drivers/net/usb/usbnet.c

   1 /*
   2  * USB Network driver infrastructure
   3  * Copyright (C) 2000-2005 by David Brownell
   4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /*
  22  * This is a generic "USB networking" framework that works with several
  23  * kinds of full and high speed networking devices:  host-to-host cables,
  24  * smart usb peripherals, and actual Ethernet adapters.
  25  *
  26  * These devices usually differ in terms of control protocols (if they
  27  * even have one!) and sometimes they define new framing to wrap or batch
  28  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  29  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  30  * issues can usefully be addressed by this framework.
  31  */
  32
  33 // #define      DEBUG                   // error path messages, extra info
  34 // #define      VERBOSE                 // more; success messages
  35
  36 #include <linux/module.h>
  37 #include <linux/init.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/etherdevice.h>
  40 #include <linux/ctype.h>
  41 #include <linux/ethtool.h>
  42 #include <linux/workqueue.h>
  43 #include <linux/mii.h>
  44 #include <linux/usb.h>
  45 #include <linux/usb/usbnet.h>
  46 #include <linux/slab.h>
  47 #include <linux/kernel.h>
  48 #include <linux/pm_runtime.h>
  49
  50 #define DRIVER_VERSION          "22-Aug-2005"
  51
  52
  53 /*-------------------------------------------------------------------------*/
  54
  55 /*
  56  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  57  * Several dozen bytes of IPv4 data can fit in two such transactions.
  58  * One maximum size Ethernet packet takes twenty four of them.
  59  * For high speed, each frame comfortably fits almost 36 max size
  60  * Ethernet packets (so queues should be bigger).
  61  *
  62  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
  63  * let the USB host controller be busy for 5msec or more before an irq
  64  * is required, under load.  Jumbograms change the equation.
  65  */
  66 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
  67 #define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  68                         (RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
  69 #define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  70                         (RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
  71
  72 // reawaken network queue this soon after stopping; else watchdog barks
  73 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  74
  75 // throttle rx/tx briefly after some faults, so khubd might disconnect()
  76 // us (it polls at HZ/4 usually) before we report too many false errors.
  77 #define THROTTLE_JIFFIES        (HZ/8)
  78
  79 // between wakeups
  80 #define UNLINK_TIMEOUT_MS       3
  81
  82 /*-------------------------------------------------------------------------*/
  83
  84 // randomly generated ethernet address
  85 static u8       node_id [ETH_ALEN];
  86
  87 static const char driver_name [] = "usbnet";
  88
  89 /* use ethtool to change the level for any given device */
  90 static int msg_level = -1;
  91 module_param (msg_level, int, 0);
  92 MODULE_PARM_DESC (msg_level, "Override default message level");
  93
  94 /*-------------------------------------------------------------------------*/
  95
  96 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  97 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  98 {
  99         int                             tmp;
 100         struct usb_host_interface       *alt = NULL;
 101         struct usb_host_endpoint        *in = NULL, *out = NULL;
 102         struct usb_host_endpoint        *status = NULL;
 103
 104         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 105                 unsigned        ep;
 106
 107                 in = out = status = NULL;
 108                 alt = intf->altsetting + tmp;
 109
 110                 /* take the first altsetting with in-bulk + out-bulk;
 111                  * remember any status endpoint, just in case;
 112                  * ignore other endpoints and altsetttings.
 113                  */
 114                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 115                         struct usb_host_endpoint        *e;
 116                         int                             intr = 0;
 117
 118                         e = alt->endpoint + ep;
 119                         switch (e->desc.bmAttributes) {
 120                         case USB_ENDPOINT_XFER_INT:
 121                                 if (!usb_endpoint_dir_in(&e->desc))
 122                                         continue;
 123                                 intr = 1;
 124                                 /* FALLTHROUGH */
 125                         case USB_ENDPOINT_XFER_BULK:
 126                                 break;
 127                         default:
 128                                 continue;
 129                         }
 130                         if (usb_endpoint_dir_in(&e->desc)) {
 131                                 if (!intr && !in)
 132                                         in = e;
 133                                 else if (intr && !status)
 134                                         status = e;
 135                         } else {
 136                                 if (!out)
 137                                         out = e;
 138                         }
 139                 }
 140                 if (in && out)
 141                         break;
 142         }
 143         if (!alt || !in || !out)
 144                 return -EINVAL;
 145
 146         if (alt->desc.bAlternateSetting != 0 ||
 147             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 148                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 149                                 alt->desc.bAlternateSetting);
 150                 if (tmp < 0)
 151                         return tmp;
 152         }
 153
 154         dev->in = usb_rcvbulkpipe (dev->udev,
 155                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156         dev->out = usb_sndbulkpipe (dev->udev,
 157                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 158         dev->status = status;
 159         return 0;
 160 }
 161 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 162
 163 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 164 {
 165         int             tmp, i;
 166         unsigned char   buf [13];
 167
 168         tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 169         if (tmp != 12) {
 170                 dev_dbg(&dev->udev->dev,
 171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172                 if (tmp >= 0)
 173                         tmp = -EINVAL;
 174                 return tmp;
 175         }
 176         for (i = tmp = 0; i < 6; i++, tmp += 2)
 177                 dev->net->dev_addr [i] =
 178                         (hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 179         return 0;
 180 }
 181 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 182
 183 static void intr_complete (struct urb *urb);
 184
 185 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 186 {
 187         char            *buf = NULL;
 188         unsigned        pipe = 0;
 189         unsigned        maxp;
 190         unsigned        period;
 191
 192         if (!dev->driver_info->status)
 193                 return 0;
 194
 195         pipe = usb_rcvintpipe (dev->udev,
 196                         dev->status->desc.bEndpointAddress
 197                                 & USB_ENDPOINT_NUMBER_MASK);
 198         maxp = usb_maxpacket (dev->udev, pipe, 0);
 199
 200         /* avoid 1 msec chatter:  min 8 msec poll rate */
 201         period = max ((int) dev->status->desc.bInterval,
 202                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 203
 204         buf = kmalloc (maxp, GFP_KERNEL);
 205         if (buf) {
 206                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 207                 if (!dev->interrupt) {
 208                         kfree (buf);
 209                         return -ENOMEM;
 210                 } else {
 211                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 212                                 buf, maxp, intr_complete, dev, period);
 213                         dev_dbg(&intf->dev,
 214                                 "status ep%din, %d bytes period %d\n",
 215                                 usb_pipeendpoint(pipe), maxp, period);
 216                 }
 217         }
 218         return 0;
 219 }
 220
 221 /* Passes this packet up the stack, updating its accounting.
