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                 /* all data was already cloned from skb inside the driver */
 396                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 397                         dev_kfree_skb_any(skb);
 398                 else
 399                         usbnet_skb_return(dev, skb);
 400                 return;
 401         }
 402
 403         netif_dbg(dev, rx_err, dev->net, "drop\n");
 404 error:
 405         dev->net->stats.rx_errors++;
 406         skb_queue_tail(&dev->done, skb);
 407 }
 408
 409 /*-------------------------------------------------------------------------*/
 410
 411 static void rx_complete (struct urb *urb)
 412 {
 413         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 414         struct skb_data         *entry = (struct skb_data *) skb->cb;
 415         struct usbnet           *dev = entry->dev;
 416         int                     urb_status = urb->status;
 417
 418         skb_put (skb, urb->actual_length);
 419         entry->state = rx_done;
 420         entry->urb = NULL;
 421
 422         switch (urb_status) {
 423         /* success */
 424         case 0:
 425                 if (skb->len < dev->net->hard_header_len) {
 426                         entry->state = rx_cleanup;
 427                         dev->net->stats.rx_errors++;
 428                         dev->net->stats.rx_length_errors++;
 429                         netif_dbg(dev, rx_err, dev->net,
 430                                   "rx length %d\n", skb->len);
 431                 }
 432                 break;
 433
 434         /* stalls need manual reset. this is rare ... except that
 435          * when going through USB 2.0 TTs, unplug appears this way.
 436          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 437          * storm, recovering as needed.
 438          */
 439         case -EPIPE:
 440                 dev->net->stats.rx_errors++;
 441                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 442                 // FALLTHROUGH
 443
 444         /* software-driven interface shutdown */
 445         case -ECONNRESET:               /* async unlink */
 446         case -ESHUTDOWN:                /* hardware gone */
 447                 netif_dbg(dev, ifdown, dev->net,
 448                           "rx shutdown, code %d\n", urb_status);
 449                 goto block;
 450
 451         /* we get controller i/o faults during khubd disconnect() delays.
 452          * throttle down resubmits, to avoid log floods; just temporarily,
 453          * so we still recover when the fault isn't a khubd delay.
 454          */
 455         case -EPROTO:
 456         case -ETIME:
 457         case -EILSEQ:
 458                 dev->net->stats.rx_errors++;
 459                 if (!timer_pending (&dev->delay)) {
 460                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 461                         netif_dbg(dev, link, dev->net,
 462                                   "rx throttle %d\n", urb_status);
 463                 }
 464 block:
 465                 entry->state = rx_cleanup;
 466                 entry->urb = urb;
 467                 urb = NULL;
 468                 break;
 469
 470         /* data overrun ... flush fifo? */
 471         case -EOVERFLOW:
 472                 dev->net->stats.rx_over_errors++;
 473                 // FALLTHROUGH
 474
 475         default:
 476                 entry->state = rx_cleanup;
 477                 dev->net->stats.rx_errors++;
 478                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 479                 break;
 480         }
 481
 482         defer_bh(dev, skb, &dev->rxq);
 483
 484         if (urb) {
 485                 if (netif_running (dev->net) &&
 486                     !test_bit (EVENT_RX_HALT, &dev->flags)) {
 487                         rx_submit (dev, urb, GFP_ATOMIC);
 488                         return;
 489                 }
 490                 usb_free_urb (urb);
 491         }
 492         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 493 }
 494
 495 static void intr_complete (struct urb *urb)
 496 {
 497         struct usbnet   *dev = urb->context;
 498         int             status = urb->status;
 499
 500         switch (status) {
 501         /* success */
 502         case 0:
 503                 dev->driver_info->status(dev, urb);
 504                 break;
 505
 506         /* software-driven interface shutdown */
 507         case -ENOENT:           /* urb killed */
 508         case -ESHUTDOWN:        /* hardware gone */
 509                 netif_dbg(dev, ifdown, dev->net,
 510                           "intr shutdown, code %d\n", status);
 511                 return;
 512
 513         /* NOTE:  not throttling like RX/TX, since this endpoint
 514          * already polls infrequently
 515          */
 516         default:
 517                 netdev_dbg(dev->net, "intr status %d\n", status);
 518                 break;
 519         }
 520
 521         if (!netif_running (dev->net))
 522                 return;
 523
 524         memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
 525         status = usb_submit_urb (urb, GFP_ATOMIC);
 526         if (status != 0)
 527                 netif_err(dev, timer, dev->net,
 528                           "intr resubmit --> %d\n", status);
 529 }
 530
