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         struct usbnet   *dev = urb->context;
 186         int             status = urb->status;
 187
 188         switch (status) {
 189         /* success */
 190         case 0:
 191                 dev->driver_info->status(dev, urb);
 192                 break;
 193
 194         /* software-driven interface shutdown */
 195         case -ENOENT:           /* urb killed */
 196         case -ESHUTDOWN:        /* hardware gone */
 197                 netif_dbg(dev, ifdown, dev->net,
 198                           "intr shutdown, code %d\n", status);
 199                 return;
 200
 201         /* NOTE:  not throttling like RX/TX, since this endpoint
 202          * already polls infrequently
 203          */
 204         default:
 205                 netdev_dbg(dev->net, "intr status %d\n", status);
 206                 break;
 207         }
 208
 209         if (!netif_running (dev->net))
 210                 return;
 211
 212         status = usb_submit_urb (urb, GFP_ATOMIC);
 213         if (status != 0)
 214                 netif_err(dev, timer, dev->net,
 215                           "intr resubmit --> %d\n", status);
 216 }
 217
 218 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 219 {
 220         char            *buf = NULL;
 221         unsigned        pipe = 0;
 222         unsigned        maxp;
 223         unsigned        period;
 224
 225         if (!dev->driver_info->status)
 226                 return 0;
 227
 228         pipe = usb_rcvintpipe (dev->udev,
 229                         dev->status->desc.bEndpointAddress
 230                                 & USB_ENDPOINT_NUMBER_MASK);
 231         maxp = usb_maxpacket (dev->udev, pipe, 0);
 232
 233         /* avoid 1 msec chatter:  min 8 msec poll rate */
 234         period = max ((int) dev->status->desc.bInterval,
 235                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 236
 237         buf = kmalloc (maxp, GFP_KERNEL);
 238         if (buf) {
 239                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 240                 if (!dev->interrupt) {
 241                         kfree (buf);
 242                         return -ENOMEM;
 243                 } else {
 244                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 245                                 buf, maxp, intr_complete, dev, period);
 246                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 247                         dev_dbg(&intf->dev,
 248                                 "status ep%din, %d bytes period %d\n",
 249                                 usb_pipeendpoint(pipe), maxp, period);
 250                 }
 251         }
 252         return 0;
 253 }
 254
 255 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 256 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 257 {
 258         int ret = 0;
 259
 260         WARN_ON_ONCE(dev->interrupt == NULL);
 261         if (dev->interrupt) {
 262                 mutex_lock(&dev->interrupt_mutex);
 263
 264                 if (++dev->interrupt_count == 1)
 265                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 266
 267                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 268                         dev->interrupt_count);
 269                 mutex_unlock(&dev->interrupt_mutex);
 270         }
 271         return ret;
 272 }
 273 EXPORT_SYMBOL_GPL(usbnet_status_start);
 274
 275 /* For resume; submit interrupt URB if previously submitted */
 276 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 277 {
 278         int ret = 0;
 279
 280         mutex_lock(&dev->interrupt_mutex);
 281         if (dev->interrupt_count) {
 282                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 283                 dev_dbg(&dev->udev->dev,
 284                         "submitted interrupt URB for resume\n");
 285         }
 286         mutex_unlock(&dev->interrupt_mutex);
 287         return ret;
 288 }
 289
 290 /* Kill the interrupt URB if all submitters want it killed */
 291 void usbnet_status_stop(struct usbnet *dev)
 292 {
 293         if (dev->interrupt) {
 294                 mutex_lock(&dev->interrupt_mutex);
 295                 WARN_ON(dev->interrupt_count == 0);
 296
 297                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 298                         usb_kill_urb(dev->interrupt);
 299
 300                 dev_dbg(&dev->udev->dev,
 301                         "decremented interrupt URB count to %d\n",
 302                         dev->interrupt_count);
 303                 mutex_unlock(&dev->interrupt_mutex);
 304         }
 305 }
 306 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 307
 308 /* For suspend; always kill interrupt URB */
 309 static void __usbnet_status_stop_force(struct usbnet *dev)
 310 {
 311         if (dev->interrupt) {
 312                 mutex_lock(&dev->interrupt_mutex);
 313                 usb_kill_urb(dev->interrupt);
 314                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 315                 mutex_unlock(&dev->interrupt_mutex);
 316         }
 317 }
 318
 319 /* Passes this packet up the stack, updating its accounting.
 320  * Some link protocols batch packets, so their rx_fixup paths
 321  * can return clones as well as just modify the original skb.
 322  */
 323 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 324 {
 325         int     status;
 326
 327         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 328                 skb_queue_tail(&dev->rxq_pause, skb);
 329                 return;
 330         }
 331
 332         skb->protocol = eth_type_trans (skb, dev->net);
 333         dev->net->stats.rx_packets++;
 334         dev->net->stats.rx_bytes += skb->len;
 335
 336         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 337                   skb->len + sizeof (struct ethhdr), skb->protocol);
 338         memset (skb->cb, 0, sizeof (struct skb_data));
 339
 340         if (skb_defer_rx_timestamp(skb))
 341                 return;
 342
 343         status = netif_rx (skb);
 344         if (status != NET_RX_SUCCESS)
 345                 netif_dbg(dev, rx_err, dev->net,
 346                           "netif_rx status %d\n", status);
 347 }
 348 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 349
 350 \f
 351 /*-------------------------------------------------------------------------
 352  *
 353  * Network Device Driver (peer link to "Host Device", from USB host)
 354  *
 355  *-------------------------------------------------------------------------*/
 356
 357 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 358 {
 359         struct usbnet   *dev = netdev_priv(net);
 360         int             ll_mtu = new_mtu + net->hard_header_len;
 361         int             old_hard_mtu = dev->hard_mtu;
 362         int             old_rx_urb_size = dev->rx_urb_size;
 363
 364         if (new_mtu <= 0)
 365                 return -EINVAL;
 366         // no second zero-length packet read wanted after mtu-sized packets
 367         if ((ll_mtu % dev->maxpacket) == 0)
 368                 return -EDOM;
 369         net->mtu = new_mtu;
 370
 371         dev->hard_mtu = net->mtu + net->hard_header_len;
 372         if (dev->rx_urb_size == old_hard_mtu) {
 373                 dev->rx_urb_size = dev->hard_mtu;
 374                 if (dev->rx_urb_size > old_rx_urb_size)
 375                         usbnet_unlink_rx_urbs(dev);
 376         }
 377
 378         return 0;
 379 }
 380 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 381
 382 /* The caller must hold list->lock */
 383 static void __usbnet_queue_skb(struct sk_buff_head *list,
 384                         struct sk_buff *newsk, enum skb_state state)
 385 {
 386         struct skb_data *entry = (struct skb_data *) newsk->cb;
 387
 388         __skb_queue_tail(list, newsk);
 389         entry->state = state;
 390 }
 391
 392 /*-------------------------------------------------------------------------*/
 393
 394 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 395  * completion callbacks.  2.5 should have fixed those bugs...
