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  * The goal is to let the USB host controller be busy for 5msec or
  63  * more before an irq is required, under load.  Jumbograms change
  64  * the equation.
  65  */
  66 #define MAX_QUEUE_MEMORY        (60 * 1518)
  67 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  68 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  69
  70 // reawaken network queue this soon after stopping; else watchdog barks
  71 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  72
  73 // throttle rx/tx briefly after some faults, so khubd might disconnect()
  74 // us (it polls at HZ/4 usually) before we report too many false errors.
  75 #define THROTTLE_JIFFIES        (HZ/8)
  76
  77 // between wakeups
  78 #define UNLINK_TIMEOUT_MS       3
  79
  80 /*-------------------------------------------------------------------------*/
  81
  82 // randomly generated ethernet address
  83 static u8       node_id [ETH_ALEN];
  84
  85 static const char driver_name [] = "usbnet";
  86
  87 /* use ethtool to change the level for any given device */
  88 static int msg_level = -1;
  89 module_param (msg_level, int, 0);
  90 MODULE_PARM_DESC (msg_level, "Override default message level");
  91
  92 /*-------------------------------------------------------------------------*/
  93
  94 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  95 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  96 {
  97         int                             tmp;
  98         struct usb_host_interface       *alt = NULL;
  99         struct usb_host_endpoint        *in = NULL, *out = NULL;
 100         struct usb_host_endpoint        *status = NULL;
 101
 102         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 103                 unsigned        ep;
 104
 105                 in = out = status = NULL;
 106                 alt = intf->altsetting + tmp;
 107
 108                 /* take the first altsetting with in-bulk + out-bulk;
 109                  * remember any status endpoint, just in case;
 110                  * ignore other endpoints and altsettings.
 111                  */
 112                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 113                         struct usb_host_endpoint        *e;
 114                         int                             intr = 0;
 115
 116                         e = alt->endpoint + ep;
 117                         switch (e->desc.bmAttributes) {
 118                         case USB_ENDPOINT_XFER_INT:
 119                                 if (!usb_endpoint_dir_in(&e->desc))
 120                                         continue;
 121                                 intr = 1;
 122                                 /* FALLTHROUGH */
 123                         case USB_ENDPOINT_XFER_BULK:
 124                                 break;
 125                         default:
 126                                 continue;
 127                         }
 128                         if (usb_endpoint_dir_in(&e->desc)) {
 129                                 if (!intr && !in)
 130                                         in = e;
 131                                 else if (intr && !status)
 132                                         status = e;
 133                         } else {
 134                                 if (!out)
 135                                         out = e;
 136                         }
 137                 }
 138                 if (in && out)
 139                         break;
 140         }
 141         if (!alt || !in || !out)
 142                 return -EINVAL;
 143
 144         if (alt->desc.bAlternateSetting != 0 ||
 145             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 146                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 147                                 alt->desc.bAlternateSetting);
 148                 if (tmp < 0)
 149                         return tmp;
 150         }
 151
 152         dev->in = usb_rcvbulkpipe (dev->udev,
 153                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 154         dev->out = usb_sndbulkpipe (dev->udev,
 155                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156         dev->status = status;
 157         return 0;
 158 }
 159 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 160
 161 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 162 {
 163         int             tmp, i;
 164         unsigned char   buf [13];
 165
 166         tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 167         if (tmp != 12) {
 168                 dev_dbg(&dev->udev->dev,
 169                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 170                 if (tmp >= 0)
 171                         tmp = -EINVAL;
 172                 return tmp;
 173         }
 174         for (i = tmp = 0; i < 6; i++, tmp += 2)
 175                 dev->net->dev_addr [i] =
 176                         (hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 177         return 0;
 178 }
 179 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 180
 181 static void intr_complete (struct urb *urb)
 182 {
 183         struct usbnet   *dev = urb->context;
 184         int             status = urb->status;
 185
 186         switch (status) {
 187         /* success */
 188         case 0:
 189                 dev->driver_info->status(dev, urb);
 190                 break;
 191
 192         /* software-driven interface shutdown */
 193         case -ENOENT:           /* urb killed */
 194         case -ESHUTDOWN:        /* hardware gone */
 195                 netif_dbg(dev, ifdown, dev->net,
 196                           "intr shutdown, code %d\n", status);
 197                 return;
 198
 199         /* NOTE:  not throttling like RX/TX, since this endpoint
 200          * already polls infrequently
 201          */
 202         default:
 203                 netdev_dbg(dev->net, "intr status %d\n", status);
 204                 break;
 205         }
 206
 207         if (!netif_running (dev->net))
 208                 return;
 209
 210         status = usb_submit_urb (urb, GFP_ATOMIC);
 211         if (status != 0)
 212                 netif_err(dev, timer, dev->net,
 213                           "intr resubmit --> %d\n", status);
 214 }
 215
 216 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 217 {
 218         char            *buf = NULL;
 219         unsigned        pipe = 0;
 220         unsigned        maxp;
 221         unsigned        period;
 222
 223         if (!dev->driver_info->status)
 224                 return 0;
 225
 226         pipe = usb_rcvintpipe (dev->udev,
 227                         dev->status->desc.bEndpointAddress
 228                                 & USB_ENDPOINT_NUMBER_MASK);
 229         maxp = usb_maxpacket (dev->udev, pipe, 0);
 230
 231         /* avoid 1 msec chatter:  min 8 msec poll rate */
 232         period = max ((int) dev->status->desc.bInterval,
 233                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 234
 235         buf = kmalloc (maxp, GFP_KERNEL);
 236         if (buf) {
 237                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 238                 if (!dev->interrupt) {
 239                         kfree (buf);
 240                         return -ENOMEM;
 241                 } else {
 242                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 243                                 buf, maxp, intr_complete, dev, period);
 244                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 245                         dev_dbg(&intf->dev,
 246                                 "status ep%din, %d bytes period %d\n",
 247                                 usb_pipeendpoint(pipe), maxp, period);
 248                 }
 249         }
 250         return 0;
 251 }
 252
 253 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 254 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 255 {
 256         int ret = 0;
 257
 258         WARN_ON_ONCE(dev->interrupt == NULL);
 259         if (dev->interrupt) {
 260                 mutex_lock(&dev->interrupt_mutex);
 261
 262                 if (++dev->interrupt_count == 1)
 263                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 264
 265                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 266                         dev->interrupt_count);
 267                 mutex_unlock(&dev->interrupt_mutex);
 268         }
 269         return ret;
 270 }
 271 EXPORT_SYMBOL_GPL(usbnet_status_start);
 272
 273 /* For resume; submit interrupt URB if previously submitted */
 274 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 275 {
 276         int ret = 0;
 277
 278         mutex_lock(&dev->interrupt_mutex);
 279         if (dev->interrupt_count) {
 280                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 281                 dev_dbg(&dev->udev->dev,
 282                         "submitted interrupt URB for resume\n");
 283         }
 284         mutex_unlock(&dev->interrupt_mutex);
 285         return ret;
 286 }
 287
 288 /* Kill the interrupt URB if all submitters want it killed */
 289 void usbnet_status_stop(struct usbnet *dev)
 290 {
 291         if (dev->interrupt) {
 292                 mutex_lock(&dev->interrupt_mutex);
 293                 WARN_ON(dev->interrupt_count == 0);
 294
 295                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 296                         usb_kill_urb(dev->interrupt);
 297
 298                 dev_dbg(&dev->udev->dev,
 299                         "decremented interrupt URB count to %d\n",
 300                         dev->interrupt_count);
 301                 mutex_unlock(&dev->interrupt_mutex);
 302         }
 303 }
 304 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 305
 306 /* For suspend; always kill interrupt URB */
 307 static void __usbnet_status_stop_force(struct usbnet *dev)
 308 {
 309         if (dev->interrupt) {
 310                 mutex_lock(&dev->interrupt_mutex);
 311                 usb_kill_urb(dev->interrupt);
 312                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 313                 mutex_unlock(&dev->interrupt_mutex);
 314         }
 315 }
 316
 317 /* Passes this packet up the stack, updating its accounting.
