drivers/net/usb/usbnet.c

   1 /*
   2  * USB Network driver infrastructure
   3  * Copyright (C) 2000-2005 by David Brownell
   4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /*
  22  * This is a generic "USB networking" framework that works with several
  23  * kinds of full and high speed networking devices:  host-to-host cables,
  24  * smart usb peripherals, and actual Ethernet adapters.
  25  *
  26  * These devices usually differ in terms of control protocols (if they
  27  * even have one!) and sometimes they define new framing to wrap or batch
  28  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  29  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  30  * issues can usefully be addressed by this framework.
  31  */
  32
  33 // #define      DEBUG                   // error path messages, extra info
  34 // #define      VERBOSE                 // more; success messages
  35
  36 #include <linux/module.h>
  37 #include <linux/init.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/etherdevice.h>
  40 #include <linux/ctype.h>
  41 #include <linux/ethtool.h>
  42 #include <linux/workqueue.h>
  43 #include <linux/mii.h>
  44 #include <linux/usb.h>
  45 #include <linux/usb/usbnet.h>
  46 #include <linux/slab.h>
  47 #include <linux/kernel.h>
  48 #include <linux/pm_runtime.h>
  49
  50 #define DRIVER_VERSION          "22-Aug-2005"
  51
  52
  53 /*-------------------------------------------------------------------------*/
  54
  55 /*
  56  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  57  * Several dozen bytes of IPv4 data can fit in two such transactions.
  58  * One maximum size Ethernet packet takes twenty four of them.
  59  * For high speed, each frame comfortably fits almost 36 max size
  60  * Ethernet packets (so queues should be bigger).
  61  *
  62  * REVISIT qlens should be members of 'struct usbnet'; the goal is to
  63  * let the USB host controller be busy for 5msec or more before an irq
  64  * is required, under load.  Jumbograms change the equation.
  65  */
  66 #define RX_MAX_QUEUE_MEMORY (60 * 1518)
  67 #define RX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  68                         (RX_MAX_QUEUE_MEMORY/(dev)->rx_urb_size) : 4)
  69 #define TX_QLEN(dev) (((dev)->udev->speed == USB_SPEED_HIGH) ? \
  70                         (RX_MAX_QUEUE_MEMORY/(dev)->hard_mtu) : 4)
  71
  72 // reawaken network queue this soon after stopping; else watchdog barks
  73 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  74
  75 // throttle rx/tx briefly after some faults, so khubd might disconnect()
  76 // us (it polls at HZ/4 usually) before we report too many false errors.
  77 #define THROTTLE_JIFFIES        (HZ/8)
  78
  79 // between wakeups
  80 #define UNLINK_TIMEOUT_MS       3
  81
  82 /*-------------------------------------------------------------------------*/
  83
  84 // randomly generated ethernet address
  85 static u8       node_id [ETH_ALEN];
  86
  87 static const char driver_name [] = "usbnet";
  88
  89 /* use ethtool to change the level for any given device */
  90 static int msg_level = -1;
  91 module_param (msg_level, int, 0);
  92 MODULE_PARM_DESC (msg_level, "Override default message level");
  93
  94 /*-------------------------------------------------------------------------*/
  95
  96 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  97 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  98 {
  99         int                             tmp;
 100         struct usb_host_interface       *alt = NULL;
 101         struct usb_host_endpoint        *in = NULL, *out = NULL;
 102         struct usb_host_endpoint        *status = NULL;
 103
 104         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 105                 unsigned        ep;
 106
 107                 in = out = status = NULL;
 108                 alt = intf->altsetting + tmp;
 109
 110                 /* take the first altsetting with in-bulk + out-bulk;
 111                  * remember any status endpoint, just in case;
 112                  * ignore other endpoints and altsettings.
 113                  */
 114                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 115                         struct usb_host_endpoint        *e;
 116                         int                             intr = 0;
 117
 118                         e = alt->endpoint + ep;
 119                         switch (e->desc.bmAttributes) {
 120                         case USB_ENDPOINT_XFER_INT:
 121                                 if (!usb_endpoint_dir_in(&e->desc))
 122                                         continue;
 123                                 intr = 1;
 124                                 /* FALLTHROUGH */
 125                         case USB_ENDPOINT_XFER_BULK:
 126                                 break;
 127                         default:
 128                                 continue;
 129                         }
 130                         if (usb_endpoint_dir_in(&e->desc)) {
 131                                 if (!intr && !in)
 132                                         in = e;
 133                                 else if (intr && !status)
 134                                         status = e;
 135                         } else {
 136                                 if (!out)
 137                                         out = e;
 138                         }
 139                 }
 140                 if (in && out)
 141                         break;
 142         }
 143         if (!alt || !in || !out)
 144                 return -EINVAL;
 145
 146         if (alt->desc.bAlternateSetting != 0 ||
 147             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 148                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 149                                 alt->desc.bAlternateSetting);
 150                 if (tmp < 0)
 151                         return tmp;
 152         }
 153
 154         dev->in = usb_rcvbulkpipe (dev->udev,
 155                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156         dev->out = usb_sndbulkpipe (dev->udev,
 157                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 158         dev->status = status;
 159         return 0;
 160 }
 161 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 162
 163 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 164 {
 165         int             tmp, i;
 166         unsigned char   buf [13];
 167
 168         tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 169         if (tmp != 12) {
 170                 dev_dbg(&dev->udev->dev,
 171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172                 if (tmp >= 0)
 173                         tmp = -EINVAL;
 174                 return tmp;
 175         }
 176         for (i = tmp = 0; i < 6; i++, tmp += 2)
 177                 dev->net->dev_addr [i] =
 178                         (hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 179         return 0;
 180 }
 181 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 182
 183 static void intr_complete (struct urb *urb);
 184
 185 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
 242         if (skb_defer_rx_timestamp(skb))
 243                 return;
 244
 245         status = netif_rx (skb);
 246         if (status != NET_RX_SUCCESS)
 247                 netif_dbg(dev, rx_err, dev->net,
 248                           "netif_rx status %d\n", status);
 249 }
 250 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 251
 252 \f
 253 /*-------------------------------------------------------------------------
 254  *
 255  * Network Device Driver (peer link to "Host Device", from USB host)
 256  *
 257  *-------------------------------------------------------------------------*/
 258
 259 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 260 {
 261         struct usbnet   *dev = netdev_priv(net);
 262         int             ll_mtu = new_mtu + net->hard_header_len;
 263         int             old_hard_mtu = dev->hard_mtu;
 264         int             old_rx_urb_size = dev->rx_urb_size;
 265
 266         if (new_mtu <= 0)
 267                 return -EINVAL;
 268         // no second zero-length packet read wanted after mtu-sized packets
 269         if ((ll_mtu % dev->maxpacket) == 0)
 270                 return -EDOM;
 271         net->mtu = new_mtu;
 272
 273         dev->hard_mtu = net->mtu + net->hard_header_len;
 274         if (dev->rx_urb_size == old_hard_mtu) {
 275                 dev->rx_urb_size = dev->hard_mtu;
 276                 if (dev->rx_urb_size > old_rx_urb_size)
 277                         usbnet_unlink_rx_urbs(dev);
 278         }
 279
 280         return 0;
 281 }
 282 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 283
 284 /* The caller must hold list->lock */
 285 static void __usbnet_queue_skb(struct sk_buff_head *list,
 286                         struct sk_buff *newsk, enum skb_state state)
 287 {
 288         struct skb_data *entry = (struct skb_data *) newsk->cb;
 289
 290         __skb_queue_tail(list, newsk);
 291         entry->state = state;
 292 }
 293
 294 /*-------------------------------------------------------------------------*/
 295
 296 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 297  * completion callbacks.  2.5 should have fixed those bugs...
