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, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * This is a generic "USB networking" framework that works with several
  22  * kinds of full and high speed networking devices:  host-to-host cables,
  23  * smart usb peripherals, and actual Ethernet adapters.
  24  *
  25  * These devices usually differ in terms of control protocols (if they
  26  * even have one!) and sometimes they define new framing to wrap or batch
  27  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  28  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  29  * issues can usefully be addressed by this framework.
  30  */
  31
  32 // #define      DEBUG                   // error path messages, extra info
  33 // #define      VERBOSE                 // more; success messages
  34
  35 #include <linux/module.h>
  36 #include <linux/init.h>
  37 #include <linux/netdevice.h>
  38 #include <linux/etherdevice.h>
  39 #include <linux/ctype.h>
  40 #include <linux/ethtool.h>
  41 #include <linux/workqueue.h>
  42 #include <linux/mii.h>
  43 #include <linux/usb.h>
  44 #include <linux/usb/usbnet.h>
  45 #include <linux/slab.h>
  46 #include <linux/kernel.h>
  47 #include <linux/pm_runtime.h>
  48
  49 #define DRIVER_VERSION          "22-Aug-2005"
  50
  51
  52 /*-------------------------------------------------------------------------*/
  53
  54 /*
  55  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  56  * Several dozen bytes of IPv4 data can fit in two such transactions.
  57  * One maximum size Ethernet packet takes twenty four of them.
  58  * For high speed, each frame comfortably fits almost 36 max size
  59  * Ethernet packets (so queues should be bigger).
  60  *
  61  * The goal is to let the USB host controller be busy for 5msec or
  62  * more before an irq is required, under load.  Jumbograms change
  63  * the equation.
  64  */
  65 #define MAX_QUEUE_MEMORY        (60 * 1518)
  66 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  67 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  68
  69 // reawaken network queue this soon after stopping; else watchdog barks
  70 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  71
  72 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  73  * us (it polls at HZ/4 usually) before we report too many false errors.
  74  */
  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 = -1, ret;
 164         unsigned char   buf [13];
 165
 166         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 167         if (ret == 12)
 168                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 169         if (tmp < 0) {
 170                 dev_dbg(&dev->udev->dev,
 171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172                 if (ret >= 0)
 173                         ret = -EINVAL;
 174                 return ret;
 175         }
 176         return 0;
 177 }
 178 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 179
 180 static void intr_complete (struct urb *urb)
 181 {
 182         struct usbnet   *dev = urb->context;
 183         int             status = urb->status;
 184
 185         switch (status) {
 186         /* success */
 187         case 0:
 188                 dev->driver_info->status(dev, urb);
 189                 break;
 190
 191         /* software-driven interface shutdown */
 192         case -ENOENT:           /* urb killed */
 193         case -ESHUTDOWN:        /* hardware gone */
 194                 netif_dbg(dev, ifdown, dev->net,
 195                           "intr shutdown, code %d\n", status);
 196                 return;
 197
 198         /* NOTE:  not throttling like RX/TX, since this endpoint
 199          * already polls infrequently
 200          */
 201         default:
 202                 netdev_dbg(dev->net, "intr status %d\n", status);
 203                 break;
 204         }
 205
 206         status = usb_submit_urb (urb, GFP_ATOMIC);
 207         if (status != 0)
 208                 netif_err(dev, timer, dev->net,
 209                           "intr resubmit --> %d\n", status);
 210 }
 211
 212 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 213 {
 214         char            *buf = NULL;
 215         unsigned        pipe = 0;
 216         unsigned        maxp;
 217         unsigned        period;
 218
 219         if (!dev->driver_info->status)
 220                 return 0;
 221
 222         pipe = usb_rcvintpipe (dev->udev,
 223                         dev->status->desc.bEndpointAddress
 224                                 & USB_ENDPOINT_NUMBER_MASK);
 225         maxp = usb_maxpacket (dev->udev, pipe, 0);
 226
 227         /* avoid 1 msec chatter:  min 8 msec poll rate */
 228         period = max ((int) dev->status->desc.bInterval,
 229                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 230
 231         buf = kmalloc (maxp, GFP_KERNEL);
 232         if (buf) {
 233                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 234                 if (!dev->interrupt) {
 235                         kfree (buf);
 236                         return -ENOMEM;
 237                 } else {
 238                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 239                                 buf, maxp, intr_complete, dev, period);
 240                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 241                         dev_dbg(&intf->dev,
 242                                 "status ep%din, %d bytes period %d\n",
 243                                 usb_pipeendpoint(pipe), maxp, period);
 244                 }
 245         }
 246         return 0;
 247 }
 248
 249 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 250 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 251 {
 252         int ret = 0;
 253
 254         WARN_ON_ONCE(dev->interrupt == NULL);
 255         if (dev->interrupt) {
 256                 mutex_lock(&dev->interrupt_mutex);
 257
 258                 if (++dev->interrupt_count == 1)
 259                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 260
 261                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 262                         dev->interrupt_count);
 263                 mutex_unlock(&dev->interrupt_mutex);
 264         }
 265         return ret;
 266 }
 267 EXPORT_SYMBOL_GPL(usbnet_status_start);
 268
 269 /* For resume; submit interrupt URB if previously submitted */
 270 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 271 {
 272         int ret = 0;
 273
 274         mutex_lock(&dev->interrupt_mutex);
 275         if (dev->interrupt_count) {
 276                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 277                 dev_dbg(&dev->udev->dev,
 278                         "submitted interrupt URB for resume\n");
 279         }
 280         mutex_unlock(&dev->interrupt_mutex);
 281         return ret;
 282 }
 283
 284 /* Kill the interrupt URB if all submitters want it killed */
 285 void usbnet_status_stop(struct usbnet *dev)
 286 {
 287         if (dev->interrupt) {
 288                 mutex_lock(&dev->interrupt_mutex);
 289                 WARN_ON(dev->interrupt_count == 0);
 290
 291                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 292                         usb_kill_urb(dev->interrupt);
 293
 294                 dev_dbg(&dev->udev->dev,
 295                         "decremented interrupt URB count to %d\n",
 296                         dev->interrupt_count);
 297                 mutex_unlock(&dev->interrupt_mutex);
 298         }
 299 }
 300 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 301
 302 /* For suspend; always kill interrupt URB */
 303 static void __usbnet_status_stop_force(struct usbnet *dev)
 304 {
 305         if (dev->interrupt) {
 306                 mutex_lock(&dev->interrupt_mutex);
 307                 usb_kill_urb(dev->interrupt);
 308                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 309                 mutex_unlock(&dev->interrupt_mutex);
 310         }
 311 }
 312
 313 /* Passes this packet up the stack, updating its accounting.
 314  * Some link protocols batch packets, so their rx_fixup paths
 315  * can return clones as well as just modify the original skb.
