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, 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         /* all data was already cloned from skb inside the driver */
 547         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 548                 goto done;
 549
 550         if (skb->len < ETH_HLEN) {
 551                 dev->net->stats.rx_errors++;
 552                 dev->net->stats.rx_length_errors++;
 553                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 554         } else {
 555                 usbnet_skb_return(dev, skb);
 556                 return;
 557         }
 558
 559 done:
 560         skb_queue_tail(&dev->done, skb);
 561 }
 562
 563 /*-------------------------------------------------------------------------*/
 564
 565 static void rx_complete (struct urb *urb)
 566 {
 567         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 568         struct skb_data         *entry = (struct skb_data *) skb->cb;
 569         struct usbnet           *dev = entry->dev;
 570         int                     urb_status = urb->status;
 571         enum skb_state          state;
 572
 573         skb_put (skb, urb->actual_length);
 574         state = rx_done;
 575         entry->urb = NULL;
 576
 577         switch (urb_status) {
 578         /* success */
 579         case 0:
 580                 break;
 581
 582         /* stalls need manual reset. this is rare ... except that
 583          * when going through USB 2.0 TTs, unplug appears this way.
 584          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 585          * storm, recovering as needed.
 586          */
 587         case -EPIPE:
 588                 dev->net->stats.rx_errors++;
 589                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 590                 // FALLTHROUGH
 591
 592         /* software-driven interface shutdown */
 593         case -ECONNRESET:               /* async unlink */
 594         case -ESHUTDOWN:                /* hardware gone */
 595                 netif_dbg(dev, ifdown, dev->net,
 596                           "rx shutdown, code %d\n", urb_status);
 597                 goto block;
 598
 599         /* we get controller i/o faults during hub_wq disconnect() delays.
 600          * throttle down resubmits, to avoid log floods; just temporarily,
 601          * so we still recover when the fault isn't a hub_wq delay.
 602          */
 603         case -EPROTO:
 604         case -ETIME:
 605         case -EILSEQ:
 606                 dev->net->stats.rx_errors++;
 607                 if (!timer_pending (&dev->delay)) {
 608                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 609                         netif_dbg(dev, link, dev->net,
 610                                   "rx throttle %d\n", urb_status);
 611                 }
 612 block:
 613                 state = rx_cleanup;
 614                 entry->urb = urb;
 615                 urb = NULL;
 616                 break;
 617
 618         /* data overrun ... flush fifo? */
 619         case -EOVERFLOW:
 620                 dev->net->stats.rx_over_errors++;
 621                 // FALLTHROUGH
 622
 623         default:
 624                 state = rx_cleanup;
 625                 dev->net->stats.rx_errors++;
 626                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 627                 break;
 628         }
 629
 630         /* stop rx if packet error rate is high */
 631         if (++dev->pkt_cnt > 30) {
 632                 dev->pkt_cnt = 0;
 633                 dev->pkt_err = 0;
 634         } else {
 635                 if (state == rx_cleanup)
 636                         dev->pkt_err++;
 637                 if (dev->pkt_err > 20)
 638                         set_bit(EVENT_RX_KILL, &dev->flags);
 639         }
 640
 641         state = defer_bh(dev, skb, &dev->rxq, state);
 642
 643         if (urb) {
 644                 if (netif_running (dev->net) &&
 645                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 646                     state != unlink_start) {
 647                         rx_submit (dev, urb, GFP_ATOMIC);
 648                         usb_mark_last_busy(dev->udev);
 649                         return;
 650                 }
 651                 usb_free_urb (urb);
 652         }
 653         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 654 }
 655
 656 /*-------------------------------------------------------------------------*/
 657 void usbnet_pause_rx(struct usbnet *dev)
 658 {
 659         set_bit(EVENT_RX_PAUSED, &dev->flags);
 660
 661         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 662 }
 663 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 664
 665 void usbnet_resume_rx(struct usbnet *dev)
 666 {
 667         struct sk_buff *skb;
 668         int num = 0;
 669
 670         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 671
 672         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 673                 usbnet_skb_return(dev, skb);
 674                 num++;
 675         }
 676
 677         tasklet_schedule(&dev->bh);
 678
 679         netif_dbg(dev, rx_status, dev->net,
 680                   "paused rx queue disabled, %d skbs requeued\n", num);
 681 }
 682 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 683
 684 void usbnet_purge_paused_rxq(struct usbnet *dev)
 685 {
 686         skb_queue_purge(&dev->rxq_pause);
 687 }
 688 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 689
 690 /*-------------------------------------------------------------------------*/
 691
 692 // unlink pending rx/tx; completion handlers do all other cleanup
 693
 694 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 695 {
 696         unsigned long           flags;
 697         struct sk_buff          *skb;
 698         int                     count = 0;
 699
 700         spin_lock_irqsave (&q->lock, flags);
 701         while (!skb_queue_empty(q)) {
 702                 struct skb_data         *entry;
 703                 struct urb              *urb;
 704                 int                     retval;
 705
 706                 skb_queue_walk(q, skb) {
 707                         entry = (struct skb_data *) skb->cb;
 708                         if (entry->state != unlink_start)
 709                                 goto found;
 710                 }
 711                 break;
 712 found:
 713                 entry->state = unlink_start;
 714                 urb = entry->urb;
 715
 716                 /*
 717                  * Get reference count of the URB to avoid it to be
 718                  * freed during usb_unlink_urb, which may trigger
 719                  * use-after-free problem inside usb_unlink_urb since
 720                  * usb_unlink_urb is always racing with .complete
 721                  * handler(include defer_bh).