 531 /*-------------------------------------------------------------------------*/
 532 void usbnet_pause_rx(struct usbnet *dev)
 533 {
 534         set_bit(EVENT_RX_PAUSED, &dev->flags);
 535
 536         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 537 }
 538 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 539
 540 void usbnet_resume_rx(struct usbnet *dev)
 541 {
 542         struct sk_buff *skb;
 543         int num = 0;
 544
 545         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 546
 547         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 548                 usbnet_skb_return(dev, skb);
 549                 num++;
 550         }
 551
 552         tasklet_schedule(&dev->bh);
 553
 554         netif_dbg(dev, rx_status, dev->net,
 555                   "paused rx queue disabled, %d skbs requeued\n", num);
 556 }
 557 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 558
 559 void usbnet_purge_paused_rxq(struct usbnet *dev)
 560 {
 561         skb_queue_purge(&dev->rxq_pause);
 562 }
 563 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 564
 565 /*-------------------------------------------------------------------------*/
 566
 567 // unlink pending rx/tx; completion handlers do all other cleanup
 568
 569 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 570 {
 571         unsigned long           flags;
 572         struct sk_buff          *skb, *skbnext;
 573         int                     count = 0;
 574
 575         spin_lock_irqsave (&q->lock, flags);
 576         skb_queue_walk_safe(q, skb, skbnext) {
 577                 struct skb_data         *entry;
 578                 struct urb              *urb;
 579                 int                     retval;
 580
 581                 entry = (struct skb_data *) skb->cb;
 582                 urb = entry->urb;
 583
 584                 // during some PM-driven resume scenarios,
 585                 // these (async) unlinks complete immediately
 586                 retval = usb_unlink_urb (urb);
 587                 if (retval != -EINPROGRESS && retval != 0)
 588                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 589                 else
 590                         count++;
 591         }
 592         spin_unlock_irqrestore (&q->lock, flags);
 593         return count;
 594 }
 595
 596 // Flush all pending rx urbs
 597 // minidrivers may need to do this when the MTU changes
 598
 599 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 600 {
 601         if (netif_running(dev->net)) {
 602                 (void) unlink_urbs (dev, &dev->rxq);
 603                 tasklet_schedule(&dev->bh);
 604         }
 605 }
 606 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 607
 608 /*-------------------------------------------------------------------------*/
 609
 610 // precondition: never called in_interrupt
 611 static void usbnet_terminate_urbs(struct usbnet *dev)
 612 {
 613         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 614         DECLARE_WAITQUEUE(wait, current);
 615         int temp;
 616
 617         /* ensure there are no more active urbs */
 618         add_wait_queue(&unlink_wakeup, &wait);
 619         set_current_state(TASK_UNINTERRUPTIBLE);
 620         dev->wait = &unlink_wakeup;
 621         temp = unlink_urbs(dev, &dev->txq) +
 622                 unlink_urbs(dev, &dev->rxq);
 623
 624         /* maybe wait for deletions to finish. */
 625         while (!skb_queue_empty(&dev->rxq)
 626                 && !skb_queue_empty(&dev->txq)
 627                 && !skb_queue_empty(&dev->done)) {
 628                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 629                         set_current_state(TASK_UNINTERRUPTIBLE);
 630                         netif_dbg(dev, ifdown, dev->net,
 631                                   "waited for %d urb completions\n", temp);
 632         }
 633         set_current_state(TASK_RUNNING);
 634         dev->wait = NULL;
 635         remove_wait_queue(&unlink_wakeup, &wait);
 636 }
 637
 638 int usbnet_stop (struct net_device *net)
 639 {
 640         struct usbnet           *dev = netdev_priv(net);
 641         struct driver_info      *info = dev->driver_info;
 642         int                     retval;
 643
 644         netif_stop_queue (net);
 645
 646         netif_info(dev, ifdown, dev->net,
 647                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 648                    net->stats.rx_packets, net->stats.tx_packets,
 649                    net->stats.rx_errors, net->stats.tx_errors);
 650
 651         /* allow minidriver to stop correctly (wireless devices to turn off
 652          * radio etc) */
 653         if (info->stop) {
 654                 retval = info->stop(dev);
 655                 if (retval < 0)
 656                         netif_info(dev, ifdown, dev->net,
 657                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 658                                    retval,
 659                                    dev->udev->bus->bus_name, dev->udev->devpath,
 660                                    info->description);
 661         }
 662
 663         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 664                 usbnet_terminate_urbs(dev);
 665
 666         usb_kill_urb(dev->interrupt);
 667
 668         usbnet_purge_paused_rxq(dev);
 669
 670         /* deferred work (task, timer, softirq) must also stop.
