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