }
 524
 525         if (!netif_running (dev->net))
 526                 return;
 527
 528         memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
 529         status = usb_submit_urb (urb, GFP_ATOMIC);
 530         if (status != 0 && netif_msg_timer (dev))
 531                 deverr(dev, "intr resubmit --> %d", status);
 532 }
 533
 534 /*-------------------------------------------------------------------------*/
 535 void usbnet_pause_rx(struct usbnet *dev)
 536 {
 537         set_bit(EVENT_RX_PAUSED, &dev->flags);
 538
 539         if (netif_msg_rx_status(dev))
 540                 devdbg(dev, "paused rx queue enabled");
 541 }
 542 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 543
 544 void usbnet_resume_rx(struct usbnet *dev)
 545 {
 546         struct sk_buff *skb;
 547         int num = 0;
 548
 549         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 550
 551         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 552                 usbnet_skb_return(dev, skb);
 553                 num++;
 554         }
 555
 556         tasklet_schedule(&dev->bh);
 557
 558         if (netif_msg_rx_status(dev))
 559                 devdbg(dev, "paused rx queue disabled, %d skbs requeued", num);
 560 }
 561 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 562
 563 void usbnet_purge_paused_rxq(struct usbnet *dev)
 564 {
 565         skb_queue_purge(&dev->rxq_pause);
 566 }
 567 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 568
 569 /*-------------------------------------------------------------------------*/
 570
 571 // unlink pending rx/tx; completion handlers do all other cleanup
 572
 573 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 574 {
 575         unsigned long           flags;
 576         struct sk_buff          *skb, *skbnext;
 577         int                     count = 0;
 578
 579         spin_lock_irqsave (&q->lock, flags);
 580         skb_queue_walk_safe(q, skb, skbnext) {
 581                 struct skb_data         *entry;
 582                 struct urb              *urb;
 583                 int                     retval;
 584
 585                 entry = (struct skb_data *) skb->cb;
 586                 urb = entry->urb;
 587
 588                 // during some PM-driven resume scenarios,
 589                 // these (async) unlinks complete immediately
 590                 retval = usb_unlink_urb (urb);
 591                 if (retval != -EINPROGRESS && retval != 0)
 592                         devdbg (dev, "unlink urb err, %d", retval);
 593                 else
 594                         count++;
 595         }
 596         spin_unlock_irqrestore (&q->lock, flags);
 597         return count;
 598 }
 599
 600 // Flush all pending rx urbs
 601 // minidrivers may need to do this when the MTU changes
 602
 603 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 604 {
 605         if (netif_running(dev->net)) {
 606                 (void) unlink_urbs (dev, &dev->rxq);
 607                 tasklet_schedule(&dev->bh);
 608         }
 609 }
 610 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 611
 612 /*-------------------------------------------------------------------------*/
 613
 614 // precondition: never called in_interrupt
 615 static void usbnet_terminate_urbs(struct usbnet *dev)
 616 {
 617         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 618         DECLARE_WAITQUEUE(wait, current);
 619         int temp;
 620
 621         /* ensure there are no more active urbs */
 622         add_wait_queue(&unlink_wakeup, &wait);
 623         set_current_state(TASK_UNINTERRUPTIBLE);
 624         dev->wait = &unlink_wakeup;
 625         temp = unlink_urbs(dev, &dev->txq) +
 626                 unlink_urbs(dev, &dev->rxq);
 627
 628         /* maybe wait for deletions to finish. */
 629         while (!skb_queue_empty(&dev->rxq)
 630                 && !skb_queue_empty(&dev->txq)
 631                 && !skb_queue_empty(&dev->done)) {
 632                         schedule_timeout(UNLINK_TIMEOUT_MS);
 633                         set_current_state(TASK_UNINTERRUPTIBLE);
 634                         if (netif_msg_ifdown(dev))
 635                                 devdbg(dev, "waited for %d urb completions",
 636                                         temp);
 637         }
 638         set_current_state(TASK_RUNNING);
 639         dev->wait = NULL;
 640         remove_wait_queue(&unlink_wakeup, &wait);
 641 }
 642
 643 int usbnet_stop (struct net_device *net)
 644 {
 645         struct usbnet           *dev = netdev_priv(net);
 646         struct driver_info      *info = dev->driver_info;
 647         int                     retval;
 648
 649         netif_stop_queue (net);
 650
 651         if (netif_msg_ifdown (dev))
 652                 devinfo (dev, "stop stats: rx/tx %ld/%ld, errs %ld/%ld",
 653                         net->stats.rx_packets, net->stats.tx_packets,
 654                         net->stats.rx_errors, net->stats.tx_errors
 655                         );
 656
 657         /* allow minidriver to stop correctly (wireless devices to turn off
 658          * radio etc) */
 659         if (info->stop) {
 660                 retval = info->stop(dev);
 661                 if (retval < 0 && netif_msg_ifdown(dev))
 662                         devinfo(dev,
 663                                 "stop fail (%d) usbnet usb-%s-%s, %s",
 664                                 retval,
 665                                 dev->udev->bus->bus_name, dev->udev->devpath,
 666                                 info->description);
 667         }
 668
 669         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 670                 usbnet_terminate_urbs(dev);
 671
 672         usb_kill_urb(dev->interrupt);
 673
 674         usbnet_purge_paused_rxq(dev);
 675
 676         /* deferred work (task, timer, softirq) must also stop.