 298  */
 299
 300 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 301                 struct sk_buff_head *list, enum skb_state state)
 302 {
 303         unsigned long           flags;
 304         enum skb_state          old_state;
 305         struct skb_data *entry = (struct skb_data *) skb->cb;
 306
 307         spin_lock_irqsave(&list->lock, flags);
 308         old_state = entry->state;
 309         entry->state = state;
 310         __skb_unlink(skb, list);
 311         spin_unlock(&list->lock);
 312         spin_lock(&dev->done.lock);
 313         __skb_queue_tail(&dev->done, skb);
 314         if (dev->done.qlen == 1)
 315                 tasklet_schedule(&dev->bh);
 316         spin_unlock_irqrestore(&dev->done.lock, flags);
 317         return old_state;
 318 }
 319
 320 /* some work can't be done in tasklets, so we use keventd
 321  *
 322  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 323  * but tasklet_schedule() doesn't.  hope the failure is rare.
 324  */
 325 void usbnet_defer_kevent (struct usbnet *dev, int work)
 326 {
 327         set_bit (work, &dev->flags);
 328         if (!schedule_work (&dev->kevent))
 329                 netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 330         else
 331                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 332 }
 333 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 334
 335 /*-------------------------------------------------------------------------*/
 336
 337 static void rx_complete (struct urb *urb);
 338
 339 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 340 {
 341         struct sk_buff          *skb;
 342         struct skb_data         *entry;
 343         int                     retval = 0;
 344         unsigned long           lockflags;
 345         size_t                  size = dev->rx_urb_size;
 346
 347         if ((skb = alloc_skb (size + NET_IP_ALIGN, flags)) == NULL) {
 348                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 349                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 350                 usb_free_urb (urb);
 351                 return -ENOMEM;
 352         }
 353         skb_reserve (skb, NET_IP_ALIGN);
 354
 355         entry = (struct skb_data *) skb->cb;
 356         entry->urb = urb;
 357         entry->dev = dev;
 358         entry->length = 0;
 359
 360         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 361                 skb->data, size, rx_complete, skb);
 362
 363         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 364
 365         if (netif_running (dev->net) &&
 366             netif_device_present (dev->net) &&
 367             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 368             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 369                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 370                 case -EPIPE:
 371                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 372                         break;
 373                 case -ENOMEM:
 374                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 375                         break;
 376                 case -ENODEV:
 377                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 378                         netif_device_detach (dev->net);
 379                         break;
 380                 case -EHOSTUNREACH:
 381                         retval = -ENOLINK;
 382                         break;
 383                 default:
 384                         netif_dbg(dev, rx_err, dev->net,
 385                                   "rx submit, %d\n", retval);
 386                         tasklet_schedule (&dev->bh);
 387                         break;
 388                 case 0:
 389                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 390                 }
 391         } else {
 392                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 393                 retval = -ENOLINK;
 394         }
 395         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 396         if (retval) {
 397                 dev_kfree_skb_any (skb);
 398                 usb_free_urb (urb);
 399         }
 400         return retval;
 401 }
 402
 403
 404 /*-------------------------------------------------------------------------*/
 405
 406 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 407 {
 408         if (dev->driver_info->rx_fixup &&
 409             !dev->driver_info->rx_fixup (dev, skb)) {
 410                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 411                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 412                         dev->net->stats.rx_errors++;
 413                 goto done;
 414         }
 415         // else network stack removes extra byte if we forced a short packet
 416
 417         if (skb->len) {
 418                 /* all data was already cloned from skb inside the driver */
 419                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 420                         dev_kfree_skb_any(skb);
 421                 else
 422                         usbnet_skb_return(dev, skb);
 423                 return;
 424         }
 425
 426         netif_dbg(dev, rx_err, dev->net, "drop\n");
 427         dev->net->stats.rx_errors++;
 428 done:
 429         skb_queue_tail(&dev->done, skb);
 430 }
 431
 432 /*-------------------------------------------------------------------------*/
 433
 434 static void rx_complete (struct urb *urb)
 435 {
 436         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 437         struct skb_data         *entry = (struct skb_data *) skb->cb;
 438         struct usbnet           *dev = entry->dev;
 439         int                     urb_status = urb->status;
 440         enum skb_state          state;
 441
 442         skb_put (skb, urb->actual_length);
 443         state = rx_done;
 444         entry->urb = NULL;
 445
 446         switch (urb_status) {
 447         /* success */
 448         case 0:
 449                 if (skb->len < dev->net->hard_header_len) {
 450                         state = rx_cleanup;
 451                         dev->net->stats.rx_errors++;
 452                         dev->net->stats.rx_length_errors++;
 453                         netif_dbg(dev, rx_err, dev->net,
 454                                   "rx length %d\n", skb->len);
 455                 }
 456                 break;
 457
 458         /* stalls need manual reset. this is rare ... except that
 459          * when going through USB 2.0 TTs, unplug appears this way.
