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 khubd might disconnect()
  73 // us (it polls at HZ/4 usually) before we report too many false errors.
  74 #define THROTTLE_JIFFIES        (HZ/8)
  75
  76 // between wakeups
  77 #define UNLINK_TIMEOUT_MS       3
  78
  79 /*-------------------------------------------------------------------------*/
  80
  81 // randomly generated ethernet address
  82 static u8       node_id [ETH_ALEN];
  83
  84 static const char driver_name [] = "usbnet";
  85
  86 /* use ethtool to change the level for any given device */
  87 static int msg_level = -1;
  88 module_param (msg_level, int, 0);
  89 MODULE_PARM_DESC (msg_level, "Override default message level");
  90
  91 /*-------------------------------------------------------------------------*/
  92
  93 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  94 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  95 {
  96         int                             tmp;
  97         struct usb_host_interface       *alt = NULL;
  98         struct usb_host_endpoint        *in = NULL, *out = NULL;
  99         struct usb_host_endpoint        *status = NULL;
 100
 101         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 102                 unsigned        ep;
 103
 104                 in = out = status = NULL;
 105                 alt = intf->altsetting + tmp;
 106
 107                 /* take the first altsetting with in-bulk + out-bulk;
 108                  * remember any status endpoint, just in case;
 109                  * ignore other endpoints and altsettings.
 110                  */
 111                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 112                         struct usb_host_endpoint        *e;
 113                         int                             intr = 0;
 114
 115                         e = alt->endpoint + ep;
 116                         switch (e->desc.bmAttributes) {
 117                         case USB_ENDPOINT_XFER_INT:
 118                                 if (!usb_endpoint_dir_in(&e->desc))
 119                                         continue;
 120                                 intr = 1;
 121                                 /* FALLTHROUGH */
 122                         case USB_ENDPOINT_XFER_BULK:
 123                                 break;
 124                         default:
 125                                 continue;
 126                         }
 127                         if (usb_endpoint_dir_in(&e->desc)) {
 128                                 if (!intr && !in)
 129                                         in = e;
 130                                 else if (intr && !status)
 131                                         status = e;
 132                         } else {
 133                                 if (!out)
 134                                         out = e;
 135                         }
 136                 }
 137                 if (in && out)
 138                         break;
 139         }
 140         if (!alt || !in || !out)
 141                 return -EINVAL;
 142
 143         if (alt->desc.bAlternateSetting != 0 ||
 144             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 145                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 146                                 alt->desc.bAlternateSetting);
 147                 if (tmp < 0)
 148                         return tmp;
 149         }
 150
 151         dev->in = usb_rcvbulkpipe (dev->udev,
 152                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 153         dev->out = usb_sndbulkpipe (dev->udev,
 154                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 155         dev->status = status;
 156         return 0;
 157 }
 158 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 159
 160 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 161 {
 162         int             tmp, i;
 163         unsigned char   buf [13];
 164
 165         tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 166         if (tmp != 12) {
 167                 dev_dbg(&dev->udev->dev,
 168                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 169                 if (tmp >= 0)
 170                         tmp = -EINVAL;
 171                 return tmp;
 172         }
 173         for (i = tmp = 0; i < 6; i++, tmp += 2)
 174                 dev->net->dev_addr [i] =
 175                         (hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 176         return 0;
 177 }
 178 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 179
 180 static void intr_complete (struct urb *urb)
 181 {
 182         struct usbnet   *dev = urb->context;
 183         int             status = urb->status;
 184
 185         switch (status) {
 186         /* success */
 187         case 0:
 188                 dev->driver_info->status(dev, urb);
 189                 break;
 190
 191         /* software-driven interface shutdown */
 192         case -ENOENT:           /* urb killed */
 193         case -ESHUTDOWN:        /* hardware gone */
 194                 netif_dbg(dev, ifdown, dev->net,
 195                           "intr shutdown, code %d\n", status);
 196                 return;
 197
 198         /* NOTE:  not throttling like RX/TX, since this endpoint
 199          * already polls infrequently
 200          */
 201         default:
 202                 netdev_dbg(dev->net, "intr status %d\n", status);
 203                 break;
 204         }
 205
 206         status = usb_submit_urb (urb, GFP_ATOMIC);
 207         if (status != 0)
 208                 netif_err(dev, timer, dev->net,
 209                           "intr resubmit --> %d\n", status);
 210 }
 211
 212 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 213 {
 214         char            *buf = NULL;
 215         unsigned        pipe = 0;
 216         unsigned        maxp;
 217         unsigned        period;
 218
 219         if (!dev->driver_info->status)
 220                 return 0;
 221
 222         pipe = usb_rcvintpipe (dev->udev,
 223                         dev->status->desc.bEndpointAddress
 224                                 & USB_ENDPOINT_NUMBER_MASK);
 225         maxp = usb_maxpacket (dev->udev, pipe, 0);
 226
 227         /* avoid 1 msec chatter:  min 8 msec poll rate */
 228         period = max ((int) dev->status->desc.bInterval,
 229                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 230
 231         buf = kmalloc (maxp, GFP_KERNEL);
 232         if (buf) {
 233                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 234                 if (!dev->interrupt) {
 235                         kfree (buf);
 236                         return -ENOMEM;
 237                 } else {
 238                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 239                                 buf, maxp, intr_complete, dev, period);
 240                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 241                         dev_dbg(&intf->dev,
 242                                 "status ep%din, %d bytes period %d\n",
 243                                 usb_pipeendpoint(pipe), maxp, period);
 244                 }
 245         }
 246         return 0;
 247 }
 248
 249 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 250 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 251 {
 252         int ret = 0;
 253
 254         WARN_ON_ONCE(dev->interrupt == NULL);
 255         if (dev->interrupt) {
 256                 mutex_lock(&dev->interrupt_mutex);
 257
 258                 if (++dev->interrupt_count == 1)
 259                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 260
 261                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 262                         dev->interrupt_count);
 263                 mutex_unlock(&dev->interrupt_mutex);
 264         }
 265         return ret;
 266 }
 267 EXPORT_SYMBOL_GPL(usbnet_status_start);
 268
 269 /* For resume; submit interrupt URB if previously submitted */
 270 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 271 {
 272         int ret = 0;
 273
 274         mutex_lock(&dev->interrupt_mutex);
 275         if (dev->interrupt_count) {
 276                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 277                 dev_dbg(&dev->udev->dev,
 278                         "submitted interrupt URB for resume\n");
 279         }
 280         mutex_unlock(&dev->interrupt_mutex);
 281         return ret;
 282 }
 283
 284 /* Kill the interrupt URB if all submitters want it killed */
 285 void usbnet_status_stop(struct usbnet *dev)
 286 {
 287         if (dev->interrupt) {
 288                 mutex_lock(&dev->interrupt_mutex);
 289                 WARN_ON(dev->interrupt_count == 0);
 290
 291                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 292                         usb_kill_urb(dev->interrupt);
 293
 294                 dev_dbg(&dev->udev->dev,
 295                         "decremented interrupt URB count to %d\n",
 296                         dev->interrupt_count);
 297                 mutex_unlock(&dev->interrupt_mutex);
 298         }
 299 }
 300 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 301
 302 /* For suspend; always kill interrupt URB */
 303 static void __usbnet_status_stop_force(struct usbnet *dev)
 304 {
 305         if (dev->interrupt) {
 306                 mutex_lock(&dev->interrupt_mutex);
 307                 usb_kill_urb(dev->interrupt);
 308                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 309                 mutex_unlock(&dev->interrupt_mutex);
 310         }
 311 }
 312
 313 /* Passes this packet up the stack, updating its accounting.
 314  * Some link protocols batch packets, so their rx_fixup paths
 315  * can return clones as well as just modify the original skb.