 222  * Some link protocols batch packets, so their rx_fixup paths
 223  * can return clones as well as just modify the original skb.
 224  */
 225 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 226 {
 227         int     status;
 228
 229         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 230                 skb_queue_tail(&dev->rxq_pause, skb);
 231                 return;
 232         }
 233
 234         skb->protocol = eth_type_trans (skb, dev->net);
 235         dev->net->stats.rx_packets++;
 236         dev->net->stats.rx_bytes += skb->len;
 237
 238         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 239                   skb->len + sizeof (struct ethhdr), skb->protocol);
 240         memset (skb->cb, 0, sizeof (struct skb_data));
 241         status = netif_rx (skb);
 242         if (status != NET_RX_SUCCESS)
 243                 netif_dbg(dev, rx_err, dev->net,
 244                           "netif_rx status %d\n", status);
 245 }
 246 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 247
 248 \f
 249 /*-------------------------------------------------------------------------
 250  *
 251  * Network Device Driver (peer link to "Host Device", from USB host)
 252  *
 253  *-------------------------------------------------------------------------*/
 254
 255 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 256 {
 257         struct usbnet   *dev = netdev_priv(net);
 258         int             ll_mtu = new_mtu + net->hard_header_len;
 259         int             old_hard_mtu = dev->hard_mtu;
 260         int             old_rx_urb_size = dev->rx_urb_size;
 261
 262         if (new_mtu <= 0)
 263                 return -EINVAL;
 264         // no second zero-length packet read wanted after mtu-sized packets
 265         if ((ll_mtu % dev->maxpacket) == 0)
 266                 return -EDOM;
 267         net->mtu = new_mtu;
 268
 269         dev->hard_mtu = net->mtu + net->hard_header_len;
 270         if (dev->rx_urb_size == old_hard_mtu) {
 271                 dev->rx_urb_size = dev->hard_mtu;
 272                 if (dev->rx_urb_size > old_rx_urb_size)
 273                         usbnet_unlink_rx_urbs(dev);
 274         }
 275
 276         return 0;
 277 }
 278 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 279
 280 /*-------------------------------------------------------------------------*/
 281
 282 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 283  * completion callbacks.  2.5 should have fixed those bugs...
 284  */
 285
 286 static void defer_bh(struct usbnet *dev, struct sk_buff *skb, struct sk_buff_head *list)
 287 {
 288         unsigned long           flags;
 289
 290         spin_lock_irqsave(&list->lock, flags);
 291         __skb_unlink(skb, list);
 292         spin_unlock(&list->lock);
 293         spin_lock(&dev->done.lock);
 294         __skb_queue_tail(&dev->done, skb);
 295         if (dev->done.qlen == 1)
 296                 tasklet_schedule(&dev->bh);
 297         spin_unlock_irqrestore(&dev->done.lock, flags);
 298 }
 299
 300 /* some work can't be done in tasklets, so we use keventd
 301  *
 302  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 303  * but tasklet_schedule() doesn't.  hope the failure is rare.
 304  */
 305 void usbnet_defer_kevent (struct usbnet *dev, int work)
 306 {
 307         set_bit (work, &dev->flags);
 308         if (!schedule_work (&dev->kevent))
 309                 netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 310         else
 311                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 312 }
 313 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 314
 315 /*-------------------------------------------------------------------------*/
 316
 317 static void rx_complete (struct urb *urb);
 318
 319 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 320 {
 321         struct sk_buff          *skb;
 322         struct skb_data         *entry;
 323         int                     retval = 0;
 324         unsigned long           lockflags;
 325         size_t                  size = dev->rx_urb_size;
 326
 327         if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
 328                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 329                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 330                 usb_free_urb (urb);
 331                 return -ENOMEM;
 332         }
 333         skb_reserve (skb, NET_IP_ALIGN);
 334
 335         entry = (struct skb_data *) skb->cb;
 336         entry->urb = urb;
 337         entry->dev = dev;
 338         entry->state = rx_start;
 339         entry->length = 0;
 340
 341         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 342                 skb->data, size, rx_complete, skb);
 343
 344         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 345
 346         if (netif_running (dev->net) &&
 347             netif_device_present (dev->net) &&
 348             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 349             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 350                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 351                 case -EPIPE:
 352                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 353                         break;
 354                 case -ENOMEM:
 355                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 356                         break;
 357                 case -ENODEV:
 358                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 359                         netif_device_detach (dev->net);
 360                         break;
 361                 case -EHOSTUNREACH:
 362                         retval = -ENOLINK;
 363                         break;
 364                 default:
 365                         netif_dbg(dev, rx_err, dev->net,
 366                                   "rx submit, %d\n", retval);
 367                         tasklet_schedule (&dev->bh);
 368                         break;
 369                 case 0:
 370                         __skb_queue_tail (&dev->rxq, skb);
 371                 }
 372         } else {
 373                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 374                 retval = -ENOLINK;
 375         }
 376         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 377         if (retval) {
 378                 dev_kfree_skb_any (skb);
 379                 usb_free_urb (urb);
 380         }
 381         return retval;
 382 }
 383
 384
 385 /*-------------------------------------------------------------------------*/
 386
 387 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 388 {
 389         if (dev->driver_info->rx_fixup &&
 390             !dev->driver_info->rx_fixup (dev, skb))
 391                 goto error;
 392         // else network stack removes extra byte if we forced a short packet
 393
 394         if (skb->len)
 395                 usbnet_skb_return (dev, skb);
 396         else {
 397                 netif_dbg(dev, rx_err, dev->net, "drop\n");
 398 error:
 399                 dev->net->stats.rx_errors++;
 400                 skb_queue_tail (&dev->done, skb);
 401         }
 402 }
 403
 404 /*-------------------------------------------------------------------------*/
 405
 406 static void rx_complete (struct urb *urb)
 407 {
 408         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 409         struct skb_data         *entry = (struct skb_data *) skb->cb;
 410         struct usbnet           *dev = entry->dev;
 411         int                     urb_status = urb->status;
 412
 413         skb_put (skb, urb->actual_length);
 414         entry->state = rx_done;
 415         entry->urb = NULL;
 416
 417         switch (urb_status) {
 418         /* success */
 419         case 0:
 420                 if (skb->len < dev->net->hard_header_len) {
 421                         entry->state = rx_cleanup;
 422                         dev->net->stats.rx_errors++;
 423                         dev->net->stats.rx_length_errors++;
 424                         netif_dbg(dev, rx_err, dev->net,
 425                                   "rx length %d\n", skb->len);
 426                 }
 427                 break;
 428
 429         /* stalls need manual reset. this is rare ... except that
 430          * when going through USB 2.0 TTs, unplug appears this way.