 722                  */
 723                 usb_get_urb(urb);
 724                 spin_unlock_irqrestore(&q->lock, flags);
 725                 // during some PM-driven resume scenarios,
 726                 // these (async) unlinks complete immediately
 727                 retval = usb_unlink_urb (urb);
 728                 if (retval != -EINPROGRESS && retval != 0)
 729                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 730                 else
 731                         count++;
 732                 usb_put_urb(urb);
 733                 spin_lock_irqsave(&q->lock, flags);
 734         }
 735         spin_unlock_irqrestore (&q->lock, flags);
 736         return count;
 737 }
 738
 739 // Flush all pending rx urbs
 740 // minidrivers may need to do this when the MTU changes
 741
 742 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 743 {
 744         if (netif_running(dev->net)) {
 745                 (void) unlink_urbs (dev, &dev->rxq);
 746                 tasklet_schedule(&dev->bh);
 747         }
 748 }
 749 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 750
 751 /*-------------------------------------------------------------------------*/
 752
 753 // precondition: never called in_interrupt
 754 static void usbnet_terminate_urbs(struct usbnet *dev)
 755 {
 756         DECLARE_WAITQUEUE(wait, current);
 757         int temp;
 758
 759         /* ensure there are no more active urbs */
 760         add_wait_queue(&dev->wait, &wait);
 761         set_current_state(TASK_UNINTERRUPTIBLE);
 762         temp = unlink_urbs(dev, &dev->txq) +
 763                 unlink_urbs(dev, &dev->rxq);
 764
 765         /* maybe wait for deletions to finish. */
 766         while (!skb_queue_empty(&dev->rxq)
 767                 && !skb_queue_empty(&dev->txq)
 768                 && !skb_queue_empty(&dev->done)) {
 769                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 770                         set_current_state(TASK_UNINTERRUPTIBLE);
 771                         netif_dbg(dev, ifdown, dev->net,
 772                                   "waited for %d urb completions\n", temp);
 773         }
 774         set_current_state(TASK_RUNNING);
 775         remove_wait_queue(&dev->wait, &wait);
 776 }
 777
 778 int usbnet_stop (struct net_device *net)
 779 {
 780         struct usbnet           *dev = netdev_priv(net);
 781         struct driver_info      *info = dev->driver_info;
 782         int                     retval, pm;
 783
 784         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 785         netif_stop_queue (net);
 786
 787         netif_info(dev, ifdown, dev->net,
 788                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 789                    net->stats.rx_packets, net->stats.tx_packets,
 790                    net->stats.rx_errors, net->stats.tx_errors);
 791
 792         /* to not race resume */
 793         pm = usb_autopm_get_interface(dev->intf);
 794         /* allow minidriver to stop correctly (wireless devices to turn off
 795          * radio etc) */
 796         if (info->stop) {
 797                 retval = info->stop(dev);
 798                 if (retval < 0)
 799                         netif_info(dev, ifdown, dev->net,
 800                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 801                                    retval,
 802                                    dev->udev->bus->bus_name, dev->udev->devpath,
 803                                    info->description);
 804         }
 805
 806         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 807                 usbnet_terminate_urbs(dev);
 808
 809         usbnet_status_stop(dev);
 810
 811         usbnet_purge_paused_rxq(dev);
 812
 813         /* deferred work (task, timer, softirq) must also stop.
 814          * can't flush_scheduled_work() until we drop rtnl (later),
 815          * else workers could deadlock; so make workers a NOP.
 816          */
 817         dev->flags = 0;
 818         del_timer_sync (&dev->delay);
 819         tasklet_kill (&dev->bh);
 820         if (!pm)
 821                 usb_autopm_put_interface(dev->intf);
 822
 823         if (info->manage_power &&
 824             !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
 825                 info->manage_power(dev, 0);
 826         else
 827                 usb_autopm_put_interface(dev->intf);
 828
 829         return 0;
 830 }
 831 EXPORT_SYMBOL_GPL(usbnet_stop);
 832
 833 /*-------------------------------------------------------------------------*/
 834
 835 // posts reads, and enables write queuing
 836
 837 // precondition: never called in_interrupt
 838
 839 int usbnet_open (struct net_device *net)
 840 {
 841         struct usbnet           *dev = netdev_priv(net);
 842         int                     retval;
 843         struct driver_info      *info = dev->driver_info;
 844
 845         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 846                 netif_info(dev, ifup, dev->net,
 847                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 848                            retval,
 849                            dev->udev->bus->bus_name,
 850                            dev->udev->devpath,
 851                            info->description);
 852                 goto done_nopm;
 853         }
 854
 855         // put into "known safe" state
 856         if (info->reset && (retval = info->reset (dev)) < 0) {
 857                 netif_info(dev, ifup, dev->net,
 858                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 859                            retval,
 860                            dev->udev->bus->bus_name,
 861                            dev->udev->devpath,
 862                            info->description);
 863                 goto done;
 864         }
 865
 866         /* hard_mtu or rx_urb_size may change in reset() */
 867         usbnet_update_max_qlen(dev);
 868
 869         // insist peer be connected
 870         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 871                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 872                 goto done;
 873         }
 874
 875         /* start any status interrupt transfer */
 876         if (dev->interrupt) {
 877                 retval = usbnet_status_start(dev, GFP_KERNEL);
 878                 if (retval < 0) {
 879                         netif_err(dev, ifup, dev->net,
 880                                   "intr submit %d\n", retval);
 881                         goto done;
 882                 }
 883         }
 884
 885         set_bit(EVENT_DEV_OPEN, &dev->flags);
 886         netif_start_queue (net);
 887         netif_info(dev, ifup, dev->net,
 888                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 889                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 890                    dev->net->mtu,
 891                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 892                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 893                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 894                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 895                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 896                    "simple");
 897
 898         /* reset rx error state */
 899         dev->pkt_cnt = 0;
 900         dev->pkt_err = 0;
 901         clear_bit(EVENT_RX_KILL, &dev->flags);
 902
 903         // delay posting reads until we're fully open
 904         tasklet_schedule (&dev->bh);
 905         if (info->manage_power) {
 906                 retval = info->manage_power(dev, 1);
 907                 if (retval < 0) {
 908                         retval = 0;
 909                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 910                 } else {
 911                         usb_autopm_put_interface(dev->intf);
 912                 }
 913         }
 914         return retval;
 915 done:
 916         usb_autopm_put_interface(dev->intf);
 917 done_nopm:
 918         return retval;
 919 }
 920 EXPORT_SYMBOL_GPL(usbnet_open);
 921
 922 /*-------------------------------------------------------------------------*/
 923
 924 /* ethtool methods; minidrivers may need to add some more, but
 925  * they'll probably want to use this base set.