 677          * can't flush_scheduled_work() until we drop rtnl (later),
 678          * else workers could deadlock; so make workers a NOP.
 679          */
 680         dev->flags = 0;
 681         del_timer_sync (&dev->delay);
 682         tasklet_kill (&dev->bh);
 683         if (info->manage_power)
 684                 info->manage_power(dev, 0);
 685         else
 686                 usb_autopm_put_interface(dev->intf);
 687
 688         return 0;
 689 }
 690 EXPORT_SYMBOL_GPL(usbnet_stop);
 691
 692 /*-------------------------------------------------------------------------*/
 693
 694 // posts reads, and enables write queuing
 695
 696 // precondition: never called in_interrupt
 697
 698 int usbnet_open (struct net_device *net)
 699 {
 700         struct usbnet           *dev = netdev_priv(net);
 701         int                     retval;
 702         struct driver_info      *info = dev->driver_info;
 703
 704         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 705                 if (netif_msg_ifup (dev))
 706                         devinfo (dev,
 707                                 "resumption fail (%d) usbnet usb-%s-%s, %s",
 708                                 retval,
 709                                 dev->udev->bus->bus_name, dev->udev->devpath,
 710                         info->description);
 711                 goto done_nopm;
 712         }
 713
 714         // put into "known safe" state
 715         if (info->reset && (retval = info->reset (dev)) < 0) {
 716                 if (netif_msg_ifup (dev))
 717                         devinfo (dev,
 718                                 "open reset fail (%d) usbnet usb-%s-%s, %s",
 719                                 retval,
 720                                 dev->udev->bus->bus_name, dev->udev->devpath,
 721                         info->description);
 722                 goto done;
 723         }
 724
 725         // insist peer be connected
 726         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 727                 if (netif_msg_ifup (dev))
 728                         devdbg (dev, "can't open; %d", retval);
 729                 goto done;
 730         }
 731
 732         /* start any status interrupt transfer */
 733         if (dev->interrupt) {
 734                 retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 735                 if (retval < 0) {
 736                         if (netif_msg_ifup (dev))
 737                                 deverr (dev, "intr submit %d", retval);
 738                         goto done;
 739                 }
 740         }
 741
 742         netif_start_queue (net);
 743         if (netif_msg_ifup (dev)) {
 744                 char    *framing;
 745
 746                 if (dev->driver_info->flags & FLAG_FRAMING_NC)
 747                         framing = "NetChip";
 748                 else if (dev->driver_info->flags & FLAG_FRAMING_GL)
 749                         framing = "GeneSys";
 750                 else if (dev->driver_info->flags & FLAG_FRAMING_Z)
 751                         framing = "Zaurus";
 752                 else if (dev->driver_info->flags & FLAG_FRAMING_RN)
 753                         framing = "RNDIS";
 754                 else if (dev->driver_info->flags & FLAG_FRAMING_AX)
 755                         framing = "ASIX";
 756                 else
 757                         framing = "simple";
 758
 759                 devinfo (dev, "open: enable queueing "
 760                                 "(rx %d, tx %d) mtu %d %s framing",
 761                         (int)RX_QLEN (dev), (int)TX_QLEN (dev), dev->net->mtu,
 762                         framing);
 763         }
 764
 765         // delay posting reads until we're fully open
 766         tasklet_schedule (&dev->bh);
 767         if (info->manage_power) {
 768                 retval = info->manage_power(dev, 1);
 769                 if (retval < 0)
 770                         goto done;
 771                 usb_autopm_put_interface(dev->intf);
 772         }
 773         return retval;
 774 done:
 775         usb_autopm_put_interface(dev->intf);
 776 done_nopm:
 777         return retval;
 778 }
 779 EXPORT_SYMBOL_GPL(usbnet_open);
 780
 781 /*-------------------------------------------------------------------------*/
 782
 783 /* ethtool methods; minidrivers may need to add some more, but
 784  * they'll probably want to use this base set.