 431          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 432          * storm, recovering as needed.
 433          */
 434         case -EPIPE:
 435                 dev->net->stats.rx_errors++;
 436                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 437                 // FALLTHROUGH
 438
 439         /* software-driven interface shutdown */
 440         case -ECONNRESET:               /* async unlink */
 441         case -ESHUTDOWN:                /* hardware gone */
 442                 netif_dbg(dev, ifdown, dev->net,
 443                           "rx shutdown, code %d\n", urb_status);
 444                 goto block;
 445
 446         /* we get controller i/o faults during khubd disconnect() delays.
 447          * throttle down resubmits, to avoid log floods; just temporarily,
 448          * so we still recover when the fault isn't a khubd delay.
 449          */
 450         case -EPROTO:
 451         case -ETIME:
 452         case -EILSEQ:
 453                 dev->net->stats.rx_errors++;
 454                 if (!timer_pending (&dev->delay)) {
 455                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 456                         netif_dbg(dev, link, dev->net,
 457                                   "rx throttle %d\n", urb_status);
 458                 }
 459 block:
 460                 entry->state = rx_cleanup;
 461                 entry->urb = urb;
 462                 urb = NULL;
 463                 break;
 464
 465         /* data overrun ... flush fifo? */
 466         case -EOVERFLOW:
 467                 dev->net->stats.rx_over_errors++;
 468                 // FALLTHROUGH
 469
 470         default:
 471                 entry->state = rx_cleanup;
 472                 dev->net->stats.rx_errors++;
 473                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 474                 break;
 475         }
 476
 477         defer_bh(dev, skb, &dev->rxq);
 478
 479         if (urb) {
 480                 if (netif_running (dev->net) &&
 481                     !test_bit (EVENT_RX_HALT, &dev->flags)) {
 482                         rx_submit (dev, urb, GFP_ATOMIC);
 483                         return;
 484                 }
 485                 usb_free_urb (urb);
 486         }
 487         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 488 }
 489
 490 static void intr_complete (struct urb *urb)
 491 {
 492         struct usbnet   *dev = urb->context;
 493         int             status = urb->status;
 494
 495         switch (status) {
 496         /* success */
 497         case 0:
 498                 dev->driver_info->status(dev, urb);
 499                 break;
 500
 501         /* software-driven interface shutdown */
 502         case -ENOENT:           /* urb killed */
 503         case -ESHUTDOWN:        /* hardware gone */
 504                 netif_dbg(dev, ifdown, dev->net,
 505                           "intr shutdown, code %d\n", status);
 506                 return;
 507
 508         /* NOTE:  not throttling like RX/TX, since this endpoint
 509          * already polls infrequently
 510          */
 511         default:
 512                 netdev_dbg(dev->net, "intr status %d\n", status);
 513                 break;
 514         }
 515
 516         if (!netif_running (dev->net))
 517                 return;
 518
 519         memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
 520         status = usb_submit_urb (urb, GFP_ATOMIC);
 521         if (status != 0)
 522                 netif_err(dev, timer, dev->net,
 523                           "intr resubmit --> %d\n", status);
 524 }
 525
 526 /*-------------------------------------------------------------------------*/
 527 void usbnet_pause_rx(struct usbnet *dev)
 528 {
 529         set_bit(EVENT_RX_PAUSED, &dev->flags);
 530
 531         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 532 }
 533 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 534
 535 void usbnet_resume_rx(struct usbnet *dev)
 536 {
 537         struct sk_buff *skb;
 538         int num = 0;
 539
 540         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 541
 542         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 543                 usbnet_skb_return(dev, skb);
 544                 num++;
 545         }
 546
 547         tasklet_schedule(&dev->bh);
 548
 549         netif_dbg(dev, rx_status, dev->net,
 550                   "paused rx queue disabled, %d skbs requeued\n", num);
 551 }
 552 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 553
 554 void usbnet_purge_paused_rxq(struct usbnet *dev)
 555 {
 556         skb_queue_purge(&dev->rxq_pause);
 557 }
 558 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 559
 560 /*-------------------------------------------------------------------------*/
 561
 562 // unlink pending rx/tx; completion handlers do all other cleanup
 563
 564 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 565 {
 566         unsigned long           flags;
 567         struct sk_buff          *skb, *skbnext;
 568         int                     count = 0;
 569
 570         spin_lock_irqsave (&q->lock, flags);
 571         skb_queue_walk_safe(q, skb, skbnext) {
 572                 struct skb_data         *entry;
 573                 struct urb              *urb;
 574                 int                     retval;
 575
 576                 entry = (struct skb_data *) skb->cb;
 577                 urb = entry->urb;
 578
 579                 // during some PM-driven resume scenarios,
 580                 // these (async) unlinks complete immediately
 581                 retval = usb_unlink_urb (urb);
 582                 if (retval != -EINPROGRESS && retval != 0)
 583                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 584                 else
 585                         count++;
 586         }
 587         spin_unlock_irqrestore (&q->lock, flags);
 588         return count;
 589 }
 590
 591 // Flush all pending rx urbs
 592 // minidrivers may need to do this when the MTU changes
 593
 594 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 595 {
 596         if (netif_running(dev->net)) {
 597                 (void) unlink_urbs (dev, &dev->rxq);
 598                 tasklet_schedule(&dev->bh);
 599         }
 600 }
 601 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 602
 603 /*-------------------------------------------------------------------------*/
 604
 605 // precondition: never called in_interrupt