 671          * can't flush_scheduled_work() until we drop rtnl (later),
 672          * else workers could deadlock; so make workers a NOP.
 673          */
 674         dev->flags = 0;
 675         del_timer_sync (&dev->delay);
 676         tasklet_kill (&dev->bh);
 677         if (info->manage_power)
 678                 info->manage_power(dev, 0);
 679         else
 680                 usb_autopm_put_interface(dev->intf);
 681
 682         return 0;
 683 }
 684 EXPORT_SYMBOL_GPL(usbnet_stop);
 685
 686 /*-------------------------------------------------------------------------*/
 687
 688 // posts reads, and enables write queuing
 689
 690 // precondition: never called in_interrupt
 691
 692 int usbnet_open (struct net_device *net)
 693 {
 694         struct usbnet           *dev = netdev_priv(net);
 695         int                     retval;
 696         struct driver_info      *info = dev->driver_info;
 697
 698         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 699                 netif_info(dev, ifup, dev->net,
 700                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 701                            retval,
 702                            dev->udev->bus->bus_name,
 703                            dev->udev->devpath,
 704                            info->description);
 705                 goto done_nopm;
 706         }
 707
 708         // put into "known safe" state
 709         if (info->reset && (retval = info->reset (dev)) < 0) {
 710                 netif_info(dev, ifup, dev->net,
 711                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 712                            retval,
 713                            dev->udev->bus->bus_name,
 714                            dev->udev->devpath,
 715                            info->description);
 716                 goto done;
 717         }
 718
 719         // insist peer be connected
 720         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 721                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 722                 goto done;
 723         }
 724
 725         /* start any status interrupt transfer */
 726         if (dev->interrupt) {
 727                 retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 728                 if (retval < 0) {
 729                         netif_err(dev, ifup, dev->net,
 730                                   "intr submit %d\n", retval);
 731                         goto done;
 732                 }
 733         }
 734
 735         netif_start_queue (net);
 736         netif_info(dev, ifup, dev->net,
 737                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 738                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 739                    dev->net->mtu,
 740                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 741                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 742                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 743                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 744                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 745                    "simple");
 746
 747         // delay posting reads until we're fully open
 748         tasklet_schedule (&dev->bh);
 749         if (info->manage_power) {
 750                 retval = info->manage_power(dev, 1);
 751                 if (retval < 0)
 752                         goto done;
 753                 usb_autopm_put_interface(dev->intf);
 754         }
 755         return retval;
 756
 757 done:
 758         usb_autopm_put_interface(dev->intf);
 759 done_nopm:
 760         return retval;
 761 }
 762 EXPORT_SYMBOL_GPL(usbnet_open);
 763
 764 /*-------------------------------------------------------------------------*/
 765
 766 /* ethtool methods; minidrivers may need to add some more, but
 767  * they'll probably want to use this base set.
 768  */
 769
 770 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 771 {
 772         struct usbnet *dev = netdev_priv(net);
 773
 774         if (!dev->mii.mdio_read)
 775                 return -EOPNOTSUPP;
 776
 777         return mii_ethtool_gset(&dev->mii, cmd);
 778 }
 779 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 780
 781 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 782 {
 783         struct usbnet *dev = netdev_priv(net);
 784         int retval;
 785
 786         if (!dev->mii.mdio_write)
 787                 return -EOPNOTSUPP;
 788
 789         retval = mii_ethtool_sset(&dev->mii, cmd);
 790
 791         /* link speed/duplex might have changed */
 792         if (dev->driver_info->link_reset)
 793                 dev->driver_info->link_reset(dev);
 794
 795         return retval;
 796
 797 }
 798 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 799
 800 u32 usbnet_get_link (struct net_device *net)
 801 {
 802         struct usbnet *dev = netdev_priv(net);
 803
 804         /* If a check_connect is defined, return its result */
 805         if (dev->driver_info->check_connect)
 806                 return dev->driver_info->check_connect (dev) == 0;
 807
 808         /* if the device has mii operations, use those */
 809         if (dev->mii.mdio_read)
 810                 return mii_link_ok(&dev->mii);
 811
 812         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 813         return ethtool_op_get_link(net);
 814 }
 815 EXPORT_SYMBOL_GPL(usbnet_get_link);
 816
 817 int usbnet_nway_reset(struct net_device *net)
 818 {
 819         struct usbnet *dev = netdev_priv(net);
 820
 821         if (!dev->mii.mdio_write)
 822                 return -EOPNOTSUPP;
 823
 824         return mii_nway_restart(&dev->mii);
 825 }
 826 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 827
 828 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 829 {
 830         struct usbnet *dev = netdev_priv(net);
 831
 832         strncpy (info->driver, dev->driver_name, sizeof info->driver);
 833         strncpy (info->version, DRIVER_VERSION, sizeof info->version);
 834         strncpy (info->fw_version, dev->driver_info->description,
 835                 sizeof info->fw_version);
 836         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 837 }
 838 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 839
 840 u32 usbnet_get_msglevel (struct net_device *net)
 841 {
 842         struct usbnet *dev = netdev_priv(net);
 843
 844         return dev->msg_enable;
 845 }
 846 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 847
 848 void usbnet_set_msglevel (struct net_device *net, u32 level)
 849 {
 850         struct usbnet *dev = netdev_priv(net);
 851
 852         dev->msg_enable = level;
