drivers/net/usb/usbnet.c

   1 /*
   2  * USB Network driver infrastructure
   3  * Copyright (C) 2000-2005 by David Brownell
   4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 /*
  22  * This is a generic "USB networking" framework that works with several
  23  * kinds of full and high speed networking devices:  host-to-host cables,
  24  * smart usb peripherals, and actual Ethernet adapters.
  25  *
  26  * These devices usually differ in terms of control protocols (if they
  27  * even have one!) and sometimes they define new framing to wrap or batch
  28  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  29  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  30  * issues can usefully be addressed by this framework.
  31  */
  32
  33 // #define      DEBUG                   // error path messages, extra info
  34 // #define      VERBOSE                 // more; success messages
  35
  36 #include <linux/module.h>
  37 #include <linux/init.h>
  38 #include <linux/netdevice.h>
  39 #include <linux/etherdevice.h>
  40 #include <linux/ctype.h>
  41 #include <linux/ethtool.h>
  42 #include <linux/workqueue.h>
  43 #include <linux/mii.h>
  44 #include <linux/usb.h>
  45 #include <linux/usb/usbnet.h>
  46 #include <linux/slab.h>
  47 #include <linux/kernel.h>
  48 #include <linux/pm_runtime.h>
  49
  50 #define DRIVER_VERSION          "22-Aug-2005"
  51
  52
  53 /*-------------------------------------------------------------------------*/
  54
  55 /*
  56  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  57  * Several dozen bytes of IPv4 data can fit in two such transactions.
  58  * One maximum size Ethernet packet takes twenty four of them.
  59  * For high speed, each frame comfortably fits almost 36 max size
  60  * Ethernet packets (so queues should be bigger).
  61  *
  62  * The goal is to let the USB host controller be busy for 5msec or
  63  * more before an irq is required, under load.  Jumbograms change
  64  * the equation.
  65  */
  66 #define MAX_QUEUE_MEMORY        (60 * 1518)
  67 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  68 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  69
  70 // reawaken network queue this soon after stopping; else watchdog barks
  71 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  72
  73 // throttle rx/tx briefly after some faults, so khubd might disconnect()
  74 // us (it polls at HZ/4 usually) before we report too many false errors.
  75 #define THROTTLE_JIFFIES        (HZ/8)
  76
  77 // between wakeups
  78 #define UNLINK_TIMEOUT_MS       3
  79
  80 /*-------------------------------------------------------------------------*/
  81
  82 // randomly generated ethernet address
  83 static u8       node_id [ETH_ALEN];
  84
  85 static const char driver_name [] = "usbnet";
  86
  87 /* use ethtool to change the level for any given device */
  88 static int msg_level = -1;
  89 module_param (msg_level, int, 0);
  90 MODULE_PARM_DESC (msg_level, "Override default message level");
  91
  92 /*-------------------------------------------------------------------------*/
  93
  94 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  95 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  96 {
  97         int                             tmp;
  98         struct usb_host_interface       *alt = NULL;
  99         struct usb_host_endpoint        *in = NULL, *out = NULL;
 100         struct usb_host_endpoint        *status = NULL;
 101
 102         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 103                 unsigned        ep;
 104
 105                 in = out = status = NULL;
 106                 alt = intf->altsetting + tmp;
 107
 108                 /* take the first altsetting with in-bulk + out-bulk;
 109                  * remember any status endpoint, just in case;
 110                  * ignore other endpoints and altsettings.
