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