 853 }
 854 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 855
 856 /* drivers may override default ethtool_ops in their bind() routine */
 857 static const struct ethtool_ops usbnet_ethtool_ops = {
 858         .get_settings           = usbnet_get_settings,
 859         .set_settings           = usbnet_set_settings,
 860         .get_link               = usbnet_get_link,
 861         .nway_reset             = usbnet_nway_reset,
 862         .get_drvinfo            = usbnet_get_drvinfo,
 863         .get_msglevel           = usbnet_get_msglevel,
 864         .set_msglevel           = usbnet_set_msglevel,
 865 };
 866
 867 /*-------------------------------------------------------------------------*/
 868
 869 /* work that cannot be done in interrupt context uses keventd.
 870  *
 871  * NOTE:  with 2.5 we could do more of this using completion callbacks,
 872  * especially now that control transfers can be queued.
 873  */
 874 static void
 875 kevent (struct work_struct *work)
 876 {
 877         struct usbnet           *dev =
 878                 container_of(work, struct usbnet, kevent);
 879         int                     status;
 880
 881         /* usb_clear_halt() needs a thread context */
 882         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 883                 unlink_urbs (dev, &dev->txq);
 884                 status = usb_autopm_get_interface(dev->intf);
 885                 if (status < 0)
 886                         goto fail_pipe;
 887                 status = usb_clear_halt (dev->udev, dev->out);
 888                 usb_autopm_put_interface(dev->intf);
 889                 if (status < 0 &&
 890                     status != -EPIPE &&
 891                     status != -ESHUTDOWN) {
 892                         if (netif_msg_tx_err (dev))
 893 fail_pipe:
 894                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
 895                                            status);
 896                 } else {
 897                         clear_bit (EVENT_TX_HALT, &dev->flags);
 898                         if (status != -ESHUTDOWN)
 899                                 netif_wake_queue (dev->net);
 900                 }
 901         }
 902         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 903                 unlink_urbs (dev, &dev->rxq);
 904                 status = usb_autopm_get_interface(dev->intf);
 905                 if (status < 0)
 906                         goto fail_halt;
 907                 status = usb_clear_halt (dev->udev, dev->in);
 908                 usb_autopm_put_interface(dev->intf);
 909                 if (status < 0 &&
 910                     status != -EPIPE &&
 911                     status != -ESHUTDOWN) {
 912                         if (netif_msg_rx_err (dev))
 913 fail_halt:
 914                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
 915                                            status);
 916                 } else {
 917                         clear_bit (EVENT_RX_HALT, &dev->flags);
 918                         tasklet_schedule (&dev->bh);
 919                 }
 920         }
 921
 922         /* tasklet could resubmit itself forever if memory is tight */
 923         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 924                 struct urb      *urb = NULL;
 925                 int resched = 1;
 926
 927                 if (netif_running (dev->net))
 928                         urb = usb_alloc_urb (0, GFP_KERNEL);
 929                 else
 930                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 931                 if (urb != NULL) {
 932                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 933                         status = usb_autopm_get_interface(dev->intf);
 934                         if (status < 0) {
 935                                 usb_free_urb(urb);
 936                                 goto fail_lowmem;
 937                         }
 938                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
 939                                 resched = 0;
 940                         usb_autopm_put_interface(dev->intf);
 941 fail_lowmem:
 942                         if (resched)
 943                                 tasklet_schedule (&dev->bh);
 944                 }
 945         }
 946
 947         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
 948                 struct driver_info      *info = dev->driver_info;
 949                 int                     retval = 0;
 950
 951                 clear_bit (EVENT_LINK_RESET, &dev->flags);
 952                 status = usb_autopm_get_interface(dev->intf);
 953                 if (status < 0)
 954                         goto skip_reset;
 955                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
 956                         usb_autopm_put_interface(dev->intf);
 957 skip_reset:
 958                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
 959                                     retval,
 960                                     dev->udev->bus->bus_name,
 961                                     dev->udev->devpath,
 962                                     info->description);
 963                 } else {
 964                         usb_autopm_put_interface(dev->intf);
 965                 }
 966         }
 967
 968         if (dev->flags)
 969                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
 970 }
 971
 972 /*-------------------------------------------------------------------------*/
 973
 974 static void tx_complete (struct urb *urb)
 975 {
 976         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 977         struct skb_data         *entry = (struct skb_data *) skb->cb;
 978         struct usbnet           *dev = entry->dev;
 979
 980         if (urb->status == 0) {
 981                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
 982                         dev->net->stats.tx_packets++;
 983                 dev->net->stats.tx_bytes += entry->length;
 984         } else {
 985                 dev->net->stats.tx_errors++;
 986
 987                 switch (urb->status) {
 988                 case -EPIPE:
 989                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
 990                         break;
 991
 992                 /* software-driven interface shutdown */
 993                 case -ECONNRESET:               // async unlink
 994                 case -ESHUTDOWN:                // hardware gone
 995                         break;
 996
 997                 // like rx, tx gets controller i/o faults during khubd delays
 998                 // and so it uses the same throttling mechanism.