 460          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 461          * storm, recovering as needed.
 462          */
 463         case -EPIPE:
 464                 dev->net->stats.rx_errors++;
 465                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 466                 // FALLTHROUGH
 467
 468         /* software-driven interface shutdown */
 469         case -ECONNRESET:               /* async unlink */
 470         case -ESHUTDOWN:                /* hardware gone */
 471                 netif_dbg(dev, ifdown, dev->net,
 472                           "rx shutdown, code %d\n", urb_status);
 473                 goto block;
 474
 475         /* we get controller i/o faults during khubd disconnect() delays.
 476          * throttle down resubmits, to avoid log floods; just temporarily,
 477          * so we still recover when the fault isn't a khubd delay.
 478          */
 479         case -EPROTO:
 480         case -ETIME:
 481         case -EILSEQ:
 482                 dev->net->stats.rx_errors++;
 483                 if (!timer_pending (&dev->delay)) {
 484                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 485                         netif_dbg(dev, link, dev->net,
 486                                   "rx throttle %d\n", urb_status);
 487                 }
 488 block:
 489                 state = rx_cleanup;
 490                 entry->urb = urb;
 491                 urb = NULL;
 492                 break;
 493
 494         /* data overrun ... flush fifo? */
 495         case -EOVERFLOW:
 496                 dev->net->stats.rx_over_errors++;
 497                 // FALLTHROUGH
 498
 499         default:
 500                 state = rx_cleanup;
 501                 dev->net->stats.rx_errors++;
 502                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 503                 break;
 504         }
 505
 506         state = defer_bh(dev, skb, &dev->rxq, state);
 507
 508         if (urb) {
 509                 if (netif_running (dev->net) &&
 510                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 511                     state != unlink_start) {
 512                         rx_submit (dev, urb, GFP_ATOMIC);
 513                         return;
 514                 }
 515                 usb_free_urb (urb);
 516         }
 517         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 518 }
 519
 520 static void intr_complete (struct urb *urb)
 521 {
 522         struct usbnet   *dev = urb->context;
 523         int             status = urb->status;
 524
 525         switch (status) {
 526         /* success */
 527         case 0:
 528                 dev->driver_info->status(dev, urb);
 529                 break;
 530
 531         /* software-driven interface shutdown */
 532         case -ENOENT:           /* urb killed */
 533         case -ESHUTDOWN:        /* hardware gone */
 534                 netif_dbg(dev, ifdown, dev->net,
 535                           "intr shutdown, code %d\n", status);
 536                 return;
 537
 538         /* NOTE:  not throttling like RX/TX, since this endpoint
 539          * already polls infrequently
 540          */
 541         default:
 542                 netdev_dbg(dev->net, "intr status %d\n", status);
 543                 break;
 544         }
 545
 546         if (!netif_running (dev->net))
 547                 return;
 548
 549         memset(urb->transfer_buffer, 0, urb->transfer_buffer_length);
 550         status = usb_submit_urb (urb, GFP_ATOMIC);
 551         if (status != 0)
 552                 netif_err(dev, timer, dev->net,
 553                           "intr resubmit --> %d\n", status);
 554 }
 555
 556 /*-------------------------------------------------------------------------*/
 557 void usbnet_pause_rx(struct usbnet *dev)
 558 {
 559         set_bit(EVENT_RX_PAUSED, &dev->flags);
 560
 561         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 562 }
 563 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 564
 565 void usbnet_resume_rx(struct usbnet *dev)
 566 {
 567         struct sk_buff *skb;
 568         int num = 0;
 569
 570         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 571
 572         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 573                 usbnet_skb_return(dev, skb);
 574                 num++;
 575         }
 576
 577         tasklet_schedule(&dev->bh);
 578
 579         netif_dbg(dev, rx_status, dev->net,
 580                   "paused rx queue disabled, %d skbs requeued\n", num);
 581 }
 582 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 583
 584 void usbnet_purge_paused_rxq(struct usbnet *dev)
 585 {
 586         skb_queue_purge(&dev->rxq_pause);
 587 }
 588 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 589
 590 /*-------------------------------------------------------------------------*/
 591
 592 // unlink pending rx/tx; completion handlers do all other cleanup
 593
 594 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 595 {
 596         unsigned long           flags;
 597         struct sk_buff          *skb;
 598         int                     count = 0;
 599
 600         spin_lock_irqsave (&q->lock, flags);
 601         while (!skb_queue_empty(q)) {
 602                 struct skb_data         *entry;
 603                 struct urb              *urb;
 604                 int                     retval;
 605
 606                 skb_queue_walk(q, skb) {
 607                         entry = (struct skb_data *) skb->cb;
 608                         if (entry->state != unlink_start)
 609                                 goto found;
 610                 }
 611                 break;
 612 found:
 613                 entry->state = unlink_start;
 614                 urb = entry->urb;
 615
 616                 /*
 617                  * Get reference count of the URB to avoid it to be
 618                  * freed during usb_unlink_urb, which may trigger
 619                  * use-after-free problem inside usb_unlink_urb since
 620                  * usb_unlink_urb is always racing with .complete
 621                  * handler(include defer_bh).