 318  * Some link protocols batch packets, so their rx_fixup paths
 319  * can return clones as well as just modify the original skb.
 320  */
 321 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 322 {
 323         int     status;
 324
 325         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 326                 skb_queue_tail(&dev->rxq_pause, skb);
 327                 return;
 328         }
 329
 330         skb->protocol = eth_type_trans (skb, dev->net);
 331         dev->net->stats.rx_packets++;
 332         dev->net->stats.rx_bytes += skb->len;
 333
 334         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 335                   skb->len + sizeof (struct ethhdr), skb->protocol);
 336         memset (skb->cb, 0, sizeof (struct skb_data));
 337
 338         if (skb_defer_rx_timestamp(skb))
 339                 return;
 340
 341         status = netif_rx (skb);
 342         if (status != NET_RX_SUCCESS)
 343                 netif_dbg(dev, rx_err, dev->net,
 344                           "netif_rx status %d\n", status);
 345 }
 346 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 347
 348 /* must be called if hard_mtu or rx_urb_size changed */
 349 void usbnet_update_max_qlen(struct usbnet *dev)
 350 {
 351         enum usb_device_speed speed = dev->udev->speed;
 352
 353         switch (speed) {
 354         case USB_SPEED_HIGH:
 355                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 356                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 357                 break;
 358         default:
 359                 dev->rx_qlen = dev->tx_qlen = 4;
 360         }
 361 }
 362 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 363
 364 \f
 365 /*-------------------------------------------------------------------------
 366  *
 367  * Network Device Driver (peer link to "Host Device", from USB host)
 368  *
 369  *-------------------------------------------------------------------------*/
 370
 371 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 372 {
 373         struct usbnet   *dev = netdev_priv(net);
 374         int             ll_mtu = new_mtu + net->hard_header_len;
 375         int             old_hard_mtu = dev->hard_mtu;
 376         int             old_rx_urb_size = dev->rx_urb_size;
 377
 378         if (new_mtu <= 0)
 379                 return -EINVAL;
 380         // no second zero-length packet read wanted after mtu-sized packets
 381         if ((ll_mtu % dev->maxpacket) == 0)
 382                 return -EDOM;
 383         net->mtu = new_mtu;
 384
 385         dev->hard_mtu = net->mtu + net->hard_header_len;
 386         if (dev->rx_urb_size == old_hard_mtu) {
 387                 dev->rx_urb_size = dev->hard_mtu;
 388                 if (dev->rx_urb_size > old_rx_urb_size)
 389                         usbnet_unlink_rx_urbs(dev);
 390         }
 391
 392         /* max qlen depend on hard_mtu and rx_urb_size */
 393         usbnet_update_max_qlen(dev);
 394
 395         return 0;
 396 }
 397 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 398
 399 /* The caller must hold list->lock */
 400 static void __usbnet_queue_skb(struct sk_buff_head *list,
 401                         struct sk_buff *newsk, enum skb_state state)
 402 {
 403         struct skb_data *entry = (struct skb_data *) newsk->cb;
 404
 405         __skb_queue_tail(list, newsk);
 406         entry->state = state;
 407 }
 408
 409 /*-------------------------------------------------------------------------*/
 410
 411 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 412  * completion callbacks.  2.5 should have fixed those bugs...
 413  */
 414
 415 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 416                 struct sk_buff_head *list, enum skb_state state)
 417 {
 418         unsigned long           flags;
 419         enum skb_state          old_state;
 420         struct skb_data *entry = (struct skb_data *) skb->cb;
 421
 422         spin_lock_irqsave(&list->lock, flags);
 423         old_state = entry->state;
 424         entry->state = state;
 425         __skb_unlink(skb, list);
 426         spin_unlock(&list->lock);
 427         spin_lock(&dev->done.lock);
 428         __skb_queue_tail(&dev->done, skb);
 429         if (dev->done.qlen == 1)
 430                 tasklet_schedule(&dev->bh);
 431         spin_unlock_irqrestore(&dev->done.lock, flags);
 432         return old_state;
 433 }
 434
 435 /* some work can't be done in tasklets, so we use keventd
 436  *
 437  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 438  * but tasklet_schedule() doesn't.  hope the failure is rare.
 439  */
 440 void usbnet_defer_kevent (struct usbnet *dev, int work)
 441 {
 442         set_bit (work, &dev->flags);
 443         if (!schedule_work (&dev->kevent)) {
 444                 if (net_ratelimit())
 445                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 446         } else {
 447                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 448         }
 449 }
 450 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 451
 452 /*-------------------------------------------------------------------------*/
 453
 454 static void rx_complete (struct urb *urb);
 455
 456 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 457 {
 458         struct sk_buff          *skb;
 459         struct skb_data         *entry;
 460         int                     retval = 0;
 461         unsigned long           lockflags;
 462         size_t                  size = dev->rx_urb_size;
 463
 464         /* prevent rx skb allocation when error ratio is high */
 465         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 466                 usb_free_urb(urb);
 467                 return -ENOLINK;
 468         }
 469
 470         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 471         if (!skb) {
 472                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 473                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 474                 usb_free_urb (urb);
 475                 return -ENOMEM;
 476         }
 477
 478         entry = (struct skb_data *) skb->cb;
 479         entry->urb = urb;
 480         entry->dev = dev;
 481         entry->length = 0;
 482
 483         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 484                 skb->data, size, rx_complete, skb);
 485
 486         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 487
 488         if (netif_running (dev->net) &&
 489             netif_device_present (dev->net) &&
 490             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 491             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 492                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 493                 case -EPIPE:
 494                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 495                         break;
 496                 case -ENOMEM:
 497                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 498                         break;
 499                 case -ENODEV:
 500                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 501                         netif_device_detach (dev->net);
 502                         break;
 503                 case -EHOSTUNREACH:
 504                         retval = -ENOLINK;
 505                         break;
 506                 default:
 507                         netif_dbg(dev, rx_err, dev->net,
 508                                   "rx submit, %d\n", retval);
 509                         tasklet_schedule (&dev->bh);
 510                         break;
 511                 case 0:
 512                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 513                 }
 514         } else {
 515                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 516                 retval = -ENOLINK;
 517         }
 518         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 519         if (retval) {
 520                 dev_kfree_skb_any (skb);
 521                 usb_free_urb (urb);
 522         }
 523         return retval;
 524 }
 525
 526
 527 /*-------------------------------------------------------------------------*/
 528
 529 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 530 {
 531         if (dev->driver_info->rx_fixup &&
 532             !dev->driver_info->rx_fixup (dev, skb)) {
 533                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 534                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 535                         dev->net->stats.rx_errors++;
 536                 goto done;
 537         }
 538         // else network stack removes extra byte if we forced a short packet
 539
 540         if (skb->len) {
 541                 /* all data was already cloned from skb inside the driver */
 542                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 543                         dev_kfree_skb_any(skb);
 544                 else
 545                         usbnet_skb_return(dev, skb);
 546                 return;
 547         }
 548
 549         netif_dbg(dev, rx_err, dev->net, "drop\n");
 550         dev->net->stats.rx_errors++;
 551 done:
 552         skb_queue_tail(&dev->done, skb);
 553 }
 554
 555 /*-------------------------------------------------------------------------*/
 556
 557 static void rx_complete (struct urb *urb)
 558 {
 559         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 560         struct skb_data         *entry = (struct skb_data *) skb->cb;
 561         struct usbnet           *dev = entry->dev;
 562         int                     urb_status = urb->status;
 563         enum skb_state          state;
 564
 565         skb_put (skb, urb->actual_length);
 566         state = rx_done;
 567         entry->urb = NULL;
 568
 569         switch (urb_status) {
 570         /* success */
 571         case 0:
 572                 if (skb->len < dev->net->hard_header_len) {
 573                         state = rx_cleanup;
 574                         dev->net->stats.rx_errors++;
 575                         dev->net->stats.rx_length_errors++;
 576                         netif_dbg(dev, rx_err, dev->net,
 577                                   "rx length %d\n", skb->len);
 578                 }
 579                 break;
 580
 581         /* stalls need manual reset. this is rare ... except that
 582          * when going through USB 2.0 TTs, unplug appears this way.