 396  */
 397
 398 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 399                 struct sk_buff_head *list, enum skb_state state)
 400 {
 401         unsigned long           flags;
 402         enum skb_state          old_state;
 403         struct skb_data *entry = (struct skb_data *) skb->cb;
 404
 405         spin_lock_irqsave(&list->lock, flags);
 406         old_state = entry->state;
 407         entry->state = state;
 408         __skb_unlink(skb, list);
 409         spin_unlock(&list->lock);
 410         spin_lock(&dev->done.lock);
 411         __skb_queue_tail(&dev->done, skb);
 412         if (dev->done.qlen == 1)
 413                 tasklet_schedule(&dev->bh);
 414         spin_unlock_irqrestore(&dev->done.lock, flags);
 415         return old_state;
 416 }
 417
 418 /* some work can't be done in tasklets, so we use keventd
 419  *
 420  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 421  * but tasklet_schedule() doesn't.  hope the failure is rare.
 422  */
 423 void usbnet_defer_kevent (struct usbnet *dev, int work)
 424 {
 425         set_bit (work, &dev->flags);
 426         if (!schedule_work (&dev->kevent)) {
 427                 if (net_ratelimit())
 428                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 429         } else {
 430                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 431         }
 432 }
 433 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 434
 435 /*-------------------------------------------------------------------------*/
 436
 437 static void rx_complete (struct urb *urb);
 438
 439 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 440 {
 441         struct sk_buff          *skb;
 442         struct skb_data         *entry;
 443         int                     retval = 0;
 444         unsigned long           lockflags;
 445         size_t                  size = dev->rx_urb_size;
 446
 447         /* prevent rx skb allocation when error ratio is high */
 448         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 449                 usb_free_urb(urb);
 450                 return -ENOLINK;
 451         }
 452
 453         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 454         if (!skb) {
 455                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 456                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 457                 usb_free_urb (urb);
 458                 return -ENOMEM;
 459         }
 460
 461         entry = (struct skb_data *) skb->cb;
 462         entry->urb = urb;
 463         entry->dev = dev;
 464         entry->length = 0;
 465
 466         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 467                 skb->data, size, rx_complete, skb);
 468
 469         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 470
 471         if (netif_running (dev->net) &&
 472             netif_device_present (dev->net) &&
 473             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 474             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 475                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 476                 case -EPIPE:
 477                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 478                         break;
 479                 case -ENOMEM:
 480                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 481                         break;
 482                 case -ENODEV:
 483                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 484                         netif_device_detach (dev->net);
 485                         break;
 486                 case -EHOSTUNREACH:
 487                         retval = -ENOLINK;
 488                         break;
 489                 default:
 490                         netif_dbg(dev, rx_err, dev->net,
 491                                   "rx submit, %d\n", retval);
 492                         tasklet_schedule (&dev->bh);
 493                         break;
 494                 case 0:
 495                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 496                 }
 497         } else {
 498                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 499                 retval = -ENOLINK;
 500         }
 501         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 502         if (retval) {
 503                 dev_kfree_skb_any (skb);
 504                 usb_free_urb (urb);
 505         }
 506         return retval;
 507 }
 508
 509
 510 /*-------------------------------------------------------------------------*/
 511
 512 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 513 {
 514         if (dev->driver_info->rx_fixup &&
 515             !dev->driver_info->rx_fixup (dev, skb)) {
 516                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 517                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 518                         dev->net->stats.rx_errors++;
 519                 goto done;
 520         }
 521         // else network stack removes extra byte if we forced a short packet
 522
 523         if (skb->len) {
 524                 /* all data was already cloned from skb inside the driver */
 525                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 526                         dev_kfree_skb_any(skb);
 527                 else
 528                         usbnet_skb_return(dev, skb);
 529                 return;
 530         }
 531
 532         netif_dbg(dev, rx_err, dev->net, "drop\n");
 533         dev->net->stats.rx_errors++;
 534 done:
 535         skb_queue_tail(&dev->done, skb);
 536 }
 537
 538 /*-------------------------------------------------------------------------*/
 539
 540 static void rx_complete (struct urb *urb)
 541 {
 542         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 543         struct skb_data         *entry = (struct skb_data *) skb->cb;
 544         struct usbnet           *dev = entry->dev;
 545         int                     urb_status = urb->status;
 546         enum skb_state          state;
 547
 548         skb_put (skb, urb->actual_length);
 549         state = rx_done;
 550         entry->urb = NULL;
 551
 552         switch (urb_status) {
 553         /* success */
 554         case 0:
 555                 if (skb->len < dev->net->hard_header_len) {
 556                         state = rx_cleanup;
 557                         dev->net->stats.rx_errors++;
 558                         dev->net->stats.rx_length_errors++;
 559                         netif_dbg(dev, rx_err, dev->net,
 560                                   "rx length %d\n", skb->len);
 561                 }
 562                 break;
 563
 564         /* stalls need manual reset. this is rare ... except that
 565          * when going through USB 2.0 TTs, unplug appears this way.
 566          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 567          * storm, recovering as needed.
 568          */
 569         case -EPIPE:
 570                 dev->net->stats.rx_errors++;
 571                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 572                 // FALLTHROUGH
 573
 574         /* software-driven interface shutdown */
 575         case -ECONNRESET:               /* async unlink */
 576         case -ESHUTDOWN:                /* hardware gone */
 577                 netif_dbg(dev, ifdown, dev->net,
 578                           "rx shutdown, code %d\n", urb_status);
 579                 goto block;
 580
 581         /* we get controller i/o faults during khubd disconnect() delays.
 582          * throttle down resubmits, to avoid log floods; just temporarily,
 583          * so we still recover when the fault isn't a khubd delay.