 606 static void usbnet_terminate_urbs(struct usbnet *dev)
 607 {
 608         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 609         DECLARE_WAITQUEUE(wait, current);
 610         int temp;
 611
 612         /* ensure there are no more active urbs */
 613         add_wait_queue(&unlink_wakeup, &wait);
 614         set_current_state(TASK_UNINTERRUPTIBLE);
 615         dev->wait = &unlink_wakeup;
 616         temp = unlink_urbs(dev, &dev->txq) +
 617                 unlink_urbs(dev, &dev->rxq);
 618
 619         /* maybe wait for deletions to finish. */
 620         while (!skb_queue_empty(&dev->rxq)
 621                 && !skb_queue_empty(&dev->txq)
 622                 && !skb_queue_empty(&dev->done)) {
 623                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 624                         set_current_state(TASK_UNINTERRUPTIBLE);
 625                         netif_dbg(dev, ifdown, dev->net,
 626                                   "waited for %d urb completions\n", temp);
 627         }
 628         set_current_state(TASK_RUNNING);
 629         dev->wait = NULL;
 630         remove_wait_queue(&unlink_wakeup, &wait);
 631 }
 632
 633 int usbnet_stop (struct net_device *net)
 634 {
 635         struct usbnet           *dev = netdev_priv(net);
 636         struct driver_info      *info = dev->driver_info;
 637         int                     retval;
 638
 639         netif_stop_queue (net);
 640
 641         netif_info(dev, ifdown, dev->net,
 642                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 643                    net->stats.rx_packets, net->stats.tx_packets,
 644                    net->stats.rx_errors, net->stats.tx_errors);
 645
 646         /* allow minidriver to stop correctly (wireless devices to turn off
 647          * radio etc) */
 648         if (info->stop) {
 649                 retval = info->stop(dev);
 650                 if (retval < 0)
 651                         netif_info(dev, ifdown, dev->net,
 652                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 653                                    retval,
 654                                    dev->udev->bus->bus_name, dev->udev->devpath,
 655                                    info->description);
 656         }
 657
 658         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 659                 usbnet_terminate_urbs(dev);
 660
 661         usb_kill_urb(dev->interrupt);
 662
 663         usbnet_purge_paused_rxq(dev);
 664
 665         /* deferred work (task, timer, softirq) must also stop.
 666          * can't flush_scheduled_work() until we drop rtnl (later),
 667          * else workers could deadlock; so make workers a NOP.
 668          */
 669         dev->flags = 0;
 670         del_timer_sync (&dev->delay);
 671         tasklet_kill (&dev->bh);
 672         if (info->manage_power)
 673                 info->manage_power(dev, 0);
 674         else
 675                 usb_autopm_put_interface(dev->intf);
 676
 677         return 0;
 678 }
 679 EXPORT_SYMBOL_GPL(usbnet_stop);
 680
 681 /*-------------------------------------------------------------------------*/
 682
 683 // posts reads, and enables write queuing
 684
 685 // precondition: never called in_interrupt
 686
 687 int usbnet_open (struct net_device *net)
 688 {
 689         struct usbnet           *dev = netdev_priv(net);
 690         int                     retval;
 691         struct driver_info      *info = dev->driver_info;
 692
 693         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 694                 netif_info(dev, ifup, dev->net,
 695                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 696                            retval,
 697                            dev->udev->bus->bus_name,
 698                            dev->udev->devpath,
 699                            info->description);
 700                 goto done_nopm;
 701         }
 702
 703         // put into "known safe" state
 704         if (info->reset && (retval = info->reset (dev)) < 0) {
 705                 netif_info(dev, ifup, dev->net,
 706                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 707                            retval,
 708                            dev->udev->bus->bus_name,
 709                            dev->udev->devpath,
 710                            info->description);
 711                 goto done;
 712         }
 713
 714         // insist peer be connected
 715         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 716                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 717                 goto done;
 718         }
 719
 720         /* start any status interrupt transfer */
 721         if (dev->interrupt) {
 722                 retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 723                 if (retval < 0) {
 724                         netif_err(dev, ifup, dev->net,
 725                                   "intr submit %d\n", retval);
 726                         goto done;
 727                 }
 728         }
 729
 730         netif_start_queue (net);
 731         netif_info(dev, ifup, dev->net,
 732                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 733                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 734                    dev->net->mtu,
 735                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 736                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 737                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 738                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 739                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 740                    "simple");
 741
 742         // delay posting reads until we're fully open
 743         tasklet_schedule (&dev->bh);
 744         if (info->manage_power) {
 745                 retval = info->manage_power(dev, 1);
 746                 if (retval < 0)
 747                         goto done;
 748                 usb_autopm_put_interface(dev->intf);
 749         }
 750         return retval;
 751
 752 done:
 753         usb_autopm_put_interface(dev->intf);
 754 done_nopm:
 755         return retval;
 756 }
 757 EXPORT_SYMBOL_GPL(usbnet_open);
 758
 759 /*-------------------------------------------------------------------------*/
 760
 761 /* ethtool methods; minidrivers may need to add some more, but
 762  * they'll probably want to use this base set.