 583          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 584          * storm, recovering as needed.
 585          */
 586         case -EPIPE:
 587                 dev->net->stats.rx_errors++;
 588                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 589                 // FALLTHROUGH
 590
 591         /* software-driven interface shutdown */
 592         case -ECONNRESET:               /* async unlink */
 593         case -ESHUTDOWN:                /* hardware gone */
 594                 netif_dbg(dev, ifdown, dev->net,
 595                           "rx shutdown, code %d\n", urb_status);
 596                 goto block;
 597
 598         /* we get controller i/o faults during khubd disconnect() delays.
 599          * throttle down resubmits, to avoid log floods; just temporarily,
 600          * so we still recover when the fault isn't a khubd delay.
 601          */
 602         case -EPROTO:
 603         case -ETIME:
 604         case -EILSEQ:
 605                 dev->net->stats.rx_errors++;
 606                 if (!timer_pending (&dev->delay)) {
 607                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 608                         netif_dbg(dev, link, dev->net,
 609                                   "rx throttle %d\n", urb_status);
 610                 }
 611 block:
 612                 state = rx_cleanup;
 613                 entry->urb = urb;
 614                 urb = NULL;
 615                 break;
 616
 617         /* data overrun ... flush fifo? */
 618         case -EOVERFLOW:
 619                 dev->net->stats.rx_over_errors++;
 620                 // FALLTHROUGH
 621
 622         default:
 623                 state = rx_cleanup;
 624                 dev->net->stats.rx_errors++;
 625                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 626                 break;
 627         }
 628
 629         /* stop rx if packet error rate is high */
 630         if (++dev->pkt_cnt > 30) {
 631                 dev->pkt_cnt = 0;
 632                 dev->pkt_err = 0;
 633         } else {
 634                 if (state == rx_cleanup)
 635                         dev->pkt_err++;
 636                 if (dev->pkt_err > 20)
 637                         set_bit(EVENT_RX_KILL, &dev->flags);
 638         }
 639
 640         state = defer_bh(dev, skb, &dev->rxq, state);
 641
 642         if (urb) {
 643                 if (netif_running (dev->net) &&
 644                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 645                     state != unlink_start) {
 646                         rx_submit (dev, urb, GFP_ATOMIC);
 647                         usb_mark_last_busy(dev->udev);
 648                         return;
 649                 }
 650                 usb_free_urb (urb);
 651         }
 652         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 653 }
 654
 655 /*-------------------------------------------------------------------------*/
 656 void usbnet_pause_rx(struct usbnet *dev)
 657 {
 658         set_bit(EVENT_RX_PAUSED, &dev->flags);
 659
 660         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 661 }
 662 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 663
 664 void usbnet_resume_rx(struct usbnet *dev)
 665 {
 666         struct sk_buff *skb;
 667         int num = 0;
 668
 669         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 670
 671         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 672                 usbnet_skb_return(dev, skb);
 673                 num++;
 674         }
 675
 676         tasklet_schedule(&dev->bh);
 677
 678         netif_dbg(dev, rx_status, dev->net,
 679                   "paused rx queue disabled, %d skbs requeued\n", num);
 680 }
 681 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 682
 683 void usbnet_purge_paused_rxq(struct usbnet *dev)
 684 {
 685         skb_queue_purge(&dev->rxq_pause);
 686 }
 687 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 688
 689 /*-------------------------------------------------------------------------*/
 690
 691 // unlink pending rx/tx; completion handlers do all other cleanup
 692
 693 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 694 {
 695         unsigned long           flags;
 696         struct sk_buff          *skb;
 697         int                     count = 0;
 698
 699         spin_lock_irqsave (&q->lock, flags);
 700         while (!skb_queue_empty(q)) {
 701                 struct skb_data         *entry;
 702                 struct urb              *urb;
 703                 int                     retval;
 704
 705                 skb_queue_walk(q, skb) {
 706                         entry = (struct skb_data *) skb->cb;
 707                         if (entry->state != unlink_start)
 708                                 goto found;
 709                 }
 710                 break;
 711 found:
 712                 entry->state = unlink_start;
 713                 urb = entry->urb;
 714
 715                 /*
 716                  * Get reference count of the URB to avoid it to be
 717                  * freed during usb_unlink_urb, which may trigger
 718                  * use-after-free problem inside usb_unlink_urb since
 719                  * usb_unlink_urb is always racing with .complete
 720                  * handler(include defer_bh).
 721                  */
 722                 usb_get_urb(urb);
 723                 spin_unlock_irqrestore(&q->lock, flags);
 724                 // during some PM-driven resume scenarios,
 725                 // these (async) unlinks complete immediately
 726                 retval = usb_unlink_urb (urb);
 727                 if (retval != -EINPROGRESS && retval != 0)
 728                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 729                 else
 730                         count++;
 731                 usb_put_urb(urb);
 732                 spin_lock_irqsave(&q->lock, flags);
 733         }
 734         spin_unlock_irqrestore (&q->lock, flags);
 735         return count;
 736 }
 737
 738 // Flush all pending rx urbs
 739 // minidrivers may need to do this when the MTU changes
 740
 741 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 742 {
 743         if (netif_running(dev->net)) {
 744                 (void) unlink_urbs (dev, &dev->rxq);
 745                 tasklet_schedule(&dev->bh);
 746         }
 747 }
 748 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 749
 750 /*-------------------------------------------------------------------------*/
 751
 752 // precondition: never called in_interrupt
 753 static void usbnet_terminate_urbs(struct usbnet *dev)
 754 {
 755         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 756         DECLARE_WAITQUEUE(wait, current);
 757         int temp;
 758
 759         /* ensure there are no more active urbs */
 760         add_wait_queue(&unlink_wakeup, &wait);
 761         set_current_state(TASK_UNINTERRUPTIBLE);
 762         dev->wait = &unlink_wakeup;
 763         temp = unlink_urbs(dev, &dev->txq) +
 764                 unlink_urbs(dev, &dev->rxq);
 765
 766         /* maybe wait for deletions to finish. */
 767         while (!skb_queue_empty(&dev->rxq)
 768                 && !skb_queue_empty(&dev->txq)
 769                 && !skb_queue_empty(&dev->done)) {
 770                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 771                         set_current_state(TASK_UNINTERRUPTIBLE);
 772                         netif_dbg(dev, ifdown, dev->net,
 773                                   "waited for %d urb completions\n", temp);
 774         }
 775         set_current_state(TASK_RUNNING);
 776         dev->wait = NULL;
 777         remove_wait_queue(&unlink_wakeup, &wait);
 778 }
 779
 780 int usbnet_stop (struct net_device *net)
 781 {
 782         struct usbnet           *dev = netdev_priv(net);
 783         struct driver_info      *info = dev->driver_info;
 784         int                     retval;
 785
 786         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 787         netif_stop_queue (net);
 788
 789         netif_info(dev, ifdown, dev->net,
 790                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 791                    net->stats.rx_packets, net->stats.tx_packets,
 792                    net->stats.rx_errors, net->stats.tx_errors);
 793
 794         /* allow minidriver to stop correctly (wireless devices to turn off
 795          * radio etc) */
 796         if (info->stop) {
 797                 retval = info->stop(dev);
 798                 if (retval < 0)
 799                         netif_info(dev, ifdown, dev->net,
 800                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 801                                    retval,
 802                                    dev->udev->bus->bus_name, dev->udev->devpath,
 803                                    info->description);
 804         }
 805
 806         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 807                 usbnet_terminate_urbs(dev);
 808
 809         usbnet_status_stop(dev);
 810
 811         usbnet_purge_paused_rxq(dev);
 812
 813         /* deferred work (task, timer, softirq) must also stop.