 316  */
 317 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 318 {
 319         int     status;
 320
 321         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 322                 skb_queue_tail(&dev->rxq_pause, skb);
 323                 return;
 324         }
 325
 326         skb->protocol = eth_type_trans (skb, dev->net);
 327         dev->net->stats.rx_packets++;
 328         dev->net->stats.rx_bytes += skb->len;
 329
 330         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 331                   skb->len + sizeof (struct ethhdr), skb->protocol);
 332         memset (skb->cb, 0, sizeof (struct skb_data));
 333
 334         if (skb_defer_rx_timestamp(skb))
 335                 return;
 336
 337         status = netif_rx (skb);
 338         if (status != NET_RX_SUCCESS)
 339                 netif_dbg(dev, rx_err, dev->net,
 340                           "netif_rx status %d\n", status);
 341 }
 342 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 343
 344 /* must be called if hard_mtu or rx_urb_size changed */
 345 void usbnet_update_max_qlen(struct usbnet *dev)
 346 {
 347         enum usb_device_speed speed = dev->udev->speed;
 348
 349         switch (speed) {
 350         case USB_SPEED_HIGH:
 351                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 352                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 353                 break;
 354         case USB_SPEED_SUPER:
 355                 /*
 356                  * Not take default 5ms qlen for super speed HC to
 357                  * save memory, and iperf tests show 2.5ms qlen can
 358                  * work well
 359                  */
 360                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 361                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 362                 break;
 363         default:
 364                 dev->rx_qlen = dev->tx_qlen = 4;
 365         }
 366 }
 367 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 368
 369 \f
 370 /*-------------------------------------------------------------------------
 371  *
 372  * Network Device Driver (peer link to "Host Device", from USB host)
 373  *
 374  *-------------------------------------------------------------------------*/
 375
 376 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 377 {
 378         struct usbnet   *dev = netdev_priv(net);
 379         int             ll_mtu = new_mtu + net->hard_header_len;
 380         int             old_hard_mtu = dev->hard_mtu;
 381         int             old_rx_urb_size = dev->rx_urb_size;
 382
 383         if (new_mtu <= 0)
 384                 return -EINVAL;
 385         // no second zero-length packet read wanted after mtu-sized packets
 386         if ((ll_mtu % dev->maxpacket) == 0)
 387                 return -EDOM;
 388         net->mtu = new_mtu;
 389
 390         dev->hard_mtu = net->mtu + net->hard_header_len;
 391         if (dev->rx_urb_size == old_hard_mtu) {
 392                 dev->rx_urb_size = dev->hard_mtu;
 393                 if (dev->rx_urb_size > old_rx_urb_size)
 394                         usbnet_unlink_rx_urbs(dev);
 395         }
 396
 397         /* max qlen depend on hard_mtu and rx_urb_size */
 398         usbnet_update_max_qlen(dev);
 399
 400         return 0;
 401 }
 402 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 403
 404 /* The caller must hold list->lock */
 405 static void __usbnet_queue_skb(struct sk_buff_head *list,
 406                         struct sk_buff *newsk, enum skb_state state)
 407 {
 408         struct skb_data *entry = (struct skb_data *) newsk->cb;
 409
 410         __skb_queue_tail(list, newsk);
 411         entry->state = state;
 412 }
 413
 414 /*-------------------------------------------------------------------------*/
 415
 416 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 417  * completion callbacks.  2.5 should have fixed those bugs...
 418  */
 419
 420 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 421                 struct sk_buff_head *list, enum skb_state state)
 422 {
 423         unsigned long           flags;
 424         enum skb_state          old_state;
 425         struct skb_data *entry = (struct skb_data *) skb->cb;
 426
 427         spin_lock_irqsave(&list->lock, flags);
 428         old_state = entry->state;
 429         entry->state = state;
 430         __skb_unlink(skb, list);
 431         spin_unlock(&list->lock);
 432         spin_lock(&dev->done.lock);
 433         __skb_queue_tail(&dev->done, skb);
 434         if (dev->done.qlen == 1)
 435                 tasklet_schedule(&dev->bh);
 436         spin_unlock_irqrestore(&dev->done.lock, flags);
 437         return old_state;
 438 }
 439
 440 /* some work can't be done in tasklets, so we use keventd
 441  *
 442  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 443  * but tasklet_schedule() doesn't.  hope the failure is rare.
 444  */
 445 void usbnet_defer_kevent (struct usbnet *dev, int work)
 446 {
 447         set_bit (work, &dev->flags);
 448         if (!schedule_work (&dev->kevent)) {
 449                 if (net_ratelimit())
 450                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 451         } else {
 452                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 453         }
 454 }
 455 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 456
 457 /*-------------------------------------------------------------------------*/
 458
 459 static void rx_complete (struct urb *urb);
 460
 461 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 462 {
 463         struct sk_buff          *skb;
 464         struct skb_data         *entry;
 465         int                     retval = 0;
 466         unsigned long           lockflags;
 467         size_t                  size = dev->rx_urb_size;
 468
 469         /* prevent rx skb allocation when error ratio is high */
 470         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 471                 usb_free_urb(urb);
 472                 return -ENOLINK;
 473         }
 474
 475         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 476         if (!skb) {
 477                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 478                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 479                 usb_free_urb (urb);
 480                 return -ENOMEM;
 481         }
 482
 483         entry = (struct skb_data *) skb->cb;
 484         entry->urb = urb;
 485         entry->dev = dev;
 486         entry->length = 0;
 487
 488         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 489                 skb->data, size, rx_complete, skb);
 490
 491         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 492
 493         if (netif_running (dev->net) &&
 494             netif_device_present (dev->net) &&
 495             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 496             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 497                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 498                 case -EPIPE:
 499                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 500                         break;
 501                 case -ENOMEM:
 502                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 503                         break;
 504                 case -ENODEV:
 505                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 506                         netif_device_detach (dev->net);
 507                         break;
 508                 case -EHOSTUNREACH:
 509                         retval = -ENOLINK;
 510                         break;
 511                 default:
 512                         netif_dbg(dev, rx_err, dev->net,
 513                                   "rx submit, %d\n", retval);
 514                         tasklet_schedule (&dev->bh);
 515                         break;
 516                 case 0:
 517                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 518                 }
 519         } else {
 520                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 521                 retval = -ENOLINK;
 522         }
 523         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 524         if (retval) {
 525                 dev_kfree_skb_any (skb);
 526                 usb_free_urb (urb);
 527         }
 528         return retval;
 529 }
 530
 531
 532 /*-------------------------------------------------------------------------*/
 533
 534 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 535 {
 536         if (dev->driver_info->rx_fixup &&
 537             !dev->driver_info->rx_fixup (dev, skb)) {
 538                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 539                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 540                         dev->net->stats.rx_errors++;
 541                 goto done;
 542         }
 543         // else network stack removes extra byte if we forced a short packet
 544
 545         if (skb->len) {
 546                 /* all data was already cloned from skb inside the driver */
 547                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 548                         dev_kfree_skb_any(skb);
 549                 else
 550                         usbnet_skb_return(dev, skb);
 551                 return;
 552         }
 553
 554         netif_dbg(dev, rx_err, dev->net, "drop\n");
 555         dev->net->stats.rx_errors++;
 556 done:
 557         skb_queue_tail(&dev->done, skb);
 558 }
 559
 560 /*-------------------------------------------------------------------------*/
 561
 562 static void rx_complete (struct urb *urb)
 563 {
 564         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 565         struct skb_data         *entry = (struct skb_data *) skb->cb;
 566         struct usbnet           *dev = entry->dev;
 567         int                     urb_status = urb->status;
 568         enum skb_state          state;
 569
 570         skb_put (skb, urb->actual_length);
 571         state = rx_done;
 572         entry->urb = NULL;
 573
 574         switch (urb_status) {
 575         /* success */
 576         case 0:
 577                 if (skb->len < dev->net->hard_header_len) {
 578                         state = rx_cleanup;
 579                         dev->net->stats.rx_errors++;
 580                         dev->net->stats.rx_length_errors++;
 581                         netif_dbg(dev, rx_err, dev->net,
 582                                   "rx length %d\n", skb->len);
 583                 }
 584                 break;
 585
 586         /* stalls need manual reset. this is rare ... except that
 587          * when going through USB 2.0 TTs, unplug appears this way.