 622                  */
 623                 usb_get_urb(urb);
 624                 spin_unlock_irqrestore(&q->lock, flags);
 625                 // during some PM-driven resume scenarios,
 626                 // these (async) unlinks complete immediately
 627                 retval = usb_unlink_urb (urb);
 628                 if (retval != -EINPROGRESS && retval != 0)
 629                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 630                 else
 631                         count++;
 632                 usb_put_urb(urb);
 633                 spin_lock_irqsave(&q->lock, flags);
 634         }
 635         spin_unlock_irqrestore (&q->lock, flags);
 636         return count;
 637 }
 638
 639 // Flush all pending rx urbs
 640 // minidrivers may need to do this when the MTU changes
 641
 642 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 643 {
 644         if (netif_running(dev->net)) {
 645                 (void) unlink_urbs (dev, &dev->rxq);
 646                 tasklet_schedule(&dev->bh);
 647         }
 648 }
 649 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 650
 651 /*-------------------------------------------------------------------------*/
 652
 653 // precondition: never called in_interrupt
 654 static void usbnet_terminate_urbs(struct usbnet *dev)
 655 {
 656         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 657         DECLARE_WAITQUEUE(wait, current);
 658         int temp;
 659
 660         /* ensure there are no more active urbs */
 661         add_wait_queue(&unlink_wakeup, &wait);
 662         set_current_state(TASK_UNINTERRUPTIBLE);
 663         dev->wait = &unlink_wakeup;
 664         temp = unlink_urbs(dev, &dev->txq) +
 665                 unlink_urbs(dev, &dev->rxq);
 666
 667         /* maybe wait for deletions to finish. */
 668         while (!skb_queue_empty(&dev->rxq)
 669                 && !skb_queue_empty(&dev->txq)
 670                 && !skb_queue_empty(&dev->done)) {
 671                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 672                         set_current_state(TASK_UNINTERRUPTIBLE);
 673                         netif_dbg(dev, ifdown, dev->net,
 674                                   "waited for %d urb completions\n", temp);
 675         }
 676         set_current_state(TASK_RUNNING);
 677         dev->wait = NULL;
 678         remove_wait_queue(&unlink_wakeup, &wait);
 679 }
 680
 681 int usbnet_stop (struct net_device *net)
 682 {
 683         struct usbnet           *dev = netdev_priv(net);
 684         struct driver_info      *info = dev->driver_info;
 685         int                     retval;
 686
 687         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 688         netif_stop_queue (net);
 689
 690         netif_info(dev, ifdown, dev->net,
 691                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 692                    net->stats.rx_packets, net->stats.tx_packets,
 693                    net->stats.rx_errors, net->stats.tx_errors);
 694
 695         /* allow minidriver to stop correctly (wireless devices to turn off
 696          * radio etc) */
 697         if (info->stop) {
 698                 retval = info->stop(dev);
 699                 if (retval < 0)
 700                         netif_info(dev, ifdown, dev->net,
 701                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 702                                    retval,
 703                                    dev->udev->bus->bus_name, dev->udev->devpath,
 704                                    info->description);
 705         }
 706
 707         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 708                 usbnet_terminate_urbs(dev);
 709
 710         usb_kill_urb(dev->interrupt);
 711
 712         usbnet_purge_paused_rxq(dev);
 713
 714         /* deferred work (task, timer, softirq) must also stop.
 715          * can't flush_scheduled_work() until we drop rtnl (later),
 716          * else workers could deadlock; so make workers a NOP.
 717          */
 718         dev->flags = 0;
 719         del_timer_sync (&dev->delay);
 720         tasklet_kill (&dev->bh);
 721         if (info->manage_power)
 722                 info->manage_power(dev, 0);
 723         else
 724                 usb_autopm_put_interface(dev->intf);
 725
 726         return 0;
 727 }
 728 EXPORT_SYMBOL_GPL(usbnet_stop);
 729
 730 /*-------------------------------------------------------------------------*/
 731
 732 // posts reads, and enables write queuing
 733
 734 // precondition: never called in_interrupt
 735
 736 int usbnet_open (struct net_device *net)
 737 {
 738         struct usbnet           *dev = netdev_priv(net);
 739         int                     retval;
 740         struct driver_info      *info = dev->driver_info;
 741
 742         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 743                 netif_info(dev, ifup, dev->net,
 744                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 745                            retval,
 746                            dev->udev->bus->bus_name,
 747                            dev->udev->devpath,
 748                            info->description);
 749                 goto done_nopm;
 750         }
 751
 752         // put into "known safe" state
 753         if (info->reset && (retval = info->reset (dev)) < 0) {
 754                 netif_info(dev, ifup, dev->net,
 755                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 756                            retval,
 757                            dev->udev->bus->bus_name,
 758                            dev->udev->devpath,
 759                            info->description);
 760                 goto done;
 761         }
 762
 763         // insist peer be connected
 764         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 765                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 766                 goto done;
 767         }
 768
 769         /* start any status interrupt transfer */
 770         if (dev->interrupt) {
 771                 retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);
 772                 if (retval < 0) {
 773                         netif_err(dev, ifup, dev->net,
 774                                   "intr submit %d\n", retval);
 775                         goto done;
 776                 }
 777         }
 778
 779         set_bit(EVENT_DEV_OPEN, &dev->flags);
 780         netif_start_queue (net);
 781         netif_info(dev, ifup, dev->net,
 782                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 783                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 784                    dev->net->mtu,
 785                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 786                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 787                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 788                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 789                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 790                    "simple");
 791
 792         // delay posting reads until we're fully open
 793         tasklet_schedule (&dev->bh);
 794         if (info->manage_power) {
 795                 retval = info->manage_power(dev, 1);
 796                 if (retval < 0)
 797                         goto done;
 798                 usb_autopm_put_interface(dev->intf);
 799         }
 800         return retval;
 801
 802 done:
 803         usb_autopm_put_interface(dev->intf);
 804 done_nopm:
 805         return retval;
 806 }
 807 EXPORT_SYMBOL_GPL(usbnet_open);
 808
 809 /*-------------------------------------------------------------------------*/
 810
 811 /* ethtool methods; minidrivers may need to add some more, but
 812  * they'll probably want to use this base set.