 814          * can't flush_scheduled_work() until we drop rtnl (later),
 815          * else workers could deadlock; so make workers a NOP.
 816          */
 817         dev->flags = 0;
 818         del_timer_sync (&dev->delay);
 819         tasklet_kill (&dev->bh);
 820         if (info->manage_power &&
 821             !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
 822                 info->manage_power(dev, 0);
 823         else
 824                 usb_autopm_put_interface(dev->intf);
 825
 826         return 0;
 827 }
 828 EXPORT_SYMBOL_GPL(usbnet_stop);
 829
 830 /*-------------------------------------------------------------------------*/
 831
 832 // posts reads, and enables write queuing
 833
 834 // precondition: never called in_interrupt
 835
 836 int usbnet_open (struct net_device *net)
 837 {
 838         struct usbnet           *dev = netdev_priv(net);
 839         int                     retval;
 840         struct driver_info      *info = dev->driver_info;
 841
 842         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 843                 netif_info(dev, ifup, dev->net,
 844                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 845                            retval,
 846                            dev->udev->bus->bus_name,
 847                            dev->udev->devpath,
 848                            info->description);
 849                 goto done_nopm;
 850         }
 851
 852         // put into "known safe" state
 853         if (info->reset && (retval = info->reset (dev)) < 0) {
 854                 netif_info(dev, ifup, dev->net,
 855                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 856                            retval,
 857                            dev->udev->bus->bus_name,
 858                            dev->udev->devpath,
 859                            info->description);
 860                 goto done;
 861         }
 862
 863         /* hard_mtu or rx_urb_size may change in reset() */
 864         usbnet_update_max_qlen(dev);
 865
 866         // insist peer be connected
 867         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 868                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 869                 goto done;
 870         }
 871
 872         /* start any status interrupt transfer */
 873         if (dev->interrupt) {
 874                 retval = usbnet_status_start(dev, GFP_KERNEL);
 875                 if (retval < 0) {
 876                         netif_err(dev, ifup, dev->net,
 877                                   "intr submit %d\n", retval);
 878                         goto done;
 879                 }
 880         }
 881
 882         set_bit(EVENT_DEV_OPEN, &dev->flags);
 883         netif_start_queue (net);
 884         netif_info(dev, ifup, dev->net,
 885                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 886                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 887                    dev->net->mtu,
 888                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 889                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 890                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 891                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 892                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 893                    "simple");
 894
 895         /* reset rx error state */
 896         dev->pkt_cnt = 0;
 897         dev->pkt_err = 0;
 898         clear_bit(EVENT_RX_KILL, &dev->flags);
 899
 900         // delay posting reads until we're fully open
 901         tasklet_schedule (&dev->bh);
 902         if (info->manage_power) {
 903                 retval = info->manage_power(dev, 1);
 904                 if (retval < 0) {
 905                         retval = 0;
 906                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 907                 } else {
 908                         usb_autopm_put_interface(dev->intf);
 909                 }
 910         }
 911         return retval;
 912 done:
 913         usb_autopm_put_interface(dev->intf);
 914 done_nopm:
 915         return retval;
 916 }
 917 EXPORT_SYMBOL_GPL(usbnet_open);
 918
 919 /*-------------------------------------------------------------------------*/
 920
 921 /* ethtool methods; minidrivers may need to add some more, but
 922  * they'll probably want to use this base set.
 923  */
 924
 925 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 926 {
 927         struct usbnet *dev = netdev_priv(net);
 928
 929         if (!dev->mii.mdio_read)
 930                 return -EOPNOTSUPP;
 931
 932         return mii_ethtool_gset(&dev->mii, cmd);
 933 }
 934 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 935
 936 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 937 {
 938         struct usbnet *dev = netdev_priv(net);
 939         int retval;
 940
 941         if (!dev->mii.mdio_write)
 942                 return -EOPNOTSUPP;
 943
 944         retval = mii_ethtool_sset(&dev->mii, cmd);
 945
 946         /* link speed/duplex might have changed */
 947         if (dev->driver_info->link_reset)
 948                 dev->driver_info->link_reset(dev);
 949
 950         /* hard_mtu or rx_urb_size may change in link_reset() */
 951         usbnet_update_max_qlen(dev);
 952
 953         return retval;
 954
 955 }
 956 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 957
 958 u32 usbnet_get_link (struct net_device *net)
 959 {
 960         struct usbnet *dev = netdev_priv(net);
 961
 962         /* If a check_connect is defined, return its result */
 963         if (dev->driver_info->check_connect)
 964                 return dev->driver_info->check_connect (dev) == 0;
 965
 966         /* if the device has mii operations, use those */
 967         if (dev->mii.mdio_read)
 968                 return mii_link_ok(&dev->mii);
 969
 970         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 971         return ethtool_op_get_link(net);
 972 }
 973 EXPORT_SYMBOL_GPL(usbnet_get_link);
 974
 975 int usbnet_nway_reset(struct net_device *net)
 976 {
 977         struct usbnet *dev = netdev_priv(net);
 978
 979         if (!dev->mii.mdio_write)
 980                 return -EOPNOTSUPP;
 981
 982         return mii_nway_restart(&dev->mii);
 983 }
 984 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 985
 986 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 987 {
 988         struct usbnet *dev = netdev_priv(net);
 989
 990         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 991         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 992         strlcpy (info->fw_version, dev->driver_info->description,
 993                 sizeof info->fw_version);
 994         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 995 }
 996 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 997
 998 u32 usbnet_get_msglevel (struct net_device *net)
 999 {
1000         struct usbnet *dev = netdev_priv(net);
1001
1002         return dev->msg_enable;
1003 }
1004 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1005
1006 void usbnet_set_msglevel (struct net_device *net, u32 level)
1007 {
1008         struct usbnet *dev = netdev_priv(net);
1009
1010         dev->msg_enable = level;
1011 }
1012 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1013
1014 /* drivers may override default ethtool_ops in their bind() routine */
1015 static const struct ethtool_ops usbnet_ethtool_ops = {
1016         .get_settings           = usbnet_get_settings,
1017         .set_settings           = usbnet_set_settings,
1018         .get_link               = usbnet_get_link,
1019         .nway_reset             = usbnet_nway_reset,
1020         .get_drvinfo            = usbnet_get_drvinfo,
1021         .get_msglevel           = usbnet_get_msglevel,
1022         .set_msglevel           = usbnet_set_msglevel,
1023         .get_ts_info            = ethtool_op_get_ts_info,
1024 };
1025
1026 /*-------------------------------------------------------------------------*/
1027
1028 static void __handle_link_change(struct usbnet *dev)
1029 {
1030         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1031                 return;
1032
1033         if (!netif_carrier_ok(dev->net)) {
1034                 /* kill URBs for reading packets to save bus bandwidth */
1035                 unlink_urbs(dev, &dev->rxq);
1036
1037                 /*
1038                  * tx_timeout will unlink URBs for sending packets and
1039                  * tx queue is stopped by netcore after link becomes off
1040                  */
1041         } else {
1042                 /* submitting URBs for reading packets */
1043                 tasklet_schedule(&dev->bh);
1044         }
1045
1046         /* hard_mtu or rx_urb_size may change during link change */
1047         usbnet_update_max_qlen(dev);
1048
1049         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1050 }
1051
1052 /* work that cannot be done in interrupt context uses keventd.