 926  */
 927
 928 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 929 {
 930         struct usbnet *dev = netdev_priv(net);
 931
 932         if (!dev->mii.mdio_read)
 933                 return -EOPNOTSUPP;
 934
 935         return mii_ethtool_gset(&dev->mii, cmd);
 936 }
 937 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 938
 939 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 940 {
 941         struct usbnet *dev = netdev_priv(net);
 942         int retval;
 943
 944         if (!dev->mii.mdio_write)
 945                 return -EOPNOTSUPP;
 946
 947         retval = mii_ethtool_sset(&dev->mii, cmd);
 948
 949         /* link speed/duplex might have changed */
 950         if (dev->driver_info->link_reset)
 951                 dev->driver_info->link_reset(dev);
 952
 953         /* hard_mtu or rx_urb_size may change in link_reset() */
 954         usbnet_update_max_qlen(dev);
 955
 956         return retval;
 957
 958 }
 959 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 960
 961 u32 usbnet_get_link (struct net_device *net)
 962 {
 963         struct usbnet *dev = netdev_priv(net);
 964
 965         /* If a check_connect is defined, return its result */
 966         if (dev->driver_info->check_connect)
 967                 return dev->driver_info->check_connect (dev) == 0;
 968
 969         /* if the device has mii operations, use those */
 970         if (dev->mii.mdio_read)
 971                 return mii_link_ok(&dev->mii);
 972
 973         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 974         return ethtool_op_get_link(net);
 975 }
 976 EXPORT_SYMBOL_GPL(usbnet_get_link);
 977
 978 int usbnet_nway_reset(struct net_device *net)
 979 {
 980         struct usbnet *dev = netdev_priv(net);
 981
 982         if (!dev->mii.mdio_write)
 983                 return -EOPNOTSUPP;
 984
 985         return mii_nway_restart(&dev->mii);
 986 }
 987 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 988
 989 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 990 {
 991         struct usbnet *dev = netdev_priv(net);
 992
 993         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 994         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 995         strlcpy (info->fw_version, dev->driver_info->description,
 996                 sizeof info->fw_version);
 997         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 998 }
 999 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1000
1001 u32 usbnet_get_msglevel (struct net_device *net)
1002 {
1003         struct usbnet *dev = netdev_priv(net);
1004
1005         return dev->msg_enable;
1006 }
1007 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1008
1009 void usbnet_set_msglevel (struct net_device *net, u32 level)
1010 {
1011         struct usbnet *dev = netdev_priv(net);
1012
1013         dev->msg_enable = level;
1014 }
1015 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1016
1017 /* drivers may override default ethtool_ops in their bind() routine */
1018 static const struct ethtool_ops usbnet_ethtool_ops = {
1019         .get_settings           = usbnet_get_settings,
1020         .set_settings           = usbnet_set_settings,
1021         .get_link               = usbnet_get_link,
1022         .nway_reset             = usbnet_nway_reset,
1023         .get_drvinfo            = usbnet_get_drvinfo,
1024         .get_msglevel           = usbnet_get_msglevel,
1025         .set_msglevel           = usbnet_set_msglevel,
1026         .get_ts_info            = ethtool_op_get_ts_info,
1027 };
1028
1029 /*-------------------------------------------------------------------------*/
1030
1031 static void __handle_link_change(struct usbnet *dev)
1032 {
1033         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1034                 return;
1035
1036         if (!netif_carrier_ok(dev->net)) {
1037                 /* kill URBs for reading packets to save bus bandwidth */
1038                 unlink_urbs(dev, &dev->rxq);
1039
1040                 /*
1041                  * tx_timeout will unlink URBs for sending packets and
1042                  * tx queue is stopped by netcore after link becomes off
1043                  */
1044         } else {
1045                 /* submitting URBs for reading packets */
1046                 tasklet_schedule(&dev->bh);
1047         }
1048
1049         /* hard_mtu or rx_urb_size may change during link change */
1050         usbnet_update_max_qlen(dev);
1051
1052         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1053 }
1054
1055 /* work that cannot be done in interrupt context uses keventd.
1056  *
1057  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1058  * especially now that control transfers can be queued.
1059  */
1060 static void
1061 kevent (struct work_struct *work)
1062 {
1063         struct usbnet           *dev =
1064                 container_of(work, struct usbnet, kevent);
1065         int                     status;
1066
1067         /* usb_clear_halt() needs a thread context */
1068         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1069                 unlink_urbs (dev, &dev->txq);
1070                 status = usb_autopm_get_interface(dev->intf);
1071                 if (status < 0)
1072                         goto fail_pipe;
1073                 status = usb_clear_halt (dev->udev, dev->out);
1074                 usb_autopm_put_interface(dev->intf);
1075                 if (status < 0 &&
1076                     status != -EPIPE &&
1077                     status != -ESHUTDOWN) {
1078                         if (netif_msg_tx_err (dev))
1079 fail_pipe:
1080                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1081                                            status);
1082                 } else {
1083                         clear_bit (EVENT_TX_HALT, &dev->flags);
1084                         if (status != -ESHUTDOWN)
1085                                 netif_wake_queue (dev->net);
1086                 }
1087         }
1088         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1089                 unlink_urbs (dev, &dev->rxq);
1090                 status = usb_autopm_get_interface(dev->intf);
1091                 if (status < 0)
1092                         goto fail_halt;
1093                 status = usb_clear_halt (dev->udev, dev->in);
1094                 usb_autopm_put_interface(dev->intf);
1095                 if (status < 0 &&
1096                     status != -EPIPE &&
1097                     status != -ESHUTDOWN) {
1098                         if (netif_msg_rx_err (dev))
1099 fail_halt:
1100                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1101                                            status);
1102                 } else {
1103                         clear_bit (EVENT_RX_HALT, &dev->flags);
1104                         tasklet_schedule (&dev->bh);
1105                 }
1106         }
1107
1108         /* tasklet could resubmit itself forever if memory is tight */
1109         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1110                 struct urb      *urb = NULL;
1111                 int resched = 1;
1112
1113                 if (netif_running (dev->net))
1114                         urb = usb_alloc_urb (0, GFP_KERNEL);
1115                 else
1116                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1117                 if (urb != NULL) {
1118                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1119                         status = usb_autopm_get_interface(dev->intf);
1120                         if (status < 0) {
1121                                 usb_free_urb(urb);
1122                                 goto fail_lowmem;
1123                         }
1124                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1125                                 resched = 0;