 813  */
 814
 815 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 816 {
 817         struct usbnet *dev = netdev_priv(net);
 818
 819         if (!dev->mii.mdio_read)
 820                 return -EOPNOTSUPP;
 821
 822         return mii_ethtool_gset(&dev->mii, cmd);
 823 }
 824 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 825
 826 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 827 {
 828         struct usbnet *dev = netdev_priv(net);
 829         int retval;
 830
 831         if (!dev->mii.mdio_write)
 832                 return -EOPNOTSUPP;
 833
 834         retval = mii_ethtool_sset(&dev->mii, cmd);
 835
 836         /* link speed/duplex might have changed */
 837         if (dev->driver_info->link_reset)
 838                 dev->driver_info->link_reset(dev);
 839
 840         return retval;
 841
 842 }
 843 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 844
 845 u32 usbnet_get_link (struct net_device *net)
 846 {
 847         struct usbnet *dev = netdev_priv(net);
 848
 849         /* If a check_connect is defined, return its result */
 850         if (dev->driver_info->check_connect)
 851                 return dev->driver_info->check_connect (dev) == 0;
 852
 853         /* if the device has mii operations, use those */
 854         if (dev->mii.mdio_read)
 855                 return mii_link_ok(&dev->mii);
 856
 857         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 858         return ethtool_op_get_link(net);
 859 }
 860 EXPORT_SYMBOL_GPL(usbnet_get_link);
 861
 862 int usbnet_nway_reset(struct net_device *net)
 863 {
 864         struct usbnet *dev = netdev_priv(net);
 865
 866         if (!dev->mii.mdio_write)
 867                 return -EOPNOTSUPP;
 868
 869         return mii_nway_restart(&dev->mii);
 870 }
 871 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 872
 873 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 874 {
 875         struct usbnet *dev = netdev_priv(net);
 876
 877         strncpy (info->driver, dev->driver_name, sizeof info->driver);
 878         strncpy (info->version, DRIVER_VERSION, sizeof info->version);
 879         strncpy (info->fw_version, dev->driver_info->description,
 880                 sizeof info->fw_version);
 881         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 882 }
 883 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 884
 885 u32 usbnet_get_msglevel (struct net_device *net)
 886 {
 887         struct usbnet *dev = netdev_priv(net);
 888
 889         return dev->msg_enable;
 890 }
 891 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 892
 893 void usbnet_set_msglevel (struct net_device *net, u32 level)
 894 {
 895         struct usbnet *dev = netdev_priv(net);
 896
 897         dev->msg_enable = level;
 898 }
 899 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 900
 901 /* drivers may override default ethtool_ops in their bind() routine */
 902 static const struct ethtool_ops usbnet_ethtool_ops = {
 903         .get_settings           = usbnet_get_settings,
 904         .set_settings           = usbnet_set_settings,
 905         .get_link               = usbnet_get_link,
 906         .nway_reset             = usbnet_nway_reset,
 907         .get_drvinfo            = usbnet_get_drvinfo,
 908         .get_msglevel           = usbnet_get_msglevel,
 909         .set_msglevel           = usbnet_set_msglevel,
 910 };
 911
 912 /*-------------------------------------------------------------------------*/
 913
 914 /* work that cannot be done in interrupt context uses keventd.
 915  *
 916  * NOTE:  with 2.5 we could do more of this using completion callbacks,
 917  * especially now that control transfers can be queued.
 918  */
 919 static void
 920 kevent (struct work_struct *work)
 921 {
 922         struct usbnet           *dev =
 923                 container_of(work, struct usbnet, kevent);
 924         int                     status;
 925
 926         /* usb_clear_halt() needs a thread context */
 927         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
 928                 unlink_urbs (dev, &dev->txq);
 929                 status = usb_autopm_get_interface(dev->intf);
 930                 if (status < 0)
 931                         goto fail_pipe;
 932                 status = usb_clear_halt (dev->udev, dev->out);
 933                 usb_autopm_put_interface(dev->intf);
 934                 if (status < 0 &&
 935                     status != -EPIPE &&
 936                     status != -ESHUTDOWN) {
 937                         if (netif_msg_tx_err (dev))
 938 fail_pipe:
 939                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
 940                                            status);
 941                 } else {
 942                         clear_bit (EVENT_TX_HALT, &dev->flags);
 943                         if (status != -ESHUTDOWN)
 944                                 netif_wake_queue (dev->net);
 945                 }
 946         }
 947         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
 948                 unlink_urbs (dev, &dev->rxq);
 949                 status = usb_autopm_get_interface(dev->intf);
 950                 if (status < 0)
 951                         goto fail_halt;
 952                 status = usb_clear_halt (dev->udev, dev->in);
 953                 usb_autopm_put_interface(dev->intf);
 954                 if (status < 0 &&
 955                     status != -EPIPE &&
 956                     status != -ESHUTDOWN) {
 957                         if (netif_msg_rx_err (dev))
 958 fail_halt:
 959                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
 960                                            status);
 961                 } else {
 962                         clear_bit (EVENT_RX_HALT, &dev->flags);
 963                         tasklet_schedule (&dev->bh);
 964                 }
 965         }
 966
 967         /* tasklet could resubmit itself forever if memory is tight */
 968         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
 969                 struct urb      *urb = NULL;
 970                 int resched = 1;
 971
 972                 if (netif_running (dev->net))
 973                         urb = usb_alloc_urb (0, GFP_KERNEL);
 974                 else
 975                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 976                 if (urb != NULL) {
 977                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
 978                         status = usb_autopm_get_interface(dev->intf);
 979                         if (status < 0) {
 980                                 usb_free_urb(urb);
 981                                 goto fail_lowmem;
 982                         }
 983                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
 984                                 resched = 0;
 985                         usb_autopm_put_interface(dev->intf);
 986 fail_lowmem:
 987                         if (resched)
 988                                 tasklet_schedule (&dev->bh);
 989                 }
 990         }
 991
 992         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
 993                 struct driver_info      *info = dev->driver_info;
 994                 int                     retval = 0;
 995
 996                 clear_bit (EVENT_LINK_RESET, &dev->flags);
 997                 status = usb_autopm_get_interface(dev->intf);
 998                 if (status < 0)
 999                         goto skip_reset;
1000                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1001                         usb_autopm_put_interface(dev->intf);
1002 skip_reset:
1003                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1004                                     retval,
1005                                     dev->udev->bus->bus_name,
1006                                     dev->udev->devpath,
1007                                     info->description);
1008                 } else {
1009                         usb_autopm_put_interface(dev->intf);
1010                 }
1011         }
1012
1013         if (dev->flags)
1014                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1015 }
1016
1017 /*-------------------------------------------------------------------------*/
1018
1019 static void tx_complete (struct urb *urb)
1020 {
1021         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1022         struct skb_data         *entry = (struct skb_data *) skb->cb;
1023         struct usbnet           *dev = entry->dev;
1024
1025         if (urb->status == 0) {
1026                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1027                         dev->net->stats.tx_packets++;
1028                 dev->net->stats.tx_bytes += entry->length;
1029         } else {
1030                 dev->net->stats.tx_errors++;
1031
1032                 switch (urb->status) {
1033                 case -EPIPE:
1034                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1035                         break;
1036
1037                 /* software-driven interface shutdown */
1038                 case -ECONNRESET:               // async unlink
1039                 case -ESHUTDOWN:                // hardware gone
1040                         break;
1041
1042                 // like rx, tx gets controller i/o faults during khubd delays
1043                 // and so it uses the same throttling mechanism.