 999                 case -EPROTO:
1000                 case -ETIME:
1001                 case -EILSEQ:
1002                         usb_mark_last_busy(dev->udev);
1003                         if (!timer_pending (&dev->delay)) {
1004                                 mod_timer (&dev->delay,
1005                                         jiffies + THROTTLE_JIFFIES);
1006                                 netif_dbg(dev, link, dev->net,
1007                                           "tx throttle %d\n", urb->status);
1008                         }
1009                         netif_stop_queue (dev->net);
1010                         break;
1011                 default:
1012                         netif_dbg(dev, tx_err, dev->net,
1013                                   "tx err %d\n", entry->urb->status);
1014                         break;
1015                 }
1016         }
1017
1018         usb_autopm_put_interface_async(dev->intf);
1019         urb->dev = NULL;
1020         entry->state = tx_done;
1021         defer_bh(dev, skb, &dev->txq);
1022 }
1023
1024 /*-------------------------------------------------------------------------*/
1025
1026 void usbnet_tx_timeout (struct net_device *net)
1027 {
1028         struct usbnet           *dev = netdev_priv(net);
1029
1030         unlink_urbs (dev, &dev->txq);
1031         tasklet_schedule (&dev->bh);
1032
1033         // FIXME: device recovery -- reset?
1034 }
1035 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1036
1037 /*-------------------------------------------------------------------------*/
1038
1039 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1040                                      struct net_device *net)
1041 {
1042         struct usbnet           *dev = netdev_priv(net);
1043         int                     length;
1044         struct urb              *urb = NULL;
1045         struct skb_data         *entry;
1046         struct driver_info      *info = dev->driver_info;
1047         unsigned long           flags;
1048         int retval;
1049
1050         // some devices want funky USB-level framing, for
1051         // win32 driver (usually) and/or hardware quirks
1052         if (info->tx_fixup) {
1053                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1054                 if (!skb) {
1055                         if (netif_msg_tx_err(dev)) {
1056                                 netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1057                                 goto drop;
1058                         } else {
1059                                 /* cdc_ncm collected packet; waits for more */
1060                                 goto not_drop;
1061                         }
1062                 }
1063         }
1064         length = skb->len;
1065
1066         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1067                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1068                 goto drop;
1069         }
1070
1071         entry = (struct skb_data *) skb->cb;
1072         entry->urb = urb;
1073         entry->dev = dev;
1074         entry->state = tx_start;
1075         entry->length = length;
1076
1077         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1078                         skb->data, skb->len, tx_complete, skb);
1079
1080         /* don't assume the hardware handles USB_ZERO_PACKET
1081          * NOTE:  strictly conforming cdc-ether devices should expect
1082          * the ZLP here, but ignore the one-byte packet.
1083          * NOTE2: CDC NCM specification is different from CDC ECM when
1084          * handling ZLP/short packets, so cdc_ncm driver will make short
1085          * packet itself if needed.