 785  */
 786
 787 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 788 {
 789         struct usbnet *dev = netdev_priv(net);
 790
 791         if (!dev->mii.mdio_read)
 792                 return -EOPNOTSUPP;
 793
 794         return mii_ethtool_gset(&dev->mii, cmd);
 795 }
 796 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 797
 798 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 799 {
 800         struct usbnet *dev = netdev_priv(net);
 801         int retval;
 802
 803         if (!dev->mii.mdio_write)
 804                 return -EOPNOTSUPP;
 805
 806         retval = mii_ethtool_sset(&dev->mii, cmd);
 807
 808         /* link speed/duplex might have changed */
 809         if (dev->driver_info->link_reset)
 810                 dev->driver_info->link_reset(dev);
 811
 812         return retval;
 813
 814 }
 815 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 816
 817 u32 usbnet_get_link (struct net_device *net)
 818 {
 819         struct usbnet *dev = netdev_priv(net);
 820
 821         /* If a check_connect is defined, return its result */
 822         if (dev->driver_info->check_connect)
 823                 return dev->driver_info->check_connect (dev) == 0;
 824
 825         /* if the device has mii operations, use those */
 826         if (dev->mii.mdio_read)
 827                 return mii_link_ok(&dev->mii);
 828
 829         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 830         return ethtool_op_get_link(net);
 831 }
 832 EXPORT_SYMBOL_GPL(usbnet_get_link);
 833
 834 int usbnet_nway_reset(struct net_device *net)
 835 {
 836         struct usbnet *dev = netdev_priv(net);
 837
 838         if (!dev->mii.mdio_write)
 839                 return -EOPNOTSUPP;
 840
 841         return mii_nway_restart(&dev->mii);
 842 }
 843 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 844
 845 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 846 {
 847         struct usbnet *dev = netdev_priv(net);
 848
 849         strncpy (info->driver, dev->driver_name, sizeof info->driver);
 850         strncpy (info->version, DRIVER_VERSION, sizeof info->version);
 851         strncpy (info->fw_version, dev->driver_info->description,
 852                 sizeof info->fw_version);
 853         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 854 }
 855 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 856
 857 u32 usbnet_get_msglevel (struct net_device *net)
 858 {
 859         struct usbnet *dev = netdev_priv(net);
 860
 861         return dev->msg_enable;
 862 }
 863 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 864
 865 void usbnet_set_msglevel (struct net_device *net, u32 level)
 866 {
 867         struct usbnet *dev = netdev_priv(net);
 868
 869         dev->msg_enable = level;
 870 }
 871 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 872
 873 /* drivers may override default ethtool_ops in their bind() routine */
 874 static const struct ethtool_ops usbnet_ethtool_ops = {
 875         .get_settings           = usbnet_get_settings,
 876         .set_settings           = usbnet_set_settings,
 877         .get_link               = usbnet_get_link,
 878         .nway_reset             = usbnet_nway_reset,
 879         .get_drvinfo            = usbnet_get_drvinfo,
 880         .get_msglevel           = usbnet_get_msglevel,
 881         .set_msglevel           = usbnet_set_msglevel,
 882 };
 883
 884 /*-------------------------------------------------------------------------*/
 885
 886 /* work that cannot be done in interrupt context uses keventd.
 887  *
 888  * NOTE:  with 2.5 we could do more of this using completion callbacks,
 889  * especially now that control transfers can be queued.