 111                  */
 112                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 113                         struct usb_host_endpoint        *e;
 114                         int                             intr = 0;
 115
 116                         e = alt->endpoint + ep;
 117                         switch (e->desc.bmAttributes) {
 118                         case USB_ENDPOINT_XFER_INT:
 119                                 if (!usb_endpoint_dir_in(&e->desc))
 120                                         continue;
 121                                 intr = 1;
 122                                 /* FALLTHROUGH */
 123                         case USB_ENDPOINT_XFER_BULK:
 124                                 break;
 125                         default:
 126                                 continue;
 127                         }
 128                         if (usb_endpoint_dir_in(&e->desc)) {
 129                                 if (!intr && !in)
 130                                         in = e;
 131                                 else if (intr && !status)
 132                                         status = e;
 133                         } else {
 134                                 if (!out)
 135                                         out = e;
 136                         }
 137                 }
 138                 if (in && out)
 139                         break;
 140         }
 141         if (!alt || !in || !out)
 142                 return -EINVAL;
 143
 144         if (alt->desc.bAlternateSetting != 0 ||
 145             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 146                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 147                                 alt->desc.bAlternateSetting);
 148                 if (tmp < 0)
 149                         return tmp;
 150         }
 151
 152         dev->in = usb_rcvbulkpipe (dev->udev,
 153                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 154         dev->out = usb_sndbulkpipe (dev->udev,
 155                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156         dev->status = status;
 157         return 0;
 158 }
 159 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 160
 161 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 162 {
 163         int             tmp, i;
 164         unsigned char   buf [13];
 165
 166         tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 167         if (tmp != 12) {
 168                 dev_dbg(&dev->udev->dev,
 169                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 170                 if (tmp >= 0)
 171                         tmp = -EINVAL;
 172                 return tmp;
 173         }
 174         for (i = tmp = 0; i < 6; i++, tmp += 2)
 175                 dev->net->dev_addr [i] =
 176                         (hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 177         return 0;
 178 }
 179 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 180
 181 static void intr_complete (struct urb *urb)
 182 {
 183         struct usbnet   *dev = urb->context;
 184         int             status = urb->status;
 185
 186         switch (status) {
 187         /* success */
 188         case 0:
 189                 dev->driver_info->status(dev, urb);
 190                 break;
 191
 192         /* software-driven interface shutdown */
 193         case -ENOENT:           /* urb killed */
 194         case -ESHUTDOWN:        /* hardware gone */
 195                 netif_dbg(dev, ifdown, dev->net,
 196                           "intr shutdown, code %d\n", status);
 197                 return;
 198
 199         /* NOTE:  not throttling like RX/TX, since this endpoint
 200          * already polls infrequently
 201          */
 202         default:
 203                 netdev_dbg(dev->net, "intr status %d\n", status);
 204                 break;
 205         }
 206
 207         if (!netif_running (dev->net))
 208                 return;
 209
 210         status = usb_submit_urb (urb, GFP_ATOMIC);
 211         if (status != 0)
 212                 netif_err(dev, timer, dev->net,
 213                           "intr resubmit --> %d\n", status);
 214 }
 215
 216 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 217 {
 218         char            *buf = NULL;
 219         unsigned        pipe = 0;
 220         unsigned        maxp;
 221         unsigned        period;
 222
 223         if (!dev->driver_info->status)
 224                 return 0;
 225
 226         pipe = usb_rcvintpipe (dev->udev,
 227                         dev->status->desc.bEndpointAddress
 228                                 & USB_ENDPOINT_NUMBER_MASK);
 229         maxp = usb_maxpacket (dev->udev, pipe, 0);
 230
 231         /* avoid 1 msec chatter:  min 8 msec poll rate */
 232         period = max ((int) dev->status->desc.bInterval,
 233                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 234
 235         buf = kmalloc (maxp, GFP_KERNEL);
 236         if (buf) {
 237                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 238                 if (!dev->interrupt) {
 239                         kfree (buf);
 240                         return -ENOMEM;
 241                 } else {
 242                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 243                                 buf, maxp, intr_complete, dev, period);
 244                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 245                         dev_dbg(&intf->dev,
 246                                 "status ep%din, %d bytes period %d\n",
 247                                 usb_pipeendpoint(pipe), maxp, period);
 248                 }
 249         }
 250         return 0;
 251 }
 252
 253 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 254 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 255 {
 256         int ret = 0;
 257
 258         WARN_ON_ONCE(dev->interrupt == NULL);
 259         if (dev->interrupt) {
 260                 mutex_lock(&dev->interrupt_mutex);
 261
 262                 if (++dev->interrupt_count == 1)
 263                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 264
 265                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 266                         dev->interrupt_count);
 267                 mutex_unlock(&dev->interrupt_mutex);
 268         }
 269         return ret;
 270 }
 271 EXPORT_SYMBOL_GPL(usbnet_status_start);
 272
 273 /* For resume; submit interrupt URB if previously submitted */
 274 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 275 {
 276         int ret = 0;
 277
 278         mutex_lock(&dev->interrupt_mutex);
 279         if (dev->interrupt_count) {
 280                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 281                 dev_dbg(&dev->udev->dev,
 282                         "submitted interrupt URB for resume\n");
 283         }
 284         mutex_unlock(&dev->interrupt_mutex);
 285         return ret;
 286 }
 287
 288 /* Kill the interrupt URB if all submitters want it killed */
 289 void usbnet_status_stop(struct usbnet *dev)
 290 {
 291         if (dev->interrupt) {
 292                 mutex_lock(&dev->interrupt_mutex);
 293                 WARN_ON(dev->interrupt_count == 0);
 294
 295                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 296                         usb_kill_urb(dev->interrupt);
 297
 298                 dev_dbg(&dev->udev->dev,
 299                         "decremented interrupt URB count to %d\n",
 300                         dev->interrupt_count);
 301                 mutex_unlock(&dev->interrupt_mutex);
 302         }
 303 }
 304 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 305
 306 /* For suspend; always kill interrupt URB */
 307 static void __usbnet_status_stop_force(struct usbnet *dev)
 308 {
 309         if (dev->interrupt) {
 310                 mutex_lock(&dev->interrupt_mutex);
 311                 usb_kill_urb(dev->interrupt);
 312                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 313                 mutex_unlock(&dev->interrupt_mutex);
 314         }
 315 }
 316
 317 /* Passes this packet up the stack, updating its accounting.