1086          */
1087         if (length % dev->maxpacket == 0) {
1088                 if (!(info->flags & FLAG_SEND_ZLP)) {
1089                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1090                                 urb->transfer_buffer_length++;
1091                                 if (skb_tailroom(skb)) {
1092                                         skb->data[skb->len] = 0;
1093                                         __skb_put(skb, 1);
1094                                 }
1095                         }
1096                 } else
1097                         urb->transfer_flags |= URB_ZERO_PACKET;
1098         }
1099
1100         spin_lock_irqsave(&dev->txq.lock, flags);
1101         retval = usb_autopm_get_interface_async(dev->intf);
1102         if (retval < 0) {
1103                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1104                 goto drop;
1105         }
1106
1107 #ifdef CONFIG_PM
1108         /* if this triggers the device is still a sleep */
1109         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1110                 /* transmission will be done in resume */
1111                 usb_anchor_urb(urb, &dev->deferred);
1112                 /* no use to process more packets */
1113                 netif_stop_queue(net);
1114                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1115                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1116                 goto deferred;
1117         }
1118 #endif
1119
1120         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1121         case -EPIPE:
1122                 netif_stop_queue (net);
1123                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1124                 usb_autopm_put_interface_async(dev->intf);
1125                 break;
1126         default:
1127                 usb_autopm_put_interface_async(dev->intf);
1128                 netif_dbg(dev, tx_err, dev->net,
1129                           "tx: submit urb err %d\n", retval);
1130                 break;
1131         case 0:
1132                 net->trans_start = jiffies;
1133                 __skb_queue_tail (&dev->txq, skb);
1134                 if (dev->txq.qlen >= TX_QLEN (dev))
1135                         netif_stop_queue (net);
1136         }
1137         spin_unlock_irqrestore (&dev->txq.lock, flags);
1138
1139         if (retval) {
1140                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1141 drop:
1142                 dev->net->stats.tx_dropped++;
1143 not_drop:
1144                 if (skb)
1145                         dev_kfree_skb_any (skb);
1146                 usb_free_urb (urb);
1147         } else
1148                 netif_dbg(dev, tx_queued, dev->net,
1149                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1150 #ifdef CONFIG_PM
1151 deferred:
1152 #endif
1153         return NETDEV_TX_OK;
1154 }
1155 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1156
1157 /*-------------------------------------------------------------------------*/
1158
1159 // tasklet (work deferred from completions, in_irq) or timer
1160
1161 static void usbnet_bh (unsigned long param)
1162 {
1163         struct usbnet           *dev = (struct usbnet *) param;
1164         struct sk_buff          *skb;
1165         struct skb_data         *entry;
1166
1167         while ((skb = skb_dequeue (&dev->done))) {
1168                 entry = (struct skb_data *) skb->cb;
1169                 switch (entry->state) {
1170                 case rx_done:
1171                         entry->state = rx_cleanup;
1172                         rx_process (dev, skb);
1173                         continue;
1174                 case tx_done:
1175                 case rx_cleanup:
1176                         usb_free_urb (entry->urb);
1177                         dev_kfree_skb (skb);
1178                         continue;
1179                 default:
1180                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1181                 }
1182         }
1183
1184         // waiting for all pending urbs to complete?
1185         if (dev->wait) {
1186                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1187                         wake_up (dev->wait);
1188                 }
1189
1190         // or are we maybe short a few urbs?
1191         } else if (netif_running (dev->net) &&
1192                    netif_device_present (dev->net) &&
1193                    !timer_pending (&dev->delay) &&
1194                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1195                 int     temp = dev->rxq.qlen;
1196                 int     qlen = RX_QLEN (dev);
1197
1198                 if (temp < qlen) {
1199                         struct urb      *urb;
1200                         int             i;
1201
1202                         // don't refill the queue all at once
1203                         for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1204                                 urb = usb_alloc_urb (0, GFP_ATOMIC);
1205                                 if (urb != NULL) {
1206                                         if (rx_submit (dev, urb, GFP_ATOMIC) ==
1207                                             -ENOLINK)
1208                                                 return;
1209                                 }
1210                         }
1211                         if (temp != dev->rxq.qlen)
1212                                 netif_dbg(dev, link, dev->net,
1213                                           "rxqlen %d --> %d\n",
1214                                           temp, dev->rxq.qlen);
1215                         if (dev->rxq.qlen < qlen)
1216                                 tasklet_schedule (&dev->bh);
1217                 }
1218                 if (dev->txq.qlen < TX_QLEN (dev))
1219                         netif_wake_queue (dev->net);
1220         }
1221 }
1222
1223
1224 /*-------------------------------------------------------------------------
1225  *
1226  * USB Device Driver support
1227  *
1228  *-------------------------------------------------------------------------*/
1229
1230 // precondition: never called in_interrupt
1231
1232 void usbnet_disconnect (struct usb_interface *intf)
1233 {
1234         struct usbnet           *dev;
1235         struct usb_device       *xdev;
1236         struct net_device       *net;
1237
1238         dev = usb_get_intfdata(intf);
1239         usb_set_intfdata(intf, NULL);
1240         if (!dev)
1241                 return;
1242
1243         xdev = interface_to_usbdev (intf);
1244
1245         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1246                    intf->dev.driver->name,
1247                    xdev->bus->bus_name, xdev->devpath,
1248                    dev->driver_info->description);
1249
1250         net = dev->net;
1251         unregister_netdev (net);
1252
1253         cancel_work_sync(&dev->kevent);
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         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1296
1297         /* usbnet already took usb runtime pm, so have to enable the feature
1298          * for usb interface, otherwise usb_autopm_get_interface may return
1299          * failure if USB_SUSPEND(RUNTIME_PM) is enabled.