 890  */
 891 static void
 892 kevent (struct work_struct *work)
 893 {
 894         struct usbnet           *dev =
 895                 container_of(work, struct usbnet, kevent);
 896         int                     status;
 897
 898         /* usb_clear_halt() needs a thread context */
 899         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 900                 unlink_urbs (dev, &dev->txq);
 901                 status = usb_autopm_get_interface(dev->intf);
 902                 if (status < 0)
 903                         goto fail_pipe;
 904                 status = usb_clear_halt (dev->udev, dev->out);
 905                 usb_autopm_put_interface(dev->intf);
 906                 if (status < 0 &&
 907                     status != -EPIPE &&
 908                     status != -ESHUTDOWN) {
 909                         if (netif_msg_tx_err (dev))
 910 fail_pipe:
 911                                 deverr (dev, "can't clear tx halt, status %d",
 912                                         status);
 913                 } else {
 914                         clear_bit (EVENT_TX_HALT, &dev->flags);
 915                         if (status != -ESHUTDOWN)
 916                                 netif_wake_queue (dev->net);
 917                 }
 918         }
 919         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 920                 unlink_urbs (dev, &dev->rxq);
 921                 status = usb_autopm_get_interface(dev->intf);
 922                 if (status < 0)
 923                         goto fail_halt;
 924                 status = usb_clear_halt (dev->udev, dev->in);
 925                 usb_autopm_put_interface(dev->intf);
 926                 if (status < 0 &&
 927                     status != -EPIPE &&
 928                     status != -ESHUTDOWN) {
 929                         if (netif_msg_rx_err (dev))
 930 fail_halt:
 931                                 deverr (dev, "can't clear rx halt, status %d",
 932                                         status);
 933                 } else {
 934                         clear_bit (EVENT_RX_HALT, &dev->flags);
 935                         tasklet_schedule (&dev->bh);
 936                 }
 937         }
 938
 939         /* tasklet could resubmit itself forever if memory is tight */
 940         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 941                 struct urb      *urb = NULL;
 942
 943                 if (netif_running (dev->net))
 944                         urb = usb_alloc_urb (0, GFP_KERNEL);
 945                 else
 946                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 947                 if (urb != NULL) {
 948                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 949                         status = usb_autopm_get_interface(dev->intf);
 950                         if (status < 0)
 951                                 goto fail_lowmem;
 952                         rx_submit (dev, urb, GFP_KERNEL);
 953                         usb_autopm_put_interface(dev->intf);
 954 fail_lowmem:
 955                         tasklet_schedule (&dev->bh);
 956                 }
 957         }
 958
 959         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
 960                 struct driver_info      *info = dev->driver_info;
 961                 int                     retval = 0;
 962
 963                 clear_bit (EVENT_LINK_RESET, &dev->flags);
 964                 status = usb_autopm_get_interface(dev->intf);
 965                 if (status < 0)
 966                         goto skip_reset;
 967                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
 968                         usb_autopm_put_interface(dev->intf);
 969 skip_reset:
 970                         devinfo(dev, "link reset failed (%d) usbnet usb-%s-%s, %s",
 971                                 retval,
 972                                 dev->udev->bus->bus_name, dev->udev->devpath,
 973                                 info->description);
 974                 } else {
 975                         usb_autopm_put_interface(dev->intf);
 976                 }
 977         }
 978
 979         if (dev->flags)
 980                 devdbg (dev, "kevent done, flags = 0x%lx",
 981                         dev->flags);
 982 }
 983
 984 /*-------------------------------------------------------------------------*/
 985
 986 static void tx_complete (struct urb *urb)
 987 {
 988         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 989         struct skb_data         *entry = (struct skb_data *) skb->cb;
 990         struct usbnet           *dev = entry->dev;
 991
 992         if (urb->status == 0) {
 993                 dev->net->stats.tx_packets++;
 994                 dev->net->stats.tx_bytes += entry->length;
 995         } else {
 996                 dev->net->stats.tx_errors++;
 997
 998                 switch (urb->status) {
 999                 case -EPIPE:
1000                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1001                         break;
1002
1003                 /* software-driven interface shutdown */
1004                 case -ECONNRESET:               // async unlink
1005                 case -ESHUTDOWN:                // hardware gone
1006                         break;
1007
1008                 // like rx, tx gets controller i/o faults during khubd delays
1009                 // and so it uses the same throttling mechanism.