1053  *
1054  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1055  * especially now that control transfers can be queued.
1056  */
1057 static void
1058 kevent (struct work_struct *work)
1059 {
1060         struct usbnet           *dev =
1061                 container_of(work, struct usbnet, kevent);
1062         int                     status;
1063
1064         /* usb_clear_halt() needs a thread context */
1065         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1066                 unlink_urbs (dev, &dev->txq);
1067                 status = usb_autopm_get_interface(dev->intf);
1068                 if (status < 0)
1069                         goto fail_pipe;
1070                 status = usb_clear_halt (dev->udev, dev->out);
1071                 usb_autopm_put_interface(dev->intf);
1072                 if (status < 0 &&
1073                     status != -EPIPE &&
1074                     status != -ESHUTDOWN) {
1075                         if (netif_msg_tx_err (dev))
1076 fail_pipe:
1077                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1078                                            status);
1079                 } else {
1080                         clear_bit (EVENT_TX_HALT, &dev->flags);
1081                         if (status != -ESHUTDOWN)
1082                                 netif_wake_queue (dev->net);
1083                 }
1084         }
1085         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1086                 unlink_urbs (dev, &dev->rxq);
1087                 status = usb_autopm_get_interface(dev->intf);
1088                 if (status < 0)
1089                         goto fail_halt;
1090                 status = usb_clear_halt (dev->udev, dev->in);
1091                 usb_autopm_put_interface(dev->intf);
1092                 if (status < 0 &&
1093                     status != -EPIPE &&
1094                     status != -ESHUTDOWN) {
1095                         if (netif_msg_rx_err (dev))
1096 fail_halt:
1097                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1098                                            status);
1099                 } else {
1100                         clear_bit (EVENT_RX_HALT, &dev->flags);
1101                         tasklet_schedule (&dev->bh);
1102                 }
1103         }
1104
1105         /* tasklet could resubmit itself forever if memory is tight */
1106         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1107                 struct urb      *urb = NULL;
1108                 int resched = 1;
1109
1110                 if (netif_running (dev->net))
1111                         urb = usb_alloc_urb (0, GFP_KERNEL);
1112                 else
1113                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1114                 if (urb != NULL) {
1115                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1116                         status = usb_autopm_get_interface(dev->intf);
1117                         if (status < 0) {
1118                                 usb_free_urb(urb);
1119                                 goto fail_lowmem;
1120                         }
1121                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1122                                 resched = 0;
1123                         usb_autopm_put_interface(dev->intf);
1124 fail_lowmem:
1125                         if (resched)
1126                                 tasklet_schedule (&dev->bh);
1127                 }
1128         }
1129
1130         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1131                 struct driver_info      *info = dev->driver_info;
1132                 int                     retval = 0;
1133
1134                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1135                 status = usb_autopm_get_interface(dev->intf);
1136                 if (status < 0)
1137                         goto skip_reset;
1138                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1139                         usb_autopm_put_interface(dev->intf);
1140 skip_reset:
1141                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1142                                     retval,
1143                                     dev->udev->bus->bus_name,
1144                                     dev->udev->devpath,
1145                                     info->description);
1146                 } else {
1147                         usb_autopm_put_interface(dev->intf);
1148                 }
1149
1150                 /* handle link change from link resetting */
1151                 __handle_link_change(dev);
1152         }
1153
1154         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1155                 __handle_link_change(dev);
1156
1157         if (dev->flags)
1158                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1159 }
1160
1161 /*-------------------------------------------------------------------------*/
1162
1163 static void tx_complete (struct urb *urb)
1164 {
1165         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1166         struct skb_data         *entry = (struct skb_data *) skb->cb;
1167         struct usbnet           *dev = entry->dev;
1168
1169         if (urb->status == 0) {
1170                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1171                         dev->net->stats.tx_packets++;
1172                 dev->net->stats.tx_bytes += entry->length;
1173         } else {
1174                 dev->net->stats.tx_errors++;
1175
1176                 switch (urb->status) {
1177                 case -EPIPE:
1178                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1179                         break;
1180
1181                 /* software-driven interface shutdown */
1182                 case -ECONNRESET:               // async unlink
1183                 case -ESHUTDOWN:                // hardware gone
1184                         break;
1185
1186                 // like rx, tx gets controller i/o faults during khubd delays
1187                 // and so it uses the same throttling mechanism.
1188                 case -EPROTO:
1189                 case -ETIME:
1190                 case -EILSEQ:
1191                         usb_mark_last_busy(dev->udev);
1192                         if (!timer_pending (&dev->delay)) {
1193                                 mod_timer (&dev->delay,
1194                                         jiffies + THROTTLE_JIFFIES);
1195                                 netif_dbg(dev, link, dev->net,
1196                                           "tx throttle %d\n", urb->status);
1197                         }
1198                         netif_stop_queue (dev->net);
1199                         break;
1200                 default:
1201                         netif_dbg(dev, tx_err, dev->net,
1202                                   "tx err %d\n", entry->urb->status);
1203                         break;
1204                 }
1205         }
1206
1207         usb_autopm_put_interface_async(dev->intf);
1208         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1209 }
1210
1211 /*-------------------------------------------------------------------------*/
1212
1213 void usbnet_tx_timeout (struct net_device *net)
1214 {
1215         struct usbnet           *dev = netdev_priv(net);
1216
1217         unlink_urbs (dev, &dev->txq);
1218         tasklet_schedule (&dev->bh);
1219
1220         // FIXME: device recovery -- reset?
1221 }
1222 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1223
1224 /*-------------------------------------------------------------------------*/
1225
1226 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1227                                      struct net_device *net)
1228 {
1229         struct usbnet           *dev = netdev_priv(net);
1230         int                     length;
1231         struct urb              *urb = NULL;
1232         struct skb_data         *entry;
1233         struct driver_info      *info = dev->driver_info;
1234         unsigned long           flags;
1235         int retval;
1236
1237         if (skb)
1238                 skb_tx_timestamp(skb);
1239
1240         // some devices want funky USB-level framing, for
1241         // win32 driver (usually) and/or hardware quirks
1242         if (info->tx_fixup) {
1243                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1244                 if (!skb) {
1245                         /* packet collected; minidriver waiting for more */
1246                         if (info->flags & FLAG_MULTI_PACKET)
1247                                 goto not_drop;
1248                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1249                         goto drop;
1250                 }
1251         }
1252         length = skb->len;
1253
1254         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1255                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1256                 goto drop;
1257         }
1258
1259         entry = (struct skb_data *) skb->cb;
1260         entry->urb = urb;
1261         entry->dev = dev;
1262         entry->length = length;
1263
1264         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1265                         skb->data, skb->len, tx_complete, skb);
1266
1267         /* don't assume the hardware handles USB_ZERO_PACKET
1268          * NOTE:  strictly conforming cdc-ether devices should expect
1269          * the ZLP here, but ignore the one-byte packet.
1270          * NOTE2: CDC NCM specification is different from CDC ECM when
1271          * handling ZLP/short packets, so cdc_ncm driver will make short
1272          * packet itself if needed.