1044                 case -EPROTO:
1045                 case -ETIME:
1046                 case -EILSEQ:
1047                         usb_mark_last_busy(dev->udev);
1048                         if (!timer_pending (&dev->delay)) {
1049                                 mod_timer (&dev->delay,
1050                                         jiffies + THROTTLE_JIFFIES);
1051                                 netif_dbg(dev, link, dev->net,
1052                                           "tx throttle %d\n", urb->status);
1053                         }
1054                         netif_stop_queue (dev->net);
1055                         break;
1056                 default:
1057                         netif_dbg(dev, tx_err, dev->net,
1058                                   "tx err %d\n", entry->urb->status);
1059                         break;
1060                 }
1061         }
1062
1063         usb_autopm_put_interface_async(dev->intf);
1064         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1065 }
1066
1067 /*-------------------------------------------------------------------------*/
1068
1069 void usbnet_tx_timeout (struct net_device *net)
1070 {
1071         struct usbnet           *dev = netdev_priv(net);
1072
1073         unlink_urbs (dev, &dev->txq);
1074         tasklet_schedule (&dev->bh);
1075
1076         // FIXME: device recovery -- reset?
1077 }
1078 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1079
1080 /*-------------------------------------------------------------------------*/
1081
1082 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1083                                      struct net_device *net)
1084 {
1085         struct usbnet           *dev = netdev_priv(net);
1086         int                     length;
1087         struct urb              *urb = NULL;
1088         struct skb_data         *entry;
1089         struct driver_info      *info = dev->driver_info;
1090         unsigned long           flags;
1091         int retval;
1092
1093         if (skb)
1094                 skb_tx_timestamp(skb);
1095
1096         // some devices want funky USB-level framing, for
1097         // win32 driver (usually) and/or hardware quirks
1098         if (info->tx_fixup) {
1099                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1100                 if (!skb) {
1101                         if (netif_msg_tx_err(dev)) {
1102                                 netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1103                                 goto drop;
1104                         } else {
1105                                 /* cdc_ncm collected packet; waits for more */
1106                                 goto not_drop;
1107                         }
1108                 }
1109         }
1110         length = skb->len;
1111
1112         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1113                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1114                 goto drop;
1115         }
1116
1117         entry = (struct skb_data *) skb->cb;
1118         entry->urb = urb;
1119         entry->dev = dev;
1120         entry->length = length;
1121
1122         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1123                         skb->data, skb->len, tx_complete, skb);
1124
1125         /* don't assume the hardware handles USB_ZERO_PACKET
1126          * NOTE:  strictly conforming cdc-ether devices should expect
1127          * the ZLP here, but ignore the one-byte packet.
1128          * NOTE2: CDC NCM specification is different from CDC ECM when
1129          * handling ZLP/short packets, so cdc_ncm driver will make short
1130          * packet itself if needed.
1131          */
1132         if (length % dev->maxpacket == 0) {
1133                 if (!(info->flags & FLAG_SEND_ZLP)) {
1134                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1135                                 urb->transfer_buffer_length++;
1136                                 if (skb_tailroom(skb)) {
1137                                         skb->data[skb->len] = 0;
1138                                         __skb_put(skb, 1);
1139                                 }
1140                         }
1141                 } else
1142                         urb->transfer_flags |= URB_ZERO_PACKET;
1143         }
1144
1145         spin_lock_irqsave(&dev->txq.lock, flags);
1146         retval = usb_autopm_get_interface_async(dev->intf);
1147         if (retval < 0) {
1148                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1149                 goto drop;
1150         }
1151
1152 #ifdef CONFIG_PM
1153         /* if this triggers the device is still a sleep */
1154         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1155                 /* transmission will be done in resume */
1156                 usb_anchor_urb(urb, &dev->deferred);
1157                 /* no use to process more packets */
1158                 netif_stop_queue(net);
1159                 usb_put_urb(urb);
1160                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1161                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1162                 goto deferred;
1163         }
1164 #endif
1165
1166         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1167         case -EPIPE:
1168                 netif_stop_queue (net);
1169                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1170                 usb_autopm_put_interface_async(dev->intf);
1171                 break;
1172         default:
1173                 usb_autopm_put_interface_async(dev->intf);
1174                 netif_dbg(dev, tx_err, dev->net,
1175                           "tx: submit urb err %d\n", retval);
1176                 break;
1177         case 0:
1178                 net->trans_start = jiffies;
1179                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1180                 if (dev->txq.qlen >= TX_QLEN (dev))
1181                         netif_stop_queue (net);
1182         }
1183         spin_unlock_irqrestore (&dev->txq.lock, flags);
1184
1185         if (retval) {
1186                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1187 drop:
1188                 dev->net->stats.tx_dropped++;
1189 not_drop:
1190                 if (skb)
1191                         dev_kfree_skb_any (skb);
1192                 usb_free_urb (urb);
1193         } else
1194                 netif_dbg(dev, tx_queued, dev->net,
1195                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1196 #ifdef CONFIG_PM
1197 deferred:
1198 #endif
1199         return NETDEV_TX_OK;
1200 }
1201 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1202
1203 /*-------------------------------------------------------------------------*/
1204
1205 // tasklet (work deferred from completions, in_irq) or timer
1206
1207 static void usbnet_bh (unsigned long param)
1208 {
1209         struct usbnet           *dev = (struct usbnet *) param;
1210         struct sk_buff          *skb;
1211         struct skb_data         *entry;
1212
1213         while ((skb = skb_dequeue (&dev->done))) {
1214                 entry = (struct skb_data *) skb->cb;
1215                 switch (entry->state) {
1216                 case rx_done:
1217                         entry->state = rx_cleanup;
1218                         rx_process (dev, skb);
1219                         continue;
1220                 case tx_done:
1221                 case rx_cleanup:
1222                         usb_free_urb (entry->urb);
1223                         dev_kfree_skb (skb);
1224                         continue;
1225                 default:
1226                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1227                 }
1228         }
1229
1230         // waiting for all pending urbs to complete?