1010                 case -EPROTO:
1011                 case -ETIME:
1012                 case -EILSEQ:
1013                         usb_mark_last_busy(dev->udev);
1014                         if (!timer_pending (&dev->delay)) {
1015                                 mod_timer (&dev->delay,
1016                                         jiffies + THROTTLE_JIFFIES);
1017                                 if (netif_msg_link (dev))
1018                                         devdbg (dev, "tx throttle %d",
1019                                                         urb->status);
1020                         }
1021                         netif_stop_queue (dev->net);
1022                         break;
1023                 default:
1024                         if (netif_msg_tx_err (dev))
1025                                 devdbg (dev, "tx err %d", entry->urb->status);
1026                         break;
1027                 }
1028         }
1029
1030         usb_autopm_put_interface_async(dev->intf);
1031         urb->dev = NULL;
1032         entry->state = tx_done;
1033         defer_bh(dev, skb, &dev->txq);
1034 }
1035
1036 /*-------------------------------------------------------------------------*/
1037
1038 void usbnet_tx_timeout (struct net_device *net)
1039 {
1040         struct usbnet           *dev = netdev_priv(net);
1041
1042         unlink_urbs (dev, &dev->txq);
1043         tasklet_schedule (&dev->bh);
1044
1045         // FIXME: device recovery -- reset?
1046 }
1047 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1048
1049 /*-------------------------------------------------------------------------*/
1050
1051 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1052                                      struct net_device *net)
1053 {
1054         struct usbnet           *dev = netdev_priv(net);
1055         int                     length;
1056         struct urb              *urb = NULL;
1057         struct skb_data         *entry;
1058         struct driver_info      *info = dev->driver_info;
1059         unsigned long           flags;
1060         int retval;
1061
1062         // some devices want funky USB-level framing, for
1063         // win32 driver (usually) and/or hardware quirks
1064         if (info->tx_fixup) {
1065                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1066                 if (!skb) {
1067                         if (netif_msg_tx_err (dev))
1068                                 devdbg (dev, "can't tx_fixup skb");
1069                         goto drop;
1070                 }
1071         }
1072         length = skb->len;
1073
1074         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1075                 if (netif_msg_tx_err (dev))
1076                         devdbg (dev, "no urb");
1077                 goto drop;
1078         }
1079
1080         entry = (struct skb_data *) skb->cb;
1081         entry->urb = urb;
1082         entry->dev = dev;
1083         entry->state = tx_start;
1084         entry->length = length;
1085
1086         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1087                         skb->data, skb->len, tx_complete, skb);
1088
1089         /* don't assume the hardware handles USB_ZERO_PACKET
1090          * NOTE:  strictly conforming cdc-ether devices should expect
1091          * the ZLP here, but ignore the one-byte packet.
1092          */
1093         if (!(info->flags & FLAG_SEND_ZLP) && (length % dev->maxpacket) == 0) {
1094                 urb->transfer_buffer_length++;
1095                 if (skb_tailroom(skb)) {
1096                         skb->data[skb->len] = 0;
1097                         __skb_put(skb, 1);
1098                 }
1099         }
1100
1101         spin_lock_irqsave(&dev->txq.lock, flags);
1102         retval = usb_autopm_get_interface_async(dev->intf);
1103         if (retval < 0) {
1104                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1105                 goto drop;
1106         }
1107
1108 #ifdef CONFIG_PM
1109         /* if this triggers the device is still a sleep */
1110         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1111                 /* transmission will be done in resume */
1112                 usb_anchor_urb(urb, &dev->deferred);
1113                 /* no use to process more packets */
1114                 netif_stop_queue(net);
1115                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1116                 devdbg(dev, "Delaying transmission for resumption");
1117                 goto deferred;
1118         }
1119 #endif
1120
1121         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1122         case -EPIPE:
1123                 netif_stop_queue (net);
1124                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1125                 usb_autopm_put_interface_async(dev->intf);
1126                 break;
1127         default:
1128                 usb_autopm_put_interface_async(dev->intf);
1129                 if (netif_msg_tx_err (dev))
1130                         devdbg (dev, "tx: submit urb err %d", retval);
1131                 break;
1132         case 0:
1133                 net->trans_start = jiffies;
1134                 __skb_queue_tail (&dev->txq, skb);
1135                 if (dev->txq.qlen >= TX_QLEN (dev))
1136                         netif_stop_queue (net);
1137         }
1138         spin_unlock_irqrestore (&dev->txq.lock, flags);
1139
1140         if (retval) {
1141                 if (netif_msg_tx_err (dev))
1142                         devdbg (dev, "drop, code %d", retval);
1143 drop:
1144                 dev->net->stats.tx_dropped++;
1145                 if (skb)
1146                         dev_kfree_skb_any (skb);
1147                 usb_free_urb (urb);
1148         } else if (netif_msg_tx_queued (dev)) {
1149                 devdbg (dev, "> tx, len %d, type 0x%x",
1150                         length, skb->protocol);
1151         }
1152 #ifdef CONFIG_PM
1153 deferred:
1154 #endif
1155         return NETDEV_TX_OK;
1156 }
1157 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1158
1159 /*-------------------------------------------------------------------------*/
1160
1161 // tasklet (work deferred from completions, in_irq) or timer
1162
1163 static void usbnet_bh (unsigned long param)
1164 {
1165         struct usbnet           *dev = (struct usbnet *) param;
1166         struct sk_buff          *skb;
1167         struct skb_data         *entry;
1168
1169         while ((skb = skb_dequeue (&dev->done))) {
1170                 entry = (struct skb_data *) skb->cb;
1171                 switch (entry->state) {
1172                 case rx_done:
1173                         entry->state = rx_cleanup;
1174                         rx_process (dev, skb);
1175                         continue;
1176                 case tx_done:
1177                 case rx_cleanup:
1178                         usb_free_urb (entry->urb);
1179                         dev_kfree_skb (skb);
1180                         continue;
1181                 default:
1182                         devdbg (dev, "bogus skb state %d", entry->state);
1183                 }
1184         }
1185
1186         // waiting for all pending urbs to complete?