 763  */
 764
 765 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 766 {
 767         struct usbnet *dev = netdev_priv(net);
 768
 769         if (!dev->mii.mdio_read)
 770                 return -EOPNOTSUPP;
 771
 772         return mii_ethtool_gset(&dev->mii, cmd);
 773 }
 774 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 775
 776 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 777 {
 778         struct usbnet *dev = netdev_priv(net);
 779         int retval;
 780
 781         if (!dev->mii.mdio_write)
 782                 return -EOPNOTSUPP;
 783
 784         retval = mii_ethtool_sset(&dev->mii, cmd);
 785
 786         /* link speed/duplex might have changed */
 787         if (dev->driver_info->link_reset)
 788                 dev->driver_info->link_reset(dev);
 789
 790         return retval;
 791
 792 }
 793 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 794
 795 u32 usbnet_get_link (struct net_device *net)
 796 {
 797         struct usbnet *dev = netdev_priv(net);
 798
 799         /* If a check_connect is defined, return its result */
 800         if (dev->driver_info->check_connect)
 801                 return dev->driver_info->check_connect (dev) == 0;
 802
 803         /* if the device has mii operations, use those */
 804         if (dev->mii.mdio_read)
 805                 return mii_link_ok(&dev->mii);
 806
 807         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 808         return ethtool_op_get_link(net);
 809 }
 810 EXPORT_SYMBOL_GPL(usbnet_get_link);
 811
 812 int usbnet_nway_reset(struct net_device *net)
 813 {
 814         struct usbnet *dev = netdev_priv(net);
 815
 816         if (!dev->mii.mdio_write)
 817                 return -EOPNOTSUPP;
 818
 819         return mii_nway_restart(&dev->mii);
 820 }
 821 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 822
 823 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 824 {
 825         struct usbnet *dev = netdev_priv(net);
 826
 827         strncpy (info->driver, dev->driver_name, sizeof info->driver);
 828         strncpy (info->version, DRIVER_VERSION, sizeof info->version);
 829         strncpy (info->fw_version, dev->driver_info->description,
 830                 sizeof info->fw_version);
 831         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 832 }
 833 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 834
 835 u32 usbnet_get_msglevel (struct net_device *net)
 836 {
 837         struct usbnet *dev = netdev_priv(net);
 838
 839         return dev->msg_enable;
 840 }
 841 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 842
 843 void usbnet_set_msglevel (struct net_device *net, u32 level)
 844 {
 845         struct usbnet *dev = netdev_priv(net);
 846
 847         dev->msg_enable = level;
 848 }
 849 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 850
 851 /* drivers may override default ethtool_ops in their bind() routine */
 852 static const struct ethtool_ops usbnet_ethtool_ops = {
 853         .get_settings           = usbnet_get_settings,
 854         .set_settings           = usbnet_set_settings,
 855         .get_link               = usbnet_get_link,
 856         .nway_reset             = usbnet_nway_reset,
 857         .get_drvinfo            = usbnet_get_drvinfo,
 858         .get_msglevel           = usbnet_get_msglevel,
 859         .set_msglevel           = usbnet_set_msglevel,
 860 };
 861
 862 /*-------------------------------------------------------------------------*/
 863
 864 /* work that cannot be done in interrupt context uses keventd.
 865  *
 866  * NOTE:  with 2.5 we could do more of this using completion callbacks,
 867  * especially now that control transfers can be queued.
 868  */
 869 static void
 870 kevent (struct work_struct *work)
 871 {
 872         struct usbnet           *dev =
 873                 container_of(work, struct usbnet, kevent);
 874         int                     status;
 875
 876         /* usb_clear_halt() needs a thread context */
 877         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 878                 unlink_urbs (dev, &dev->txq);
 879                 status = usb_autopm_get_interface(dev->intf);
 880                 if (status < 0)
 881                         goto fail_pipe;
 882                 status = usb_clear_halt (dev->udev, dev->out);
 883                 usb_autopm_put_interface(dev->intf);
 884                 if (status < 0 &&
 885                     status != -EPIPE &&
 886                     status != -ESHUTDOWN) {
 887                         if (netif_msg_tx_err (dev))
 888 fail_pipe:
 889                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
 890                                            status);
 891                 } else {
 892                         clear_bit (EVENT_TX_HALT, &dev->flags);
 893                         if (status != -ESHUTDOWN)
 894                                 netif_wake_queue (dev->net);
 895                 }
 896         }
 897         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 898                 unlink_urbs (dev, &dev->rxq);
 899                 status = usb_autopm_get_interface(dev->intf);
 900                 if (status < 0)
 901                         goto fail_halt;
 902                 status = usb_clear_halt (dev->udev, dev->in);
 903                 usb_autopm_put_interface(dev->intf);
 904                 if (status < 0 &&
 905                     status != -EPIPE &&
 906                     status != -ESHUTDOWN) {
 907                         if (netif_msg_rx_err (dev))
 908 fail_halt:
 909                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
 910                                            status);
 911                 } else {
 912                         clear_bit (EVENT_RX_HALT, &dev->flags);
 913                         tasklet_schedule (&dev->bh);
 914                 }
 915         }
 916
 917         /* tasklet could resubmit itself forever if memory is tight */
 918         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 919                 struct urb      *urb = NULL;
 920                 int resched = 1;
 921
 922                 if (netif_running (dev->net))
 923                         urb = usb_alloc_urb (0, GFP_KERNEL);
 924                 else
 925                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 926                 if (urb != NULL) {
 927                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 928                         status = usb_autopm_get_interface(dev->intf);
 929                         if (status < 0)
 930                                 goto fail_lowmem;
 931                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
 932                                 resched = 0;
 933                         usb_autopm_put_interface(dev->intf);
 934 fail_lowmem:
 935                         if (resched)
 936                                 tasklet_schedule (&dev->bh);
 937                 }
 938         }
 939
 940         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
 941                 struct driver_info      *info = dev->driver_info;
 942                 int                     retval = 0;
 943
 944                 clear_bit (EVENT_LINK_RESET, &dev->flags);
 945                 status = usb_autopm_get_interface(dev->intf);
 946                 if (status < 0)
 947                         goto skip_reset;
 948                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
 949                         usb_autopm_put_interface(dev->intf);
 950 skip_reset:
 951                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
 952                                     retval,
 953                                     dev->udev->bus->bus_name,
 954                                     dev->udev->devpath,
 955                                     info->description);
 956                 } else {
 957                         usb_autopm_put_interface(dev->intf);
 958                 }
 959         }
 960
 961         if (dev->flags)
 962                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
 963 }
 964
 965 /*-------------------------------------------------------------------------*/
 966
 967 static void tx_complete (struct urb *urb)
 968 {
 969         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 970         struct skb_data         *entry = (struct skb_data *) skb->cb;
 971         struct usbnet           *dev = entry->dev;
 972
 973         if (urb->status == 0) {
 974                 dev->net->stats.tx_packets++;
 975                 dev->net->stats.tx_bytes += entry->length;
 976         } else {
 977                 dev->net->stats.tx_errors++;
 978
 979                 switch (urb->status) {
 980                 case -EPIPE:
 981                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
 982                         break;
 983
 984                 /* software-driven interface shutdown */
 985                 case -ECONNRESET:               // async unlink
 986                 case -ESHUTDOWN:                // hardware gone
 987                         break;
 988
 989                 // like rx, tx gets controller i/o faults during khubd delays
 990                 // and so it uses the same throttling mechanism.