 316  */
 317 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 318 {
 319         int     status;
 320
 321         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 322                 skb_queue_tail(&dev->rxq_pause, skb);
 323                 return;
 324         }
 325
 326         /* only update if unset to allow minidriver rx_fixup override */
 327         if (skb->protocol == 0)
 328                 skb->protocol = eth_type_trans (skb, dev->net);
 329
 330         dev->net->stats.rx_packets++;
 331         dev->net->stats.rx_bytes += skb->len;
 332
 333         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 334                   skb->len + sizeof (struct ethhdr), skb->protocol);
 335         memset (skb->cb, 0, sizeof (struct skb_data));
 336
 337         if (skb_defer_rx_timestamp(skb))
 338                 return;
 339
 340         status = netif_rx (skb);
 341         if (status != NET_RX_SUCCESS)
 342                 netif_dbg(dev, rx_err, dev->net,
 343                           "netif_rx status %d\n", status);
 344 }
 345 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 346
 347 /* must be called if hard_mtu or rx_urb_size changed */
 348 void usbnet_update_max_qlen(struct usbnet *dev)
 349 {
 350         enum usb_device_speed speed = dev->udev->speed;
 351
 352         switch (speed) {
 353         case USB_SPEED_HIGH:
 354                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 355                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 356                 break;
 357         case USB_SPEED_SUPER:
 358         case USB_SPEED_SUPER_PLUS:
 359                 /*
 360                  * Not take default 5ms qlen for super speed HC to
 361                  * save memory, and iperf tests show 2.5ms qlen can
 362                  * work well
 363                  */
 364                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 365                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 366                 break;
 367         default:
 368                 dev->rx_qlen = dev->tx_qlen = 4;
 369         }
 370 }
 371 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 372
 373 \f
 374 /*-------------------------------------------------------------------------
 375  *
 376  * Network Device Driver (peer link to "Host Device", from USB host)
 377  *
 378  *-------------------------------------------------------------------------*/
 379
 380 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 381 {
 382         struct usbnet   *dev = netdev_priv(net);
 383         int             ll_mtu = new_mtu + net->hard_header_len;
 384         int             old_hard_mtu = dev->hard_mtu;
 385         int             old_rx_urb_size = dev->rx_urb_size;
 386
 387         if (new_mtu <= 0)
 388                 return -EINVAL;
 389         // no second zero-length packet read wanted after mtu-sized packets
 390         if ((ll_mtu % dev->maxpacket) == 0)
 391                 return -EDOM;
 392         net->mtu = new_mtu;
 393
 394         dev->hard_mtu = net->mtu + net->hard_header_len;
 395         if (dev->rx_urb_size == old_hard_mtu) {
 396                 dev->rx_urb_size = dev->hard_mtu;
 397                 if (dev->rx_urb_size > old_rx_urb_size) {
 398                         usbnet_pause_rx(dev);
 399                         usbnet_unlink_rx_urbs(dev);
 400                         usbnet_resume_rx(dev);
 401                 }
 402         }
 403
 404         /* max qlen depend on hard_mtu and rx_urb_size */
 405         usbnet_update_max_qlen(dev);
 406
 407         return 0;
 408 }
 409 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 410
 411 /* The caller must hold list->lock */
 412 static void __usbnet_queue_skb(struct sk_buff_head *list,
 413                         struct sk_buff *newsk, enum skb_state state)
 414 {
 415         struct skb_data *entry = (struct skb_data *) newsk->cb;
 416
 417         __skb_queue_tail(list, newsk);
 418         entry->state = state;
 419 }
 420
 421 /*-------------------------------------------------------------------------*/
 422
 423 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 424  * completion callbacks.  2.5 should have fixed those bugs...
 425  */
 426
 427 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 428                 struct sk_buff_head *list, enum skb_state state)
 429 {
 430         unsigned long           flags;
 431         enum skb_state          old_state;
 432         struct skb_data *entry = (struct skb_data *) skb->cb;
 433
 434         spin_lock_irqsave(&list->lock, flags);
 435         old_state = entry->state;
 436         entry->state = state;
 437         __skb_unlink(skb, list);
 438
 439         /* defer_bh() is never called with list == &dev->done.
 440          * spin_lock_nested() tells lockdep that it is OK to take
 441          * dev->done.lock here with list->lock held.
 442          */
 443         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 444
 445         __skb_queue_tail(&dev->done, skb);
 446         if (dev->done.qlen == 1)
 447                 tasklet_schedule(&dev->bh);
 448         spin_unlock(&dev->done.lock);
 449         spin_unlock_irqrestore(&list->lock, flags);
 450         return old_state;
 451 }
 452
 453 /* some work can't be done in tasklets, so we use keventd
 454  *
 455  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 456  * but tasklet_schedule() doesn't.  hope the failure is rare.
 457  */
 458 void usbnet_defer_kevent (struct usbnet *dev, int work)
 459 {
 460         set_bit (work, &dev->flags);
 461         if (!schedule_work (&dev->kevent)) {
 462                 if (net_ratelimit())
 463                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 464         } else {
 465                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 466         }
 467 }
 468 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 469
 470 /*-------------------------------------------------------------------------*/
 471
 472 static void rx_complete (struct urb *urb);
 473
 474 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 475 {
 476         struct sk_buff          *skb;
 477         struct skb_data         *entry;
 478         int                     retval = 0;
 479         unsigned long           lockflags;
 480         size_t                  size = dev->rx_urb_size;
 481
 482         /* prevent rx skb allocation when error ratio is high */
 483         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 484                 usb_free_urb(urb);
 485                 return -ENOLINK;
 486         }
 487
 488         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 489                 skb = __netdev_alloc_skb(dev->net, size, flags);
 490         else
 491                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 492         if (!skb) {
 493                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 494                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 495                 usb_free_urb (urb);
 496                 return -ENOMEM;
 497         }
 498
 499         entry = (struct skb_data *) skb->cb;
 500         entry->urb = urb;
 501         entry->dev = dev;
 502         entry->length = 0;
 503
 504         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 505                 skb->data, size, rx_complete, skb);
 506
 507         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 508
 509         if (netif_running (dev->net) &&
 510             netif_device_present (dev->net) &&
 511             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 512             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 513                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 514                 case -EPIPE:
 515                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 516                         break;
 517                 case -ENOMEM:
 518                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 519                         break;
 520                 case -ENODEV:
 521                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 522                         netif_device_detach (dev->net);
 523                         break;
 524                 case -EHOSTUNREACH:
 525                         retval = -ENOLINK;
 526                         break;
 527                 default:
 528                         netif_dbg(dev, rx_err, dev->net,
 529                                   "rx submit, %d\n", retval);
 530                         tasklet_schedule (&dev->bh);
 531                         break;
 532                 case 0:
 533                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 534                 }
 535         } else {
 536                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 537                 retval = -ENOLINK;
 538         }
 539         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 540         if (retval) {
 541                 dev_kfree_skb_any (skb);
 542                 usb_free_urb (urb);
 543         }
 544         return retval;
 545 }
 546
 547
 548 /*-------------------------------------------------------------------------*/
 549
 550 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 551 {
 552         if (dev->driver_info->rx_fixup &&
 553             !dev->driver_info->rx_fixup (dev, skb)) {
 554                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 555                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 556                         dev->net->stats.rx_errors++;
 557                 goto done;
 558         }
 559         // else network stack removes extra byte if we forced a short packet
 560
 561         /* all data was already cloned from skb inside the driver */
 562         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 563                 goto done;
 564
 565         if (skb->len < ETH_HLEN) {
 566                 dev->net->stats.rx_errors++;
 567                 dev->net->stats.rx_length_errors++;
 568                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 569         } else {
 570                 usbnet_skb_return(dev, skb);
 571                 return;
 572         }
 573
 574 done:
 575         skb_queue_tail(&dev->done, skb);
 576 }
 577
 578 /*-------------------------------------------------------------------------*/
 579
 580 static void rx_complete (struct urb *urb)
 581 {
 582         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 583         struct skb_data         *entry = (struct skb_data *) skb->cb;
 584         struct usbnet           *dev = entry->dev;
 585         int                     urb_status = urb->status;
 586         enum skb_state          state;
 587
 588         skb_put (skb, urb->actual_length);
 589         state = rx_done;
 590         entry->urb = NULL;
 591
 592         switch (urb_status) {
 593         /* success */
 594         case 0:
 595                 break;
 596
 597         /* stalls need manual reset. this is rare ... except that
 598          * when going through USB 2.0 TTs, unplug appears this way.
 599          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 600          * storm, recovering as needed.
 601          */
 602         case -EPIPE:
 603                 dev->net->stats.rx_errors++;
 604                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 605                 // FALLTHROUGH
 606
 607         /* software-driven interface shutdown */
 608         case -ECONNRESET:               /* async unlink */
 609         case -ESHUTDOWN:                /* hardware gone */
 610                 netif_dbg(dev, ifdown, dev->net,
 611                           "rx shutdown, code %d\n", urb_status);
 612                 goto block;
 613
 614         /* we get controller i/o faults during hub_wq disconnect() delays.
 615          * throttle down resubmits, to avoid log floods; just temporarily,
 616          * so we still recover when the fault isn't a hub_wq delay.