1187         if (dev->wait) {
1188                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1189                         wake_up (dev->wait);
1190                 }
1191
1192         // or are we maybe short a few urbs?
1193         } else if (netif_running (dev->net) &&
1194                    netif_device_present (dev->net) &&
1195                    !timer_pending (&dev->delay) &&
1196                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1197                 int     temp = dev->rxq.qlen;
1198                 int     qlen = RX_QLEN (dev);
1199
1200                 if (temp < qlen) {
1201                         struct urb      *urb;
1202                         int             i;
1203
1204                         // don't refill the queue all at once
1205                         for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1206                                 urb = usb_alloc_urb (0, GFP_ATOMIC);
1207                                 if (urb != NULL)
1208                                         rx_submit (dev, urb, GFP_ATOMIC);
1209                         }
1210                         if (temp != dev->rxq.qlen && netif_msg_link (dev))
1211                                 devdbg (dev, "rxqlen %d --> %d",
1212                                                 temp, dev->rxq.qlen);
1213                         if (dev->rxq.qlen < qlen)
1214                                 tasklet_schedule (&dev->bh);
1215                 }
1216                 if (dev->txq.qlen < TX_QLEN (dev))
1217                         netif_wake_queue (dev->net);
1218         }
1219 }
1220
1221
1222 /*-------------------------------------------------------------------------
1223  *
1224  * USB Device Driver support
1225  *
1226  *-------------------------------------------------------------------------*/
1227
1228 // precondition: never called in_interrupt
1229
1230 void usbnet_disconnect (struct usb_interface *intf)
1231 {
1232         struct usbnet           *dev;
1233         struct usb_device       *xdev;
1234         struct net_device       *net;
1235
1236         dev = usb_get_intfdata(intf);
1237         usb_set_intfdata(intf, NULL);
1238         if (!dev)
1239                 return;
1240
1241         xdev = interface_to_usbdev (intf);
1242
1243         if (netif_msg_probe (dev))
1244                 devinfo (dev, "unregister '%s' usb-%s-%s, %s",
1245                         intf->dev.driver->name,
1246                         xdev->bus->bus_name, xdev->devpath,
1247                         dev->driver_info->description);
1248
1249         net = dev->net;
1250         unregister_netdev (net);
1251
1252         /* we don't hold rtnl here ... */
1253         flush_scheduled_work ();
1254
1255         if (dev->driver_info->unbind)
1256                 dev->driver_info->unbind (dev, intf);
1257
1258         free_netdev(net);
1259         usb_put_dev (xdev);
1260 }
1261 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1262
1263 static const struct net_device_ops usbnet_netdev_ops = {
1264         .ndo_open               = usbnet_open,
1265         .ndo_stop               = usbnet_stop,
1266         .ndo_start_xmit         = usbnet_start_xmit,
1267         .ndo_tx_timeout         = usbnet_tx_timeout,
1268         .ndo_change_mtu         = usbnet_change_mtu,
1269         .ndo_set_mac_address    = eth_mac_addr,
1270         .ndo_validate_addr      = eth_validate_addr,
1271 };
1272
1273 /*-------------------------------------------------------------------------*/
1274
1275 // precondition: never called in_interrupt
1276
1277 static struct device_type wlan_type = {
1278         .name   = "wlan",
1279 };
1280
1281 static struct device_type wwan_type = {
1282         .name   = "wwan",
1283 };
1284
1285 int
1286 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1287 {
1288         struct usbnet                   *dev;
1289         struct net_device               *net;
1290         struct usb_host_interface       *interface;
1291         struct driver_info              *info;
1292         struct usb_device               *xdev;
1293         int                             status;
1294         const char                      *name;
1295
1296         name = udev->dev.driver->name;
1297         info = (struct driver_info *) prod->driver_info;
1298         if (!info) {
1299                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1300                 return -ENODEV;
1301         }
1302         xdev = interface_to_usbdev (udev);
1303         interface = udev->cur_altsetting;
1304
1305         usb_get_dev (xdev);
1306
1307         status = -ENOMEM;
1308
1309         // set up our own records
1310         net = alloc_etherdev(sizeof(*dev));
1311         if (!net) {
1312                 dbg ("can't kmalloc dev");