 991                 case -EPROTO:
 992                 case -ETIME:
 993                 case -EILSEQ:
 994                         usb_mark_last_busy(dev->udev);
 995                         if (!timer_pending (&dev->delay)) {
 996                                 mod_timer (&dev->delay,
 997                                         jiffies + THROTTLE_JIFFIES);
 998                                 netif_dbg(dev, link, dev->net,
 999                                           "tx throttle %d\n", urb->status);
1000                         }
1001                         netif_stop_queue (dev->net);
1002                         break;
1003                 default:
1004                         netif_dbg(dev, tx_err, dev->net,
1005                                   "tx err %d\n", entry->urb->status);
1006                         break;
1007                 }
1008         }
1009
1010         usb_autopm_put_interface_async(dev->intf);
1011         urb->dev = NULL;
1012         entry->state = tx_done;
1013         defer_bh(dev, skb, &dev->txq);
1014 }
1015
1016 /*-------------------------------------------------------------------------*/
1017
1018 void usbnet_tx_timeout (struct net_device *net)
1019 {
1020         struct usbnet           *dev = netdev_priv(net);
1021
1022         unlink_urbs (dev, &dev->txq);
1023         tasklet_schedule (&dev->bh);
1024
1025         // FIXME: device recovery -- reset?
1026 }
1027 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1028
1029 /*-------------------------------------------------------------------------*/
1030
1031 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1032                                      struct net_device *net)
1033 {
1034         struct usbnet           *dev = netdev_priv(net);
1035         int                     length;
1036         struct urb              *urb = NULL;
1037         struct skb_data         *entry;
1038         struct driver_info      *info = dev->driver_info;
1039         unsigned long           flags;
1040         int retval;
1041
1042         // some devices want funky USB-level framing, for
1043         // win32 driver (usually) and/or hardware quirks
1044         if (info->tx_fixup) {
1045                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1046                 if (!skb) {
1047                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1048                         goto drop;
1049                 }
1050         }
1051         length = skb->len;
1052
1053         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1054                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1055                 goto drop;
1056         }
1057
1058         entry = (struct skb_data *) skb->cb;
1059         entry->urb = urb;
1060         entry->dev = dev;
1061         entry->state = tx_start;
1062         entry->length = length;
1063
1064         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1065                         skb->data, skb->len, tx_complete, skb);
1066
1067         /* don't assume the hardware handles USB_ZERO_PACKET
1068          * NOTE:  strictly conforming cdc-ether devices should expect
1069          * the ZLP here, but ignore the one-byte packet.
1070          */
1071         if (length % dev->maxpacket == 0) {
1072                 if (!(info->flags & FLAG_SEND_ZLP)) {
1073                         urb->transfer_buffer_length++;
1074                         if (skb_tailroom(skb)) {
1075                                 skb->data[skb->len] = 0;
1076                                 __skb_put(skb, 1);
1077                         }
1078                 } else
1079                         urb->transfer_flags |= URB_ZERO_PACKET;
1080         }
1081
1082         spin_lock_irqsave(&dev->txq.lock, flags);
1083         retval = usb_autopm_get_interface_async(dev->intf);
1084         if (retval < 0) {
1085                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1086                 goto drop;
1087         }
1088
1089 #ifdef CONFIG_PM
1090         /* if this triggers the device is still a sleep */
1091         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1092                 /* transmission will be done in resume */
1093                 usb_anchor_urb(urb, &dev->deferred);
1094                 /* no use to process more packets */
1095                 netif_stop_queue(net);
1096                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1097                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1098                 goto deferred;
1099         }
1100 #endif
1101
1102         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1103         case -EPIPE:
1104                 netif_stop_queue (net);
1105                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1106                 usb_autopm_put_interface_async(dev->intf);
1107                 break;
1108         default:
1109                 usb_autopm_put_interface_async(dev->intf);
1110                 netif_dbg(dev, tx_err, dev->net,
1111                           "tx: submit urb err %d\n", retval);
1112                 break;
1113         case 0:
1114                 net->trans_start = jiffies;
1115                 __skb_queue_tail (&dev->txq, skb);
1116                 if (dev->txq.qlen >= TX_QLEN (dev))
1117                         netif_stop_queue (net);
1118         }
1119         spin_unlock_irqrestore (&dev->txq.lock, flags);
1120
1121         if (retval) {
1122                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1123 drop:
1124                 dev->net->stats.tx_dropped++;
1125                 if (skb)
1126                         dev_kfree_skb_any (skb);
1127                 usb_free_urb (urb);
1128         } else
1129                 netif_dbg(dev, tx_queued, dev->net,
1130                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1131 #ifdef CONFIG_PM
1132 deferred:
1133 #endif
1134         return NETDEV_TX_OK;
1135 }
1136 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1137
1138 /*-------------------------------------------------------------------------*/
1139
1140 // tasklet (work deferred from completions, in_irq) or timer
1141
1142 static void usbnet_bh (unsigned long param)
1143 {
1144         struct usbnet           *dev = (struct usbnet *) param;
1145         struct sk_buff          *skb;
1146         struct skb_data         *entry;
1147
1148         while ((skb = skb_dequeue (&dev->done))) {
1149                 entry = (struct skb_data *) skb->cb;
1150                 switch (entry->state) {
1151                 case rx_done:
1152                         entry->state = rx_cleanup;
1153                         rx_process (dev, skb);
1154                         continue;
1155                 case tx_done:
1156                 case rx_cleanup:
1157                         usb_free_urb (entry->urb);
1158                         dev_kfree_skb (skb);
1159                         continue;
1160                 default:
1161                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1162                 }
1163         }
1164
1165         // waiting for all pending urbs to complete?