 617          */
 618         case -EPROTO:
 619         case -ETIME:
 620         case -EILSEQ:
 621                 dev->net->stats.rx_errors++;
 622                 if (!timer_pending (&dev->delay)) {
 623                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 624                         netif_dbg(dev, link, dev->net,
 625                                   "rx throttle %d\n", urb_status);
 626                 }
 627 block:
 628                 state = rx_cleanup;
 629                 entry->urb = urb;
 630                 urb = NULL;
 631                 break;
 632
 633         /* data overrun ... flush fifo? */
 634         case -EOVERFLOW:
 635                 dev->net->stats.rx_over_errors++;
 636                 // FALLTHROUGH
 637
 638         default:
 639                 state = rx_cleanup;
 640                 dev->net->stats.rx_errors++;
 641                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 642                 break;
 643         }
 644
 645         /* stop rx if packet error rate is high */
 646         if (++dev->pkt_cnt > 30) {
 647                 dev->pkt_cnt = 0;
 648                 dev->pkt_err = 0;
 649         } else {
 650                 if (state == rx_cleanup)
 651                         dev->pkt_err++;
 652                 if (dev->pkt_err > 20)
 653                         set_bit(EVENT_RX_KILL, &dev->flags);
 654         }
 655
 656         state = defer_bh(dev, skb, &dev->rxq, state);
 657
 658         if (urb) {
 659                 if (netif_running (dev->net) &&
 660                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 661                     state != unlink_start) {
 662                         rx_submit (dev, urb, GFP_ATOMIC);
 663                         usb_mark_last_busy(dev->udev);
 664                         return;
 665                 }
 666                 usb_free_urb (urb);
 667         }
 668         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 669 }
 670
 671 /*-------------------------------------------------------------------------*/
 672 void usbnet_pause_rx(struct usbnet *dev)
 673 {
 674         set_bit(EVENT_RX_PAUSED, &dev->flags);
 675
 676         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 677 }
 678 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 679
 680 void usbnet_resume_rx(struct usbnet *dev)
 681 {
 682         struct sk_buff *skb;
 683         int num = 0;
 684
 685         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 686
 687         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 688                 usbnet_skb_return(dev, skb);
 689                 num++;
 690         }
 691
 692         tasklet_schedule(&dev->bh);
 693
 694         netif_dbg(dev, rx_status, dev->net,
 695                   "paused rx queue disabled, %d skbs requeued\n", num);
 696 }
 697 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 698
 699 void usbnet_purge_paused_rxq(struct usbnet *dev)
 700 {
 701         skb_queue_purge(&dev->rxq_pause);
 702 }
 703 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 704
 705 /*-------------------------------------------------------------------------*/
 706
 707 // unlink pending rx/tx; completion handlers do all other cleanup
 708
 709 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 710 {
 711         unsigned long           flags;
 712         struct sk_buff          *skb;
 713         int                     count = 0;
 714
 715         spin_lock_irqsave (&q->lock, flags);
 716         while (!skb_queue_empty(q)) {
 717                 struct skb_data         *entry;
 718                 struct urb              *urb;
 719                 int                     retval;
 720
 721                 skb_queue_walk(q, skb) {
 722                         entry = (struct skb_data *) skb->cb;
 723                         if (entry->state != unlink_start)
 724                                 goto found;
 725                 }
 726                 break;
 727 found:
 728                 entry->state = unlink_start;
 729                 urb = entry->urb;
 730
 731                 /*
 732                  * Get reference count of the URB to avoid it to be
 733                  * freed during usb_unlink_urb, which may trigger
 734                  * use-after-free problem inside usb_unlink_urb since
 735                  * usb_unlink_urb is always racing with .complete
 736                  * handler(include defer_bh).
 737                  */
 738                 usb_get_urb(urb);
 739                 spin_unlock_irqrestore(&q->lock, flags);
 740                 // during some PM-driven resume scenarios,
 741                 // these (async) unlinks complete immediately
 742                 retval = usb_unlink_urb (urb);
 743                 if (retval != -EINPROGRESS && retval != 0)
 744                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 745                 else
 746                         count++;
 747                 usb_put_urb(urb);
 748                 spin_lock_irqsave(&q->lock, flags);
 749         }
 750         spin_unlock_irqrestore (&q->lock, flags);
 751         return count;
 752 }
 753
 754 // Flush all pending rx urbs
 755 // minidrivers may need to do this when the MTU changes
 756
 757 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 758 {
 759         if (netif_running(dev->net)) {
 760                 (void) unlink_urbs (dev, &dev->rxq);
 761                 tasklet_schedule(&dev->bh);
 762         }
 763 }
 764 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 765
 766 /*-------------------------------------------------------------------------*/
 767
 768 static void wait_skb_queue_empty(struct sk_buff_head *q)
 769 {
 770         unsigned long flags;
 771
 772         spin_lock_irqsave(&q->lock, flags);
 773         while (!skb_queue_empty(q)) {
 774                 spin_unlock_irqrestore(&q->lock, flags);
 775                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 776                 set_current_state(TASK_UNINTERRUPTIBLE);
 777                 spin_lock_irqsave(&q->lock, flags);
 778         }
 779         spin_unlock_irqrestore(&q->lock, flags);
 780 }
 781
 782 // precondition: never called in_interrupt
 783 static void usbnet_terminate_urbs(struct usbnet *dev)
 784 {
 785         DECLARE_WAITQUEUE(wait, current);
 786         int temp;
 787
 788         /* ensure there are no more active urbs */
 789         add_wait_queue(&dev->wait, &wait);
 790         set_current_state(TASK_UNINTERRUPTIBLE);
 791         temp = unlink_urbs(dev, &dev->txq) +
 792                 unlink_urbs(dev, &dev->rxq);
 793
 794         /* maybe wait for deletions to finish. */
 795         wait_skb_queue_empty(&dev->rxq);
 796         wait_skb_queue_empty(&dev->txq);
 797         wait_skb_queue_empty(&dev->done);
 798         netif_dbg(dev, ifdown, dev->net,
 799                   "waited for %d urb completions\n", temp);
 800         set_current_state(TASK_RUNNING);
 801         remove_wait_queue(&dev->wait, &wait);
 802 }
 803
 804 int usbnet_stop (struct net_device *net)
 805 {
 806         struct usbnet           *dev = netdev_priv(net);
 807         struct driver_info      *info = dev->driver_info;
 808         int                     retval, pm, mpn;
 809
 810         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 811         netif_stop_queue (net);
 812
 813         netif_info(dev, ifdown, dev->net,
 814                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 815                    net->stats.rx_packets, net->stats.tx_packets,
 816                    net->stats.rx_errors, net->stats.tx_errors);
 817
 818         /* to not race resume */
 819         pm = usb_autopm_get_interface(dev->intf);
 820         /* allow minidriver to stop correctly (wireless devices to turn off
 821          * radio etc) */
 822         if (info->stop) {
 823                 retval = info->stop(dev);
 824                 if (retval < 0)
 825                         netif_info(dev, ifdown, dev->net,
 826                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 827                                    retval,
 828                                    dev->udev->bus->bus_name, dev->udev->devpath,
 829                                    info->description);
 830         }
 831
 832         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 833                 usbnet_terminate_urbs(dev);
 834
 835         usbnet_status_stop(dev);
 836
 837         usbnet_purge_paused_rxq(dev);
 838
 839         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 840
 841         /* deferred work (task, timer, softirq) must also stop.
 842          * can't flush_scheduled_work() until we drop rtnl (later),
 843          * else workers could deadlock; so make workers a NOP.