1300          */
1301         if (!driver->supports_autosuspend) {
1302                 driver->supports_autosuspend = 1;
1303                 pm_runtime_enable(&udev->dev);
1304         }
1305
1306         name = udev->dev.driver->name;
1307         info = (struct driver_info *) prod->driver_info;
1308         if (!info) {
1309                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1310                 return -ENODEV;
1311         }
1312         xdev = interface_to_usbdev (udev);
1313         interface = udev->cur_altsetting;
1314
1315         usb_get_dev (xdev);
1316
1317         status = -ENOMEM;
1318
1319         // set up our own records
1320         net = alloc_etherdev(sizeof(*dev));
1321         if (!net) {
1322                 dbg ("can't kmalloc dev");
1323                 goto out;
1324         }
1325
1326         /* netdev_printk() needs this so do it as early as possible */
1327         SET_NETDEV_DEV(net, &udev->dev);
1328
1329         dev = netdev_priv(net);
1330         dev->udev = xdev;
1331         dev->intf = udev;
1332         dev->driver_info = info;
1333         dev->driver_name = name;
1334         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1335                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1336         skb_queue_head_init (&dev->rxq);
1337         skb_queue_head_init (&dev->txq);
1338         skb_queue_head_init (&dev->done);
1339         skb_queue_head_init(&dev->rxq_pause);
1340         dev->bh.func = usbnet_bh;
1341         dev->bh.data = (unsigned long) dev;
1342         INIT_WORK (&dev->kevent, kevent);
1343         init_usb_anchor(&dev->deferred);
1344         dev->delay.function = usbnet_bh;
1345         dev->delay.data = (unsigned long) dev;
1346         init_timer (&dev->delay);
1347         mutex_init (&dev->phy_mutex);
1348
1349         dev->net = net;
1350         strcpy (net->name, "usb%d");
1351         memcpy (net->dev_addr, node_id, sizeof node_id);
1352
1353         /* rx and tx sides can use different message sizes;
1354          * bind() should set rx_urb_size in that case.
1355          */
1356         dev->hard_mtu = net->mtu + net->hard_header_len;
1357 #if 0
1358 // dma_supported() is deeply broken on almost all architectures
1359         // possible with some EHCI controllers
1360         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1361                 net->features |= NETIF_F_HIGHDMA;
1362 #endif
1363
1364         net->netdev_ops = &usbnet_netdev_ops;
1365         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1366         net->ethtool_ops = &usbnet_ethtool_ops;
1367
1368         // allow device-specific bind/init procedures
1369         // NOTE net->name still not usable ...
1370         if (info->bind) {
1371                 status = info->bind (dev, udev);
1372                 if (status < 0)
1373                         goto out1;
1374
1375                 // heuristic:  "usb%d" for links we know are two-host,
1376                 // else "eth%d" when there's reasonable doubt.  userspace
1377                 // can rename the link if it knows better.
1378                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1379                     (net->dev_addr [0] & 0x02) == 0)
1380                         strcpy (net->name, "eth%d");
1381                 /* WLAN devices should always be named "wlan%d" */
1382                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1383                         strcpy(net->name, "wlan%d");
1384                 /* WWAN devices should always be named "wwan%d" */
1385                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1386                         strcpy(net->name, "wwan%d");
1387
1388                 /* maybe the remote can't receive an Ethernet MTU */
1389                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1390                         net->mtu = dev->hard_mtu - net->hard_header_len;
1391         } else if (!info->in || !info->out)
1392                 status = usbnet_get_endpoints (dev, udev);
1393         else {
1394                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1395                 dev->out = usb_sndbulkpipe (xdev, info->out);
1396                 if (!(info->flags & FLAG_NO_SETINT))
1397                         status = usb_set_interface (xdev,
1398                                 interface->desc.bInterfaceNumber,
1399                                 interface->desc.bAlternateSetting);
1400                 else
1401                         status = 0;
1402
1403         }
1404         if (status >= 0 && dev->status)
1405                 status = init_status (dev, udev);
1406         if (status < 0)
1407                 goto out3;
1408
1409         if (!dev->rx_urb_size)
1410                 dev->rx_urb_size = dev->hard_mtu;
1411         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1412
1413         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1414                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1415         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1416                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1417
1418         status = register_netdev (net);
1419         if (status)
1420                 goto out3;
1421         netif_info(dev, probe, dev->net,
1422                    "register '%s' at usb-%s-%s, %s, %pM\n",
1423                    udev->dev.driver->name,
1424                    xdev->bus->bus_name, xdev->devpath,
1425                    dev->driver_info->description,
1426                    net->dev_addr);
1427
1428         // ok, it's ready to go.