 588          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 589          * storm, recovering as needed.
 590          */
 591         case -EPIPE:
 592                 dev->net->stats.rx_errors++;
 593                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 594                 // FALLTHROUGH
 595
 596         /* software-driven interface shutdown */
 597         case -ECONNRESET:               /* async unlink */
 598         case -ESHUTDOWN:                /* hardware gone */
 599                 netif_dbg(dev, ifdown, dev->net,
 600                           "rx shutdown, code %d\n", urb_status);
 601                 goto block;
 602
 603         /* we get controller i/o faults during khubd disconnect() delays.
 604          * throttle down resubmits, to avoid log floods; just temporarily,
 605          * so we still recover when the fault isn't a khubd delay.
 606          */
 607         case -EPROTO:
 608         case -ETIME:
 609         case -EILSEQ:
 610                 dev->net->stats.rx_errors++;
 611                 if (!timer_pending (&dev->delay)) {
 612                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 613                         netif_dbg(dev, link, dev->net,
 614                                   "rx throttle %d\n", urb_status);
 615                 }
 616 block:
 617                 state = rx_cleanup;
 618                 entry->urb = urb;
 619                 urb = NULL;
 620                 break;
 621
 622         /* data overrun ... flush fifo? */
 623         case -EOVERFLOW:
 624                 dev->net->stats.rx_over_errors++;
 625                 // FALLTHROUGH
 626
 627         default:
 628                 state = rx_cleanup;
 629                 dev->net->stats.rx_errors++;
 630                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 631                 break;
 632         }
 633
 634         /* stop rx if packet error rate is high */
 635         if (++dev->pkt_cnt > 30) {
 636                 dev->pkt_cnt = 0;
 637                 dev->pkt_err = 0;
 638         } else {
 639                 if (state == rx_cleanup)
 640                         dev->pkt_err++;
 641                 if (dev->pkt_err > 20)
 642                         set_bit(EVENT_RX_KILL, &dev->flags);
 643         }
 644
 645         state = defer_bh(dev, skb, &dev->rxq, state);
 646
 647         if (urb) {
 648                 if (netif_running (dev->net) &&
 649                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 650                     state != unlink_start) {
 651                         rx_submit (dev, urb, GFP_ATOMIC);
 652                         usb_mark_last_busy(dev->udev);
 653                         return;
 654                 }
 655                 usb_free_urb (urb);
 656         }
 657         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 658 }
 659
 660 /*-------------------------------------------------------------------------*/
 661 void usbnet_pause_rx(struct usbnet *dev)
 662 {
 663         set_bit(EVENT_RX_PAUSED, &dev->flags);
 664
 665         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 666 }
 667 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 668
 669 void usbnet_resume_rx(struct usbnet *dev)
 670 {
 671         struct sk_buff *skb;
 672         int num = 0;
 673
 674         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 675
 676         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 677                 usbnet_skb_return(dev, skb);
 678                 num++;
 679         }
 680
 681         tasklet_schedule(&dev->bh);
 682
 683         netif_dbg(dev, rx_status, dev->net,
 684                   "paused rx queue disabled, %d skbs requeued\n", num);
 685 }
 686 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 687
 688 void usbnet_purge_paused_rxq(struct usbnet *dev)
 689 {
 690         skb_queue_purge(&dev->rxq_pause);
 691 }
 692 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 693
 694 /*-------------------------------------------------------------------------*/
 695
 696 // unlink pending rx/tx; completion handlers do all other cleanup
 697
 698 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 699 {
 700         unsigned long           flags;
 701         struct sk_buff          *skb;
 702         int                     count = 0;
 703
 704         spin_lock_irqsave (&q->lock, flags);
 705         while (!skb_queue_empty(q)) {
 706                 struct skb_data         *entry;
 707                 struct urb              *urb;
 708                 int                     retval;
 709
 710                 skb_queue_walk(q, skb) {
 711                         entry = (struct skb_data *) skb->cb;
 712                         if (entry->state != unlink_start)
 713                                 goto found;
 714                 }
 715                 break;
 716 found:
 717                 entry->state = unlink_start;
 718                 urb = entry->urb;
 719
 720                 /*
 721                  * Get reference count of the URB to avoid it to be
 722                  * freed during usb_unlink_urb, which may trigger
 723                  * use-after-free problem inside usb_unlink_urb since
 724                  * usb_unlink_urb is always racing with .complete
 725                  * handler(include defer_bh).
 726                  */
 727                 usb_get_urb(urb);
 728                 spin_unlock_irqrestore(&q->lock, flags);
 729                 // during some PM-driven resume scenarios,
 730                 // these (async) unlinks complete immediately
 731                 retval = usb_unlink_urb (urb);
 732                 if (retval != -EINPROGRESS && retval != 0)
 733                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 734                 else
 735                         count++;
 736                 usb_put_urb(urb);
 737                 spin_lock_irqsave(&q->lock, flags);
 738         }
 739         spin_unlock_irqrestore (&q->lock, flags);
 740         return count;
 741 }
 742
 743 // Flush all pending rx urbs
 744 // minidrivers may need to do this when the MTU changes
 745
 746 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 747 {
 748         if (netif_running(dev->net)) {
 749                 (void) unlink_urbs (dev, &dev->rxq);
 750                 tasklet_schedule(&dev->bh);
 751         }
 752 }
 753 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 754
 755 /*-------------------------------------------------------------------------*/
 756
 757 // precondition: never called in_interrupt
 758 static void usbnet_terminate_urbs(struct usbnet *dev)
 759 {
 760         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 761         DECLARE_WAITQUEUE(wait, current);
 762         int temp;
 763
 764         /* ensure there are no more active urbs */
 765         add_wait_queue(&unlink_wakeup, &wait);
 766         set_current_state(TASK_UNINTERRUPTIBLE);
 767         dev->wait = &unlink_wakeup;
 768         temp = unlink_urbs(dev, &dev->txq) +
 769                 unlink_urbs(dev, &dev->rxq);
 770
 771         /* maybe wait for deletions to finish. */
 772         while (!skb_queue_empty(&dev->rxq)
 773                 && !skb_queue_empty(&dev->txq)
 774                 && !skb_queue_empty(&dev->done)) {
 775                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 776                         set_current_state(TASK_UNINTERRUPTIBLE);
 777                         netif_dbg(dev, ifdown, dev->net,
 778                                   "waited for %d urb completions\n", temp);
 779         }
 780         set_current_state(TASK_RUNNING);
 781         dev->wait = NULL;
 782         remove_wait_queue(&unlink_wakeup, &wait);
 783 }
 784
 785 int usbnet_stop (struct net_device *net)
 786 {
 787         struct usbnet           *dev = netdev_priv(net);
 788         struct driver_info      *info = dev->driver_info;
 789         int                     retval;
 790
 791         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 792         netif_stop_queue (net);
 793
 794         netif_info(dev, ifdown, dev->net,
 795                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 796                    net->stats.rx_packets, net->stats.tx_packets,
 797                    net->stats.rx_errors, net->stats.tx_errors);
 798
 799         /* allow minidriver to stop correctly (wireless devices to turn off
 800          * radio etc) */
 801         if (info->stop) {
 802                 retval = info->stop(dev);
 803                 if (retval < 0)
 804                         netif_info(dev, ifdown, dev->net,
 805                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 806                                    retval,
 807                                    dev->udev->bus->bus_name, dev->udev->devpath,
 808                                    info->description);
 809         }
 810
 811         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 812                 usbnet_terminate_urbs(dev);
 813
 814         usbnet_status_stop(dev);
 815
 816         usbnet_purge_paused_rxq(dev);
 817
 818         /* deferred work (task, timer, softirq) must also stop.