1231         if (dev->wait) {
1232                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1233                         wake_up (dev->wait);
1234                 }
1235
1236         // or are we maybe short a few urbs?
1237         } else if (netif_running (dev->net) &&
1238                    netif_device_present (dev->net) &&
1239                    !timer_pending (&dev->delay) &&
1240                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1241                 int     temp = dev->rxq.qlen;
1242                 int     qlen = RX_QLEN (dev);
1243
1244                 if (temp < qlen) {
1245                         struct urb      *urb;
1246                         int             i;
1247
1248                         // don't refill the queue all at once
1249                         for (i = 0; i < 10 && dev->rxq.qlen < qlen; i++) {
1250                                 urb = usb_alloc_urb (0, GFP_ATOMIC);
1251                                 if (urb != NULL) {
1252                                         if (rx_submit (dev, urb, GFP_ATOMIC) ==
1253                                             -ENOLINK)
1254                                                 return;
1255                                 }
1256                         }
1257                         if (temp != dev->rxq.qlen)
1258                                 netif_dbg(dev, link, dev->net,
1259                                           "rxqlen %d --> %d\n",
1260                                           temp, dev->rxq.qlen);
1261                         if (dev->rxq.qlen < qlen)
1262                                 tasklet_schedule (&dev->bh);
1263                 }
1264                 if (dev->txq.qlen < TX_QLEN (dev))
1265                         netif_wake_queue (dev->net);
1266         }
1267 }
1268
1269
1270 /*-------------------------------------------------------------------------
1271  *
1272  * USB Device Driver support
1273  *
1274  *-------------------------------------------------------------------------*/
1275
1276 // precondition: never called in_interrupt
1277
1278 void usbnet_disconnect (struct usb_interface *intf)
1279 {
1280         struct usbnet           *dev;
1281         struct usb_device       *xdev;
1282         struct net_device       *net;
1283
1284         dev = usb_get_intfdata(intf);
1285         usb_set_intfdata(intf, NULL);
1286         if (!dev)
1287                 return;
1288
1289         xdev = interface_to_usbdev (intf);
1290
1291         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1292                    intf->dev.driver->name,
1293                    xdev->bus->bus_name, xdev->devpath,
1294                    dev->driver_info->description);
1295
1296         net = dev->net;
1297         unregister_netdev (net);
1298
1299         cancel_work_sync(&dev->kevent);
1300
1301         usb_scuttle_anchored_urbs(&dev->deferred);
1302
1303         if (dev->driver_info->unbind)
1304                 dev->driver_info->unbind (dev, intf);
1305
1306         usb_kill_urb(dev->interrupt);
1307         usb_free_urb(dev->interrupt);
1308
1309         free_netdev(net);
1310         usb_put_dev (xdev);
1311 }
1312 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1313
1314 static const struct net_device_ops usbnet_netdev_ops = {
1315         .ndo_open               = usbnet_open,
1316         .ndo_stop               = usbnet_stop,
1317         .ndo_start_xmit         = usbnet_start_xmit,
1318         .ndo_tx_timeout         = usbnet_tx_timeout,
1319         .ndo_change_mtu         = usbnet_change_mtu,
1320         .ndo_set_mac_address    = eth_mac_addr,
1321         .ndo_validate_addr      = eth_validate_addr,
1322 };
1323
1324 /*-------------------------------------------------------------------------*/
1325
1326 // precondition: never called in_interrupt
1327
1328 static struct device_type wlan_type = {
1329         .name   = "wlan",
1330 };
1331
1332 static struct device_type wwan_type = {
1333         .name   = "wwan",
1334 };
1335
1336 int
1337 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1338 {
1339         struct usbnet                   *dev;
1340         struct net_device               *net;
1341         struct usb_host_interface       *interface;
1342         struct driver_info              *info;
1343         struct usb_device               *xdev;
1344         int                             status;
1345         const char                      *name;
1346         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1347
1348         /* usbnet already took usb runtime pm, so have to enable the feature
1349          * for usb interface, otherwise usb_autopm_get_interface may return
1350          * failure if USB_SUSPEND(RUNTIME_PM) is enabled.
1351          */
1352         if (!driver->supports_autosuspend) {
1353                 driver->supports_autosuspend = 1;
1354                 pm_runtime_enable(&udev->dev);
1355         }
1356
1357         name = udev->dev.driver->name;
1358         info = (struct driver_info *) prod->driver_info;
1359         if (!info) {
1360                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1361                 return -ENODEV;
1362         }
1363         xdev = interface_to_usbdev (udev);
1364         interface = udev->cur_altsetting;
1365
1366         usb_get_dev (xdev);
1367
1368         status = -ENOMEM;
1369
1370         // set up our own records
1371         net = alloc_etherdev(sizeof(*dev));
1372         if (!net) {
1373                 dbg ("can't kmalloc dev");
1374                 goto out;
1375         }
1376
1377         /* netdev_printk() needs this so do it as early as possible */
1378         SET_NETDEV_DEV(net, &udev->dev);
1379
1380         dev = netdev_priv(net);
1381         dev->udev = xdev;
1382         dev->intf = udev;
1383         dev->driver_info = info;
1384         dev->driver_name = name;
1385         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1386                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1387         skb_queue_head_init (&dev->rxq);
1388         skb_queue_head_init (&dev->txq);
1389         skb_queue_head_init (&dev->done);
1390         skb_queue_head_init(&dev->rxq_pause);
1391         dev->bh.func = usbnet_bh;
1392         dev->bh.data = (unsigned long) dev;
1393         INIT_WORK (&dev->kevent, kevent);
1394         init_usb_anchor(&dev->deferred);
1395         dev->delay.function = usbnet_bh;
1396         dev->delay.data = (unsigned long) dev;
1397         init_timer (&dev->delay);
1398         mutex_init (&dev->phy_mutex);
1399
1400         dev->net = net;
1401         strcpy (net->name, "usb%d");
1402         memcpy (net->dev_addr, node_id, sizeof node_id);
1403
1404         /* rx and tx sides can use different message sizes;
1405          * bind() should set rx_urb_size in that case.