 584          */
 585         case -EPROTO:
 586         case -ETIME:
 587         case -EILSEQ:
 588                 dev->net->stats.rx_errors++;
 589                 if (!timer_pending (&dev->delay)) {
 590                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 591                         netif_dbg(dev, link, dev->net,
 592                                   "rx throttle %d\n", urb_status);
 593                 }
 594 block:
 595                 state = rx_cleanup;
 596                 entry->urb = urb;
 597                 urb = NULL;
 598                 break;
 599
 600         /* data overrun ... flush fifo? */
 601         case -EOVERFLOW:
 602                 dev->net->stats.rx_over_errors++;
 603                 // FALLTHROUGH
 604
 605         default:
 606                 state = rx_cleanup;
 607                 dev->net->stats.rx_errors++;
 608                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 609                 break;
 610         }
 611
 612         /* stop rx if packet error rate is high */
 613         if (++dev->pkt_cnt > 30) {
 614                 dev->pkt_cnt = 0;
 615                 dev->pkt_err = 0;
 616         } else {
 617                 if (state == rx_cleanup)
 618                         dev->pkt_err++;
 619                 if (dev->pkt_err > 20)
 620                         set_bit(EVENT_RX_KILL, &dev->flags);
 621         }
 622
 623         state = defer_bh(dev, skb, &dev->rxq, state);
 624
 625         if (urb) {
 626                 if (netif_running (dev->net) &&
 627                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 628                     state != unlink_start) {
 629                         rx_submit (dev, urb, GFP_ATOMIC);
 630                         usb_mark_last_busy(dev->udev);
 631                         return;
 632                 }
 633                 usb_free_urb (urb);
 634         }
 635         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 636 }
 637
 638 /*-------------------------------------------------------------------------*/
 639 void usbnet_pause_rx(struct usbnet *dev)
 640 {
 641         set_bit(EVENT_RX_PAUSED, &dev->flags);
 642
 643         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 644 }
 645 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 646
 647 void usbnet_resume_rx(struct usbnet *dev)
 648 {
 649         struct sk_buff *skb;
 650         int num = 0;
 651
 652         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 653
 654         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 655                 usbnet_skb_return(dev, skb);
 656                 num++;
 657         }
 658
 659         tasklet_schedule(&dev->bh);
 660
 661         netif_dbg(dev, rx_status, dev->net,
 662                   "paused rx queue disabled, %d skbs requeued\n", num);
 663 }
 664 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 665
 666 void usbnet_purge_paused_rxq(struct usbnet *dev)
 667 {
 668         skb_queue_purge(&dev->rxq_pause);
 669 }
 670 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 671
 672 /*-------------------------------------------------------------------------*/
 673
 674 // unlink pending rx/tx; completion handlers do all other cleanup
 675
 676 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 677 {
 678         unsigned long           flags;
 679         struct sk_buff          *skb;
 680         int                     count = 0;
 681
 682         spin_lock_irqsave (&q->lock, flags);
 683         while (!skb_queue_empty(q)) {
 684                 struct skb_data         *entry;
 685                 struct urb              *urb;
 686                 int                     retval;
 687
 688                 skb_queue_walk(q, skb) {
 689                         entry = (struct skb_data *) skb->cb;
 690                         if (entry->state != unlink_start)
 691                                 goto found;
 692                 }
 693                 break;
 694 found:
 695                 entry->state = unlink_start;
 696                 urb = entry->urb;
 697
 698                 /*
 699                  * Get reference count of the URB to avoid it to be
 700                  * freed during usb_unlink_urb, which may trigger
 701                  * use-after-free problem inside usb_unlink_urb since
 702                  * usb_unlink_urb is always racing with .complete
 703                  * handler(include defer_bh).
 704                  */
 705                 usb_get_urb(urb);
 706                 spin_unlock_irqrestore(&q->lock, flags);
 707                 // during some PM-driven resume scenarios,
 708                 // these (async) unlinks complete immediately
 709                 retval = usb_unlink_urb (urb);
 710                 if (retval != -EINPROGRESS && retval != 0)
 711                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 712                 else
 713                         count++;
 714                 usb_put_urb(urb);
 715                 spin_lock_irqsave(&q->lock, flags);
 716         }
 717         spin_unlock_irqrestore (&q->lock, flags);
 718         return count;
 719 }
 720
 721 // Flush all pending rx urbs
 722 // minidrivers may need to do this when the MTU changes
 723
 724 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 725 {
 726         if (netif_running(dev->net)) {
 727                 (void) unlink_urbs (dev, &dev->rxq);
 728                 tasklet_schedule(&dev->bh);
 729         }
 730 }
 731 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 732
 733 /*-------------------------------------------------------------------------*/
 734
 735 // precondition: never called in_interrupt
 736 static void usbnet_terminate_urbs(struct usbnet *dev)
 737 {
 738         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 739         DECLARE_WAITQUEUE(wait, current);
 740         int temp;
 741
 742         /* ensure there are no more active urbs */
 743         add_wait_queue(&unlink_wakeup, &wait);
 744         set_current_state(TASK_UNINTERRUPTIBLE);
 745         dev->wait = &unlink_wakeup;
 746         temp = unlink_urbs(dev, &dev->txq) +
 747                 unlink_urbs(dev, &dev->rxq);
 748
 749         /* maybe wait for deletions to finish. */
 750         while (!skb_queue_empty(&dev->rxq)
 751                 && !skb_queue_empty(&dev->txq)
 752                 && !skb_queue_empty(&dev->done)) {
 753                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 754                         set_current_state(TASK_UNINTERRUPTIBLE);
 755                         netif_dbg(dev, ifdown, dev->net,
 756                                   "waited for %d urb completions\n", temp);
 757         }
 758         set_current_state(TASK_RUNNING);
 759         dev->wait = NULL;
 760         remove_wait_queue(&unlink_wakeup, &wait);
 761 }
 762
 763 int usbnet_stop (struct net_device *net)
 764 {
 765         struct usbnet           *dev = netdev_priv(net);
 766         struct driver_info      *info = dev->driver_info;
 767         int                     retval;
 768
 769         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 770         netif_stop_queue (net);
 771
 772         netif_info(dev, ifdown, dev->net,
 773                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 774                    net->stats.rx_packets, net->stats.tx_packets,
 775                    net->stats.rx_errors, net->stats.tx_errors);
 776
 777         /* allow minidriver to stop correctly (wireless devices to turn off
 778          * radio etc) */
 779         if (info->stop) {
 780                 retval = info->stop(dev);
 781                 if (retval < 0)
 782                         netif_info(dev, ifdown, dev->net,
 783                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 784                                    retval,
 785                                    dev->udev->bus->bus_name, dev->udev->devpath,
 786                                    info->description);
 787         }
 788
 789         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 790                 usbnet_terminate_urbs(dev);
 791
 792         usbnet_status_stop(dev);
 793
 794         usbnet_purge_paused_rxq(dev);
 795
 796         /* deferred work (task, timer, softirq) must also stop.
 797          * can't flush_scheduled_work() until we drop rtnl (later),
 798          * else workers could deadlock; so make workers a NOP.