 318  * Some link protocols batch packets, so their rx_fixup paths
 319  * can return clones as well as just modify the original skb.
 320  */
 321 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 322 {
 323         int     status;
 324
 325         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 326                 skb_queue_tail(&dev->rxq_pause, skb);
 327                 return;
 328         }
 329
 330         skb->protocol = eth_type_trans (skb, dev->net);
 331         dev->net->stats.rx_packets++;
 332         dev->net->stats.rx_bytes += skb->len;
 333
 334         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 335                   skb->len + sizeof (struct ethhdr), skb->protocol);
 336         memset (skb->cb, 0, sizeof (struct skb_data));
 337
 338         if (skb_defer_rx_timestamp(skb))
 339                 return;
 340
 341         status = netif_rx (skb);
 342         if (status != NET_RX_SUCCESS)
 343                 netif_dbg(dev, rx_err, dev->net,
 344                           "netif_rx status %d\n", status);
 345 }
 346 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 347
 348 /* must be called if hard_mtu or rx_urb_size changed */
 349 void usbnet_update_max_qlen(struct usbnet *dev)
 350 {
 351         enum usb_device_speed speed = dev->udev->speed;
 352
 353         switch (speed) {
 354         case USB_SPEED_HIGH:
 355                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 356                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 357                 break;
 358         case USB_SPEED_SUPER:
 359                 /*
 360                  * Not take default 5ms qlen for super speed HC to
 361                  * save memory, and iperf tests show 2.5ms qlen can
 362                  * work well
 363                  */
 364                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 365                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 366                 break;
 367         default:
 368                 dev->rx_qlen = dev->tx_qlen = 4;
 369         }
 370 }
 371 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 372
 373 \f
 374 /*-------------------------------------------------------------------------
 375  *
 376  * Network Device Driver (peer link to "Host Device", from USB host)
 377  *
 378  *-------------------------------------------------------------------------*/
 379
 380 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 381 {
 382         struct usbnet   *dev = netdev_priv(net);
 383         int             ll_mtu = new_mtu + net->hard_header_len;
 384         int             old_hard_mtu = dev->hard_mtu;
 385         int             old_rx_urb_size = dev->rx_urb_size;
 386
 387         if (new_mtu <= 0)
 388                 return -EINVAL;
 389         // no second zero-length packet read wanted after mtu-sized packets
 390         if ((ll_mtu % dev->maxpacket) == 0)
 391                 return -EDOM;
 392         net->mtu = new_mtu;
 393
 394         dev->hard_mtu = net->mtu + net->hard_header_len;
 395         if (dev->rx_urb_size == old_hard_mtu) {
 396                 dev->rx_urb_size = dev->hard_mtu;
 397                 if (dev->rx_urb_size > old_rx_urb_size)
 398                         usbnet_unlink_rx_urbs(dev);
 399         }
 400
 401         /* max qlen depend on hard_mtu and rx_urb_size */
 402         usbnet_update_max_qlen(dev);
 403
 404         return 0;
 405 }
 406 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 407
 408 /* The caller must hold list->lock */
 409 static void __usbnet_queue_skb(struct sk_buff_head *list,
 410                         struct sk_buff *newsk, enum skb_state state)
 411 {
 412         struct skb_data *entry = (struct skb_data *) newsk->cb;
 413
 414         __skb_queue_tail(list, newsk);
 415         entry->state = state;
 416 }
 417
 418 /*-------------------------------------------------------------------------*/
 419
 420 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 421  * completion callbacks.  2.5 should have fixed those bugs...