1126                         usb_autopm_put_interface(dev->intf);
1127 fail_lowmem:
1128                         if (resched)
1129                                 tasklet_schedule (&dev->bh);
1130                 }
1131         }
1132
1133         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1134                 struct driver_info      *info = dev->driver_info;
1135                 int                     retval = 0;
1136
1137                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1138                 status = usb_autopm_get_interface(dev->intf);
1139                 if (status < 0)
1140                         goto skip_reset;
1141                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1142                         usb_autopm_put_interface(dev->intf);
1143 skip_reset:
1144                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1145                                     retval,
1146                                     dev->udev->bus->bus_name,
1147                                     dev->udev->devpath,
1148                                     info->description);
1149                 } else {
1150                         usb_autopm_put_interface(dev->intf);
1151                 }
1152
1153                 /* handle link change from link resetting */
1154                 __handle_link_change(dev);
1155         }
1156
1157         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1158                 __handle_link_change(dev);
1159
1160         if (dev->flags)
1161                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1162 }
1163
1164 /*-------------------------------------------------------------------------*/
1165
1166 static void tx_complete (struct urb *urb)
1167 {
1168         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1169         struct skb_data         *entry = (struct skb_data *) skb->cb;
1170         struct usbnet           *dev = entry->dev;
1171
1172         if (urb->status == 0) {
1173                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1174                         dev->net->stats.tx_packets++;
1175                 dev->net->stats.tx_bytes += entry->length;
1176         } else {
1177                 dev->net->stats.tx_errors++;
1178
1179                 switch (urb->status) {
1180                 case -EPIPE:
1181                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1182                         break;
1183
1184                 /* software-driven interface shutdown */
1185                 case -ECONNRESET:               // async unlink
1186                 case -ESHUTDOWN:                // hardware gone
1187                         break;
1188
1189                 /* like rx, tx gets controller i/o faults during hub_wq
1190                  * delays and so it uses the same throttling mechanism.
1191                  */
1192                 case -EPROTO:
1193                 case -ETIME:
1194                 case -EILSEQ:
1195                         usb_mark_last_busy(dev->udev);
1196                         if (!timer_pending (&dev->delay)) {
1197                                 mod_timer (&dev->delay,
1198                                         jiffies + THROTTLE_JIFFIES);
1199                                 netif_dbg(dev, link, dev->net,
1200                                           "tx throttle %d\n", urb->status);
1201                         }
1202                         netif_stop_queue (dev->net);
1203                         break;
1204                 default:
1205                         netif_dbg(dev, tx_err, dev->net,
1206                                   "tx err %d\n", entry->urb->status);
1207                         break;
1208                 }
1209         }
1210
1211         usb_autopm_put_interface_async(dev->intf);
1212         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1213 }
1214
1215 /*-------------------------------------------------------------------------*/
1216
1217 void usbnet_tx_timeout (struct net_device *net)
1218 {
1219         struct usbnet           *dev = netdev_priv(net);
1220
1221         unlink_urbs (dev, &dev->txq);
1222         tasklet_schedule (&dev->bh);
1223         /* this needs to be handled individually because the generic layer
1224          * doesn't know what is sufficient and could not restore private
1225          * information if a remedy of an unconditional reset were used.
1226          */
1227         if (dev->driver_info->recover)
1228                 (dev->driver_info->recover)(dev);
1229 }
1230 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1231
1232 /*-------------------------------------------------------------------------*/
1233
1234 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1235 {
1236         unsigned num_sgs, total_len = 0;
1237         int i, s = 0;
1238
1239         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1240         if (num_sgs == 1)
1241                 return 0;
1242
1243         /* reserve one for zero packet */
1244         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1245                           GFP_ATOMIC);
1246         if (!urb->sg)
1247                 return -ENOMEM;
1248
1249         urb->num_sgs = num_sgs;
1250         sg_init_table(urb->sg, urb->num_sgs + 1);
1251
1252         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1253         total_len += skb_headlen(skb);
1254
1255         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1256                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1257
1258                 total_len += skb_frag_size(f);
1259                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1260                                 f->page_offset);
1261         }
1262         urb->transfer_buffer_length = total_len;
1263
1264         return 1;
1265 }
1266
1267 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1268                                      struct net_device *net)
1269 {
1270         struct usbnet           *dev = netdev_priv(net);
1271         int                     length;
1272         struct urb              *urb = NULL;
1273         struct skb_data         *entry;
1274         struct driver_info      *info = dev->driver_info;
1275         unsigned long           flags;
1276         int retval;
1277
1278         if (skb)
1279                 skb_tx_timestamp(skb);
1280
1281         // some devices want funky USB-level framing, for
1282         // win32 driver (usually) and/or hardware quirks
1283         if (info->tx_fixup) {
1284                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1285                 if (!skb) {
1286                         /* packet collected; minidriver waiting for more */
1287                         if (info->flags & FLAG_MULTI_PACKET)
1288                                 goto not_drop;
1289                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1290                         goto drop;
1291                 }
1292         }
1293
1294         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1295                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1296                 goto drop;
1297         }
1298
1299         entry = (struct skb_data *) skb->cb;
1300         entry->urb = urb;
1301         entry->dev = dev;
1302
1303         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1304                         skb->data, skb->len, tx_complete, skb);
1305         if (dev->can_dma_sg) {
1306                 if (build_dma_sg(skb, urb) < 0)
1307                         goto drop;
1308         }
1309         length = urb->transfer_buffer_length;
1310
1311         /* don't assume the hardware handles USB_ZERO_PACKET
1312          * NOTE:  strictly conforming cdc-ether devices should expect
1313          * the ZLP here, but ignore the one-byte packet.