 819          * can't flush_scheduled_work() until we drop rtnl (later),
 820          * else workers could deadlock; so make workers a NOP.
 821          */
 822         dev->flags = 0;
 823         del_timer_sync (&dev->delay);
 824         tasklet_kill (&dev->bh);
 825         if (info->manage_power &&
 826             !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
 827                 info->manage_power(dev, 0);
 828         else
 829                 usb_autopm_put_interface(dev->intf);
 830
 831         return 0;
 832 }
 833 EXPORT_SYMBOL_GPL(usbnet_stop);
 834
 835 /*-------------------------------------------------------------------------*/
 836
 837 // posts reads, and enables write queuing
 838
 839 // precondition: never called in_interrupt
 840
 841 int usbnet_open (struct net_device *net)
 842 {
 843         struct usbnet           *dev = netdev_priv(net);
 844         int                     retval;
 845         struct driver_info      *info = dev->driver_info;
 846
 847         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 848                 netif_info(dev, ifup, dev->net,
 849                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 850                            retval,
 851                            dev->udev->bus->bus_name,
 852                            dev->udev->devpath,
 853                            info->description);
 854                 goto done_nopm;
 855         }
 856
 857         // put into "known safe" state
 858         if (info->reset && (retval = info->reset (dev)) < 0) {
 859                 netif_info(dev, ifup, dev->net,
 860                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 861                            retval,
 862                            dev->udev->bus->bus_name,
 863                            dev->udev->devpath,
 864                            info->description);
 865                 goto done;
 866         }
 867
 868         /* hard_mtu or rx_urb_size may change in reset() */
 869         usbnet_update_max_qlen(dev);
 870
 871         // insist peer be connected
 872         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 873                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 874                 goto done;
 875         }
 876
 877         /* start any status interrupt transfer */
 878         if (dev->interrupt) {
 879                 retval = usbnet_status_start(dev, GFP_KERNEL);
 880                 if (retval < 0) {
 881                         netif_err(dev, ifup, dev->net,
 882                                   "intr submit %d\n", retval);
 883                         goto done;
 884                 }
 885         }
 886
 887         set_bit(EVENT_DEV_OPEN, &dev->flags);
 888         netif_start_queue (net);
 889         netif_info(dev, ifup, dev->net,
 890                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 891                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 892                    dev->net->mtu,
 893                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 894                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 895                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 896                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 897                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 898                    "simple");
 899
 900         /* reset rx error state */
 901         dev->pkt_cnt = 0;
 902         dev->pkt_err = 0;
 903         clear_bit(EVENT_RX_KILL, &dev->flags);
 904
 905         // delay posting reads until we're fully open
 906         tasklet_schedule (&dev->bh);
 907         if (info->manage_power) {
 908                 retval = info->manage_power(dev, 1);
 909                 if (retval < 0) {
 910                         retval = 0;
 911                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 912                 } else {
 913                         usb_autopm_put_interface(dev->intf);
 914                 }
 915         }
 916         return retval;
 917 done:
 918         usb_autopm_put_interface(dev->intf);
 919 done_nopm:
 920         return retval;
 921 }
 922 EXPORT_SYMBOL_GPL(usbnet_open);
 923
 924 /*-------------------------------------------------------------------------*/
 925
 926 /* ethtool methods; minidrivers may need to add some more, but
 927  * they'll probably want to use this base set.
 928  */
 929
 930 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 931 {
 932         struct usbnet *dev = netdev_priv(net);
 933
 934         if (!dev->mii.mdio_read)
 935                 return -EOPNOTSUPP;
 936
 937         return mii_ethtool_gset(&dev->mii, cmd);
 938 }
 939 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 940
 941 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 942 {
 943         struct usbnet *dev = netdev_priv(net);
 944         int retval;
 945
 946         if (!dev->mii.mdio_write)
 947                 return -EOPNOTSUPP;
 948
 949         retval = mii_ethtool_sset(&dev->mii, cmd);
 950
 951         /* link speed/duplex might have changed */
 952         if (dev->driver_info->link_reset)
 953                 dev->driver_info->link_reset(dev);
 954
 955         /* hard_mtu or rx_urb_size may change in link_reset() */
 956         usbnet_update_max_qlen(dev);
 957
 958         return retval;
 959
 960 }
 961 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 962
 963 u32 usbnet_get_link (struct net_device *net)
 964 {
 965         struct usbnet *dev = netdev_priv(net);
 966
 967         /* If a check_connect is defined, return its result */
 968         if (dev->driver_info->check_connect)
 969                 return dev->driver_info->check_connect (dev) == 0;
 970
 971         /* if the device has mii operations, use those */
 972         if (dev->mii.mdio_read)
 973                 return mii_link_ok(&dev->mii);
 974
 975         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 976         return ethtool_op_get_link(net);
 977 }
 978 EXPORT_SYMBOL_GPL(usbnet_get_link);
 979
 980 int usbnet_nway_reset(struct net_device *net)
 981 {
 982         struct usbnet *dev = netdev_priv(net);
 983
 984         if (!dev->mii.mdio_write)
 985                 return -EOPNOTSUPP;
 986
 987         return mii_nway_restart(&dev->mii);
 988 }
 989 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 990
 991 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 992 {
 993         struct usbnet *dev = netdev_priv(net);
 994
 995         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 996         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 997         strlcpy (info->fw_version, dev->driver_info->description,
 998                 sizeof info->fw_version);
 999         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1000 }
1001 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1002
1003 u32 usbnet_get_msglevel (struct net_device *net)
1004 {
1005         struct usbnet *dev = netdev_priv(net);
1006
1007         return dev->msg_enable;
1008 }
1009 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1010
1011 void usbnet_set_msglevel (struct net_device *net, u32 level)
1012 {
1013         struct usbnet *dev = netdev_priv(net);
1014
1015         dev->msg_enable = level;
1016 }
1017 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1018
1019 /* drivers may override default ethtool_ops in their bind() routine */
1020 static const struct ethtool_ops usbnet_ethtool_ops = {
1021         .get_settings           = usbnet_get_settings,
1022         .set_settings           = usbnet_set_settings,
1023         .get_link               = usbnet_get_link,
1024         .nway_reset             = usbnet_nway_reset,
1025         .get_drvinfo            = usbnet_get_drvinfo,
1026         .get_msglevel           = usbnet_get_msglevel,
1027         .set_msglevel           = usbnet_set_msglevel,
1028         .get_ts_info            = ethtool_op_get_ts_info,
1029 };
1030
1031 /*-------------------------------------------------------------------------*/
1032
1033 static void __handle_link_change(struct usbnet *dev)
1034 {
1035         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1036                 return;
1037
1038         if (!netif_carrier_ok(dev->net)) {
1039                 /* kill URBs for reading packets to save bus bandwidth */
1040                 unlink_urbs(dev, &dev->rxq);
1041
1042                 /*
1043                  * tx_timeout will unlink URBs for sending packets and
1044                  * tx queue is stopped by netcore after link becomes off
1045                  */
1046         } else {
1047                 /* submitting URBs for reading packets */
1048                 tasklet_schedule(&dev->bh);
1049         }
1050
1051         /* hard_mtu or rx_urb_size may change during link change */
1052         usbnet_update_max_qlen(dev);
1053
1054         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1055 }
1056
1057 /* work that cannot be done in interrupt context uses keventd.
1058  *
1059  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1060  * especially now that control transfers can be queued.