 799          */
 800         dev->flags = 0;
 801         del_timer_sync (&dev->delay);
 802         tasklet_kill (&dev->bh);
 803         if (info->manage_power &&
 804             !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
 805                 info->manage_power(dev, 0);
 806         else
 807                 usb_autopm_put_interface(dev->intf);
 808
 809         return 0;
 810 }
 811 EXPORT_SYMBOL_GPL(usbnet_stop);
 812
 813 /*-------------------------------------------------------------------------*/
 814
 815 // posts reads, and enables write queuing
 816
 817 // precondition: never called in_interrupt
 818
 819 int usbnet_open (struct net_device *net)
 820 {
 821         struct usbnet           *dev = netdev_priv(net);
 822         int                     retval;
 823         struct driver_info      *info = dev->driver_info;
 824
 825         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 826                 netif_info(dev, ifup, dev->net,
 827                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 828                            retval,
 829                            dev->udev->bus->bus_name,
 830                            dev->udev->devpath,
 831                            info->description);
 832                 goto done_nopm;
 833         }
 834
 835         // put into "known safe" state
 836         if (info->reset && (retval = info->reset (dev)) < 0) {
 837                 netif_info(dev, ifup, dev->net,
 838                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 839                            retval,
 840                            dev->udev->bus->bus_name,
 841                            dev->udev->devpath,
 842                            info->description);
 843                 goto done;
 844         }
 845
 846         // insist peer be connected
 847         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 848                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 849                 goto done;
 850         }
 851
 852         /* start any status interrupt transfer */
 853         if (dev->interrupt) {
 854                 retval = usbnet_status_start(dev, GFP_KERNEL);
 855                 if (retval < 0) {
 856                         netif_err(dev, ifup, dev->net,
 857                                   "intr submit %d\n", retval);
 858                         goto done;
 859                 }
 860         }
 861
 862         set_bit(EVENT_DEV_OPEN, &dev->flags);
 863         netif_start_queue (net);
 864         netif_info(dev, ifup, dev->net,
 865                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 866                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 867                    dev->net->mtu,
 868                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 869                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 870                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 871                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 872                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 873                    "simple");
 874
 875         /* reset rx error state */
 876         dev->pkt_cnt = 0;
 877         dev->pkt_err = 0;
 878         clear_bit(EVENT_RX_KILL, &dev->flags);
 879
 880         // delay posting reads until we're fully open
 881         tasklet_schedule (&dev->bh);
 882         if (info->manage_power) {
 883                 retval = info->manage_power(dev, 1);
 884                 if (retval < 0) {
 885                         retval = 0;
 886                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 887                 } else {
 888                         usb_autopm_put_interface(dev->intf);
 889                 }
 890         }
 891         return retval;
 892 done:
 893         usb_autopm_put_interface(dev->intf);
 894 done_nopm:
 895         return retval;
 896 }
 897 EXPORT_SYMBOL_GPL(usbnet_open);
 898
 899 /*-------------------------------------------------------------------------*/
 900
 901 /* ethtool methods; minidrivers may need to add some more, but
 902  * they'll probably want to use this base set.
 903  */
 904
 905 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 906 {
 907         struct usbnet *dev = netdev_priv(net);
 908
 909         if (!dev->mii.mdio_read)
 910                 return -EOPNOTSUPP;
 911
 912         return mii_ethtool_gset(&dev->mii, cmd);
 913 }
 914 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 915
 916 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 917 {
 918         struct usbnet *dev = netdev_priv(net);
 919         int retval;
 920
 921         if (!dev->mii.mdio_write)
 922                 return -EOPNOTSUPP;
 923
 924         retval = mii_ethtool_sset(&dev->mii, cmd);
 925
 926         /* link speed/duplex might have changed */
 927         if (dev->driver_info->link_reset)
 928                 dev->driver_info->link_reset(dev);
 929
 930         return retval;
 931
 932 }
 933 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 934
 935 u32 usbnet_get_link (struct net_device *net)
 936 {
 937         struct usbnet *dev = netdev_priv(net);
 938
 939         /* If a check_connect is defined, return its result */
 940         if (dev->driver_info->check_connect)
 941                 return dev->driver_info->check_connect (dev) == 0;
 942
 943         /* if the device has mii operations, use those */
 944         if (dev->mii.mdio_read)
 945                 return mii_link_ok(&dev->mii);
 946
 947         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 948         return ethtool_op_get_link(net);
 949 }
 950 EXPORT_SYMBOL_GPL(usbnet_get_link);
 951
 952 int usbnet_nway_reset(struct net_device *net)
 953 {
 954         struct usbnet *dev = netdev_priv(net);
 955
 956         if (!dev->mii.mdio_write)
 957                 return -EOPNOTSUPP;
 958
 959         return mii_nway_restart(&dev->mii);
 960 }
 961 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 962
 963 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 964 {
 965         struct usbnet *dev = netdev_priv(net);
 966
 967         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 968         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 969         strlcpy (info->fw_version, dev->driver_info->description,
 970                 sizeof info->fw_version);
 971         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 972 }
 973 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 974
 975 u32 usbnet_get_msglevel (struct net_device *net)
 976 {
 977         struct usbnet *dev = netdev_priv(net);
 978
 979         return dev->msg_enable;
 980 }
 981 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
 982
 983 void usbnet_set_msglevel (struct net_device *net, u32 level)
 984 {
 985         struct usbnet *dev = netdev_priv(net);
 986
 987         dev->msg_enable = level;
 988 }
 989 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
 990
 991 /* drivers may override default ethtool_ops in their bind() routine */
 992 static const struct ethtool_ops usbnet_ethtool_ops = {
 993         .get_settings           = usbnet_get_settings,
 994         .set_settings           = usbnet_set_settings,
 995         .get_link               = usbnet_get_link,
 996         .nway_reset             = usbnet_nway_reset,
 997         .get_drvinfo            = usbnet_get_drvinfo,
 998         .get_msglevel           = usbnet_get_msglevel,
 999         .set_msglevel           = usbnet_set_msglevel,
1000         .get_ts_info            = ethtool_op_get_ts_info,
1001 };
1002
1003 /*-------------------------------------------------------------------------*/
1004
1005 static void __handle_link_change(struct usbnet *dev)
1006 {
1007         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1008                 return;
1009
1010         if (!netif_carrier_ok(dev->net)) {
1011                 /* kill URBs for reading packets to save bus bandwidth */
1012                 unlink_urbs(dev, &dev->rxq);
1013
1014                 /*
1015                  * tx_timeout will unlink URBs for sending packets and
1016                  * tx queue is stopped by netcore after link becomes off
1017                  */
1018         } else {
1019                 /* submitting URBs for reading packets */
1020                 tasklet_schedule(&dev->bh);
1021         }
1022
1023         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1024 }
1025
1026 /* work that cannot be done in interrupt context uses keventd.
1027  *
1028  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1029  * especially now that control transfers can be queued.