 422  */
 423
 424 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 425                 struct sk_buff_head *list, enum skb_state state)
 426 {
 427         unsigned long           flags;
 428         enum skb_state          old_state;
 429         struct skb_data *entry = (struct skb_data *) skb->cb;
 430
 431         spin_lock_irqsave(&list->lock, flags);
 432         old_state = entry->state;
 433         entry->state = state;
 434         __skb_unlink(skb, list);
 435         spin_unlock(&list->lock);
 436         spin_lock(&dev->done.lock);
 437         __skb_queue_tail(&dev->done, skb);
 438         if (dev->done.qlen == 1)
 439                 tasklet_schedule(&dev->bh);
 440         spin_unlock_irqrestore(&dev->done.lock, flags);
 441         return old_state;
 442 }
 443
 444 /* some work can't be done in tasklets, so we use keventd
 445  *
 446  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 447  * but tasklet_schedule() doesn't.  hope the failure is rare.
 448  */
 449 void usbnet_defer_kevent (struct usbnet *dev, int work)
 450 {
 451         set_bit (work, &dev->flags);
 452         if (!schedule_work (&dev->kevent)) {
 453                 if (net_ratelimit())
 454                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 455         } else {
 456                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 457         }
 458 }
 459 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 460
 461 /*-------------------------------------------------------------------------*/
 462
 463 static void rx_complete (struct urb *urb);
 464
 465 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 466 {
 467         struct sk_buff          *skb;
 468         struct skb_data         *entry;
 469         int                     retval = 0;
 470         unsigned long           lockflags;
 471         size_t                  size = dev->rx_urb_size;
 472
 473         /* prevent rx skb allocation when error ratio is high */
 474         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 475                 usb_free_urb(urb);
 476                 return -ENOLINK;
 477         }
 478
 479         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 480         if (!skb) {
 481                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 482                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 483                 usb_free_urb (urb);
 484                 return -ENOMEM;
 485         }
 486
 487         entry = (struct skb_data *) skb->cb;
 488         entry->urb = urb;
 489         entry->dev = dev;
 490         entry->length = 0;
 491
 492         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 493                 skb->data, size, rx_complete, skb);
 494
 495         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 496
 497         if (netif_running (dev->net) &&
 498             netif_device_present (dev->net) &&
 499             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 500             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 501                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 502                 case -EPIPE:
 503                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 504                         break;
 505                 case -ENOMEM:
 506                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 507                         break;
 508                 case -ENODEV:
 509                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 510                         netif_device_detach (dev->net);
 511                         break;
 512                 case -EHOSTUNREACH:
 513                         retval = -ENOLINK;
 514                         break;
 515                 default:
 516                         netif_dbg(dev, rx_err, dev->net,
 517                                   "rx submit, %d\n", retval);
 518                         tasklet_schedule (&dev->bh);
 519                         break;
 520                 case 0:
 521                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 522                 }
 523         } else {
 524                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 525                 retval = -ENOLINK;
 526         }
 527         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 528         if (retval) {
 529                 dev_kfree_skb_any (skb);
 530                 usb_free_urb (urb);
 531         }
 532         return retval;
 533 }
 534
 535
 536 /*-------------------------------------------------------------------------*/
 537
 538 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 539 {
 540         if (dev->driver_info->rx_fixup &&
 541             !dev->driver_info->rx_fixup (dev, skb)) {
 542                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 543                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 544                         dev->net->stats.rx_errors++;
 545                 goto done;
 546         }
 547         // else network stack removes extra byte if we forced a short packet
 548
 549         if (skb->len) {
 550                 /* all data was already cloned from skb inside the driver */
 551                 if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 552                         dev_kfree_skb_any(skb);
 553                 else
 554                         usbnet_skb_return(dev, skb);
 555                 return;
 556         }
 557
 558         netif_dbg(dev, rx_err, dev->net, "drop\n");
 559         dev->net->stats.rx_errors++;
 560 done:
 561         skb_queue_tail(&dev->done, skb);
 562 }
 563
 564 /*-------------------------------------------------------------------------*/
 565
 566 static void rx_complete (struct urb *urb)
 567 {
 568         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 569         struct skb_data         *entry = (struct skb_data *) skb->cb;
 570         struct usbnet           *dev = entry->dev;
 571         int                     urb_status = urb->status;
 572         enum skb_state          state;
 573
 574         skb_put (skb, urb->actual_length);
 575         state = rx_done;
 576         entry->urb = NULL;
 577
 578         switch (urb_status) {
 579         /* success */
 580         case 0:
 581                 if (skb->len < dev->net->hard_header_len) {
 582                         state = rx_cleanup;
 583                         dev->net->stats.rx_errors++;
 584                         dev->net->stats.rx_length_errors++;
 585                         netif_dbg(dev, rx_err, dev->net,
 586                                   "rx length %d\n", skb->len);
 587                 }
 588                 break;
 589
 590         /* stalls need manual reset. this is rare ... except that
 591          * when going through USB 2.0 TTs, unplug appears this way.