1313                 goto out;
1314         }
1315
1316         dev = netdev_priv(net);
1317         dev->udev = xdev;
1318         dev->intf = udev;
1319         dev->driver_info = info;
1320         dev->driver_name = name;
1321         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1322                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1323         skb_queue_head_init (&dev->rxq);
1324         skb_queue_head_init (&dev->txq);
1325         skb_queue_head_init (&dev->done);
1326         skb_queue_head_init(&dev->rxq_pause);
1327         dev->bh.func = usbnet_bh;
1328         dev->bh.data = (unsigned long) dev;
1329         INIT_WORK (&dev->kevent, kevent);
1330         init_usb_anchor(&dev->deferred);
1331         dev->delay.function = usbnet_bh;
1332         dev->delay.data = (unsigned long) dev;
1333         init_timer (&dev->delay);
1334         mutex_init (&dev->phy_mutex);
1335
1336         dev->net = net;
1337         strcpy (net->name, "usb%d");
1338         memcpy (net->dev_addr, node_id, sizeof node_id);
1339
1340         /* rx and tx sides can use different message sizes;
1341          * bind() should set rx_urb_size in that case.
1342          */
1343         dev->hard_mtu = net->mtu + net->hard_header_len;
1344 #if 0
1345 // dma_supported() is deeply broken on almost all architectures
1346         // possible with some EHCI controllers
1347         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1348                 net->features |= NETIF_F_HIGHDMA;
1349 #endif
1350
1351         net->netdev_ops = &usbnet_netdev_ops;
1352         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1353         net->ethtool_ops = &usbnet_ethtool_ops;
1354
1355         // allow device-specific bind/init procedures
1356         // NOTE net->name still not usable ...
1357         if (info->bind) {
1358                 status = info->bind (dev, udev);
1359                 if (status < 0)
1360                         goto out1;
1361
1362                 // heuristic:  "usb%d" for links we know are two-host,
1363                 // else "eth%d" when there's reasonable doubt.  userspace
1364                 // can rename the link if it knows better.
1365                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1366                     (net->dev_addr [0] & 0x02) == 0)
1367                         strcpy (net->name, "eth%d");
1368                 /* WLAN devices should always be named "wlan%d" */
1369                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1370                         strcpy(net->name, "wlan%d");
1371                 /* WWAN devices should always be named "wwan%d" */
1372                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1373                         strcpy(net->name, "wwan%d");
1374
1375                 /* maybe the remote can't receive an Ethernet MTU */
1376                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1377                         net->mtu = dev->hard_mtu - net->hard_header_len;
1378         } else if (!info->in || !info->out)
1379                 status = usbnet_get_endpoints (dev, udev);
1380         else {
1381                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1382                 dev->out = usb_sndbulkpipe (xdev, info->out);
1383                 if (!(info->flags & FLAG_NO_SETINT))
1384                         status = usb_set_interface (xdev,
1385                                 interface->desc.bInterfaceNumber,
1386                                 interface->desc.bAlternateSetting);
1387                 else
1388                         status = 0;
1389
1390         }
1391         if (status >= 0 && dev->status)
1392                 status = init_status (dev, udev);
1393         if (status < 0)
1394                 goto out3;
1395
1396         if (!dev->rx_urb_size)
1397                 dev->rx_urb_size = dev->hard_mtu;
1398         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1399
1400         SET_NETDEV_DEV(net, &udev->dev);
1401
1402         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1403                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1404         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1405                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1406
1407         status = register_netdev (net);
1408         if (status)
1409                 goto out3;
1410         if (netif_msg_probe (dev))
1411                 devinfo (dev, "register '%s' at usb-%s-%s, %s, %pM",
1412                         udev->dev.driver->name,
1413                         xdev->bus->bus_name, xdev->devpath,
1414                         dev->driver_info->description,
1415                         net->dev_addr);
1416
1417         // ok, it's ready to go.