1030  */
1031 static void
1032 kevent (struct work_struct *work)
1033 {
1034         struct usbnet           *dev =
1035                 container_of(work, struct usbnet, kevent);
1036         int                     status;
1037
1038         /* usb_clear_halt() needs a thread context */
1039         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1040                 unlink_urbs (dev, &dev->txq);
1041                 status = usb_autopm_get_interface(dev->intf);
1042                 if (status < 0)
1043                         goto fail_pipe;
1044                 status = usb_clear_halt (dev->udev, dev->out);
1045                 usb_autopm_put_interface(dev->intf);
1046                 if (status < 0 &&
1047                     status != -EPIPE &&
1048                     status != -ESHUTDOWN) {
1049                         if (netif_msg_tx_err (dev))
1050 fail_pipe:
1051                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1052                                            status);
1053                 } else {
1054                         clear_bit (EVENT_TX_HALT, &dev->flags);
1055                         if (status != -ESHUTDOWN)
1056                                 netif_wake_queue (dev->net);
1057                 }
1058         }
1059         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1060                 unlink_urbs (dev, &dev->rxq);
1061                 status = usb_autopm_get_interface(dev->intf);
1062                 if (status < 0)
1063                         goto fail_halt;
1064                 status = usb_clear_halt (dev->udev, dev->in);
1065                 usb_autopm_put_interface(dev->intf);
1066                 if (status < 0 &&
1067                     status != -EPIPE &&
1068                     status != -ESHUTDOWN) {
1069                         if (netif_msg_rx_err (dev))
1070 fail_halt:
1071                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1072                                            status);
1073                 } else {
1074                         clear_bit (EVENT_RX_HALT, &dev->flags);
1075                         tasklet_schedule (&dev->bh);
1076                 }
1077         }
1078
1079         /* tasklet could resubmit itself forever if memory is tight */
1080         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1081                 struct urb      *urb = NULL;
1082                 int resched = 1;
1083
1084                 if (netif_running (dev->net))
1085                         urb = usb_alloc_urb (0, GFP_KERNEL);
1086                 else
1087                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1088                 if (urb != NULL) {
1089                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1090                         status = usb_autopm_get_interface(dev->intf);
1091                         if (status < 0) {
1092                                 usb_free_urb(urb);
1093                                 goto fail_lowmem;
1094                         }
1095                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1096                                 resched = 0;
1097                         usb_autopm_put_interface(dev->intf);
1098 fail_lowmem:
1099                         if (resched)
1100                                 tasklet_schedule (&dev->bh);
1101                 }
1102         }
1103
1104         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1105                 struct driver_info      *info = dev->driver_info;
1106                 int                     retval = 0;
1107
1108                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1109                 status = usb_autopm_get_interface(dev->intf);
1110                 if (status < 0)
1111                         goto skip_reset;
1112                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1113                         usb_autopm_put_interface(dev->intf);
1114 skip_reset:
1115                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1116                                     retval,
1117                                     dev->udev->bus->bus_name,
1118                                     dev->udev->devpath,
1119                                     info->description);
1120                 } else {
1121                         usb_autopm_put_interface(dev->intf);
1122                 }
1123
1124                 /* handle link change from link resetting */
1125                 __handle_link_change(dev);
1126         }
1127
1128         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1129                 __handle_link_change(dev);
1130
1131         if (dev->flags)
1132                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1133 }
1134
1135 /*-------------------------------------------------------------------------*/
1136
1137 static void tx_complete (struct urb *urb)
1138 {
1139         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1140         struct skb_data         *entry = (struct skb_data *) skb->cb;
1141         struct usbnet           *dev = entry->dev;
1142
1143         if (urb->status == 0) {
1144                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1145                         dev->net->stats.tx_packets++;
1146                 dev->net->stats.tx_bytes += entry->length;
1147         } else {
1148                 dev->net->stats.tx_errors++;
1149
1150                 switch (urb->status) {
1151                 case -EPIPE:
1152                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1153                         break;
1154
1155                 /* software-driven interface shutdown */
1156                 case -ECONNRESET:               // async unlink
1157                 case -ESHUTDOWN:                // hardware gone
1158                         break;
1159
1160                 // like rx, tx gets controller i/o faults during khubd delays
1161                 // and so it uses the same throttling mechanism.
1162                 case -EPROTO:
1163                 case -ETIME:
1164                 case -EILSEQ:
1165                         usb_mark_last_busy(dev->udev);
1166                         if (!timer_pending (&dev->delay)) {
1167                                 mod_timer (&dev->delay,
1168                                         jiffies + THROTTLE_JIFFIES);
1169                                 netif_dbg(dev, link, dev->net,
1170                                           "tx throttle %d\n", urb->status);
1171                         }
1172                         netif_stop_queue (dev->net);
1173                         break;
1174                 default:
1175                         netif_dbg(dev, tx_err, dev->net,
1176                                   "tx err %d\n", entry->urb->status);
1177                         break;
1178                 }
1179         }
1180
1181         usb_autopm_put_interface_async(dev->intf);
1182         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1183 }
1184
1185 /*-------------------------------------------------------------------------*/
1186
1187 void usbnet_tx_timeout (struct net_device *net)
1188 {
1189         struct usbnet           *dev = netdev_priv(net);
1190
1191         unlink_urbs (dev, &dev->txq);
1192         tasklet_schedule (&dev->bh);
1193
1194         // FIXME: device recovery -- reset?
1195 }
1196 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1197
1198 /*-------------------------------------------------------------------------*/
1199
1200 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1201                                      struct net_device *net)
1202 {
1203         struct usbnet           *dev = netdev_priv(net);
1204         int                     length;
1205         struct urb              *urb = NULL;
1206         struct skb_data         *entry;
1207         struct driver_info      *info = dev->driver_info;
1208         unsigned long           flags;
1209         int retval;
1210
1211         if (skb)
1212                 skb_tx_timestamp(skb);
1213
1214         // some devices want funky USB-level framing, for
1215         // win32 driver (usually) and/or hardware quirks
1216         if (info->tx_fixup) {
1217                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1218                 if (!skb) {
1219                         /* packet collected; minidriver waiting for more */
1220                         if (info->flags & FLAG_MULTI_PACKET)
1221                                 goto not_drop;
1222                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1223                         goto drop;
1224                 }
1225         }
1226         length = skb->len;
1227
1228         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1229                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1230                 goto drop;
1231         }
1232
1233         entry = (struct skb_data *) skb->cb;
1234         entry->urb = urb;
1235         entry->dev = dev;
1236         entry->length = length;
1237
1238         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1239                         skb->data, skb->len, tx_complete, skb);
1240
1241         /* don't assume the hardware handles USB_ZERO_PACKET
1242          * NOTE:  strictly conforming cdc-ether devices should expect
1243          * the ZLP here, but ignore the one-byte packet.
1244          * NOTE2: CDC NCM specification is different from CDC ECM when
1245          * handling ZLP/short packets, so cdc_ncm driver will make short
1246          * packet itself if needed.