1314          * NOTE2: CDC NCM specification is different from CDC ECM when
1315          * handling ZLP/short packets, so cdc_ncm driver will make short
1316          * packet itself if needed.
1317          */
1318         if (length % dev->maxpacket == 0) {
1319                 if (!(info->flags & FLAG_SEND_ZLP)) {
1320                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1321                                 length++;
1322                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1323                                         skb->data[skb->len] = 0;
1324                                         __skb_put(skb, 1);
1325                                 } else if (urb->num_sgs)
1326                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1327                                                         dev->padding_pkt, 1);
1328                         }
1329                 } else
1330                         urb->transfer_flags |= URB_ZERO_PACKET;
1331         }
1332         entry->length = urb->transfer_buffer_length = length;
1333
1334         spin_lock_irqsave(&dev->txq.lock, flags);
1335         retval = usb_autopm_get_interface_async(dev->intf);
1336         if (retval < 0) {
1337                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1338                 goto drop;
1339         }
1340
1341 #ifdef CONFIG_PM
1342         /* if this triggers the device is still a sleep */
1343         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1344                 /* transmission will be done in resume */
1345                 usb_anchor_urb(urb, &dev->deferred);
1346                 /* no use to process more packets */
1347                 netif_stop_queue(net);
1348                 usb_put_urb(urb);
1349                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1350                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1351                 goto deferred;
1352         }
1353 #endif
1354
1355         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1356         case -EPIPE:
1357                 netif_stop_queue (net);
1358                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1359                 usb_autopm_put_interface_async(dev->intf);
1360                 break;
1361         default:
1362                 usb_autopm_put_interface_async(dev->intf);
1363                 netif_dbg(dev, tx_err, dev->net,
1364                           "tx: submit urb err %d\n", retval);
1365                 break;
1366         case 0:
1367                 net->trans_start = jiffies;
1368                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1369                 if (dev->txq.qlen >= TX_QLEN (dev))
1370                         netif_stop_queue (net);
1371         }
1372         spin_unlock_irqrestore (&dev->txq.lock, flags);
1373
1374         if (retval) {
1375                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1376 drop:
1377                 dev->net->stats.tx_dropped++;
1378 not_drop:
1379                 if (skb)
1380                         dev_kfree_skb_any (skb);
1381                 if (urb) {
1382                         kfree(urb->sg);
1383                         usb_free_urb(urb);
1384                 }
1385         } else
1386                 netif_dbg(dev, tx_queued, dev->net,
1387                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1388 #ifdef CONFIG_PM
1389 deferred:
1390 #endif
1391         return NETDEV_TX_OK;
1392 }
1393 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1394
1395 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1396 {
1397         struct urb      *urb;
1398         int             i;
1399         int             ret = 0;
1400
1401         /* don't refill the queue all at once */
1402         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1403                 urb = usb_alloc_urb(0, flags);
1404                 if (urb != NULL) {
1405                         ret = rx_submit(dev, urb, flags);
1406                         if (ret)
1407                                 goto err;
1408                 } else {
1409                         ret = -ENOMEM;
1410                         goto err;
1411                 }
1412         }
1413 err:
1414         return ret;
1415 }
1416
1417 /*-------------------------------------------------------------------------*/
1418
1419 // tasklet (work deferred from completions, in_irq) or timer
1420
1421 static void usbnet_bh (unsigned long param)
1422 {
1423         struct usbnet           *dev = (struct usbnet *) param;
1424         struct sk_buff          *skb;
1425         struct skb_data         *entry;
1426
1427         while ((skb = skb_dequeue (&dev->done))) {
1428                 entry = (struct skb_data *) skb->cb;
1429                 switch (entry->state) {
1430                 case rx_done:
1431                         entry->state = rx_cleanup;
1432                         rx_process (dev, skb);
1433                         continue;
1434                 case tx_done:
1435                         kfree(entry->urb->sg);
1436                 case rx_cleanup:
1437                         usb_free_urb (entry->urb);
1438                         dev_kfree_skb (skb);
1439                         continue;
1440                 default:
1441                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1442                 }
1443         }
1444
1445         /* restart RX again after disabling due to high error rate */
1446         clear_bit(EVENT_RX_KILL, &dev->flags);
1447
1448         /* waiting for all pending urbs to complete?
1449          * only then can we forgo submitting anew
1450          */
1451         if (waitqueue_active(&dev->wait)) {
1452                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1453                         wake_up_all(&dev->wait);
1454
1455         // or are we maybe short a few urbs?