1273          */
1274         if (length % dev->maxpacket == 0) {
1275                 if (!(info->flags & FLAG_SEND_ZLP)) {
1276                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1277                                 urb->transfer_buffer_length++;
1278                                 if (skb_tailroom(skb)) {
1279                                         skb->data[skb->len] = 0;
1280                                         __skb_put(skb, 1);
1281                                 }
1282                         }
1283                 } else
1284                         urb->transfer_flags |= URB_ZERO_PACKET;
1285         }
1286
1287         spin_lock_irqsave(&dev->txq.lock, flags);
1288         retval = usb_autopm_get_interface_async(dev->intf);
1289         if (retval < 0) {
1290                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1291                 goto drop;
1292         }
1293
1294 #ifdef CONFIG_PM
1295         /* if this triggers the device is still a sleep */
1296         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1297                 /* transmission will be done in resume */
1298                 usb_anchor_urb(urb, &dev->deferred);
1299                 /* no use to process more packets */
1300                 netif_stop_queue(net);
1301                 usb_put_urb(urb);
1302                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1303                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1304                 goto deferred;
1305         }
1306 #endif
1307
1308         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1309         case -EPIPE:
1310                 netif_stop_queue (net);
1311                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1312                 usb_autopm_put_interface_async(dev->intf);
1313                 break;
1314         default:
1315                 usb_autopm_put_interface_async(dev->intf);
1316                 netif_dbg(dev, tx_err, dev->net,
1317                           "tx: submit urb err %d\n", retval);
1318                 break;
1319         case 0:
1320                 net->trans_start = jiffies;
1321                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1322                 if (dev->txq.qlen >= TX_QLEN (dev))
1323                         netif_stop_queue (net);
1324         }
1325         spin_unlock_irqrestore (&dev->txq.lock, flags);
1326
1327         if (retval) {
1328                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1329 drop:
1330                 dev->net->stats.tx_dropped++;
1331 not_drop:
1332                 if (skb)
1333                         dev_kfree_skb_any (skb);
1334                 usb_free_urb (urb);
1335         } else
1336                 netif_dbg(dev, tx_queued, dev->net,
1337                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1338 #ifdef CONFIG_PM
1339 deferred:
1340 #endif
1341         return NETDEV_TX_OK;
1342 }
1343 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1344
1345 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1346 {
1347         struct urb      *urb;
1348         int             i;
1349         int             ret = 0;
1350
1351         /* don't refill the queue all at once */
1352         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1353                 urb = usb_alloc_urb(0, flags);
1354                 if (urb != NULL) {
1355                         ret = rx_submit(dev, urb, flags);
1356                         if (ret)
1357                                 goto err;
1358                 } else {
1359                         ret = -ENOMEM;
1360                         goto err;
1361                 }
1362         }
1363 err:
1364         return ret;
1365 }
1366
1367 /*-------------------------------------------------------------------------*/
1368
1369 // tasklet (work deferred from completions, in_irq) or timer
1370
1371 static void usbnet_bh (unsigned long param)
1372 {
1373         struct usbnet           *dev = (struct usbnet *) param;
1374         struct sk_buff          *skb;
1375         struct skb_data         *entry;
1376
1377         while ((skb = skb_dequeue (&dev->done))) {
1378                 entry = (struct skb_data *) skb->cb;
1379                 switch (entry->state) {
1380                 case rx_done:
1381                         entry->state = rx_cleanup;
1382                         rx_process (dev, skb);
1383                         continue;
1384                 case tx_done:
1385                 case rx_cleanup:
1386                         usb_free_urb (entry->urb);
1387                         dev_kfree_skb (skb);
1388                         continue;
1389                 default:
1390                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1391                 }
1392         }
1393
1394         /* restart RX again after disabling due to high error rate */
1395         clear_bit(EVENT_RX_KILL, &dev->flags);
1396
1397         // waiting for all pending urbs to complete?
1398         if (dev->wait) {
1399                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1400                         wake_up (dev->wait);
1401                 }
1402
1403         // or are we maybe short a few urbs?
1404         } else if (netif_running (dev->net) &&
1405                    netif_device_present (dev->net) &&
1406                    netif_carrier_ok(dev->net) &&
1407                    !timer_pending (&dev->delay) &&
1408                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1409                 int     temp = dev->rxq.qlen;
1410
1411                 if (temp < RX_QLEN(dev)) {
1412                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1413                                 return;
1414                         if (temp != dev->rxq.qlen)
1415                                 netif_dbg(dev, link, dev->net,
1416                                           "rxqlen %d --> %d\n",
1417                                           temp, dev->rxq.qlen);
1418                         if (dev->rxq.qlen < RX_QLEN(dev))
1419                                 tasklet_schedule (&dev->bh);
1420                 }
1421                 if (dev->txq.qlen < TX_QLEN (dev))
1422                         netif_wake_queue (dev->net);
1423         }
1424 }
1425
1426
1427 /*-------------------------------------------------------------------------
1428  *
1429  * USB Device Driver support
1430  *
1431  *-------------------------------------------------------------------------*/
1432
1433 // precondition: never called in_interrupt
1434
1435 void usbnet_disconnect (struct usb_interface *intf)
1436 {
1437         struct usbnet           *dev;
1438         struct usb_device       *xdev;
1439         struct net_device       *net;
1440
1441         dev = usb_get_intfdata(intf);
1442         usb_set_intfdata(intf, NULL);
1443         if (!dev)
1444                 return;
1445
1446         xdev = interface_to_usbdev (intf);
1447
1448         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1449                    intf->dev.driver->name,
1450                    xdev->bus->bus_name, xdev->devpath,
1451                    dev->driver_info->description);
1452
1453         net = dev->net;
1454         unregister_netdev (net);
1455
1456         cancel_work_sync(&dev->kevent);
1457
1458         usb_scuttle_anchored_urbs(&dev->deferred);
1459
1460         if (dev->driver_info->unbind)
1461                 dev->driver_info->unbind (dev, intf);
1462
1463         usb_kill_urb(dev->interrupt);
1464         usb_free_urb(dev->interrupt);
1465
1466         free_netdev(net);
1467 }
1468 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1469
1470 static const struct net_device_ops usbnet_netdev_ops = {
1471         .ndo_open               = usbnet_open,
1472         .ndo_stop               = usbnet_stop,
1473         .ndo_start_xmit         = usbnet_start_xmit,
1474         .ndo_tx_timeout         = usbnet_tx_timeout,
1475         .ndo_change_mtu         = usbnet_change_mtu,
1476         .ndo_set_mac_address    = eth_mac_addr,
1477         .ndo_validate_addr      = eth_validate_addr,
1478 };
1479
1480 /*-------------------------------------------------------------------------*/
1481
1482 // precondition: never called in_interrupt
1483
1484 static struct device_type wlan_type = {
1485         .name   = "wlan",
1486 };
1487
1488 static struct device_type wwan_type = {
1489         .name   = "wwan",
1490 };
1491
1492 int
1493 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1494 {
1495         struct usbnet                   *dev;
1496         struct net_device               *net;
1497         struct usb_host_interface       *interface;
1498         struct driver_info              *info;
1499         struct usb_device               *xdev;
1500         int                             status;
1501         const char                      *name;
1502         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1503
1504         /* usbnet already took usb runtime pm, so have to enable the feature
1505          * for usb interface, otherwise usb_autopm_get_interface may return
1506          * failure if RUNTIME_PM is enabled.