1247          */
1248         if (length % dev->maxpacket == 0) {
1249                 if (!(info->flags & FLAG_SEND_ZLP)) {
1250                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1251                                 urb->transfer_buffer_length++;
1252                                 if (skb_tailroom(skb)) {
1253                                         skb->data[skb->len] = 0;
1254                                         __skb_put(skb, 1);
1255                                 }
1256                         }
1257                 } else
1258                         urb->transfer_flags |= URB_ZERO_PACKET;
1259         }
1260
1261         spin_lock_irqsave(&dev->txq.lock, flags);
1262         retval = usb_autopm_get_interface_async(dev->intf);
1263         if (retval < 0) {
1264                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1265                 goto drop;
1266         }
1267
1268 #ifdef CONFIG_PM
1269         /* if this triggers the device is still a sleep */
1270         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1271                 /* transmission will be done in resume */
1272                 usb_anchor_urb(urb, &dev->deferred);
1273                 /* no use to process more packets */
1274                 netif_stop_queue(net);
1275                 usb_put_urb(urb);
1276                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1277                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1278                 goto deferred;
1279         }
1280 #endif
1281
1282         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1283         case -EPIPE:
1284                 netif_stop_queue (net);
1285                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1286                 usb_autopm_put_interface_async(dev->intf);
1287                 break;
1288         default:
1289                 usb_autopm_put_interface_async(dev->intf);
1290                 netif_dbg(dev, tx_err, dev->net,
1291                           "tx: submit urb err %d\n", retval);
1292                 break;
1293         case 0:
1294                 net->trans_start = jiffies;
1295                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1296                 if (dev->txq.qlen >= TX_QLEN (dev))
1297                         netif_stop_queue (net);
1298         }
1299         spin_unlock_irqrestore (&dev->txq.lock, flags);
1300
1301         if (retval) {
1302                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1303 drop:
1304                 dev->net->stats.tx_dropped++;
1305 not_drop:
1306                 if (skb)
1307                         dev_kfree_skb_any (skb);
1308                 usb_free_urb (urb);
1309         } else
1310                 netif_dbg(dev, tx_queued, dev->net,
1311                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1312 #ifdef CONFIG_PM
1313 deferred:
1314 #endif
1315         return NETDEV_TX_OK;
1316 }
1317 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1318
1319 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1320 {
1321         struct urb      *urb;
1322         int             i;
1323         int             ret = 0;
1324
1325         /* don't refill the queue all at once */
1326         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1327                 urb = usb_alloc_urb(0, flags);
1328                 if (urb != NULL) {
1329                         ret = rx_submit(dev, urb, flags);
1330                         if (ret)
1331                                 goto err;
1332                 } else {
1333                         ret = -ENOMEM;
1334                         goto err;
1335                 }
1336         }
1337 err:
1338         return ret;
1339 }
1340
1341 /*-------------------------------------------------------------------------*/
1342
1343 // tasklet (work deferred from completions, in_irq) or timer
1344
1345 static void usbnet_bh (unsigned long param)
1346 {
1347         struct usbnet           *dev = (struct usbnet *) param;
1348         struct sk_buff          *skb;
1349         struct skb_data         *entry;
1350
1351         while ((skb = skb_dequeue (&dev->done))) {
1352                 entry = (struct skb_data *) skb->cb;
1353                 switch (entry->state) {
1354                 case rx_done:
1355                         entry->state = rx_cleanup;
1356                         rx_process (dev, skb);
1357                         continue;
1358                 case tx_done:
1359                 case rx_cleanup:
1360                         usb_free_urb (entry->urb);
1361                         dev_kfree_skb (skb);
1362                         continue;
1363                 default:
1364                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1365                 }
1366         }
1367
1368         /* restart RX again after disabling due to high error rate */
1369         clear_bit(EVENT_RX_KILL, &dev->flags);
1370
1371         // waiting for all pending urbs to complete?
1372         if (dev->wait) {
1373                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1374                         wake_up (dev->wait);
1375                 }
1376
1377         // or are we maybe short a few urbs?
1378         } else if (netif_running (dev->net) &&
1379                    netif_device_present (dev->net) &&
1380                    netif_carrier_ok(dev->net) &&
1381                    !timer_pending (&dev->delay) &&
1382                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1383                 int     temp = dev->rxq.qlen;
1384
1385                 if (temp < RX_QLEN(dev)) {
1386                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1387                                 return;
1388                         if (temp != dev->rxq.qlen)
1389                                 netif_dbg(dev, link, dev->net,
1390                                           "rxqlen %d --> %d\n",
1391                                           temp, dev->rxq.qlen);
1392                         if (dev->rxq.qlen < RX_QLEN(dev))
1393                                 tasklet_schedule (&dev->bh);
1394                 }
1395                 if (dev->txq.qlen < TX_QLEN (dev))
1396                         netif_wake_queue (dev->net);
1397         }
1398 }
1399
1400
1401 /*-------------------------------------------------------------------------
1402  *
1403  * USB Device Driver support
1404  *
1405  *-------------------------------------------------------------------------*/
1406
1407 // precondition: never called in_interrupt
1408
1409 void usbnet_disconnect (struct usb_interface *intf)
1410 {
1411         struct usbnet           *dev;
1412         struct usb_device       *xdev;
1413         struct net_device       *net;
1414
1415         dev = usb_get_intfdata(intf);
1416         usb_set_intfdata(intf, NULL);
1417         if (!dev)
1418                 return;
1419
1420         xdev = interface_to_usbdev (intf);
1421
1422         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1423                    intf->dev.driver->name,
1424                    xdev->bus->bus_name, xdev->devpath,
1425                    dev->driver_info->description);
1426
1427         net = dev->net;
1428         unregister_netdev (net);
1429
1430         cancel_work_sync(&dev->kevent);
1431
1432         usb_scuttle_anchored_urbs(&dev->deferred);
1433
1434         if (dev->driver_info->unbind)
1435                 dev->driver_info->unbind (dev, intf);
1436
1437         usb_kill_urb(dev->interrupt);
1438         usb_free_urb(dev->interrupt);
1439
1440         free_netdev(net);
1441 }
1442 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1443
1444 static const struct net_device_ops usbnet_netdev_ops = {
1445         .ndo_open               = usbnet_open,
1446         .ndo_stop               = usbnet_stop,
1447         .ndo_start_xmit         = usbnet_start_xmit,
1448         .ndo_tx_timeout         = usbnet_tx_timeout,
1449         .ndo_change_mtu         = usbnet_change_mtu,
1450         .ndo_set_mac_address    = eth_mac_addr,
1451         .ndo_validate_addr      = eth_validate_addr,
1452 };
1453
1454 /*-------------------------------------------------------------------------*/
1455
1456 // precondition: never called in_interrupt
1457
1458 static struct device_type wlan_type = {
1459         .name   = "wlan",
1460 };
1461
1462 static struct device_type wwan_type = {
1463         .name   = "wwan",
1464 };
1465
1466 int
1467 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1468 {
1469         struct usbnet                   *dev;
1470         struct net_device               *net;
1471         struct usb_host_interface       *interface;
1472         struct driver_info              *info;
1473         struct usb_device               *xdev;
1474         int                             status;
1475         const char                      *name;
1476         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1477
1478         /* usbnet already took usb runtime pm, so have to enable the feature
1479          * for usb interface, otherwise usb_autopm_get_interface may return
1480          * failure if RUNTIME_PM is enabled.
1481          */
1482         if (!driver->supports_autosuspend) {
1483                 driver->supports_autosuspend = 1;
1484                 pm_runtime_enable(&udev->dev);
1485         }
1486
1487         name = udev->dev.driver->name;
1488         info = (struct driver_info *) prod->driver_info;
1489         if (!info) {
1490                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1491                 return -ENODEV;
1492         }
1493         xdev = interface_to_usbdev (udev);
1494         interface = udev->cur_altsetting;
1495
1496         status = -ENOMEM;
1497
1498         // set up our own records
1499         net = alloc_etherdev(sizeof(*dev));
1500         if (!net)
1501                 goto out;
1502
1503         /* netdev_printk() needs this so do it as early as possible */
1504         SET_NETDEV_DEV(net, &udev->dev);
1505
1506         dev = netdev_priv(net);
1507         dev->udev = xdev;
1508         dev->intf = udev;
1509         dev->driver_info = info;
1510         dev->driver_name = name;
1511         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1512                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1513         skb_queue_head_init (&dev->rxq);
1514         skb_queue_head_init (&dev->txq);
1515         skb_queue_head_init (&dev->done);
1516         skb_queue_head_init(&dev->rxq_pause);
1517         dev->bh.func = usbnet_bh;
1518         dev->bh.data = (unsigned long) dev;
1519         INIT_WORK (&dev->kevent, kevent);
1520         init_usb_anchor(&dev->deferred);
1521         dev->delay.function = usbnet_bh;
1522         dev->delay.data = (unsigned long) dev;
1523         init_timer (&dev->delay);
1524         mutex_init (&dev->phy_mutex);
1525         mutex_init(&dev->interrupt_mutex);
1526         dev->interrupt_count = 0;
1527
1528         dev->net = net;
1529         strcpy (net->name, "usb%d");
1530         memcpy (net->dev_addr, node_id, sizeof node_id);
1531
1532         /* rx and tx sides can use different message sizes;
1533          * bind() should set rx_urb_size in that case.