1456         } else if (netif_running (dev->net) &&
1457                    netif_device_present (dev->net) &&
1458                    netif_carrier_ok(dev->net) &&
1459                    !timer_pending (&dev->delay) &&
1460                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1461                 int     temp = dev->rxq.qlen;
1462
1463                 if (temp < RX_QLEN(dev)) {
1464                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1465                                 return;
1466                         if (temp != dev->rxq.qlen)
1467                                 netif_dbg(dev, link, dev->net,
1468                                           "rxqlen %d --> %d\n",
1469                                           temp, dev->rxq.qlen);
1470                         if (dev->rxq.qlen < RX_QLEN(dev))
1471                                 tasklet_schedule (&dev->bh);
1472                 }
1473                 if (dev->txq.qlen < TX_QLEN (dev))
1474                         netif_wake_queue (dev->net);
1475         }
1476 }
1477
1478
1479 /*-------------------------------------------------------------------------
1480  *
1481  * USB Device Driver support
1482  *
1483  *-------------------------------------------------------------------------*/
1484
1485 // precondition: never called in_interrupt
1486
1487 void usbnet_disconnect (struct usb_interface *intf)
1488 {
1489         struct usbnet           *dev;
1490         struct usb_device       *xdev;
1491         struct net_device       *net;
1492
1493         dev = usb_get_intfdata(intf);
1494         usb_set_intfdata(intf, NULL);
1495         if (!dev)
1496                 return;
1497
1498         xdev = interface_to_usbdev (intf);
1499
1500         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1501                    intf->dev.driver->name,
1502                    xdev->bus->bus_name, xdev->devpath,
1503                    dev->driver_info->description);
1504
1505         net = dev->net;
1506         unregister_netdev (net);
1507
1508         cancel_work_sync(&dev->kevent);
1509
1510         usb_scuttle_anchored_urbs(&dev->deferred);
1511
1512         if (dev->driver_info->unbind)
1513                 dev->driver_info->unbind (dev, intf);
1514
1515         usb_kill_urb(dev->interrupt);
1516         usb_free_urb(dev->interrupt);
1517         kfree(dev->padding_pkt);
1518
1519         free_netdev(net);
1520 }
1521 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1522
1523 static const struct net_device_ops usbnet_netdev_ops = {
1524         .ndo_open               = usbnet_open,
1525         .ndo_stop               = usbnet_stop,
1526         .ndo_start_xmit         = usbnet_start_xmit,
1527         .ndo_tx_timeout         = usbnet_tx_timeout,
1528         .ndo_change_mtu         = usbnet_change_mtu,
1529         .ndo_set_mac_address    = eth_mac_addr,
1530         .ndo_validate_addr      = eth_validate_addr,
1531 };
1532
1533 /*-------------------------------------------------------------------------*/
1534
1535 // precondition: never called in_interrupt
1536
1537 static struct device_type wlan_type = {
1538         .name   = "wlan",
1539 };
1540
1541 static struct device_type wwan_type = {
1542         .name   = "wwan",
1543 };
1544
1545 int
1546 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1547 {
1548         struct usbnet                   *dev;
1549         struct net_device               *net;
1550         struct usb_host_interface       *interface;
1551         struct driver_info              *info;
1552         struct usb_device               *xdev;
1553         int                             status;
1554         const char                      *name;
1555         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1556
1557         /* usbnet already took usb runtime pm, so have to enable the feature
1558          * for usb interface, otherwise usb_autopm_get_interface may return
1559          * failure if RUNTIME_PM is enabled.
1560          */
1561         if (!driver->supports_autosuspend) {
1562                 driver->supports_autosuspend = 1;
1563                 pm_runtime_enable(&udev->dev);
1564         }
1565
1566         name = udev->dev.driver->name;
1567         info = (struct driver_info *) prod->driver_info;
1568         if (!info) {
1569                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1570                 return -ENODEV;
1571         }
1572         xdev = interface_to_usbdev (udev);
1573         interface = udev->cur_altsetting;
1574
1575         status = -ENOMEM;
1576
1577         // set up our own records
1578         net = alloc_etherdev(sizeof(*dev));
1579         if (!net)
1580                 goto out;
1581
1582         /* netdev_printk() needs this so do it as early as possible */
1583         SET_NETDEV_DEV(net, &udev->dev);
1584
1585         dev = netdev_priv(net);
1586         dev->udev = xdev;
1587         dev->intf = udev;
1588         dev->driver_info = info;
1589         dev->driver_name = name;
1590         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1591                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1592         init_waitqueue_head(&dev->wait);
1593         skb_queue_head_init (&dev->rxq);
1594         skb_queue_head_init (&dev->txq);
1595         skb_queue_head_init (&dev->done);
1596         skb_queue_head_init(&dev->rxq_pause);
1597         dev->bh.func = usbnet_bh;
1598         dev->bh.data = (unsigned long) dev;
1599         INIT_WORK (&dev->kevent, kevent);
1600         init_usb_anchor(&dev->deferred);
1601         dev->delay.function = usbnet_bh;
1602         dev->delay.data = (unsigned long) dev;
1603         init_timer (&dev->delay);
1604         mutex_init (&dev->phy_mutex);
1605         mutex_init(&dev->interrupt_mutex);
1606         dev->interrupt_count = 0;
1607
1608         dev->net = net;
1609         strcpy (net->name, "usb%d");
1610         memcpy (net->dev_addr, node_id, sizeof node_id);
1611
1612         /* rx and tx sides can use different message sizes;
1613          * bind() should set rx_urb_size in that case.
1614          */
1615         dev->hard_mtu = net->mtu + net->hard_header_len;
1616 #if 0
1617 // dma_supported() is deeply broken on almost all architectures
1618         // possible with some EHCI controllers
1619         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1620                 net->features |= NETIF_F_HIGHDMA;
1621 #endif
1622
1623         net->netdev_ops = &usbnet_netdev_ops;
1624         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1625         net->ethtool_ops = &usbnet_ethtool_ops;
1626
1627         // allow device-specific bind/init procedures
1628         // NOTE net->name still not usable ...
1629         if (info->bind) {
1630                 status = info->bind (dev, udev);
1631                 if (status < 0)
1632                         goto out1;
1633
1634                 // heuristic:  "usb%d" for links we know are two-host,
1635                 // else "eth%d" when there's reasonable doubt.  userspace
1636                 // can rename the link if it knows better.
1637                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1638                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1639                      (net->dev_addr [0] & 0x02) == 0))
1640                         strcpy (net->name, "eth%d");
1641                 /* WLAN devices should always be named "wlan%d" */
1642                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1643                         strcpy(net->name, "wlan%d");
1644                 /* WWAN devices should always be named "wwan%d" */
1645                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1646                         strcpy(net->name, "wwan%d");
1647
1648                 /* devices that cannot do ARP */
1649                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1650                         net->flags |= IFF_NOARP;
1651
1652                 /* maybe the remote can't receive an Ethernet MTU */
1653                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1654                         net->mtu = dev->hard_mtu - net->hard_header_len;
1655         } else if (!info->in || !info->out)
1656                 status = usbnet_get_endpoints (dev, udev);
1657         else {
1658                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1659                 dev->out = usb_sndbulkpipe (xdev, info->out);
1660                 if (!(info->flags & FLAG_NO_SETINT))
1661                         status = usb_set_interface (xdev,
1662                                 interface->desc.bInterfaceNumber,
1663                                 interface->desc.bAlternateSetting);
1664                 else
1665                         status = 0;
1666
1667         }
1668         if (status >= 0 && dev->status)
1669                 status = init_status (dev, udev);
1670         if (status < 0)
1671                 goto out3;
1672
1673         if (!dev->rx_urb_size)
1674                 dev->rx_urb_size = dev->hard_mtu;
1675         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1676
1677         /* let userspace know we have a random address */
1678         if (ether_addr_equal(net->dev_addr, node_id))
1679                 net->addr_assign_type = NET_ADDR_RANDOM;
1680
1681         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1682                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1683         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1684                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1685
1686         /* initialize max rx_qlen and tx_qlen */
1687         usbnet_update_max_qlen(dev);
1688
1689         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1690                 !(info->flags & FLAG_MULTI_PACKET)) {
1691                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1692                 if (!dev->padding_pkt) {
1693                         status = -ENOMEM;
1694                         goto out4;
1695                 }
1696         }
1697
1698         status = register_netdev (net);
1699         if (status)
1700                 goto out5;
1701         netif_info(dev, probe, dev->net,
1702                    "register '%s' at usb-%s-%s, %s, %pM\n",
1703                    udev->dev.driver->name,
1704                    xdev->bus->bus_name, xdev->devpath,
1705                    dev->driver_info->description,
1706                    net->dev_addr);
1707
1708         // ok, it's ready to go.