1166         if (dev->wait) {
1167                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1168                         wake_up (dev->wait);
1169                 }
1170
1171         // or are we maybe short a few urbs?
1172         } else if (netif_running (dev->net) &&
1173                    netif_device_present (dev->net) &&
1174                    !timer_pending (&dev->delay) &&
1175                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1176                 int     temp = dev->rxq.qlen;
1177                 int     qlen = RX_QLEN (dev);
1178
1179                 if (temp < qlen) {
1180                         struct urb      *urb;
1181                         int             i;
1182
1183                         // don't refill the queue all at once
1184                         for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1185                                 urb = usb_alloc_urb (0, GFP_ATOMIC);
1186                                 if (urb != NULL) {
1187                                         if (rx_submit (dev, urb, GFP_ATOMIC) ==
1188                                             -ENOLINK)
1189                                                 return;
1190                                 }
1191                         }
1192                         if (temp != dev->rxq.qlen)
1193                                 netif_dbg(dev, link, dev->net,
1194                                           "rxqlen %d --> %d\n",
1195                                           temp, dev->rxq.qlen);
1196                         if (dev->rxq.qlen < qlen)
1197                                 tasklet_schedule (&dev->bh);
1198                 }
1199                 if (dev->txq.qlen < TX_QLEN (dev))
1200                         netif_wake_queue (dev->net);
1201         }
1202 }
1203
1204
1205 /*-------------------------------------------------------------------------
1206  *
1207  * USB Device Driver support
1208  *
1209  *-------------------------------------------------------------------------*/
1210
1211 // precondition: never called in_interrupt
1212
1213 void usbnet_disconnect (struct usb_interface *intf)
1214 {
1215         struct usbnet           *dev;
1216         struct usb_device       *xdev;
1217         struct net_device       *net;
1218
1219         dev = usb_get_intfdata(intf);
1220         usb_set_intfdata(intf, NULL);
1221         if (!dev)
1222                 return;
1223
1224         xdev = interface_to_usbdev (intf);
1225
1226         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1227                    intf->dev.driver->name,
1228                    xdev->bus->bus_name, xdev->devpath,
1229                    dev->driver_info->description);
1230
1231         net = dev->net;
1232         unregister_netdev (net);
1233
1234         /* we don't hold rtnl here ... */
1235         flush_scheduled_work ();
1236
1237         if (dev->driver_info->unbind)
1238                 dev->driver_info->unbind (dev, intf);
1239
1240         free_netdev(net);
1241         usb_put_dev (xdev);
1242 }
1243 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1244
1245 static const struct net_device_ops usbnet_netdev_ops = {
1246         .ndo_open               = usbnet_open,
1247         .ndo_stop               = usbnet_stop,
1248         .ndo_start_xmit         = usbnet_start_xmit,
1249         .ndo_tx_timeout         = usbnet_tx_timeout,
1250         .ndo_change_mtu         = usbnet_change_mtu,
1251         .ndo_set_mac_address    = eth_mac_addr,
1252         .ndo_validate_addr      = eth_validate_addr,
1253 };
1254
1255 /*-------------------------------------------------------------------------*/
1256
1257 // precondition: never called in_interrupt
1258
1259 static struct device_type wlan_type = {
1260         .name   = "wlan",
1261 };
1262
1263 static struct device_type wwan_type = {
1264         .name   = "wwan",
1265 };
1266
1267 int
1268 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1269 {
1270         struct usbnet                   *dev;
1271         struct net_device               *net;
1272         struct usb_host_interface       *interface;
1273         struct driver_info              *info;
1274         struct usb_device               *xdev;
1275         int                             status;
1276         const char                      *name;
1277         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1278
1279         /* usbnet already took usb runtime pm, so have to enable the feature
1280          * for usb interface, otherwise usb_autopm_get_interface may return
1281          * failure if USB_SUSPEND(RUNTIME_PM) is enabled.
1282          */
1283         if (!driver->supports_autosuspend) {
1284                 driver->supports_autosuspend = 1;
1285                 pm_runtime_enable(&udev->dev);
1286         }
1287
1288         name = udev->dev.driver->name;
1289         info = (struct driver_info *) prod->driver_info;
1290         if (!info) {
1291                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1292                 return -ENODEV;
1293         }
1294         xdev = interface_to_usbdev (udev);
1295         interface = udev->cur_altsetting;
1296
1297         usb_get_dev (xdev);
1298
1299         status = -ENOMEM;
1300
1301         // set up our own records
1302         net = alloc_etherdev(sizeof(*dev));
1303         if (!net) {
1304                 dbg ("can't kmalloc dev");
1305                 goto out;
1306         }
1307
1308         /* netdev_printk() needs this so do it as early as possible */
1309         SET_NETDEV_DEV(net, &udev->dev);
1310
1311         dev = netdev_priv(net);
1312         dev->udev = xdev;
1313         dev->intf = udev;
1314         dev->driver_info = info;
1315         dev->driver_name = name;
1316         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1317                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1318         skb_queue_head_init (&dev->rxq);
1319         skb_queue_head_init (&dev->txq);
1320         skb_queue_head_init (&dev->done);
1321         skb_queue_head_init(&dev->rxq_pause);
1322         dev->bh.func = usbnet_bh;
1323         dev->bh.data = (unsigned long) dev;
1324         INIT_WORK (&dev->kevent, kevent);
1325         init_usb_anchor(&dev->deferred);
1326         dev->delay.function = usbnet_bh;
1327         dev->delay.data = (unsigned long) dev;
1328         init_timer (&dev->delay);
1329         mutex_init (&dev->phy_mutex);
1330
1331         dev->net = net;
1332         strcpy (net->name, "usb%d");
1333         memcpy (net->dev_addr, node_id, sizeof node_id);
1334
1335         /* rx and tx sides can use different message sizes;
1336          * bind() should set rx_urb_size in that case.