 844          */
 845         dev->flags = 0;
 846         del_timer_sync (&dev->delay);
 847         tasklet_kill (&dev->bh);
 848         if (!pm)
 849                 usb_autopm_put_interface(dev->intf);
 850
 851         if (info->manage_power && mpn)
 852                 info->manage_power(dev, 0);
 853         else
 854                 usb_autopm_put_interface(dev->intf);
 855
 856         return 0;
 857 }
 858 EXPORT_SYMBOL_GPL(usbnet_stop);
 859
 860 /*-------------------------------------------------------------------------*/
 861
 862 // posts reads, and enables write queuing
 863
 864 // precondition: never called in_interrupt
 865
 866 int usbnet_open (struct net_device *net)
 867 {
 868         struct usbnet           *dev = netdev_priv(net);
 869         int                     retval;
 870         struct driver_info      *info = dev->driver_info;
 871
 872         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 873                 netif_info(dev, ifup, dev->net,
 874                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 875                            retval,
 876                            dev->udev->bus->bus_name,
 877                            dev->udev->devpath,
 878                            info->description);
 879                 goto done_nopm;
 880         }
 881
 882         // put into "known safe" state
 883         if (info->reset && (retval = info->reset (dev)) < 0) {
 884                 netif_info(dev, ifup, dev->net,
 885                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 886                            retval,
 887                            dev->udev->bus->bus_name,
 888                            dev->udev->devpath,
 889                            info->description);
 890                 goto done;
 891         }
 892
 893         /* hard_mtu or rx_urb_size may change in reset() */
 894         usbnet_update_max_qlen(dev);
 895
 896         // insist peer be connected
 897         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 898                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 899                 goto done;
 900         }
 901
 902         /* start any status interrupt transfer */
 903         if (dev->interrupt) {
 904                 retval = usbnet_status_start(dev, GFP_KERNEL);
 905                 if (retval < 0) {
 906                         netif_err(dev, ifup, dev->net,
 907                                   "intr submit %d\n", retval);
 908                         goto done;
 909                 }
 910         }
 911
 912         set_bit(EVENT_DEV_OPEN, &dev->flags);
 913         netif_start_queue (net);
 914         netif_info(dev, ifup, dev->net,
 915                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 916                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 917                    dev->net->mtu,
 918                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 919                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 920                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 921                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 922                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 923                    "simple");
 924
 925         /* reset rx error state */
 926         dev->pkt_cnt = 0;
 927         dev->pkt_err = 0;
 928         clear_bit(EVENT_RX_KILL, &dev->flags);
 929
 930         // delay posting reads until we're fully open
 931         tasklet_schedule (&dev->bh);
 932         if (info->manage_power) {
 933                 retval = info->manage_power(dev, 1);
 934                 if (retval < 0) {
 935                         retval = 0;
 936                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 937                 } else {
 938                         usb_autopm_put_interface(dev->intf);
 939                 }
 940         }
 941         return retval;
 942 done:
 943         usb_autopm_put_interface(dev->intf);
 944 done_nopm:
 945         return retval;
 946 }
 947 EXPORT_SYMBOL_GPL(usbnet_open);
 948
 949 /*-------------------------------------------------------------------------*/
 950
 951 /* ethtool methods; minidrivers may need to add some more, but
 952  * they'll probably want to use this base set.
 953  */
 954
 955 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 956 {
 957         struct usbnet *dev = netdev_priv(net);
 958
 959         if (!dev->mii.mdio_read)
 960                 return -EOPNOTSUPP;
 961
 962         return mii_ethtool_gset(&dev->mii, cmd);
 963 }
 964 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 965
 966 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 967 {
 968         struct usbnet *dev = netdev_priv(net);
 969         int retval;
 970
 971         if (!dev->mii.mdio_write)
 972                 return -EOPNOTSUPP;
 973
 974         retval = mii_ethtool_sset(&dev->mii, cmd);
 975
 976         /* link speed/duplex might have changed */
 977         if (dev->driver_info->link_reset)
 978                 dev->driver_info->link_reset(dev);
 979
 980         /* hard_mtu or rx_urb_size may change in link_reset() */
 981         usbnet_update_max_qlen(dev);
 982
 983         return retval;
 984
 985 }
 986 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 987
 988 u32 usbnet_get_link (struct net_device *net)
 989 {
 990         struct usbnet *dev = netdev_priv(net);
 991
 992         /* If a check_connect is defined, return its result */
 993         if (dev->driver_info->check_connect)
 994                 return dev->driver_info->check_connect (dev) == 0;
 995
 996         /* if the device has mii operations, use those */
 997         if (dev->mii.mdio_read)
 998                 return mii_link_ok(&dev->mii);
 999
1000         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1001         return ethtool_op_get_link(net);
1002 }
1003 EXPORT_SYMBOL_GPL(usbnet_get_link);
1004
1005 int usbnet_nway_reset(struct net_device *net)
1006 {
1007         struct usbnet *dev = netdev_priv(net);
1008
1009         if (!dev->mii.mdio_write)
1010                 return -EOPNOTSUPP;
1011
1012         return mii_nway_restart(&dev->mii);
1013 }
1014 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1015
1016 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1017 {
1018         struct usbnet *dev = netdev_priv(net);
1019
1020         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1021         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1022         strlcpy (info->fw_version, dev->driver_info->description,
1023                 sizeof info->fw_version);
1024         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1025 }
1026 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1027
1028 u32 usbnet_get_msglevel (struct net_device *net)
1029 {
1030         struct usbnet *dev = netdev_priv(net);
1031
1032         return dev->msg_enable;
1033 }
1034 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1035
1036 void usbnet_set_msglevel (struct net_device *net, u32 level)
1037 {
1038         struct usbnet *dev = netdev_priv(net);
1039
1040         dev->msg_enable = level;
1041 }
1042 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1043
1044 /* drivers may override default ethtool_ops in their bind() routine */
1045 static const struct ethtool_ops usbnet_ethtool_ops = {
1046         .get_settings           = usbnet_get_settings,
1047         .set_settings           = usbnet_set_settings,
1048         .get_link               = usbnet_get_link,
1049         .nway_reset             = usbnet_nway_reset,
1050         .get_drvinfo            = usbnet_get_drvinfo,
1051         .get_msglevel           = usbnet_get_msglevel,
1052         .set_msglevel           = usbnet_set_msglevel,
1053         .get_ts_info            = ethtool_op_get_ts_info,
1054 };
1055
1056 /*-------------------------------------------------------------------------*/
1057
1058 static void __handle_link_change(struct usbnet *dev)
1059 {
1060         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1061                 return;
1062
1063         if (!netif_carrier_ok(dev->net)) {
1064                 /* kill URBs for reading packets to save bus bandwidth */
1065                 unlink_urbs(dev, &dev->rxq);
1066
1067                 /*
1068                  * tx_timeout will unlink URBs for sending packets and
1069                  * tx queue is stopped by netcore after link becomes off
1070                  */
1071         } else {
1072                 /* submitting URBs for reading packets */
1073                 tasklet_schedule(&dev->bh);
1074         }
1075
1076         /* hard_mtu or rx_urb_size may change during link change */
1077         usbnet_update_max_qlen(dev);
1078
1079         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1080 }
1081
1082 static void usbnet_set_rx_mode(struct net_device *net)
1083 {
1084         struct usbnet           *dev = netdev_priv(net);
1085
1086         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1087 }
1088
1089 static void __handle_set_rx_mode(struct usbnet *dev)
1090 {
1091         if (dev->driver_info->set_rx_mode)
1092                 (dev->driver_info->set_rx_mode)(dev);
1093
1094         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1095 }
1096
1097 /* work that cannot be done in interrupt context uses keventd.
1098  *
1099  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1100  * especially now that control transfers can be queued.