1709         usb_set_intfdata (udev, dev);
1710
1711         netif_device_attach (net);
1712
1713         if (dev->driver_info->flags & FLAG_LINK_INTR)
1714                 usbnet_link_change(dev, 0, 0);
1715
1716         return 0;
1717
1718 out5:
1719         kfree(dev->padding_pkt);
1720 out4:
1721         usb_free_urb(dev->interrupt);
1722 out3:
1723         if (info->unbind)
1724                 info->unbind (dev, udev);
1725 out1:
1726         free_netdev(net);
1727 out:
1728         return status;
1729 }
1730 EXPORT_SYMBOL_GPL(usbnet_probe);
1731
1732 /*-------------------------------------------------------------------------*/
1733
1734 /*
1735  * suspend the whole driver as soon as the first interface is suspended
1736  * resume only when the last interface is resumed
1737  */
1738
1739 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1740 {
1741         struct usbnet           *dev = usb_get_intfdata(intf);
1742
1743         if (!dev->suspend_count++) {
1744                 spin_lock_irq(&dev->txq.lock);
1745                 /* don't autosuspend while transmitting */
1746                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1747                         dev->suspend_count--;
1748                         spin_unlock_irq(&dev->txq.lock);
1749                         return -EBUSY;
1750                 } else {
1751                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1752                         spin_unlock_irq(&dev->txq.lock);
1753                 }
1754                 /*
1755                  * accelerate emptying of the rx and queues, to avoid
1756                  * having everything error out.
1757                  */
1758                 netif_device_detach (dev->net);
1759                 usbnet_terminate_urbs(dev);
1760                 __usbnet_status_stop_force(dev);
1761
1762                 /*
1763                  * reattach so runtime management can use and
1764                  * wake the device
1765                  */
1766                 netif_device_attach (dev->net);
1767         }
1768         return 0;
1769 }
1770 EXPORT_SYMBOL_GPL(usbnet_suspend);
1771
1772 int usbnet_resume (struct usb_interface *intf)
1773 {
1774         struct usbnet           *dev = usb_get_intfdata(intf);
1775         struct sk_buff          *skb;
1776         struct urb              *res;
1777         int                     retval;
1778
1779         if (!--dev->suspend_count) {
1780                 /* resume interrupt URB if it was previously submitted */
1781                 __usbnet_status_start_force(dev, GFP_NOIO);
1782
1783                 spin_lock_irq(&dev->txq.lock);
1784                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1785
1786                         skb = (struct sk_buff *)res->context;
1787                         retval = usb_submit_urb(res, GFP_ATOMIC);
1788                         if (retval < 0) {
1789                                 dev_kfree_skb_any(skb);
1790                                 kfree(res->sg);
1791                                 usb_free_urb(res);
1792                                 usb_autopm_put_interface_async(dev->intf);
1793                         } else {
1794                                 dev->net->trans_start = jiffies;
1795                                 __skb_queue_tail(&dev->txq, skb);
1796                         }
1797                 }
1798
1799                 smp_mb();
1800                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1801                 spin_unlock_irq(&dev->txq.lock);
1802
1803                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1804                         /* handle remote wakeup ASAP
1805                          * we cannot race against stop
1806                          */
1807                         if (netif_device_present(dev->net) &&
1808                                 !timer_pending(&dev->delay) &&
1809                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1810                                         rx_alloc_submit(dev, GFP_NOIO);
1811
1812                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1813                                 netif_tx_wake_all_queues(dev->net);
1814                         tasklet_schedule (&dev->bh);
1815                 }
1816         }
1817
1818         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1819                 usb_autopm_get_interface_no_resume(intf);
1820
1821         return 0;
1822 }
1823 EXPORT_SYMBOL_GPL(usbnet_resume);
1824
1825 /*
1826  * Either a subdriver implements manage_power, then it is assumed to always
1827  * be ready to be suspended or it reports the readiness to be suspended
1828  * explicitly
1829  */
1830 void usbnet_device_suggests_idle(struct usbnet *dev)
1831 {
1832         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1833                 dev->intf->needs_remote_wakeup = 1;
1834                 usb_autopm_put_interface_async(dev->intf);
1835         }
1836 }
1837 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1838
1839 /*
1840  * For devices that can do without special commands
1841  */
1842 int usbnet_manage_power(struct usbnet *dev, int on)
1843 {
1844         dev->intf->needs_remote_wakeup = on;
1845         return 0;
1846 }
1847 EXPORT_SYMBOL(usbnet_manage_power);
1848
1849 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1850 {
1851         /* update link after link is reseted */
1852         if (link && !need_reset)
1853                 netif_carrier_on(dev->net);
1854         else
1855                 netif_carrier_off(dev->net);
1856
1857         if (need_reset && link)
1858                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1859         else
1860                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1861 }
1862 EXPORT_SYMBOL(usbnet_link_change);
1863
1864 /*-------------------------------------------------------------------------*/
1865 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1866                              u16 value, u16 index, void *data, u16 size)
1867 {
1868         void *buf = NULL;
1869         int err = -ENOMEM;
1870
1871         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1872                    " value=0x%04x index=0x%04x size=%d\n",
1873                    cmd, reqtype, value, index, size);
1874
1875         if (data) {
1876                 buf = kmalloc(size, GFP_KERNEL);
1877                 if (!buf)
1878                         goto out;
1879         }
1880
1881         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1882                               cmd, reqtype, value, index, buf, size,
1883                               USB_CTRL_GET_TIMEOUT);
1884         if (err > 0 && err <= size)
1885                 memcpy(data, buf, err);
1886         kfree(buf);
1887 out:
1888         return err;
1889 }
1890
1891 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1892                               u16 value, u16 index, const void *data,
1893                               u16 size)
1894 {
1895         void *buf = NULL;
1896         int err = -ENOMEM;
1897
1898         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1899                    " value=0x%04x index=0x%04x size=%d\n",
1900                    cmd, reqtype, value, index, size);
1901
1902         if (data) {
1903                 buf = kmemdup(data, size, GFP_KERNEL);
1904                 if (!buf)
1905                         goto out;
1906         }
1907
1908         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1909                               cmd, reqtype, value, index, buf, size,
1910                               USB_CTRL_SET_TIMEOUT);
1911         kfree(buf);
1912
1913 out:
1914         return err;
1915 }
1916
1917 /*
1918  * The function can't be called inside suspend/resume callback,
1919  * otherwise deadlock will be caused.