 592          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 593          * storm, recovering as needed.
 594          */
 595         case -EPIPE:
 596                 dev->net->stats.rx_errors++;
 597                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 598                 // FALLTHROUGH
 599
 600         /* software-driven interface shutdown */
 601         case -ECONNRESET:               /* async unlink */
 602         case -ESHUTDOWN:                /* hardware gone */
 603                 netif_dbg(dev, ifdown, dev->net,
 604                           "rx shutdown, code %d\n", urb_status);
 605                 goto block;
 606
 607         /* we get controller i/o faults during khubd disconnect() delays.
 608          * throttle down resubmits, to avoid log floods; just temporarily,
 609          * so we still recover when the fault isn't a khubd delay.
 610          */
 611         case -EPROTO:
 612         case -ETIME:
 613         case -EILSEQ:
 614                 dev->net->stats.rx_errors++;
 615                 if (!timer_pending (&dev->delay)) {
 616                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 617                         netif_dbg(dev, link, dev->net,
 618                                   "rx throttle %d\n", urb_status);
 619                 }
 620 block:
 621                 state = rx_cleanup;
 622                 entry->urb = urb;
 623                 urb = NULL;
 624                 break;
 625
 626         /* data overrun ... flush fifo? */
 627         case -EOVERFLOW:
 628                 dev->net->stats.rx_over_errors++;
 629                 // FALLTHROUGH
 630
 631         default:
 632                 state = rx_cleanup;
 633                 dev->net->stats.rx_errors++;
 634                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 635                 break;
 636         }
 637
 638         /* stop rx if packet error rate is high */
 639         if (++dev->pkt_cnt > 30) {
 640                 dev->pkt_cnt = 0;
 641                 dev->pkt_err = 0;
 642         } else {
 643                 if (state == rx_cleanup)
 644                         dev->pkt_err++;
 645                 if (dev->pkt_err > 20)
 646                         set_bit(EVENT_RX_KILL, &dev->flags);
 647         }
 648
 649         state = defer_bh(dev, skb, &dev->rxq, state);
 650
 651         if (urb) {
 652                 if (netif_running (dev->net) &&
 653                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 654                     state != unlink_start) {
 655                         rx_submit (dev, urb, GFP_ATOMIC);
 656                         usb_mark_last_busy(dev->udev);
 657                         return;
 658                 }
 659                 usb_free_urb (urb);
 660         }
 661         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 662 }
 663
 664 /*-------------------------------------------------------------------------*/
 665 void usbnet_pause_rx(struct usbnet *dev)
 666 {
 667         set_bit(EVENT_RX_PAUSED, &dev->flags);
 668
 669         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 670 }
 671 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 672
 673 void usbnet_resume_rx(struct usbnet *dev)
 674 {
 675         struct sk_buff *skb;
 676         int num = 0;
 677
 678         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 679
 680         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 681                 usbnet_skb_return(dev, skb);
 682                 num++;
 683         }
 684
 685         tasklet_schedule(&dev->bh);
 686
 687         netif_dbg(dev, rx_status, dev->net,
 688                   "paused rx queue disabled, %d skbs requeued\n", num);
 689 }
 690 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 691
 692 void usbnet_purge_paused_rxq(struct usbnet *dev)
 693 {
 694         skb_queue_purge(&dev->rxq_pause);
 695 }
 696 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 697
 698 /*-------------------------------------------------------------------------*/
 699
 700 // unlink pending rx/tx; completion handlers do all other cleanup
 701
 702 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 703 {
 704         unsigned long           flags;
 705         struct sk_buff          *skb;
 706         int                     count = 0;
 707
 708         spin_lock_irqsave (&q->lock, flags);
 709         while (!skb_queue_empty(q)) {
 710                 struct skb_data         *entry;
 711                 struct urb              *urb;
 712                 int                     retval;
 713
 714                 skb_queue_walk(q, skb) {
 715                         entry = (struct skb_data *) skb->cb;
 716                         if (entry->state != unlink_start)
 717                                 goto found;
 718                 }
 719                 break;
 720 found:
 721                 entry->state = unlink_start;
 722                 urb = entry->urb;
 723
 724                 /*
 725                  * Get reference count of the URB to avoid it to be
 726                  * freed during usb_unlink_urb, which may trigger
 727                  * use-after-free problem inside usb_unlink_urb since
 728                  * usb_unlink_urb is always racing with .complete
 729                  * handler(include defer_bh).