1061  */
1062 static void
1063 kevent (struct work_struct *work)
1064 {
1065         struct usbnet           *dev =
1066                 container_of(work, struct usbnet, kevent);
1067         int                     status;
1068
1069         /* usb_clear_halt() needs a thread context */
1070         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1071                 unlink_urbs (dev, &dev->txq);
1072                 status = usb_autopm_get_interface(dev->intf);
1073                 if (status < 0)
1074                         goto fail_pipe;
1075                 status = usb_clear_halt (dev->udev, dev->out);
1076                 usb_autopm_put_interface(dev->intf);
1077                 if (status < 0 &&
1078                     status != -EPIPE &&
1079                     status != -ESHUTDOWN) {
1080                         if (netif_msg_tx_err (dev))
1081 fail_pipe:
1082                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1083                                            status);
1084                 } else {
1085                         clear_bit (EVENT_TX_HALT, &dev->flags);
1086                         if (status != -ESHUTDOWN)
1087                                 netif_wake_queue (dev->net);
1088                 }
1089         }
1090         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1091                 unlink_urbs (dev, &dev->rxq);
1092                 status = usb_autopm_get_interface(dev->intf);
1093                 if (status < 0)
1094                         goto fail_halt;
1095                 status = usb_clear_halt (dev->udev, dev->in);
1096                 usb_autopm_put_interface(dev->intf);
1097                 if (status < 0 &&
1098                     status != -EPIPE &&
1099                     status != -ESHUTDOWN) {
1100                         if (netif_msg_rx_err (dev))
1101 fail_halt:
1102                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1103                                            status);
1104                 } else {
1105                         clear_bit (EVENT_RX_HALT, &dev->flags);
1106                         tasklet_schedule (&dev->bh);
1107                 }
1108         }
1109
1110         /* tasklet could resubmit itself forever if memory is tight */
1111         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1112                 struct urb      *urb = NULL;
1113                 int resched = 1;
1114
1115                 if (netif_running (dev->net))
1116                         urb = usb_alloc_urb (0, GFP_KERNEL);
1117                 else
1118                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1119                 if (urb != NULL) {
1120                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1121                         status = usb_autopm_get_interface(dev->intf);
1122                         if (status < 0) {
1123                                 usb_free_urb(urb);
1124                                 goto fail_lowmem;
1125                         }
1126                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1127                                 resched = 0;
1128                         usb_autopm_put_interface(dev->intf);
1129 fail_lowmem:
1130                         if (resched)
1131                                 tasklet_schedule (&dev->bh);
1132                 }
1133         }
1134
1135         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1136                 struct driver_info      *info = dev->driver_info;
1137                 int                     retval = 0;
1138
1139                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1140                 status = usb_autopm_get_interface(dev->intf);
1141                 if (status < 0)
1142                         goto skip_reset;
1143                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1144                         usb_autopm_put_interface(dev->intf);
1145 skip_reset:
1146                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1147                                     retval,
1148                                     dev->udev->bus->bus_name,
1149                                     dev->udev->devpath,
1150                                     info->description);
1151                 } else {
1152                         usb_autopm_put_interface(dev->intf);
1153                 }
1154
1155                 /* handle link change from link resetting */
1156                 __handle_link_change(dev);
1157         }
1158
1159         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1160                 __handle_link_change(dev);
1161
1162         if (dev->flags)
1163                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1164 }
1165
1166 /*-------------------------------------------------------------------------*/
1167
1168 static void tx_complete (struct urb *urb)
1169 {
1170         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1171         struct skb_data         *entry = (struct skb_data *) skb->cb;
1172         struct usbnet           *dev = entry->dev;
1173
1174         if (urb->status == 0) {
1175                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1176                         dev->net->stats.tx_packets++;
1177                 dev->net->stats.tx_bytes += entry->length;
1178         } else {
1179                 dev->net->stats.tx_errors++;
1180
1181                 switch (urb->status) {
1182                 case -EPIPE:
1183                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1184                         break;
1185
1186                 /* software-driven interface shutdown */
1187                 case -ECONNRESET:               // async unlink
1188                 case -ESHUTDOWN:                // hardware gone
1189                         break;
1190
1191                 // like rx, tx gets controller i/o faults during khubd delays
1192                 // and so it uses the same throttling mechanism.
1193                 case -EPROTO:
1194                 case -ETIME:
1195                 case -EILSEQ:
1196                         usb_mark_last_busy(dev->udev);
1197                         if (!timer_pending (&dev->delay)) {
1198                                 mod_timer (&dev->delay,
1199                                         jiffies + THROTTLE_JIFFIES);
1200                                 netif_dbg(dev, link, dev->net,
1201                                           "tx throttle %d\n", urb->status);
1202                         }
1203                         netif_stop_queue (dev->net);
1204                         break;
1205                 default:
1206                         netif_dbg(dev, tx_err, dev->net,
1207                                   "tx err %d\n", entry->urb->status);
1208                         break;
1209                 }
1210         }
1211
1212         usb_autopm_put_interface_async(dev->intf);
1213         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1214 }
1215
1216 /*-------------------------------------------------------------------------*/
1217
1218 void usbnet_tx_timeout (struct net_device *net)
1219 {
1220         struct usbnet           *dev = netdev_priv(net);
1221
1222         unlink_urbs (dev, &dev->txq);
1223         tasklet_schedule (&dev->bh);
1224
1225         // FIXME: device recovery -- reset?
1226 }
1227 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1228
1229 /*-------------------------------------------------------------------------*/
1230
1231 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1232 {
1233         unsigned num_sgs, total_len = 0;
1234         int i, s = 0;
1235
1236         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1237         if (num_sgs == 1)
1238                 return 0;
1239
1240         /* reserve one for zero packet */
1241         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1242                           GFP_ATOMIC);
1243         if (!urb->sg)
1244                 return -ENOMEM;
1245
1246         urb->num_sgs = num_sgs;
1247         sg_init_table(urb->sg, urb->num_sgs);
1248
1249         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1250         total_len += skb_headlen(skb);
1251
1252         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1253                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1254
1255                 total_len += skb_frag_size(f);
1256                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1257                                 f->page_offset);
1258         }
1259         urb->transfer_buffer_length = total_len;
1260
1261         return 1;
1262 }
1263
1264 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1265                                      struct net_device *net)
1266 {
1267         struct usbnet           *dev = netdev_priv(net);
1268         int                     length;
1269         struct urb              *urb = NULL;
1270         struct skb_data         *entry;
1271         struct driver_info      *info = dev->driver_info;
1272         unsigned long           flags;
1273         int retval;
1274
1275         if (skb)
1276                 skb_tx_timestamp(skb);
1277
1278         // some devices want funky USB-level framing, for
1279         // win32 driver (usually) and/or hardware quirks
1280         if (info->tx_fixup) {
1281                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1282                 if (!skb) {
1283                         /* packet collected; minidriver waiting for more */
1284                         if (info->flags & FLAG_MULTI_PACKET)
1285                                 goto not_drop;
1286                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1287                         goto drop;
1288                 }
1289         }
1290
1291         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1292                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1293                 goto drop;
1294         }
1295
1296         entry = (struct skb_data *) skb->cb;
1297         entry->urb = urb;
1298         entry->dev = dev;
1299
1300         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1301                         skb->data, skb->len, tx_complete, skb);
1302         if (dev->can_dma_sg) {
1303                 if (build_dma_sg(skb, urb) < 0)
1304                         goto drop;
1305         }
1306         length = urb->transfer_buffer_length;
1307
1308         /* don't assume the hardware handles USB_ZERO_PACKET
1309          * NOTE:  strictly conforming cdc-ether devices should expect
1310          * the ZLP here, but ignore the one-byte packet.
1311          * NOTE2: CDC NCM specification is different from CDC ECM when
1312          * handling ZLP/short packets, so cdc_ncm driver will make short
1313          * packet itself if needed.