1418         usb_set_intfdata (udev, dev);
1419
1420         netif_device_attach (net);
1421
1422         if (dev->driver_info->flags & FLAG_LINK_INTR)
1423                 netif_carrier_off(net);
1424
1425         return 0;
1426
1427 out3:
1428         if (info->unbind)
1429                 info->unbind (dev, udev);
1430 out1:
1431         free_netdev(net);
1432 out:
1433         usb_put_dev(xdev);
1434         return status;
1435 }
1436 EXPORT_SYMBOL_GPL(usbnet_probe);
1437
1438 /*-------------------------------------------------------------------------*/
1439
1440 /*
1441  * suspend the whole driver as soon as the first interface is suspended
1442  * resume only when the last interface is resumed
1443  */
1444
1445 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1446 {
1447         struct usbnet           *dev = usb_get_intfdata(intf);
1448
1449         if (!dev->suspend_count++) {
1450                 spin_lock_irq(&dev->txq.lock);
1451                 /* don't autosuspend while transmitting */
1452                 if (dev->txq.qlen && (message.event & PM_EVENT_AUTO)) {
1453                         spin_unlock_irq(&dev->txq.lock);
1454                         return -EBUSY;
1455                 } else {
1456                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1457                         spin_unlock_irq(&dev->txq.lock);
1458                 }
1459                 /*
1460                  * accelerate emptying of the rx and queues, to avoid
1461                  * having everything error out.
1462                  */
1463                 netif_device_detach (dev->net);
1464                 usbnet_terminate_urbs(dev);
1465                 usb_kill_urb(dev->interrupt);
1466
1467                 /*
1468                  * reattach so runtime management can use and
1469                  * wake the device
1470                  */
1471                 netif_device_attach (dev->net);
1472         }
1473         return 0;
1474 }
1475 EXPORT_SYMBOL_GPL(usbnet_suspend);
1476
1477 int usbnet_resume (struct usb_interface *intf)
1478 {
1479         struct usbnet           *dev = usb_get_intfdata(intf);
1480         struct sk_buff          *skb;
1481         struct urb              *res;
1482         int                     retval;
1483
1484         if (!--dev->suspend_count) {
1485                 spin_lock_irq(&dev->txq.lock);
1486                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1487
1488                         printk(KERN_INFO"%s has delayed data\n", __func__);
1489                         skb = (struct sk_buff *)res->context;
1490                         retval = usb_submit_urb(res, GFP_ATOMIC);
1491                         if (retval < 0) {
1492                                 dev_kfree_skb_any(skb);
1493                                 usb_free_urb(res);
1494                                 usb_autopm_put_interface_async(dev->intf);
1495                         } else {
1496                                 dev->net->trans_start = jiffies;
1497                                 __skb_queue_tail(&dev->txq, skb);
1498                         }
1499                 }
1500
1501                 smp_mb();
1502                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1503                 spin_unlock_irq(&dev->txq.lock);
1504                 if (!(dev->txq.qlen >= TX_QLEN(dev)))
1505                         netif_start_queue(dev->net);
1506                 tasklet_schedule (&dev->bh);
1507         }
1508         return 0;
1509 }
1510 EXPORT_SYMBOL_GPL(usbnet_resume);
1511
1512
1513 /*-------------------------------------------------------------------------*/
1514
1515 static int __init usbnet_init(void)
1516 {
1517         /* compiler should optimize this out */
1518         BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
1519                         < sizeof (struct skb_data));
1520
1521         random_ether_addr(node_id);
1522         return 0;
1523 }
1524 module_init(usbnet_init);
1525
1526 static void __exit usbnet_exit(void)
1527 {
1528 }
1529 module_exit(usbnet_exit);
1530
1531 MODULE_AUTHOR("David Brownell");
1532 MODULE_DESCRIPTION("USB network driver framework");
1533 MODULE_LICENSE("GPL");