1534          */
1535         dev->hard_mtu = net->mtu + net->hard_header_len;
1536 #if 0
1537 // dma_supported() is deeply broken on almost all architectures
1538         // possible with some EHCI controllers
1539         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1540                 net->features |= NETIF_F_HIGHDMA;
1541 #endif
1542
1543         net->netdev_ops = &usbnet_netdev_ops;
1544         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1545         net->ethtool_ops = &usbnet_ethtool_ops;
1546
1547         // allow device-specific bind/init procedures
1548         // NOTE net->name still not usable ...
1549         if (info->bind) {
1550                 status = info->bind (dev, udev);
1551                 if (status < 0)
1552                         goto out1;
1553
1554                 // heuristic:  "usb%d" for links we know are two-host,
1555                 // else "eth%d" when there's reasonable doubt.  userspace
1556                 // can rename the link if it knows better.
1557                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1558                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1559                      (net->dev_addr [0] & 0x02) == 0))
1560                         strcpy (net->name, "eth%d");
1561                 /* WLAN devices should always be named "wlan%d" */
1562                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1563                         strcpy(net->name, "wlan%d");
1564                 /* WWAN devices should always be named "wwan%d" */
1565                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1566                         strcpy(net->name, "wwan%d");
1567
1568                 /* devices that cannot do ARP */
1569                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1570                         net->flags |= IFF_NOARP;
1571
1572                 /* maybe the remote can't receive an Ethernet MTU */
1573                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1574                         net->mtu = dev->hard_mtu - net->hard_header_len;
1575         } else if (!info->in || !info->out)
1576                 status = usbnet_get_endpoints (dev, udev);
1577         else {
1578                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1579                 dev->out = usb_sndbulkpipe (xdev, info->out);
1580                 if (!(info->flags & FLAG_NO_SETINT))
1581                         status = usb_set_interface (xdev,
1582                                 interface->desc.bInterfaceNumber,
1583                                 interface->desc.bAlternateSetting);
1584                 else
1585                         status = 0;
1586
1587         }
1588         if (status >= 0 && dev->status)
1589                 status = init_status (dev, udev);
1590         if (status < 0)
1591                 goto out3;
1592
1593         if (!dev->rx_urb_size)
1594                 dev->rx_urb_size = dev->hard_mtu;
1595         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1596
1597         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1598                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1599         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1600                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1601
1602         status = register_netdev (net);
1603         if (status)
1604                 goto out4;
1605         netif_info(dev, probe, dev->net,
1606                    "register '%s' at usb-%s-%s, %s, %pM\n",
1607                    udev->dev.driver->name,
1608                    xdev->bus->bus_name, xdev->devpath,
1609                    dev->driver_info->description,
1610                    net->dev_addr);
1611
1612         // ok, it's ready to go.
1613         usb_set_intfdata (udev, dev);
1614
1615         netif_device_attach (net);
1616
1617         if (dev->driver_info->flags & FLAG_LINK_INTR)
1618                 usbnet_link_change(dev, 0, 0);
1619
1620         return 0;
1621
1622 out4:
1623         usb_free_urb(dev->interrupt);
1624 out3:
1625         if (info->unbind)
1626                 info->unbind (dev, udev);
1627 out1:
1628         free_netdev(net);
1629 out:
1630         return status;
1631 }
1632 EXPORT_SYMBOL_GPL(usbnet_probe);
1633
1634 /*-------------------------------------------------------------------------*/
1635
1636 /*
1637  * suspend the whole driver as soon as the first interface is suspended
1638  * resume only when the last interface is resumed
1639  */
1640
1641 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1642 {
1643         struct usbnet           *dev = usb_get_intfdata(intf);
1644
1645         if (!dev->suspend_count++) {
1646                 spin_lock_irq(&dev->txq.lock);
1647                 /* don't autosuspend while transmitting */
1648                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1649                         dev->suspend_count--;
1650                         spin_unlock_irq(&dev->txq.lock);
1651                         return -EBUSY;
1652                 } else {
1653                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1654                         spin_unlock_irq(&dev->txq.lock);
1655                 }
1656                 /*
1657                  * accelerate emptying of the rx and queues, to avoid
1658                  * having everything error out.
1659                  */
1660                 netif_device_detach (dev->net);
1661                 usbnet_terminate_urbs(dev);
1662                 __usbnet_status_stop_force(dev);
1663
1664                 /*
1665                  * reattach so runtime management can use and
1666                  * wake the device
1667                  */
1668                 netif_device_attach (dev->net);
1669         }
1670         return 0;
1671 }
1672 EXPORT_SYMBOL_GPL(usbnet_suspend);
1673
1674 int usbnet_resume (struct usb_interface *intf)
1675 {
1676         struct usbnet           *dev = usb_get_intfdata(intf);
1677         struct sk_buff          *skb;
1678         struct urb              *res;
1679         int                     retval;
1680
1681         if (!--dev->suspend_count) {
1682                 /* resume interrupt URB if it was previously submitted */
1683                 __usbnet_status_start_force(dev, GFP_NOIO);
1684
1685                 spin_lock_irq(&dev->txq.lock);
1686                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1687
1688                         skb = (struct sk_buff *)res->context;
1689                         retval = usb_submit_urb(res, GFP_ATOMIC);
1690                         if (retval < 0) {
1691                                 dev_kfree_skb_any(skb);
1692                                 usb_free_urb(res);
1693                                 usb_autopm_put_interface_async(dev->intf);
1694                         } else {
1695                                 dev->net->trans_start = jiffies;
1696                                 __skb_queue_tail(&dev->txq, skb);
1697                         }
1698                 }
1699
1700                 smp_mb();
1701                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1702                 spin_unlock_irq(&dev->txq.lock);
1703
1704                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1705                         /* handle remote wakeup ASAP */
1706                         if (!dev->wait &&
1707                                 netif_device_present(dev->net) &&
1708                                 !timer_pending(&dev->delay) &&
1709                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1710                                         rx_alloc_submit(dev, GFP_NOIO);
1711
1712                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1713                                 netif_tx_wake_all_queues(dev->net);
1714                         tasklet_schedule (&dev->bh);
1715                 }
1716         }
1717
1718         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1719                 usb_autopm_get_interface_no_resume(intf);
1720
1721         return 0;
1722 }
1723 EXPORT_SYMBOL_GPL(usbnet_resume);
1724
1725 /*
1726  * Either a subdriver implements manage_power, then it is assumed to always
1727  * be ready to be suspended or it reports the readiness to be suspended
1728  * explicitly
1729  */
1730 void usbnet_device_suggests_idle(struct usbnet *dev)
1731 {
1732         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1733                 dev->intf->needs_remote_wakeup = 1;