1314          */
1315         if (length % dev->maxpacket == 0) {
1316                 if (!(info->flags & FLAG_SEND_ZLP)) {
1317                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1318                                 length++;
1319                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1320                                         skb->data[skb->len] = 0;
1321                                         __skb_put(skb, 1);
1322                                 } else if (urb->num_sgs)
1323                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1324                                                         dev->padding_pkt, 1);
1325                         }
1326                 } else
1327                         urb->transfer_flags |= URB_ZERO_PACKET;
1328         }
1329         entry->length = urb->transfer_buffer_length = length;
1330
1331         spin_lock_irqsave(&dev->txq.lock, flags);
1332         retval = usb_autopm_get_interface_async(dev->intf);
1333         if (retval < 0) {
1334                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1335                 goto drop;
1336         }
1337
1338 #ifdef CONFIG_PM
1339         /* if this triggers the device is still a sleep */
1340         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1341                 /* transmission will be done in resume */
1342                 usb_anchor_urb(urb, &dev->deferred);
1343                 /* no use to process more packets */
1344                 netif_stop_queue(net);
1345                 usb_put_urb(urb);
1346                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1347                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1348                 goto deferred;
1349         }
1350 #endif
1351
1352         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1353         case -EPIPE:
1354                 netif_stop_queue (net);
1355                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1356                 usb_autopm_put_interface_async(dev->intf);
1357                 break;
1358         default:
1359                 usb_autopm_put_interface_async(dev->intf);
1360                 netif_dbg(dev, tx_err, dev->net,
1361                           "tx: submit urb err %d\n", retval);
1362                 break;
1363         case 0:
1364                 net->trans_start = jiffies;
1365                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1366                 if (dev->txq.qlen >= TX_QLEN (dev))
1367                         netif_stop_queue (net);
1368         }
1369         spin_unlock_irqrestore (&dev->txq.lock, flags);
1370
1371         if (retval) {
1372                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1373 drop:
1374                 dev->net->stats.tx_dropped++;
1375 not_drop:
1376                 if (skb)
1377                         dev_kfree_skb_any (skb);
1378                 if (urb) {
1379                         kfree(urb->sg);
1380                         usb_free_urb(urb);
1381                 }
1382         } else
1383                 netif_dbg(dev, tx_queued, dev->net,
1384                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1385 #ifdef CONFIG_PM
1386 deferred:
1387 #endif
1388         return NETDEV_TX_OK;
1389 }
1390 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1391
1392 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1393 {
1394         struct urb      *urb;
1395         int             i;
1396         int             ret = 0;
1397
1398         /* don't refill the queue all at once */
1399         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1400                 urb = usb_alloc_urb(0, flags);
1401                 if (urb != NULL) {
1402                         ret = rx_submit(dev, urb, flags);
1403                         if (ret)
1404                                 goto err;
1405                 } else {
1406                         ret = -ENOMEM;
1407                         goto err;
1408                 }
1409         }
1410 err:
1411         return ret;
1412 }
1413
1414 /*-------------------------------------------------------------------------*/
1415
1416 // tasklet (work deferred from completions, in_irq) or timer
1417
1418 static void usbnet_bh (unsigned long param)
1419 {
1420         struct usbnet           *dev = (struct usbnet *) param;
1421         struct sk_buff          *skb;
1422         struct skb_data         *entry;
1423
1424         while ((skb = skb_dequeue (&dev->done))) {
1425                 entry = (struct skb_data *) skb->cb;
1426                 switch (entry->state) {
1427                 case rx_done:
1428                         entry->state = rx_cleanup;
1429                         rx_process (dev, skb);
1430                         continue;
1431                 case tx_done:
1432                         kfree(entry->urb->sg);
1433                 case rx_cleanup:
1434                         usb_free_urb (entry->urb);
1435                         dev_kfree_skb (skb);
1436                         continue;
1437                 default:
1438                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1439                 }
1440         }
1441
1442         /* restart RX again after disabling due to high error rate */
1443         clear_bit(EVENT_RX_KILL, &dev->flags);
1444
1445         // waiting for all pending urbs to complete?
1446         if (dev->wait) {
1447                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1448                         wake_up (dev->wait);
1449                 }
1450
1451         // or are we maybe short a few urbs?
1452         } else if (netif_running (dev->net) &&
1453                    netif_device_present (dev->net) &&
1454                    netif_carrier_ok(dev->net) &&
1455                    !timer_pending (&dev->delay) &&
1456                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1457                 int     temp = dev->rxq.qlen;
1458
1459                 if (temp < RX_QLEN(dev)) {
1460                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1461                                 return;
1462                         if (temp != dev->rxq.qlen)
1463                                 netif_dbg(dev, link, dev->net,
1464                                           "rxqlen %d --> %d\n",
1465                                           temp, dev->rxq.qlen);
1466                         if (dev->rxq.qlen < RX_QLEN(dev))
1467                                 tasklet_schedule (&dev->bh);
1468                 }
1469                 if (dev->txq.qlen < TX_QLEN (dev))
1470                         netif_wake_queue (dev->net);
1471         }
1472 }
1473
1474
1475 /*-------------------------------------------------------------------------
1476  *
1477  * USB Device Driver support
1478  *
1479  *-------------------------------------------------------------------------*/
1480
1481 // precondition: never called in_interrupt
1482
1483 void usbnet_disconnect (struct usb_interface *intf)
1484 {
1485         struct usbnet           *dev;
1486         struct usb_device       *xdev;
1487         struct net_device       *net;
1488
1489         dev = usb_get_intfdata(intf);
1490         usb_set_intfdata(intf, NULL);
1491         if (!dev)
1492                 return;
1493
1494         xdev = interface_to_usbdev (intf);
1495
1496         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1497                    intf->dev.driver->name,
1498                    xdev->bus->bus_name, xdev->devpath,
1499                    dev->driver_info->description);
1500
1501         net = dev->net;
1502         unregister_netdev (net);
1503
1504         cancel_work_sync(&dev->kevent);
1505
1506         usb_scuttle_anchored_urbs(&dev->deferred);
1507
1508         if (dev->driver_info->unbind)
1509                 dev->driver_info->unbind (dev, intf);
1510
1511         usb_kill_urb(dev->interrupt);
1512         usb_free_urb(dev->interrupt);
1513         kfree(dev->padding_pkt);
1514
1515         free_netdev(net);
1516 }
1517 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1518
1519 static const struct net_device_ops usbnet_netdev_ops = {
1520         .ndo_open               = usbnet_open,
1521         .ndo_stop               = usbnet_stop,
1522         .ndo_start_xmit         = usbnet_start_xmit,
1523         .ndo_tx_timeout         = usbnet_tx_timeout,
1524         .ndo_change_mtu         = usbnet_change_mtu,
1525         .ndo_set_mac_address    = eth_mac_addr,
1526         .ndo_validate_addr      = eth_validate_addr,
1527 };
1528
1529 /*-------------------------------------------------------------------------*/
1530
1531 // precondition: never called in_interrupt
1532
1533 static struct device_type wlan_type = {
1534         .name   = "wlan",
1535 };
1536
1537 static struct device_type wwan_type = {
1538         .name   = "wwan",
1539 };
1540
1541 int
1542 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1543 {
1544         struct usbnet                   *dev;
1545         struct net_device               *net;
1546         struct usb_host_interface       *interface;
1547         struct driver_info              *info;
1548         struct usb_device               *xdev;
1549         int                             status;
1550         const char                      *name;
1551         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1552
1553         /* usbnet already took usb runtime pm, so have to enable the feature
1554          * for usb interface, otherwise usb_autopm_get_interface may return
1555          * failure if RUNTIME_PM is enabled.