1507          */
1508         if (!driver->supports_autosuspend) {
1509                 driver->supports_autosuspend = 1;
1510                 pm_runtime_enable(&udev->dev);
1511         }
1512
1513         name = udev->dev.driver->name;
1514         info = (struct driver_info *) prod->driver_info;
1515         if (!info) {
1516                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1517                 return -ENODEV;
1518         }
1519         xdev = interface_to_usbdev (udev);
1520         interface = udev->cur_altsetting;
1521
1522         status = -ENOMEM;
1523
1524         // set up our own records
1525         net = alloc_etherdev(sizeof(*dev));
1526         if (!net)
1527                 goto out;
1528
1529         /* netdev_printk() needs this so do it as early as possible */
1530         SET_NETDEV_DEV(net, &udev->dev);
1531
1532         dev = netdev_priv(net);
1533         dev->udev = xdev;
1534         dev->intf = udev;
1535         dev->driver_info = info;
1536         dev->driver_name = name;
1537         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1538                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1539         skb_queue_head_init (&dev->rxq);
1540         skb_queue_head_init (&dev->txq);
1541         skb_queue_head_init (&dev->done);
1542         skb_queue_head_init(&dev->rxq_pause);
1543         dev->bh.func = usbnet_bh;
1544         dev->bh.data = (unsigned long) dev;
1545         INIT_WORK (&dev->kevent, kevent);
1546         init_usb_anchor(&dev->deferred);
1547         dev->delay.function = usbnet_bh;
1548         dev->delay.data = (unsigned long) dev;
1549         init_timer (&dev->delay);
1550         mutex_init (&dev->phy_mutex);
1551         mutex_init(&dev->interrupt_mutex);
1552         dev->interrupt_count = 0;
1553
1554         dev->net = net;
1555         strcpy (net->name, "usb%d");
1556         memcpy (net->dev_addr, node_id, sizeof node_id);
1557
1558         /* rx and tx sides can use different message sizes;
1559          * bind() should set rx_urb_size in that case.
1560          */
1561         dev->hard_mtu = net->mtu + net->hard_header_len;
1562 #if 0
1563 // dma_supported() is deeply broken on almost all architectures
1564         // possible with some EHCI controllers
1565         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1566                 net->features |= NETIF_F_HIGHDMA;
1567 #endif
1568
1569         net->netdev_ops = &usbnet_netdev_ops;
1570         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1571         net->ethtool_ops = &usbnet_ethtool_ops;
1572
1573         // allow device-specific bind/init procedures
1574         // NOTE net->name still not usable ...
1575         if (info->bind) {
1576                 status = info->bind (dev, udev);
1577                 if (status < 0)
1578                         goto out1;
1579
1580                 // heuristic:  "usb%d" for links we know are two-host,
1581                 // else "eth%d" when there's reasonable doubt.  userspace
1582                 // can rename the link if it knows better.
1583                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1584                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1585                      (net->dev_addr [0] & 0x02) == 0))
1586                         strcpy (net->name, "eth%d");
1587                 /* WLAN devices should always be named "wlan%d" */
1588                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1589                         strcpy(net->name, "wlan%d");
1590                 /* WWAN devices should always be named "wwan%d" */
1591                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1592                         strcpy(net->name, "wwan%d");
1593
1594                 /* devices that cannot do ARP */
1595                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1596                         net->flags |= IFF_NOARP;
1597
1598                 /* maybe the remote can't receive an Ethernet MTU */
1599                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1600                         net->mtu = dev->hard_mtu - net->hard_header_len;
1601         } else if (!info->in || !info->out)
1602                 status = usbnet_get_endpoints (dev, udev);
1603         else {
1604                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1605                 dev->out = usb_sndbulkpipe (xdev, info->out);
1606                 if (!(info->flags & FLAG_NO_SETINT))
1607                         status = usb_set_interface (xdev,
1608                                 interface->desc.bInterfaceNumber,
1609                                 interface->desc.bAlternateSetting);
1610                 else
1611                         status = 0;
1612
1613         }
1614         if (status >= 0 && dev->status)
1615                 status = init_status (dev, udev);
1616         if (status < 0)
1617                 goto out3;
1618
1619         if (!dev->rx_urb_size)
1620                 dev->rx_urb_size = dev->hard_mtu;
1621         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1622
1623         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1624                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1625         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1626                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1627
1628         /* initialize max rx_qlen and tx_qlen */
1629         usbnet_update_max_qlen(dev);
1630
1631         status = register_netdev (net);
1632         if (status)
1633                 goto out4;
1634         netif_info(dev, probe, dev->net,
1635                    "register '%s' at usb-%s-%s, %s, %pM\n",
1636                    udev->dev.driver->name,
1637                    xdev->bus->bus_name, xdev->devpath,
1638                    dev->driver_info->description,
1639                    net->dev_addr);
1640
1641         // ok, it's ready to go.
1642         usb_set_intfdata (udev, dev);
1643
1644         netif_device_attach (net);
1645
1646         if (dev->driver_info->flags & FLAG_LINK_INTR)
1647                 usbnet_link_change(dev, 0, 0);
1648
1649         return 0;
1650
1651 out4:
1652         usb_free_urb(dev->interrupt);
1653 out3:
1654         if (info->unbind)
1655                 info->unbind (dev, udev);
1656 out1:
1657         free_netdev(net);
1658 out:
1659         return status;
1660 }
1661 EXPORT_SYMBOL_GPL(usbnet_probe);
1662
1663 /*-------------------------------------------------------------------------*/
1664
1665 /*
1666  * suspend the whole driver as soon as the first interface is suspended
1667  * resume only when the last interface is resumed
1668  */
1669
1670 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1671 {
1672         struct usbnet           *dev = usb_get_intfdata(intf);
1673
1674         if (!dev->suspend_count++) {
1675                 spin_lock_irq(&dev->txq.lock);
1676                 /* don't autosuspend while transmitting */
1677                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1678                         dev->suspend_count--;
1679                         spin_unlock_irq(&dev->txq.lock);
1680                         return -EBUSY;
1681                 } else {
1682                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1683                         spin_unlock_irq(&dev->txq.lock);
1684                 }
1685                 /*
1686                  * accelerate emptying of the rx and queues, to avoid
1687                  * having everything error out.