1734                 usb_autopm_put_interface_async(dev->intf);
1735         }
1736 }
1737 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1738
1739 /*
1740  * For devices that can do without special commands
1741  */
1742 int usbnet_manage_power(struct usbnet *dev, int on)
1743 {
1744         dev->intf->needs_remote_wakeup = on;
1745         return 0;
1746 }
1747 EXPORT_SYMBOL(usbnet_manage_power);
1748
1749 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1750 {
1751         /* update link after link is reseted */
1752         if (link && !need_reset)
1753                 netif_carrier_on(dev->net);
1754         else
1755                 netif_carrier_off(dev->net);
1756
1757         if (need_reset && link)
1758                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1759         else
1760                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1761 }
1762 EXPORT_SYMBOL(usbnet_link_change);
1763
1764 /*-------------------------------------------------------------------------*/
1765 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1766                              u16 value, u16 index, void *data, u16 size)
1767 {
1768         void *buf = NULL;
1769         int err = -ENOMEM;
1770
1771         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1772                    " value=0x%04x index=0x%04x size=%d\n",
1773                    cmd, reqtype, value, index, size);
1774
1775         if (data) {
1776                 buf = kmalloc(size, GFP_KERNEL);
1777                 if (!buf)
1778                         goto out;
1779         }
1780
1781         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1782                               cmd, reqtype, value, index, buf, size,
1783                               USB_CTRL_GET_TIMEOUT);
1784         if (err > 0 && err <= size)
1785                 memcpy(data, buf, err);
1786         kfree(buf);
1787 out:
1788         return err;
1789 }
1790
1791 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1792                               u16 value, u16 index, const void *data,
1793                               u16 size)
1794 {
1795         void *buf = NULL;
1796         int err = -ENOMEM;
1797
1798         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1799                    " value=0x%04x index=0x%04x size=%d\n",
1800                    cmd, reqtype, value, index, size);
1801
1802         if (data) {
1803                 buf = kmemdup(data, size, GFP_KERNEL);
1804                 if (!buf)
1805                         goto out;
1806         }
1807
1808         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1809                               cmd, reqtype, value, index, buf, size,
1810                               USB_CTRL_SET_TIMEOUT);
1811         kfree(buf);
1812
1813 out:
1814         return err;
1815 }
1816
1817 /*
1818  * The function can't be called inside suspend/resume callback,
1819  * otherwise deadlock will be caused.
1820  */
1821 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1822                     u16 value, u16 index, void *data, u16 size)
1823 {
1824         int ret;
1825
1826         if (usb_autopm_get_interface(dev->intf) < 0)
1827                 return -ENODEV;
1828         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1829                                 data, size);
1830         usb_autopm_put_interface(dev->intf);
1831         return ret;
1832 }
1833 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1834
1835 /*
1836  * The function can't be called inside suspend/resume callback,
1837  * otherwise deadlock will be caused.
1838  */
1839 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1840                      u16 value, u16 index, const void *data, u16 size)
1841 {
1842         int ret;
1843
1844         if (usb_autopm_get_interface(dev->intf) < 0)
1845                 return -ENODEV;
1846         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1847                                  data, size);
1848         usb_autopm_put_interface(dev->intf);
1849         return ret;
1850 }
1851 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1852
1853 /*
1854  * The function can be called inside suspend/resume callback safely
1855  * and should only be called by suspend/resume callback generally.
1856  */
1857 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1858                           u16 value, u16 index, void *data, u16 size)
1859 {
1860         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1861                                  data, size);
1862 }
1863 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1864
1865 /*
1866  * The function can be called inside suspend/resume callback safely
1867  * and should only be called by suspend/resume callback generally.
1868  */
1869 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1870                           u16 value, u16 index, const void *data,
1871                           u16 size)
1872 {
1873         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1874                                   data, size);
1875 }
1876 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1877
1878 static void usbnet_async_cmd_cb(struct urb *urb)
1879 {
1880         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
1881         int status = urb->status;
1882
1883         if (status < 0)
1884                 dev_dbg(&urb->dev->dev, "%s failed with %d",
1885                         __func__, status);
1886
1887         kfree(req);
1888         usb_free_urb(urb);
1889 }
1890
1891 /*
1892  * The caller must make sure that device can't be put into suspend
1893  * state until the control URB completes.
1894  */
1895 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
1896                            u16 value, u16 index, const void *data, u16 size)
1897 {
1898         struct usb_ctrlrequest *req = NULL;
1899         struct urb *urb;
1900         int err = -ENOMEM;
1901         void *buf = NULL;
1902
1903         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1904                    " value=0x%04x index=0x%04x size=%d\n",
1905                    cmd, reqtype, value, index, size);
1906
1907         urb = usb_alloc_urb(0, GFP_ATOMIC);
1908         if (!urb) {
1909                 netdev_err(dev->net, "Error allocating URB in"
1910                            " %s!\n", __func__);
1911                 goto fail;
1912         }
1913
1914         if (data) {
1915                 buf = kmemdup(data, size, GFP_ATOMIC);
1916                 if (!buf) {
1917                         netdev_err(dev->net, "Error allocating buffer"
1918                                    " in %s!\n", __func__);
1919                         goto fail_free;
1920                 }
1921         }
1922
1923         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
1924         if (!req)
1925                 goto fail_free_buf;
1926
1927         req->bRequestType = reqtype;
1928         req->bRequest = cmd;
1929         req->wValue = cpu_to_le16(value);
1930         req->wIndex = cpu_to_le16(index);
1931         req->wLength = cpu_to_le16(size);
1932
1933         usb_fill_control_urb(urb, dev->udev,
1934                              usb_sndctrlpipe(dev->udev, 0),
1935                              (void *)req, buf, size,
1936                              usbnet_async_cmd_cb, req);
1937         urb->transfer_flags |= URB_FREE_BUFFER;
1938
1939         err = usb_submit_urb(urb, GFP_ATOMIC);
1940         if (err < 0) {
1941                 netdev_err(dev->net, "Error submitting the control"
1942                            " message: status=%d\n", err);
1943                 goto fail_free;
1944         }
1945         return 0;
1946
1947 fail_free_buf:
1948         kfree(buf);
1949 fail_free:
1950         kfree(req);
1951         usb_free_urb(urb);
1952 fail:
1953         return err;
1954
1955 }
1956 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
1957 /*-------------------------------------------------------------------------*/
1958
1959 static int __init usbnet_init(void)
1960 {
1961         /* Compiler should optimize this out. */
1962         BUILD_BUG_ON(
1963                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
1964
1965         eth_random_addr(node_id);
1966         return 0;
1967 }
1968 module_init(usbnet_init);
1969
1970 static void __exit usbnet_exit(void)
1971 {
1972 }
1973 module_exit(usbnet_exit);
1974
1975 MODULE_AUTHOR("David Brownell");
1976 MODULE_DESCRIPTION("USB network driver framework");
1977 MODULE_LICENSE("GPL");