1101  */
1102 static void
1103 usbnet_deferred_kevent (struct work_struct *work)
1104 {
1105         struct usbnet           *dev =
1106                 container_of(work, struct usbnet, kevent);
1107         int                     status;
1108
1109         /* usb_clear_halt() needs a thread context */
1110         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1111                 unlink_urbs (dev, &dev->txq);
1112                 status = usb_autopm_get_interface(dev->intf);
1113                 if (status < 0)
1114                         goto fail_pipe;
1115                 status = usb_clear_halt (dev->udev, dev->out);
1116                 usb_autopm_put_interface(dev->intf);
1117                 if (status < 0 &&
1118                     status != -EPIPE &&
1119                     status != -ESHUTDOWN) {
1120                         if (netif_msg_tx_err (dev))
1121 fail_pipe:
1122                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1123                                            status);
1124                 } else {
1125                         clear_bit (EVENT_TX_HALT, &dev->flags);
1126                         if (status != -ESHUTDOWN)
1127                                 netif_wake_queue (dev->net);
1128                 }
1129         }
1130         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1131                 unlink_urbs (dev, &dev->rxq);
1132                 status = usb_autopm_get_interface(dev->intf);
1133                 if (status < 0)
1134                         goto fail_halt;
1135                 status = usb_clear_halt (dev->udev, dev->in);
1136                 usb_autopm_put_interface(dev->intf);
1137                 if (status < 0 &&
1138                     status != -EPIPE &&
1139                     status != -ESHUTDOWN) {
1140                         if (netif_msg_rx_err (dev))
1141 fail_halt:
1142                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1143                                            status);
1144                 } else {
1145                         clear_bit (EVENT_RX_HALT, &dev->flags);
1146                         tasklet_schedule (&dev->bh);
1147                 }
1148         }
1149
1150         /* tasklet could resubmit itself forever if memory is tight */
1151         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1152                 struct urb      *urb = NULL;
1153                 int resched = 1;
1154
1155                 if (netif_running (dev->net))
1156                         urb = usb_alloc_urb (0, GFP_KERNEL);
1157                 else
1158                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1159                 if (urb != NULL) {
1160                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1161                         status = usb_autopm_get_interface(dev->intf);
1162                         if (status < 0) {
1163                                 usb_free_urb(urb);
1164                                 goto fail_lowmem;
1165                         }
1166                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1167                                 resched = 0;
1168                         usb_autopm_put_interface(dev->intf);
1169 fail_lowmem:
1170                         if (resched)
1171                                 tasklet_schedule (&dev->bh);
1172                 }
1173         }
1174
1175         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1176                 struct driver_info      *info = dev->driver_info;
1177                 int                     retval = 0;
1178
1179                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1180                 status = usb_autopm_get_interface(dev->intf);
1181                 if (status < 0)
1182                         goto skip_reset;
1183                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1184                         usb_autopm_put_interface(dev->intf);
1185 skip_reset:
1186                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1187                                     retval,
1188                                     dev->udev->bus->bus_name,
1189                                     dev->udev->devpath,
1190                                     info->description);
1191                 } else {
1192                         usb_autopm_put_interface(dev->intf);
1193                 }
1194
1195                 /* handle link change from link resetting */
1196                 __handle_link_change(dev);
1197         }
1198
1199         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1200                 __handle_link_change(dev);
1201
1202         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1203                 __handle_set_rx_mode(dev);
1204
1205
1206         if (dev->flags)
1207                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1208 }
1209
1210 /*-------------------------------------------------------------------------*/
1211
1212 static void tx_complete (struct urb *urb)
1213 {
1214         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1215         struct skb_data         *entry = (struct skb_data *) skb->cb;
1216         struct usbnet           *dev = entry->dev;
1217
1218         if (urb->status == 0) {
1219                 dev->net->stats.tx_packets += entry->packets;
1220                 dev->net->stats.tx_bytes += entry->length;
1221         } else {
1222                 dev->net->stats.tx_errors++;
1223
1224                 switch (urb->status) {
1225                 case -EPIPE:
1226                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1227                         break;
1228
1229                 /* software-driven interface shutdown */
1230                 case -ECONNRESET:               // async unlink
1231                 case -ESHUTDOWN:                // hardware gone
1232                         break;
1233
1234                 /* like rx, tx gets controller i/o faults during hub_wq
1235                  * delays and so it uses the same throttling mechanism.
1236                  */
1237                 case -EPROTO:
1238                 case -ETIME:
1239                 case -EILSEQ:
1240                         usb_mark_last_busy(dev->udev);
1241                         if (!timer_pending (&dev->delay)) {
1242                                 mod_timer (&dev->delay,
1243                                         jiffies + THROTTLE_JIFFIES);
1244                                 netif_dbg(dev, link, dev->net,
1245                                           "tx throttle %d\n", urb->status);
1246                         }
1247                         netif_stop_queue (dev->net);
1248                         break;
1249                 default:
1250                         netif_dbg(dev, tx_err, dev->net,
1251                                   "tx err %d\n", entry->urb->status);
1252                         break;
1253                 }
1254         }
1255
1256         usb_autopm_put_interface_async(dev->intf);
1257         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1258 }
1259
1260 /*-------------------------------------------------------------------------*/
1261
1262 void usbnet_tx_timeout (struct net_device *net)
1263 {
1264         struct usbnet           *dev = netdev_priv(net);
1265
1266         unlink_urbs (dev, &dev->txq);
1267         tasklet_schedule (&dev->bh);
1268         /* this needs to be handled individually because the generic layer
1269          * doesn't know what is sufficient and could not restore private
1270          * information if a remedy of an unconditional reset were used.
1271          */
1272         if (dev->driver_info->recover)
1273                 (dev->driver_info->recover)(dev);
1274 }
1275 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1276
1277 /*-------------------------------------------------------------------------*/
1278
1279 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1280 {
1281         unsigned num_sgs, total_len = 0;
1282         int i, s = 0;
1283
1284         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1285         if (num_sgs == 1)
1286                 return 0;
1287
1288         /* reserve one for zero packet */
1289         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1290                           GFP_ATOMIC);
1291         if (!urb->sg)
1292                 return -ENOMEM;
1293
1294         urb->num_sgs = num_sgs;
1295         sg_init_table(urb->sg, urb->num_sgs + 1);
1296
1297         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1298         total_len += skb_headlen(skb);
1299
1300         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1301                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1302
1303                 total_len += skb_frag_size(f);
1304                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1305                                 f->page_offset);
1306         }
1307         urb->transfer_buffer_length = total_len;
1308
1309         return 1;
1310 }
1311
1312 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1313                                      struct net_device *net)
1314 {
1315         struct usbnet           *dev = netdev_priv(net);
1316         unsigned int                    length;
1317         struct urb              *urb = NULL;
1318         struct skb_data         *entry;
1319         struct driver_info      *info = dev->driver_info;
1320         unsigned long           flags;
1321         int retval;
1322
1323         if (skb)
1324                 skb_tx_timestamp(skb);
1325
1326         // some devices want funky USB-level framing, for
1327         // win32 driver (usually) and/or hardware quirks
1328         if (info->tx_fixup) {
1329                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1330                 if (!skb) {
1331                         /* packet collected; minidriver waiting for more */
1332                         if (info->flags & FLAG_MULTI_PACKET)
1333                                 goto not_drop;
1334                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1335                         goto drop;
1336                 }
1337         }
1338
1339         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1340                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1341                 goto drop;
1342         }
1343
1344         entry = (struct skb_data *) skb->cb;
1345         entry->urb = urb;
1346         entry->dev = dev;
1347
1348         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1349                         skb->data, skb->len, tx_complete, skb);
1350         if (dev->can_dma_sg) {
1351                 if (build_dma_sg(skb, urb) < 0)
1352                         goto drop;
1353         }
1354         length = urb->transfer_buffer_length;
1355
1356         /* don't assume the hardware handles USB_ZERO_PACKET
1357          * NOTE:  strictly conforming cdc-ether devices should expect
1358          * the ZLP here, but ignore the one-byte packet.
1359          * NOTE2: CDC NCM specification is different from CDC ECM when
1360          * handling ZLP/short packets, so cdc_ncm driver will make short
1361          * packet itself if needed.
1362          */
1363         if (length % dev->maxpacket == 0) {
1364                 if (!(info->flags & FLAG_SEND_ZLP)) {
1365                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1366                                 length++;
1367                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1368                                         skb->data[skb->len] = 0;
1369                                         __skb_put(skb, 1);
1370                                 } else if (urb->num_sgs)
1371                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1372                                                         dev->padding_pkt, 1);
1373                         }
1374                 } else
1375                         urb->transfer_flags |= URB_ZERO_PACKET;
1376         }
1377         urb->transfer_buffer_length = length;
1378
1379         if (info->flags & FLAG_MULTI_PACKET) {
1380                 /* Driver has set number of packets and a length delta.