1556          */
1557         if (!driver->supports_autosuspend) {
1558                 driver->supports_autosuspend = 1;
1559                 pm_runtime_enable(&udev->dev);
1560         }
1561
1562         name = udev->dev.driver->name;
1563         info = (struct driver_info *) prod->driver_info;
1564         if (!info) {
1565                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1566                 return -ENODEV;
1567         }
1568         xdev = interface_to_usbdev (udev);
1569         interface = udev->cur_altsetting;
1570
1571         status = -ENOMEM;
1572
1573         // set up our own records
1574         net = alloc_etherdev(sizeof(*dev));
1575         if (!net)
1576                 goto out;
1577
1578         /* netdev_printk() needs this so do it as early as possible */
1579         SET_NETDEV_DEV(net, &udev->dev);
1580
1581         dev = netdev_priv(net);
1582         dev->udev = xdev;
1583         dev->intf = udev;
1584         dev->driver_info = info;
1585         dev->driver_name = name;
1586         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1587                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1588         skb_queue_head_init (&dev->rxq);
1589         skb_queue_head_init (&dev->txq);
1590         skb_queue_head_init (&dev->done);
1591         skb_queue_head_init(&dev->rxq_pause);
1592         dev->bh.func = usbnet_bh;
1593         dev->bh.data = (unsigned long) dev;
1594         INIT_WORK (&dev->kevent, kevent);
1595         init_usb_anchor(&dev->deferred);
1596         dev->delay.function = usbnet_bh;
1597         dev->delay.data = (unsigned long) dev;
1598         init_timer (&dev->delay);
1599         mutex_init (&dev->phy_mutex);
1600         mutex_init(&dev->interrupt_mutex);
1601         dev->interrupt_count = 0;
1602
1603         dev->net = net;
1604         strcpy (net->name, "usb%d");
1605         memcpy (net->dev_addr, node_id, sizeof node_id);
1606
1607         /* rx and tx sides can use different message sizes;
1608          * bind() should set rx_urb_size in that case.
1609          */
1610         dev->hard_mtu = net->mtu + net->hard_header_len;
1611 #if 0
1612 // dma_supported() is deeply broken on almost all architectures
1613         // possible with some EHCI controllers
1614         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1615                 net->features |= NETIF_F_HIGHDMA;
1616 #endif
1617
1618         net->netdev_ops = &usbnet_netdev_ops;
1619         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1620         net->ethtool_ops = &usbnet_ethtool_ops;
1621
1622         // allow device-specific bind/init procedures
1623         // NOTE net->name still not usable ...
1624         if (info->bind) {
1625                 status = info->bind (dev, udev);
1626                 if (status < 0)
1627                         goto out1;
1628
1629                 // heuristic:  "usb%d" for links we know are two-host,
1630                 // else "eth%d" when there's reasonable doubt.  userspace
1631                 // can rename the link if it knows better.
1632                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1633                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1634                      (net->dev_addr [0] & 0x02) == 0))
1635                         strcpy (net->name, "eth%d");
1636                 /* WLAN devices should always be named "wlan%d" */
1637                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1638                         strcpy(net->name, "wlan%d");
1639                 /* WWAN devices should always be named "wwan%d" */
1640                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1641                         strcpy(net->name, "wwan%d");
1642
1643                 /* devices that cannot do ARP */
1644                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1645                         net->flags |= IFF_NOARP;
1646
1647                 /* maybe the remote can't receive an Ethernet MTU */
1648                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1649                         net->mtu = dev->hard_mtu - net->hard_header_len;
1650         } else if (!info->in || !info->out)
1651                 status = usbnet_get_endpoints (dev, udev);
1652         else {
1653                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1654                 dev->out = usb_sndbulkpipe (xdev, info->out);
1655                 if (!(info->flags & FLAG_NO_SETINT))
1656                         status = usb_set_interface (xdev,
1657                                 interface->desc.bInterfaceNumber,
1658                                 interface->desc.bAlternateSetting);
1659                 else
1660                         status = 0;
1661
1662         }
1663         if (status >= 0 && dev->status)
1664                 status = init_status (dev, udev);
1665         if (status < 0)
1666                 goto out3;
1667
1668         if (!dev->rx_urb_size)
1669                 dev->rx_urb_size = dev->hard_mtu;
1670         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1671
1672         /* let userspace know we have a random address */
1673         if (ether_addr_equal(net->dev_addr, node_id))
1674                 net->addr_assign_type = NET_ADDR_RANDOM;
1675
1676         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1677                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1678         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1679                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1680
1681         /* initialize max rx_qlen and tx_qlen */
1682         usbnet_update_max_qlen(dev);
1683
1684         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1685                 !(info->flags & FLAG_MULTI_PACKET)) {
1686                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1687                 if (!dev->padding_pkt) {
1688                         status = -ENOMEM;
1689                         goto out4;
1690                 }
1691         }
1692
1693         status = register_netdev (net);
1694         if (status)
1695                 goto out5;
1696         netif_info(dev, probe, dev->net,
1697                    "register '%s' at usb-%s-%s, %s, %pM\n",
1698                    udev->dev.driver->name,
1699                    xdev->bus->bus_name, xdev->devpath,
1700                    dev->driver_info->description,
1701                    net->dev_addr);
1702
1703         // ok, it's ready to go.
1704         usb_set_intfdata (udev, dev);
1705
1706         netif_device_attach (net);
1707
1708         if (dev->driver_info->flags & FLAG_LINK_INTR)
1709                 usbnet_link_change(dev, 0, 0);
1710
1711         return 0;
1712
1713 out5:
1714         kfree(dev->padding_pkt);
1715 out4:
1716         usb_free_urb(dev->interrupt);
1717 out3:
1718         if (info->unbind)
1719                 info->unbind (dev, udev);
1720 out1:
1721         free_netdev(net);
1722 out:
1723         return status;
1724 }
1725 EXPORT_SYMBOL_GPL(usbnet_probe);
1726
1727 /*-------------------------------------------------------------------------*/
1728
1729 /*
1730  * suspend the whole driver as soon as the first interface is suspended
1731  * resume only when the last interface is resumed
1732  */
1733
1734 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1735 {
1736         struct usbnet           *dev = usb_get_intfdata(intf);
1737
1738         if (!dev->suspend_count++) {
1739                 spin_lock_irq(&dev->txq.lock);
1740                 /* don't autosuspend while transmitting */
1741                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1742                         dev->suspend_count--;
1743                         spin_unlock_irq(&dev->txq.lock);
1744                         return -EBUSY;
1745                 } else {
1746                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1747                         spin_unlock_irq(&dev->txq.lock);
1748                 }
1749                 /*
1750                  * accelerate emptying of the rx and queues, to avoid
1751                  * having everything error out.