1920  */
1921 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1922                     u16 value, u16 index, void *data, u16 size)
1923 {
1924         int ret;
1925
1926         if (usb_autopm_get_interface(dev->intf) < 0)
1927                 return -ENODEV;
1928         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1929                                 data, size);
1930         usb_autopm_put_interface(dev->intf);
1931         return ret;
1932 }
1933 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1934
1935 /*
1936  * The function can't be called inside suspend/resume callback,
1937  * otherwise deadlock will be caused.
1938  */
1939 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1940                      u16 value, u16 index, const void *data, u16 size)
1941 {
1942         int ret;
1943
1944         if (usb_autopm_get_interface(dev->intf) < 0)
1945                 return -ENODEV;
1946         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1947                                  data, size);
1948         usb_autopm_put_interface(dev->intf);
1949         return ret;
1950 }
1951 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1952
1953 /*
1954  * The function can be called inside suspend/resume callback safely
1955  * and should only be called by suspend/resume callback generally.
1956  */
1957 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1958                           u16 value, u16 index, void *data, u16 size)
1959 {
1960         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1961                                  data, size);
1962 }
1963 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1964
1965 /*
1966  * The function can be called inside suspend/resume callback safely
1967  * and should only be called by suspend/resume callback generally.
1968  */
1969 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1970                           u16 value, u16 index, const void *data,
1971                           u16 size)
1972 {
1973         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1974                                   data, size);
1975 }
1976 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1977
1978 static void usbnet_async_cmd_cb(struct urb *urb)
1979 {
1980         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
1981         int status = urb->status;
1982
1983         if (status < 0)
1984                 dev_dbg(&urb->dev->dev, "%s failed with %d",
1985                         __func__, status);
1986
1987         kfree(req);
1988         usb_free_urb(urb);
1989 }
1990
1991 /*
1992  * The caller must make sure that device can't be put into suspend
1993  * state until the control URB completes.
1994  */
1995 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
1996                            u16 value, u16 index, const void *data, u16 size)
1997 {
1998         struct usb_ctrlrequest *req = NULL;
1999         struct urb *urb;
2000         int err = -ENOMEM;
2001         void *buf = NULL;
2002
2003         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2004                    " value=0x%04x index=0x%04x size=%d\n",
2005                    cmd, reqtype, value, index, size);
2006
2007         urb = usb_alloc_urb(0, GFP_ATOMIC);
2008         if (!urb) {
2009                 netdev_err(dev->net, "Error allocating URB in"
2010                            " %s!\n", __func__);
2011                 goto fail;
2012         }
2013
2014         if (data) {
2015                 buf = kmemdup(data, size, GFP_ATOMIC);
2016                 if (!buf) {
2017                         netdev_err(dev->net, "Error allocating buffer"
2018                                    " in %s!\n", __func__);
2019                         goto fail_free;
2020                 }
2021         }
2022
2023         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2024         if (!req)
2025                 goto fail_free_buf;
2026
2027         req->bRequestType = reqtype;
2028         req->bRequest = cmd;
2029         req->wValue = cpu_to_le16(value);
2030         req->wIndex = cpu_to_le16(index);
2031         req->wLength = cpu_to_le16(size);
2032
2033         usb_fill_control_urb(urb, dev->udev,
2034                              usb_sndctrlpipe(dev->udev, 0),
2035                              (void *)req, buf, size,
2036                              usbnet_async_cmd_cb, req);
2037         urb->transfer_flags |= URB_FREE_BUFFER;
2038
2039         err = usb_submit_urb(urb, GFP_ATOMIC);
2040         if (err < 0) {
2041                 netdev_err(dev->net, "Error submitting the control"
2042                            " message: status=%d\n", err);
2043                 goto fail_free;
2044         }
2045         return 0;
2046
2047 fail_free_buf:
2048         kfree(buf);
2049 fail_free:
2050         kfree(req);
2051         usb_free_urb(urb);
2052 fail:
2053         return err;
2054
2055 }
2056 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2057 /*-------------------------------------------------------------------------*/
2058
2059 static int __init usbnet_init(void)
2060 {
2061         /* Compiler should optimize this out. */
2062         BUILD_BUG_ON(
2063                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2064
2065         eth_random_addr(node_id);
2066         return 0;
2067 }
2068 module_init(usbnet_init);
2069
2070 static void __exit usbnet_exit(void)
2071 {
2072 }
2073 module_exit(usbnet_exit);
2074
2075 MODULE_AUTHOR("David Brownell");
2076 MODULE_DESCRIPTION("USB network driver framework");
2077 MODULE_LICENSE("GPL");