1381                  * Calculate the complete length and ensure that it's
1382                  * positive.
1383                  */
1384                 entry->length += length;
1385                 if (WARN_ON_ONCE(entry->length <= 0))
1386                         entry->length = length;
1387         } else {
1388                 usbnet_set_skb_tx_stats(skb, 1, length);
1389         }
1390
1391         spin_lock_irqsave(&dev->txq.lock, flags);
1392         retval = usb_autopm_get_interface_async(dev->intf);
1393         if (retval < 0) {
1394                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1395                 goto drop;
1396         }
1397
1398 #ifdef CONFIG_PM
1399         /* if this triggers the device is still a sleep */
1400         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1401                 /* transmission will be done in resume */
1402                 usb_anchor_urb(urb, &dev->deferred);
1403                 /* no use to process more packets */
1404                 netif_stop_queue(net);
1405                 usb_put_urb(urb);
1406                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1407                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1408                 goto deferred;
1409         }
1410 #endif
1411
1412         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1413         case -EPIPE:
1414                 netif_stop_queue (net);
1415                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1416                 usb_autopm_put_interface_async(dev->intf);
1417                 break;
1418         default:
1419                 usb_autopm_put_interface_async(dev->intf);
1420                 netif_dbg(dev, tx_err, dev->net,
1421                           "tx: submit urb err %d\n", retval);
1422                 break;
1423         case 0:
1424                 netif_trans_update(net);
1425                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1426                 if (dev->txq.qlen >= TX_QLEN (dev))
1427                         netif_stop_queue (net);
1428         }
1429         spin_unlock_irqrestore (&dev->txq.lock, flags);
1430
1431         if (retval) {
1432                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1433 drop:
1434                 dev->net->stats.tx_dropped++;
1435 not_drop:
1436                 if (skb)
1437                         dev_kfree_skb_any (skb);
1438                 if (urb) {
1439                         kfree(urb->sg);
1440                         usb_free_urb(urb);
1441                 }
1442         } else
1443                 netif_dbg(dev, tx_queued, dev->net,
1444                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1445 #ifdef CONFIG_PM
1446 deferred:
1447 #endif
1448         return NETDEV_TX_OK;
1449 }
1450 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1451
1452 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1453 {
1454         struct urb      *urb;
1455         int             i;
1456         int             ret = 0;
1457
1458         /* don't refill the queue all at once */
1459         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1460                 urb = usb_alloc_urb(0, flags);
1461                 if (urb != NULL) {
1462                         ret = rx_submit(dev, urb, flags);
1463                         if (ret)
1464                                 goto err;
1465                 } else {
1466                         ret = -ENOMEM;
1467                         goto err;
1468                 }
1469         }
1470 err:
1471         return ret;
1472 }
1473
1474 /*-------------------------------------------------------------------------*/
1475
1476 // tasklet (work deferred from completions, in_irq) or timer
1477
1478 static void usbnet_bh (unsigned long param)
1479 {
1480         struct usbnet           *dev = (struct usbnet *) param;
1481         struct sk_buff          *skb;
1482         struct skb_data         *entry;
1483
1484         while ((skb = skb_dequeue (&dev->done))) {
1485                 entry = (struct skb_data *) skb->cb;
1486                 switch (entry->state) {
1487                 case rx_done:
1488                         entry->state = rx_cleanup;
1489                         rx_process (dev, skb);
1490                         continue;
1491                 case tx_done:
1492                         kfree(entry->urb->sg);
1493                 case rx_cleanup:
1494                         usb_free_urb (entry->urb);
1495                         dev_kfree_skb (skb);
1496                         continue;
1497                 default:
1498                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1499                 }
1500         }
1501
1502         /* restart RX again after disabling due to high error rate */
1503         clear_bit(EVENT_RX_KILL, &dev->flags);
1504
1505         /* waiting for all pending urbs to complete?
1506          * only then can we forgo submitting anew
1507          */
1508         if (waitqueue_active(&dev->wait)) {
1509                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1510                         wake_up_all(&dev->wait);
1511
1512         // or are we maybe short a few urbs?
1513         } else if (netif_running (dev->net) &&
1514                    netif_device_present (dev->net) &&
1515                    netif_carrier_ok(dev->net) &&
1516                    !timer_pending(&dev->delay) &&
1517                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1518                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1519                 int     temp = dev->rxq.qlen;
1520
1521                 if (temp < RX_QLEN(dev)) {
1522                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1523                                 return;
1524                         if (temp != dev->rxq.qlen)
1525                                 netif_dbg(dev, link, dev->net,
1526                                           "rxqlen %d --> %d\n",
1527                                           temp, dev->rxq.qlen);
1528                         if (dev->rxq.qlen < RX_QLEN(dev))
1529                                 tasklet_schedule (&dev->bh);
1530                 }
1531                 if (dev->txq.qlen < TX_QLEN (dev))
1532                         netif_wake_queue (dev->net);
1533         }
1534 }
1535
1536
1537 /*-------------------------------------------------------------------------
1538  *
1539  * USB Device Driver support
1540  *
1541  *-------------------------------------------------------------------------*/
1542
1543 // precondition: never called in_interrupt
1544
1545 void usbnet_disconnect (struct usb_interface *intf)
1546 {
1547         struct usbnet           *dev;
1548         struct usb_device       *xdev;
1549         struct net_device       *net;
1550
1551         dev = usb_get_intfdata(intf);
1552         usb_set_intfdata(intf, NULL);
1553         if (!dev)
1554                 return;
1555
1556         xdev = interface_to_usbdev (intf);
1557
1558         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1559                    intf->dev.driver->name,
1560                    xdev->bus->bus_name, xdev->devpath,
1561                    dev->driver_info->description);
1562
1563         net = dev->net;
1564         unregister_netdev (net);
1565
1566         cancel_work_sync(&dev->kevent);
1567
1568         usb_scuttle_anchored_urbs(&dev->deferred);
1569
1570         if (dev->driver_info->unbind)
1571                 dev->driver_info->unbind (dev, intf);
1572
1573         usb_kill_urb(dev->interrupt);
1574         usb_free_urb(dev->interrupt);
1575         kfree(dev->padding_pkt);
1576
1577         free_netdev(net);
1578 }
1579 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1580
1581 static const struct net_device_ops usbnet_netdev_ops = {
1582         .ndo_open               = usbnet_open,
1583         .ndo_stop               = usbnet_stop,
1584         .ndo_start_xmit         = usbnet_start_xmit,
1585         .ndo_tx_timeout         = usbnet_tx_timeout,
1586         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1587         .ndo_change_mtu         = usbnet_change_mtu,
1588         .ndo_set_mac_address    = eth_mac_addr,
1589         .ndo_validate_addr      = eth_validate_addr,
1590 };
1591
1592 /*-------------------------------------------------------------------------*/
1593
1594 // precondition: never called in_interrupt
1595
1596 static struct device_type wlan_type = {
1597         .name   = "wlan",
1598 };
1599
1600 static struct device_type wwan_type = {
1601         .name   = "wwan",
1602 };
1603
1604 int
1605 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1606 {
1607         struct usbnet                   *dev;
1608         struct net_device               *net;
1609         struct usb_host_interface       *interface;
1610         struct driver_info              *info;
1611         struct usb_device               *xdev;
1612         int                             status;
1613         const char                      *name;
1614         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1615
1616         /* usbnet already took usb runtime pm, so have to enable the feature
1617          * for usb interface, otherwise usb_autopm_get_interface may return
1618          * failure if RUNTIME_PM is enabled.