1429         usb_set_intfdata (udev, dev);
1430
1431         netif_device_attach (net);
1432
1433         if (dev->driver_info->flags & FLAG_LINK_INTR)
1434                 netif_carrier_off(net);
1435
1436         return 0;
1437
1438 out3:
1439         if (info->unbind)
1440                 info->unbind (dev, udev);
1441 out1:
1442         free_netdev(net);
1443 out:
1444         usb_put_dev(xdev);
1445         return status;
1446 }
1447 EXPORT_SYMBOL_GPL(usbnet_probe);
1448
1449 /*-------------------------------------------------------------------------*/
1450
1451 /*
1452  * suspend the whole driver as soon as the first interface is suspended
1453  * resume only when the last interface is resumed
1454  */
1455
1456 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1457 {
1458         struct usbnet           *dev = usb_get_intfdata(intf);
1459
1460         if (!dev->suspend_count++) {
1461                 spin_lock_irq(&dev->txq.lock);
1462                 /* don't autosuspend while transmitting */
1463                 if (dev->txq.qlen && (message.event & PM_EVENT_AUTO)) {
1464                         spin_unlock_irq(&dev->txq.lock);
1465                         return -EBUSY;
1466                 } else {
1467                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1468                         spin_unlock_irq(&dev->txq.lock);
1469                 }
1470                 /*
1471                  * accelerate emptying of the rx and queues, to avoid
1472                  * having everything error out.
1473                  */
1474                 netif_device_detach (dev->net);
1475                 usbnet_terminate_urbs(dev);
1476                 usb_kill_urb(dev->interrupt);
1477
1478                 /*
1479                  * reattach so runtime management can use and
1480                  * wake the device
1481                  */
1482                 netif_device_attach (dev->net);
1483         }
1484         return 0;
1485 }
1486 EXPORT_SYMBOL_GPL(usbnet_suspend);
1487
1488 int usbnet_resume (struct usb_interface *intf)
1489 {
1490         struct usbnet           *dev = usb_get_intfdata(intf);
1491         struct sk_buff          *skb;
1492         struct urb              *res;
1493         int                     retval;
1494
1495         if (!--dev->suspend_count) {
1496                 spin_lock_irq(&dev->txq.lock);
1497                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1498
1499                         skb = (struct sk_buff *)res->context;
1500                         retval = usb_submit_urb(res, GFP_ATOMIC);
1501                         if (retval < 0) {
1502                                 dev_kfree_skb_any(skb);
1503                                 usb_free_urb(res);
1504                                 usb_autopm_put_interface_async(dev->intf);
1505                         } else {
1506                                 dev->net->trans_start = jiffies;
1507                                 __skb_queue_tail(&dev->txq, skb);
1508                         }
1509                 }
1510
1511                 smp_mb();
1512                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1513                 spin_unlock_irq(&dev->txq.lock);
1514                 if (!(dev->txq.qlen >= TX_QLEN(dev)))
1515                         netif_start_queue(dev->net);
1516                 tasklet_schedule (&dev->bh);
1517         }
1518         return 0;
1519 }
1520 EXPORT_SYMBOL_GPL(usbnet_resume);
1521
1522
1523 /*-------------------------------------------------------------------------*/
1524
1525 static int __init usbnet_init(void)
1526 {
1527         /* compiler should optimize this out */
1528         BUILD_BUG_ON (sizeof (((struct sk_buff *)0)->cb)
1529                         < sizeof (struct skb_data));
1530
1531         random_ether_addr(node_id);
1532         return 0;
1533 }
1534 module_init(usbnet_init);
1535
1536 static void __exit usbnet_exit(void)
1537 {
1538 }
1539 module_exit(usbnet_exit);
1540
1541 MODULE_AUTHOR("David Brownell");
1542 MODULE_DESCRIPTION("USB network driver framework");
1543 MODULE_LICENSE("GPL");