1752                  */
1753                 netif_device_detach (dev->net);
1754                 usbnet_terminate_urbs(dev);
1755                 __usbnet_status_stop_force(dev);
1756
1757                 /*
1758                  * reattach so runtime management can use and
1759                  * wake the device
1760                  */
1761                 netif_device_attach (dev->net);
1762         }
1763         return 0;
1764 }
1765 EXPORT_SYMBOL_GPL(usbnet_suspend);
1766
1767 int usbnet_resume (struct usb_interface *intf)
1768 {
1769         struct usbnet           *dev = usb_get_intfdata(intf);
1770         struct sk_buff          *skb;
1771         struct urb              *res;
1772         int                     retval;
1773
1774         if (!--dev->suspend_count) {
1775                 /* resume interrupt URB if it was previously submitted */
1776                 __usbnet_status_start_force(dev, GFP_NOIO);
1777
1778                 spin_lock_irq(&dev->txq.lock);
1779                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1780
1781                         skb = (struct sk_buff *)res->context;
1782                         retval = usb_submit_urb(res, GFP_ATOMIC);
1783                         if (retval < 0) {
1784                                 dev_kfree_skb_any(skb);
1785                                 kfree(res->sg);
1786                                 usb_free_urb(res);
1787                                 usb_autopm_put_interface_async(dev->intf);
1788                         } else {
1789                                 dev->net->trans_start = jiffies;
1790                                 __skb_queue_tail(&dev->txq, skb);
1791                         }
1792                 }
1793
1794                 smp_mb();
1795                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1796                 spin_unlock_irq(&dev->txq.lock);
1797
1798                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1799                         /* handle remote wakeup ASAP */
1800                         if (!dev->wait &&
1801                                 netif_device_present(dev->net) &&
1802                                 !timer_pending(&dev->delay) &&
1803                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1804                                         rx_alloc_submit(dev, GFP_NOIO);
1805
1806                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1807                                 netif_tx_wake_all_queues(dev->net);
1808                         tasklet_schedule (&dev->bh);
1809                 }
1810         }
1811
1812         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1813                 usb_autopm_get_interface_no_resume(intf);
1814
1815         return 0;
1816 }
1817 EXPORT_SYMBOL_GPL(usbnet_resume);
1818
1819 /*
1820  * Either a subdriver implements manage_power, then it is assumed to always
1821  * be ready to be suspended or it reports the readiness to be suspended
1822  * explicitly
1823  */
1824 void usbnet_device_suggests_idle(struct usbnet *dev)
1825 {
1826         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1827                 dev->intf->needs_remote_wakeup = 1;
1828                 usb_autopm_put_interface_async(dev->intf);
1829         }
1830 }
1831 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1832
1833 /*
1834  * For devices that can do without special commands
1835  */
1836 int usbnet_manage_power(struct usbnet *dev, int on)
1837 {
1838         dev->intf->needs_remote_wakeup = on;
1839         return 0;
1840 }
1841 EXPORT_SYMBOL(usbnet_manage_power);
1842
1843 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1844 {
1845         /* update link after link is reseted */
1846         if (link && !need_reset)
1847                 netif_carrier_on(dev->net);
1848         else
1849                 netif_carrier_off(dev->net);
1850
1851         if (need_reset && link)
1852                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1853         else
1854                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1855 }
1856 EXPORT_SYMBOL(usbnet_link_change);
1857
1858 /*-------------------------------------------------------------------------*/
1859 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1860                              u16 value, u16 index, void *data, u16 size)
1861 {
1862         void *buf = NULL;
1863         int err = -ENOMEM;
1864
1865         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1866                    " value=0x%04x index=0x%04x size=%d\n",
1867                    cmd, reqtype, value, index, size);
1868
1869         if (data) {
1870                 buf = kmalloc(size, GFP_KERNEL);
1871                 if (!buf)
1872                         goto out;
1873         }
1874
1875         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1876                               cmd, reqtype, value, index, buf, size,
1877                               USB_CTRL_GET_TIMEOUT);
1878         if (err > 0 && err <= size)
1879                 memcpy(data, buf, err);
1880         kfree(buf);
1881 out:
1882         return err;
1883 }
1884
1885 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1886                               u16 value, u16 index, const void *data,
1887                               u16 size)
1888 {
1889         void *buf = NULL;
1890         int err = -ENOMEM;
1891
1892         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1893                    " value=0x%04x index=0x%04x size=%d\n",
1894                    cmd, reqtype, value, index, size);
1895
1896         if (data) {
1897                 buf = kmemdup(data, size, GFP_KERNEL);
1898                 if (!buf)
1899                         goto out;
1900         }
1901
1902         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1903                               cmd, reqtype, value, index, buf, size,
1904                               USB_CTRL_SET_TIMEOUT);
1905         kfree(buf);
1906
1907 out:
1908         return err;
1909 }
1910
1911 /*
1912  * The function can't be called inside suspend/resume callback,
1913  * otherwise deadlock will be caused.
1914  */
1915 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1916                     u16 value, u16 index, void *data, u16 size)
1917 {
1918         int ret;
1919
1920         if (usb_autopm_get_interface(dev->intf) < 0)
1921                 return -ENODEV;
1922         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1923                                 data, size);
1924         usb_autopm_put_interface(dev->intf);
1925         return ret;
1926 }
1927 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1928
1929 /*
1930  * The function can't be called inside suspend/resume callback,
1931  * otherwise deadlock will be caused.
1932  */
1933 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1934                      u16 value, u16 index, const void *data, u16 size)
1935 {
1936         int ret;
1937
1938         if (usb_autopm_get_interface(dev->intf) < 0)
1939                 return -ENODEV;
1940         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1941                                  data, size);
1942         usb_autopm_put_interface(dev->intf);
1943         return ret;
1944 }
1945 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1946
1947 /*
1948  * The function can be called inside suspend/resume callback safely
1949  * and should only be called by suspend/resume callback generally.
1950  */
1951 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1952                           u16 value, u16 index, void *data, u16 size)
1953 {
1954         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1955                                  data, size);
1956 }
1957 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1958
1959 /*
1960  * The function can be called inside suspend/resume callback safely
1961  * and should only be called by suspend/resume callback generally.
1962  */
1963 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1964                           u16 value, u16 index, const void *data,
1965                           u16 size)
1966 {
1967         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1968                                   data, size);
1969 }
1970 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1971
1972 static void usbnet_async_cmd_cb(struct urb *urb)
1973 {
1974         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
1975         int status = urb->status;
1976
1977         if (status < 0)
1978                 dev_dbg(&urb->dev->dev, "%s failed with %d",
1979                         __func__, status);
1980
1981         kfree(req);
1982         usb_free_urb(urb);
1983 }
1984
1985 /*
1986  * The caller must make sure that device can't be put into suspend
1987  * state until the control URB completes.
1988  */
1989 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
1990                            u16 value, u16 index, const void *data, u16 size)
1991 {
1992         struct usb_ctrlrequest *req = NULL;
1993         struct urb *urb;
1994         int err = -ENOMEM;
1995         void *buf = NULL;
1996
1997         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1998                    " value=0x%04x index=0x%04x size=%d\n",
1999                    cmd, reqtype, value, index, size);
2000
2001         urb = usb_alloc_urb(0, GFP_ATOMIC);
2002         if (!urb) {
2003                 netdev_err(dev->net, "Error allocating URB in"
2004                            " %s!\n", __func__);
2005                 goto fail;
2006         }
2007
2008         if (data) {
2009                 buf = kmemdup(data, size, GFP_ATOMIC);
2010                 if (!buf) {
2011                         netdev_err(dev->net, "Error allocating buffer"
2012                                    " in %s!\n", __func__);
2013                         goto fail_free;
2014                 }
2015         }
2016
2017         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2018         if (!req)
2019                 goto fail_free_buf;
2020
2021         req->bRequestType = reqtype;
2022         req->bRequest = cmd;
2023         req->wValue = cpu_to_le16(value);
2024         req->wIndex = cpu_to_le16(index);
2025         req->wLength = cpu_to_le16(size);
2026
2027         usb_fill_control_urb(urb, dev->udev,
2028                              usb_sndctrlpipe(dev->udev, 0),
2029                              (void *)req, buf, size,
2030                              usbnet_async_cmd_cb, req);
2031         urb->transfer_flags |= URB_FREE_BUFFER;
2032
2033         err = usb_submit_urb(urb, GFP_ATOMIC);
2034         if (err < 0) {
2035                 netdev_err(dev->net, "Error submitting the control"
2036                            " message: status=%d\n", err);
2037                 goto fail_free;
2038         }
2039         return 0;
2040
2041 fail_free_buf:
2042         kfree(buf);
2043 fail_free:
2044         kfree(req);
2045         usb_free_urb(urb);
2046 fail:
2047         return err;
2048
2049 }
2050 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2051 /*-------------------------------------------------------------------------*/
2052
2053 static int __init usbnet_init(void)
2054 {
2055         /* Compiler should optimize this out. */
2056         BUILD_BUG_ON(
2057                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2058
2059         eth_random_addr(node_id);
2060         return 0;
2061 }
2062 module_init(usbnet_init);
2063
2064 static void __exit usbnet_exit(void)
2065 {
2066 }
2067 module_exit(usbnet_exit);
2068
2069 MODULE_AUTHOR("David Brownell");
2070 MODULE_DESCRIPTION("USB network driver framework");
2071 MODULE_LICENSE("GPL");