1619          */
1620         if (!driver->supports_autosuspend) {
1621                 driver->supports_autosuspend = 1;
1622                 pm_runtime_enable(&udev->dev);
1623         }
1624
1625         name = udev->dev.driver->name;
1626         info = (struct driver_info *) prod->driver_info;
1627         if (!info) {
1628                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1629                 return -ENODEV;
1630         }
1631         xdev = interface_to_usbdev (udev);
1632         interface = udev->cur_altsetting;
1633
1634         status = -ENOMEM;
1635
1636         // set up our own records
1637         net = alloc_etherdev(sizeof(*dev));
1638         if (!net)
1639                 goto out;
1640
1641         /* netdev_printk() needs this so do it as early as possible */
1642         SET_NETDEV_DEV(net, &udev->dev);
1643
1644         dev = netdev_priv(net);
1645         dev->udev = xdev;
1646         dev->intf = udev;
1647         dev->driver_info = info;
1648         dev->driver_name = name;
1649         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1650                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1651         init_waitqueue_head(&dev->wait);
1652         skb_queue_head_init (&dev->rxq);
1653         skb_queue_head_init (&dev->txq);
1654         skb_queue_head_init (&dev->done);
1655         skb_queue_head_init(&dev->rxq_pause);
1656         dev->bh.func = usbnet_bh;
1657         dev->bh.data = (unsigned long) dev;
1658         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1659         init_usb_anchor(&dev->deferred);
1660         dev->delay.function = usbnet_bh;
1661         dev->delay.data = (unsigned long) dev;
1662         init_timer (&dev->delay);
1663         mutex_init (&dev->phy_mutex);
1664         mutex_init(&dev->interrupt_mutex);
1665         dev->interrupt_count = 0;
1666
1667         dev->net = net;
1668         strcpy (net->name, "usb%d");
1669         memcpy (net->dev_addr, node_id, sizeof node_id);
1670
1671         /* rx and tx sides can use different message sizes;
1672          * bind() should set rx_urb_size in that case.
1673          */
1674         dev->hard_mtu = net->mtu + net->hard_header_len;
1675
1676         net->netdev_ops = &usbnet_netdev_ops;
1677         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1678         net->ethtool_ops = &usbnet_ethtool_ops;
1679
1680         // allow device-specific bind/init procedures
1681         // NOTE net->name still not usable ...
1682         if (info->bind) {
1683                 status = info->bind (dev, udev);
1684                 if (status < 0)
1685                         goto out1;
1686
1687                 // heuristic:  "usb%d" for links we know are two-host,
1688                 // else "eth%d" when there's reasonable doubt.  userspace
1689                 // can rename the link if it knows better.
1690                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1691                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1692                      (net->dev_addr [0] & 0x02) == 0))
1693                         strcpy (net->name, "eth%d");
1694                 /* WLAN devices should always be named "wlan%d" */
1695                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1696                         strcpy(net->name, "wlan%d");
1697                 /* WWAN devices should always be named "wwan%d" */
1698                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1699                         strcpy(net->name, "wwan%d");
1700
1701                 /* devices that cannot do ARP */
1702                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1703                         net->flags |= IFF_NOARP;
1704
1705                 /* maybe the remote can't receive an Ethernet MTU */
1706                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1707                         net->mtu = dev->hard_mtu - net->hard_header_len;
1708         } else if (!info->in || !info->out)
1709                 status = usbnet_get_endpoints (dev, udev);
1710         else {
1711                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1712                 dev->out = usb_sndbulkpipe (xdev, info->out);
1713                 if (!(info->flags & FLAG_NO_SETINT))
1714                         status = usb_set_interface (xdev,
1715                                 interface->desc.bInterfaceNumber,
1716                                 interface->desc.bAlternateSetting);
1717                 else
1718                         status = 0;
1719
1720         }
1721         if (status >= 0 && dev->status)
1722                 status = init_status (dev, udev);
1723         if (status < 0)
1724                 goto out3;
1725
1726         if (!dev->rx_urb_size)
1727                 dev->rx_urb_size = dev->hard_mtu;
1728         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1729
1730         /* let userspace know we have a random address */
1731         if (ether_addr_equal(net->dev_addr, node_id))
1732                 net->addr_assign_type = NET_ADDR_RANDOM;
1733
1734         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1735                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1736         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1737                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1738
1739         /* initialize max rx_qlen and tx_qlen */
1740         usbnet_update_max_qlen(dev);
1741
1742         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1743                 !(info->flags & FLAG_MULTI_PACKET)) {
1744                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1745                 if (!dev->padding_pkt) {
1746                         status = -ENOMEM;
1747                         goto out4;
1748                 }
1749         }
1750
1751         status = register_netdev (net);
1752         if (status)
1753                 goto out5;
1754         netif_info(dev, probe, dev->net,
1755                    "register '%s' at usb-%s-%s, %s, %pM\n",
1756                    udev->dev.driver->name,
1757                    xdev->bus->bus_name, xdev->devpath,
1758                    dev->driver_info->description,
1759                    net->dev_addr);
1760
1761         // ok, it's ready to go.
1762         usb_set_intfdata (udev, dev);
1763
1764         netif_device_attach (net);
1765
1766         if (dev->driver_info->flags & FLAG_LINK_INTR)
1767                 usbnet_link_change(dev, 0, 0);
1768
1769         return 0;
1770
1771 out5:
1772         kfree(dev->padding_pkt);
1773 out4:
1774         usb_free_urb(dev->interrupt);
1775 out3:
1776         if (info->unbind)
1777                 info->unbind (dev, udev);
1778 out1:
1779         /* subdrivers must undo all they did in bind() if they
1780          * fail it, but we may fail later and a deferred kevent
1781          * may trigger an error resubmitting itself and, worse,
1782          * schedule a timer. So we kill it all just in case.
1783          */
1784         cancel_work_sync(&dev->kevent);
1785         del_timer_sync(&dev->delay);
1786         free_netdev(net);
1787 out:
1788         return status;
1789 }
1790 EXPORT_SYMBOL_GPL(usbnet_probe);
1791
1792 /*-------------------------------------------------------------------------*/
1793
1794 /*
1795  * suspend the whole driver as soon as the first interface is suspended
1796  * resume only when the last interface is resumed
1797  */
1798
1799 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1800 {
1801         struct usbnet           *dev = usb_get_intfdata(intf);
1802
1803         if (!dev->suspend_count++) {
1804                 spin_lock_irq(&dev->txq.lock);
1805                 /* don't autosuspend while transmitting */
1806                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1807                         dev->suspend_count--;
1808                         spin_unlock_irq(&dev->txq.lock);
1809                         return -EBUSY;
1810                 } else {
1811                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1812                         spin_unlock_irq(&dev->txq.lock);
1813                 }
1814                 /*
1815                  * accelerate emptying of the rx and queues, to avoid
1816                  * having everything error out.