1406          */
1407         dev->hard_mtu = net->mtu + net->hard_header_len;
1408 #if 0
1409 // dma_supported() is deeply broken on almost all architectures
1410         // possible with some EHCI controllers
1411         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1412                 net->features |= NETIF_F_HIGHDMA;
1413 #endif
1414
1415         net->netdev_ops = &usbnet_netdev_ops;
1416         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1417         net->ethtool_ops = &usbnet_ethtool_ops;
1418
1419         // allow device-specific bind/init procedures
1420         // NOTE net->name still not usable ...
1421         if (info->bind) {
1422                 status = info->bind (dev, udev);
1423                 if (status < 0)
1424                         goto out1;
1425
1426                 // heuristic:  "usb%d" for links we know are two-host,
1427                 // else "eth%d" when there's reasonable doubt.  userspace
1428                 // can rename the link if it knows better.
1429                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1430                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1431                      (net->dev_addr [0] & 0x02) == 0))
1432                         strcpy (net->name, "eth%d");
1433                 /* WLAN devices should always be named "wlan%d" */
1434                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1435                         strcpy(net->name, "wlan%d");
1436                 /* WWAN devices should always be named "wwan%d" */
1437                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1438                         strcpy(net->name, "wwan%d");
1439
1440                 /* maybe the remote can't receive an Ethernet MTU */
1441                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1442                         net->mtu = dev->hard_mtu - net->hard_header_len;
1443         } else if (!info->in || !info->out)
1444                 status = usbnet_get_endpoints (dev, udev);
1445         else {
1446                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1447                 dev->out = usb_sndbulkpipe (xdev, info->out);
1448                 if (!(info->flags & FLAG_NO_SETINT))
1449                         status = usb_set_interface (xdev,
1450                                 interface->desc.bInterfaceNumber,
1451                                 interface->desc.bAlternateSetting);
1452                 else
1453                         status = 0;
1454
1455         }
1456         if (status >= 0 && dev->status)
1457                 status = init_status (dev, udev);
1458         if (status < 0)
1459                 goto out3;
1460
1461         if (!dev->rx_urb_size)
1462                 dev->rx_urb_size = dev->hard_mtu;
1463         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1464
1465         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1466                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1467         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1468                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1469
1470         status = register_netdev (net);
1471         if (status)
1472                 goto out3;
1473         netif_info(dev, probe, dev->net,
1474                    "register '%s' at usb-%s-%s, %s, %pM\n",
1475                    udev->dev.driver->name,
1476                    xdev->bus->bus_name, xdev->devpath,
1477                    dev->driver_info->description,
1478                    net->dev_addr);
1479
1480         // ok, it's ready to go.
1481         usb_set_intfdata (udev, dev);
1482
1483         netif_device_attach (net);
1484
1485         if (dev->driver_info->flags & FLAG_LINK_INTR)
1486                 netif_carrier_off(net);
1487
1488         return 0;
1489
1490 out3:
1491         if (info->unbind)
1492                 info->unbind (dev, udev);
1493 out1:
1494         free_netdev(net);
1495 out:
1496         usb_put_dev(xdev);
1497         return status;
1498 }
1499 EXPORT_SYMBOL_GPL(usbnet_probe);
1500
1501 /*-------------------------------------------------------------------------*/
1502
1503 /*
1504  * suspend the whole driver as soon as the first interface is suspended
1505  * resume only when the last interface is resumed
1506  */
1507
1508 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1509 {
1510         struct usbnet           *dev = usb_get_intfdata(intf);
1511
1512         if (!dev->suspend_count++) {
1513                 spin_lock_irq(&dev->txq.lock);
1514                 /* don't autosuspend while transmitting */
1515                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1516                         spin_unlock_irq(&dev->txq.lock);
1517                         return -EBUSY;
1518                 } else {
1519                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1520                         spin_unlock_irq(&dev->txq.lock);
1521                 }
1522                 /*
1523                  * accelerate emptying of the rx and queues, to avoid
1524                  * having everything error out.
1525                  */
1526                 netif_device_detach (dev->net);
1527                 usbnet_terminate_urbs(dev);
1528                 usb_kill_urb(dev->interrupt);
1529
1530                 /*
1531                  * reattach so runtime management can use and
1532                  * wake the device
1533                  */
1534                 netif_device_attach (dev->net);
1535         }
1536         return 0;
1537 }
1538 EXPORT_SYMBOL_GPL(usbnet_suspend);
1539
1540 int usbnet_resume (struct usb_interface *intf)
1541 {
1542         struct usbnet           *dev = usb_get_intfdata(intf);
1543         struct sk_buff          *skb;
1544         struct urb              *res;
1545         int                     retval;
1546
1547         if (!--dev->suspend_count) {
1548                 /* resume interrupt URBs */
1549                 if (dev->interrupt && test_bit(EVENT_DEV_OPEN, &dev->flags))
1550                         usb_submit_urb(dev->interrupt, GFP_NOIO);
1551
1552                 spin_lock_irq(&dev->txq.lock);
1553                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1554
1555                         skb = (struct sk_buff *)res->context;
1556                         retval = usb_submit_urb(res, GFP_ATOMIC);
1557                         if (retval < 0) {
1558                                 dev_kfree_skb_any(skb);
1559                                 usb_free_urb(res);
1560                                 usb_autopm_put_interface_async(dev->intf);
1561                         } else {
1562                                 dev->net->trans_start = jiffies;
1563                                 __skb_queue_tail(&dev->txq, skb);
1564                         }
1565                 }
1566
1567                 smp_mb();
1568                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1569                 spin_unlock_irq(&dev->txq.lock);
1570
1571                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1572                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1573                                 netif_start_queue(dev->net);
1574                         tasklet_schedule (&dev->bh);
1575                 }
1576         }
1577         return 0;
1578 }
1579 EXPORT_SYMBOL_GPL(usbnet_resume);
1580
1581
1582 /*-------------------------------------------------------------------------*/
1583
1584 static int __init usbnet_init(void)
1585 {
1586         /* Compiler should optimize this out. */
1587         BUILD_BUG_ON(
1588                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
1589
1590         random_ether_addr(node_id);
1591         return 0;
1592 }
1593 module_init(usbnet_init);
1594
1595 static void __exit usbnet_exit(void)
1596 {
1597 }
1598 module_exit(usbnet_exit);
1599
1600 MODULE_AUTHOR("David Brownell");
1601 MODULE_DESCRIPTION("USB network driver framework");
1602 MODULE_LICENSE("GPL");