1688                  */
1689                 netif_device_detach (dev->net);
1690                 usbnet_terminate_urbs(dev);
1691                 __usbnet_status_stop_force(dev);
1692
1693                 /*
1694                  * reattach so runtime management can use and
1695                  * wake the device
1696                  */
1697                 netif_device_attach (dev->net);
1698         }
1699         return 0;
1700 }
1701 EXPORT_SYMBOL_GPL(usbnet_suspend);
1702
1703 int usbnet_resume (struct usb_interface *intf)
1704 {
1705         struct usbnet           *dev = usb_get_intfdata(intf);
1706         struct sk_buff          *skb;
1707         struct urb              *res;
1708         int                     retval;
1709
1710         if (!--dev->suspend_count) {
1711                 /* resume interrupt URB if it was previously submitted */
1712                 __usbnet_status_start_force(dev, GFP_NOIO);
1713
1714                 spin_lock_irq(&dev->txq.lock);
1715                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1716
1717                         skb = (struct sk_buff *)res->context;
1718                         retval = usb_submit_urb(res, GFP_ATOMIC);
1719                         if (retval < 0) {
1720                                 dev_kfree_skb_any(skb);
1721                                 usb_free_urb(res);
1722                                 usb_autopm_put_interface_async(dev->intf);
1723                         } else {
1724                                 dev->net->trans_start = jiffies;
1725                                 __skb_queue_tail(&dev->txq, skb);
1726                         }
1727                 }
1728
1729                 smp_mb();
1730                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1731                 spin_unlock_irq(&dev->txq.lock);
1732
1733                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1734                         /* handle remote wakeup ASAP */
1735                         if (!dev->wait &&
1736                                 netif_device_present(dev->net) &&
1737                                 !timer_pending(&dev->delay) &&
1738                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1739                                         rx_alloc_submit(dev, GFP_NOIO);
1740
1741                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1742                                 netif_tx_wake_all_queues(dev->net);
1743                         tasklet_schedule (&dev->bh);
1744                 }
1745         }
1746
1747         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1748                 usb_autopm_get_interface_no_resume(intf);
1749
1750         return 0;
1751 }
1752 EXPORT_SYMBOL_GPL(usbnet_resume);
1753
1754 /*
1755  * Either a subdriver implements manage_power, then it is assumed to always
1756  * be ready to be suspended or it reports the readiness to be suspended
1757  * explicitly
1758  */
1759 void usbnet_device_suggests_idle(struct usbnet *dev)
1760 {
1761         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1762                 dev->intf->needs_remote_wakeup = 1;
1763                 usb_autopm_put_interface_async(dev->intf);
1764         }
1765 }
1766 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1767
1768 /*
1769  * For devices that can do without special commands
1770  */
1771 int usbnet_manage_power(struct usbnet *dev, int on)
1772 {
1773         dev->intf->needs_remote_wakeup = on;
1774         return 0;
1775 }
1776 EXPORT_SYMBOL(usbnet_manage_power);
1777
1778 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1779 {
1780         /* update link after link is reseted */
1781         if (link && !need_reset)
1782                 netif_carrier_on(dev->net);
1783         else
1784                 netif_carrier_off(dev->net);
1785
1786         if (need_reset && link)
1787                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1788         else
1789                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1790 }
1791 EXPORT_SYMBOL(usbnet_link_change);
1792
1793 /*-------------------------------------------------------------------------*/
1794 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1795                              u16 value, u16 index, void *data, u16 size)
1796 {
1797         void *buf = NULL;
1798         int err = -ENOMEM;
1799
1800         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1801                    " value=0x%04x index=0x%04x size=%d\n",
1802                    cmd, reqtype, value, index, size);
1803
1804         if (data) {
1805                 buf = kmalloc(size, GFP_KERNEL);
1806                 if (!buf)
1807                         goto out;
1808         }
1809
1810         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1811                               cmd, reqtype, value, index, buf, size,
1812                               USB_CTRL_GET_TIMEOUT);
1813         if (err > 0 && err <= size)
1814                 memcpy(data, buf, err);
1815         kfree(buf);
1816 out:
1817         return err;
1818 }
1819
1820 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1821                               u16 value, u16 index, const void *data,
1822                               u16 size)
1823 {
1824         void *buf = NULL;
1825         int err = -ENOMEM;
1826
1827         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1828                    " value=0x%04x index=0x%04x size=%d\n",
1829                    cmd, reqtype, value, index, size);
1830
1831         if (data) {
1832                 buf = kmemdup(data, size, GFP_KERNEL);
1833                 if (!buf)
1834                         goto out;
1835         }
1836
1837         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1838                               cmd, reqtype, value, index, buf, size,
1839                               USB_CTRL_SET_TIMEOUT);
1840         kfree(buf);
1841
1842 out:
1843         return err;
1844 }
1845
1846 /*
1847  * The function can't be called inside suspend/resume callback,
1848  * otherwise deadlock will be caused.
1849  */
1850 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1851                     u16 value, u16 index, void *data, u16 size)
1852 {
1853         int ret;
1854
1855         if (usb_autopm_get_interface(dev->intf) < 0)
1856                 return -ENODEV;
1857         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1858                                 data, size);
1859         usb_autopm_put_interface(dev->intf);
1860         return ret;
1861 }
1862 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1863
1864 /*
1865  * The function can't be called inside suspend/resume callback,
1866  * otherwise deadlock will be caused.
1867  */
1868 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1869                      u16 value, u16 index, const void *data, u16 size)
1870 {
1871         int ret;
1872
1873         if (usb_autopm_get_interface(dev->intf) < 0)
1874                 return -ENODEV;
1875         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1876                                  data, size);
1877         usb_autopm_put_interface(dev->intf);
1878         return ret;
1879 }
1880 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1881
1882 /*
1883  * The function can be called inside suspend/resume callback safely
1884  * and should only be called by suspend/resume callback generally.
1885  */
1886 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1887                           u16 value, u16 index, void *data, u16 size)
1888 {
1889         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1890                                  data, size);
1891 }
1892 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1893
1894 /*
1895  * The function can be called inside suspend/resume callback safely
1896  * and should only be called by suspend/resume callback generally.
1897  */
1898 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1899                           u16 value, u16 index, const void *data,
1900                           u16 size)
1901 {
1902         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1903                                   data, size);
1904 }
1905 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1906
1907 static void usbnet_async_cmd_cb(struct urb *urb)
1908 {
1909         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
1910         int status = urb->status;
1911
1912         if (status < 0)
1913                 dev_dbg(&urb->dev->dev, "%s failed with %d",
1914                         __func__, status);
1915
1916         kfree(req);
1917         usb_free_urb(urb);
1918 }
1919
1920 /*
1921  * The caller must make sure that device can't be put into suspend
1922  * state until the control URB completes.
1923  */
1924 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
1925                            u16 value, u16 index, const void *data, u16 size)
1926 {
1927         struct usb_ctrlrequest *req = NULL;
1928         struct urb *urb;
1929         int err = -ENOMEM;
1930         void *buf = NULL;
1931
1932         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1933                    " value=0x%04x index=0x%04x size=%d\n",
1934                    cmd, reqtype, value, index, size);
1935
1936         urb = usb_alloc_urb(0, GFP_ATOMIC);
1937         if (!urb) {
1938                 netdev_err(dev->net, "Error allocating URB in"
1939                            " %s!\n", __func__);
1940                 goto fail;
1941         }
1942
1943         if (data) {
1944                 buf = kmemdup(data, size, GFP_ATOMIC);
1945                 if (!buf) {
1946                         netdev_err(dev->net, "Error allocating buffer"
1947                                    " in %s!\n", __func__);
1948                         goto fail_free;
1949                 }
1950         }
1951
1952         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
1953         if (!req)
1954                 goto fail_free_buf;
1955
1956         req->bRequestType = reqtype;
1957         req->bRequest = cmd;
1958         req->wValue = cpu_to_le16(value);
1959         req->wIndex = cpu_to_le16(index);
1960         req->wLength = cpu_to_le16(size);
1961
1962         usb_fill_control_urb(urb, dev->udev,
1963                              usb_sndctrlpipe(dev->udev, 0),
1964                              (void *)req, buf, size,
1965                              usbnet_async_cmd_cb, req);
1966         urb->transfer_flags |= URB_FREE_BUFFER;
1967
1968         err = usb_submit_urb(urb, GFP_ATOMIC);
1969         if (err < 0) {
1970                 netdev_err(dev->net, "Error submitting the control"
1971                            " message: status=%d\n", err);
1972                 goto fail_free;
1973         }
1974         return 0;
1975
1976 fail_free_buf:
1977         kfree(buf);
1978 fail_free:
1979         kfree(req);
1980         usb_free_urb(urb);
1981 fail:
1982         return err;
1983
1984 }
1985 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
1986 /*-------------------------------------------------------------------------*/
1987
1988 static int __init usbnet_init(void)
1989 {
1990         /* Compiler should optimize this out. */
1991         BUILD_BUG_ON(
1992                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
1993
1994         eth_random_addr(node_id);
1995         return 0;
1996 }
1997 module_init(usbnet_init);
1998
1999 static void __exit usbnet_exit(void)
2000 {
2001 }
2002 module_exit(usbnet_exit);
2003
2004 MODULE_AUTHOR("David Brownell");
2005 MODULE_DESCRIPTION("USB network driver framework");
2006 MODULE_LICENSE("GPL");