1817                  */
1818                 netif_device_detach (dev->net);
1819                 usbnet_terminate_urbs(dev);
1820                 __usbnet_status_stop_force(dev);
1821
1822                 /*
1823                  * reattach so runtime management can use and
1824                  * wake the device
1825                  */
1826                 netif_device_attach (dev->net);
1827         }
1828         return 0;
1829 }
1830 EXPORT_SYMBOL_GPL(usbnet_suspend);
1831
1832 int usbnet_resume (struct usb_interface *intf)
1833 {
1834         struct usbnet           *dev = usb_get_intfdata(intf);
1835         struct sk_buff          *skb;
1836         struct urb              *res;
1837         int                     retval;
1838
1839         if (!--dev->suspend_count) {
1840                 /* resume interrupt URB if it was previously submitted */
1841                 __usbnet_status_start_force(dev, GFP_NOIO);
1842
1843                 spin_lock_irq(&dev->txq.lock);
1844                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1845
1846                         skb = (struct sk_buff *)res->context;
1847                         retval = usb_submit_urb(res, GFP_ATOMIC);
1848                         if (retval < 0) {
1849                                 dev_kfree_skb_any(skb);
1850                                 kfree(res->sg);
1851                                 usb_free_urb(res);
1852                                 usb_autopm_put_interface_async(dev->intf);
1853                         } else {
1854                                 netif_trans_update(dev->net);
1855                                 __skb_queue_tail(&dev->txq, skb);
1856                         }
1857                 }
1858
1859                 smp_mb();
1860                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1861                 spin_unlock_irq(&dev->txq.lock);
1862
1863                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1864                         /* handle remote wakeup ASAP
1865                          * we cannot race against stop
1866                          */
1867                         if (netif_device_present(dev->net) &&
1868                                 !timer_pending(&dev->delay) &&
1869                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1870                                         rx_alloc_submit(dev, GFP_NOIO);
1871
1872                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1873                                 netif_tx_wake_all_queues(dev->net);
1874                         tasklet_schedule (&dev->bh);
1875                 }
1876         }
1877
1878         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1879                 usb_autopm_get_interface_no_resume(intf);
1880
1881         return 0;
1882 }
1883 EXPORT_SYMBOL_GPL(usbnet_resume);
1884
1885 /*
1886  * Either a subdriver implements manage_power, then it is assumed to always
1887  * be ready to be suspended or it reports the readiness to be suspended
1888  * explicitly
1889  */
1890 void usbnet_device_suggests_idle(struct usbnet *dev)
1891 {
1892         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1893                 dev->intf->needs_remote_wakeup = 1;
1894                 usb_autopm_put_interface_async(dev->intf);
1895         }
1896 }
1897 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1898
1899 /*
1900  * For devices that can do without special commands
1901  */
1902 int usbnet_manage_power(struct usbnet *dev, int on)
1903 {
1904         dev->intf->needs_remote_wakeup = on;
1905         return 0;
1906 }
1907 EXPORT_SYMBOL(usbnet_manage_power);
1908
1909 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1910 {
1911         /* update link after link is reseted */
1912         if (link && !need_reset)
1913                 netif_carrier_on(dev->net);
1914         else
1915                 netif_carrier_off(dev->net);
1916
1917         if (need_reset && link)
1918                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1919         else
1920                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1921 }
1922 EXPORT_SYMBOL(usbnet_link_change);
1923
1924 /*-------------------------------------------------------------------------*/
1925 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1926                              u16 value, u16 index, void *data, u16 size)
1927 {
1928         void *buf = NULL;
1929         int err = -ENOMEM;
1930
1931         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1932                    " value=0x%04x index=0x%04x size=%d\n",
1933                    cmd, reqtype, value, index, size);
1934
1935         if (data) {
1936                 buf = kmalloc(size, GFP_KERNEL);
1937                 if (!buf)
1938                         goto out;
1939         }
1940
1941         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1942                               cmd, reqtype, value, index, buf, size,
1943                               USB_CTRL_GET_TIMEOUT);
1944         if (err > 0 && err <= size)
1945                 memcpy(data, buf, err);
1946         kfree(buf);
1947 out:
1948         return err;
1949 }
1950
1951 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1952                               u16 value, u16 index, const void *data,
1953                               u16 size)
1954 {
1955         void *buf = NULL;
1956         int err = -ENOMEM;
1957
1958         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1959                    " value=0x%04x index=0x%04x size=%d\n",
1960                    cmd, reqtype, value, index, size);
1961
1962         if (data) {
1963                 buf = kmemdup(data, size, GFP_KERNEL);
1964                 if (!buf)
1965                         goto out;
1966         }
1967
1968         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1969                               cmd, reqtype, value, index, buf, size,
1970                               USB_CTRL_SET_TIMEOUT);
1971         kfree(buf);
1972
1973 out:
1974         return err;
1975 }
1976
1977 /*
1978  * The function can't be called inside suspend/resume callback,
1979  * otherwise deadlock will be caused.
1980  */
1981 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1982                     u16 value, u16 index, void *data, u16 size)
1983 {
1984         int ret;
1985
1986         if (usb_autopm_get_interface(dev->intf) < 0)
1987                 return -ENODEV;
1988         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1989                                 data, size);
1990         usb_autopm_put_interface(dev->intf);
1991         return ret;
1992 }
1993 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1994
1995 /*
1996  * The function can't be called inside suspend/resume callback,
1997  * otherwise deadlock will be caused.
1998  */
1999 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2000                      u16 value, u16 index, const void *data, u16 size)
2001 {
2002         int ret;
2003
2004         if (usb_autopm_get_interface(dev->intf) < 0)
2005                 return -ENODEV;
2006         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2007                                  data, size);
2008         usb_autopm_put_interface(dev->intf);
2009         return ret;
2010 }
2011 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2012
2013 /*
2014  * The function can be called inside suspend/resume callback safely
2015  * and should only be called by suspend/resume callback generally.
2016  */
2017 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2018                           u16 value, u16 index, void *data, u16 size)
2019 {
2020         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2021                                  data, size);
2022 }
2023 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2024
2025 /*
2026  * The function can be called inside suspend/resume callback safely
2027  * and should only be called by suspend/resume callback generally.
2028  */
2029 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2030                           u16 value, u16 index, const void *data,
2031                           u16 size)
2032 {
2033         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2034                                   data, size);
2035 }
2036 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2037
2038 static void usbnet_async_cmd_cb(struct urb *urb)
2039 {
2040         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2041         int status = urb->status;
2042
2043         if (status < 0)
2044                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2045                         __func__, status);
2046
2047         kfree(req);
2048         usb_free_urb(urb);
2049 }
2050
2051 /*
2052  * The caller must make sure that device can't be put into suspend
2053  * state until the control URB completes.
2054  */
2055 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2056                            u16 value, u16 index, const void *data, u16 size)
2057 {
2058         struct usb_ctrlrequest *req = NULL;
2059         struct urb *urb;
2060         int err = -ENOMEM;
2061         void *buf = NULL;
2062
2063         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2064                    " value=0x%04x index=0x%04x size=%d\n",
2065                    cmd, reqtype, value, index, size);
2066
2067         urb = usb_alloc_urb(0, GFP_ATOMIC);
2068         if (!urb)
2069                 goto fail;
2070
2071         if (data) {
2072                 buf = kmemdup(data, size, GFP_ATOMIC);
2073                 if (!buf) {
2074                         netdev_err(dev->net, "Error allocating buffer"
2075                                    " in %s!\n", __func__);
2076                         goto fail_free;
2077                 }
2078         }
2079
2080         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2081         if (!req)
2082                 goto fail_free_buf;
2083
2084         req->bRequestType = reqtype;
2085         req->bRequest = cmd;
2086         req->wValue = cpu_to_le16(value);
2087         req->wIndex = cpu_to_le16(index);
2088         req->wLength = cpu_to_le16(size);
2089
2090         usb_fill_control_urb(urb, dev->udev,
2091                              usb_sndctrlpipe(dev->udev, 0),
2092                              (void *)req, buf, size,
2093                              usbnet_async_cmd_cb, req);
2094         urb->transfer_flags |= URB_FREE_BUFFER;
2095
2096         err = usb_submit_urb(urb, GFP_ATOMIC);
2097         if (err < 0) {
2098                 netdev_err(dev->net, "Error submitting the control"
2099                            " message: status=%d\n", err);
2100                 goto fail_free;
2101         }
2102         return 0;
2103
2104 fail_free_buf:
2105         kfree(buf);
2106 fail_free:
2107         kfree(req);
2108         usb_free_urb(urb);
2109 fail:
2110         return err;
2111
2112 }
2113 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2114 /*-------------------------------------------------------------------------*/
2115
2116 static int __init usbnet_init(void)
2117 {
2118         /* Compiler should optimize this out. */
2119         BUILD_BUG_ON(
2120                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2121
2122         eth_random_addr(node_id);
2123         return 0;
2124 }
2125 module_init(usbnet_init);
2126
2127 static void __exit usbnet_exit(void)
2128 {
2129 }
2130 module_exit(usbnet_exit);
2131
2132 MODULE_AUTHOR("David Brownell");
2133 MODULE_DESCRIPTION("USB network driver framework");
2134 MODULE_LICENSE("GPL");