1337          */
1338         dev->hard_mtu = net->mtu + net->hard_header_len;
1339 #if 0
1340 // dma_supported() is deeply broken on almost all architectures
1341         // possible with some EHCI controllers
1342         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1343                 net->features |= NETIF_F_HIGHDMA;
1344 #endif
1345
1346         net->netdev_ops = &usbnet_netdev_ops;
1347         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1348         net->ethtool_ops = &usbnet_ethtool_ops;
1349
1350         // allow device-specific bind/init procedures
1351         // NOTE net->name still not usable ...
1352         if (info->bind) {
1353                 status = info->bind (dev, udev);
1354                 if (status < 0)
1355                         goto out1;
1356
1357                 // heuristic:  "usb%d" for links we know are two-host,
1358                 // else "eth%d" when there's reasonable doubt.  userspace
1359                 // can rename the link if it knows better.
1360                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1361                     (net->dev_addr [0] & 0x02) == 0)
1362                         strcpy (net->name, "eth%d");
1363                 /* WLAN devices should always be named "wlan%d" */
1364                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1365                         strcpy(net->name, "wlan%d");
1366                 /* WWAN devices should always be named "wwan%d" */
1367                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1368                         strcpy(net->name, "wwan%d");
1369
1370                 /* maybe the remote can't receive an Ethernet MTU */
1371                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1372                         net->mtu = dev->hard_mtu - net->hard_header_len;
1373         } else if (!info->in || !info->out)
1374                 status = usbnet_get_endpoints (dev, udev);
1375         else {
1376                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1377                 dev->out = usb_sndbulkpipe (xdev, info->out);
1378                 if (!(info->flags & FLAG_NO_SETINT))
1379                         status = usb_set_interface (xdev,
1380                                 interface->desc.bInterfaceNumber,
1381                                 interface->desc.bAlternateSetting);
1382                 else
1383                         status = 0;
1384
1385         }
1386         if (status >= 0 && dev->status)
1387                 status = init_status (dev, udev);
1388         if (status < 0)
1389                 goto out3;
1390
1391         if (!dev->rx_urb_size)
1392                 dev->rx_urb_size = dev->hard_mtu;
1393         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1394
1395         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1396                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1397         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1398                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1399
1400         status = register_netdev (net);
1401         if (status)
1402                 goto out3;
1403         netif_info(dev, probe, dev->net,
1404                    "register '%s' at usb-%s-%s, %s, %pM\n",
1405                    udev->dev.driver->name,
1406                    xdev->bus->bus_name, xdev->devpath,
1407                    dev->driver_info->description,
1408                    net->dev_addr);
1409
1410         // ok, it's ready to go.
1411         usb_set_intfdata (udev, dev);
1412
1413         netif_device_attach (net);
1414
1415         if (dev->driver_info->flags & FLAG_LINK_INTR)
1416                 netif_carrier_off(net);
1417
1418         return 0;
1419
1420 out3:
1421         if (info->unbind)
1422                 info->unbind (dev, udev);
1423 out1:
1424         free_netdev(net);
1425 out:
1426         usb_put_dev(xdev);
1427         return status;
1428 }
1429 EXPORT_SYMBOL_GPL(usbnet_probe);
1430
1431 /*-------------------------------------------------------------------------*/
1432
1433 /*
1434  * suspend the whole driver as soon as the first interface is suspended
1435  * resume only when the last interface is resumed
1436  */
1437
1438 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1439 {
1440         struct usbnet           *dev = usb_get_intfdata(intf);
1441
1442         if (!dev->suspend_count++) {
1443                 spin_lock_irq(&dev->txq.lock);
1444                 /* don't autosuspend while transmitting */
1445                 if (dev->txq.qlen && (message.event & PM_EVENT_AUTO)) {
1446                         spin_unlock_irq(&dev->txq.lock);
1447                         return -EBUSY;
1448                 } else {
1449                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1450                         spin_unlock_irq(&dev->txq.lock);
1451                 }
1452                 /*
1453                  * accelerate emptying of the rx and queues, to avoid
1454                  * having everything error out.
1455                  */
1456                 netif_device_detach (dev->net);
1457                 usbnet_terminate_urbs(dev);
1458                 usb_kill_urb(dev->interrupt);
1459
1460                 /*
1461                  * reattach so runtime management can use and
1462                  * wake the device
1463                  */
1464                 netif_device_attach (dev->net);
1465         }
1466         return 0;
1467 }
1468 EXPORT_SYMBOL_GPL(usbnet_suspend);
1469
1470 int usbnet_resume (struct usb_interface *intf)
1471 {
1472         struct usbnet           *dev = usb_get_intfdata(intf);
1473         struct sk_buff          *skb;
1474         struct urb              *res;
1475         int                     retval;
1476
1477         if (!--dev->suspend_count) {
1478                 spin_lock_irq(&dev->txq.lock);
1479                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1480
1481                         skb = (struct sk_buff *)res->context;
1482                         retval = usb_submit_urb(res, GFP_ATOMIC);
1483                         if (retval < 0) {
1484                                 dev_kfree_skb_any(skb);
1485                                 usb_free_urb(res);
1486                                 usb_autopm_put_interface_async(dev->intf);
1487                         } else {
1488                                 dev->net->trans_start = jiffies;
1489                                 __skb_queue_tail(&dev->txq, skb);
1490                         }
1491                 }
1492
1493                 smp_mb();
1494                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1495                 spin_unlock_irq(&dev->txq.lock);
1496                 if (!(dev->txq.qlen >= TX_QLEN(dev)))
1497                         netif_start_queue(dev->net);
1498                 tasklet_schedule (&dev->bh);
1499         }
1500         return 0;
1501 }
1502 EXPORT_SYMBOL_GPL(usbnet_resume);
1503
1504
1505 /*-------------------------------------------------------------------------*/
1506
1507 static int __init usbnet_init(void)
1508 {
1509         /* compiler should optimize this out */
1510         BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
1511                         < sizeof (struct skb_data));
1512
1513         random_ether_addr(node_id);
1514         return 0;
1515 }
1516 module_init(usbnet_init);
1517
1518 static void __exit usbnet_exit(void)
1519 {
1520 }
1521 module_exit(usbnet_exit);
1522
1523 MODULE_AUTHOR("David Brownell");
1524 MODULE_DESCRIPTION("USB network driver framework");
1525 MODULE_LICENSE("GPL");