 730                  */
 731                 usb_get_urb(urb);
 732                 spin_unlock_irqrestore(&q->lock, flags);
 733                 // during some PM-driven resume scenarios,
 734                 // these (async) unlinks complete immediately
 735                 retval = usb_unlink_urb (urb);
 736                 if (retval != -EINPROGRESS && retval != 0)
 737                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 738                 else
 739                         count++;
 740                 usb_put_urb(urb);
 741                 spin_lock_irqsave(&q->lock, flags);
 742         }
 743         spin_unlock_irqrestore (&q->lock, flags);
 744         return count;
 745 }
 746
 747 // Flush all pending rx urbs
 748 // minidrivers may need to do this when the MTU changes
 749
 750 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 751 {
 752         if (netif_running(dev->net)) {
 753                 (void) unlink_urbs (dev, &dev->rxq);
 754                 tasklet_schedule(&dev->bh);
 755         }
 756 }
 757 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 758
 759 /*-------------------------------------------------------------------------*/
 760
 761 // precondition: never called in_interrupt
 762 static void usbnet_terminate_urbs(struct usbnet *dev)
 763 {
 764         DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
 765         DECLARE_WAITQUEUE(wait, current);
 766         int temp;
 767
 768         /* ensure there are no more active urbs */
 769         add_wait_queue(&unlink_wakeup, &wait);
 770         set_current_state(TASK_UNINTERRUPTIBLE);
 771         dev->wait = &unlink_wakeup;
 772         temp = unlink_urbs(dev, &dev->txq) +
 773                 unlink_urbs(dev, &dev->rxq);
 774
 775         /* maybe wait for deletions to finish. */
 776         while (!skb_queue_empty(&dev->rxq)
 777                 && !skb_queue_empty(&dev->txq)
 778                 && !skb_queue_empty(&dev->done)) {
 779                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 780                         set_current_state(TASK_UNINTERRUPTIBLE);
 781                         netif_dbg(dev, ifdown, dev->net,
 782                                   "waited for %d urb completions\n", temp);
 783         }
 784         set_current_state(TASK_RUNNING);
 785         dev->wait = NULL;
 786         remove_wait_queue(&unlink_wakeup, &wait);
 787 }
 788
 789 int usbnet_stop (struct net_device *net)
 790 {
 791         struct usbnet           *dev = netdev_priv(net);
 792         struct driver_info      *info = dev->driver_info;
 793         int                     retval;
 794
 795         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 796         netif_stop_queue (net);
 797
 798         netif_info(dev, ifdown, dev->net,
 799                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 800                    net->stats.rx_packets, net->stats.tx_packets,
 801                    net->stats.rx_errors, net->stats.tx_errors);
 802
 803         /* allow minidriver to stop correctly (wireless devices to turn off
 804          * radio etc) */
 805         if (info->stop) {
 806                 retval = info->stop(dev);
 807                 if (retval < 0)
 808                         netif_info(dev, ifdown, dev->net,
 809                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 810                                    retval,
 811                                    dev->udev->bus->bus_name, dev->udev->devpath,
 812                                    info->description);
 813         }
 814
 815         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 816                 usbnet_terminate_urbs(dev);
 817
 818         usbnet_status_stop(dev);
 819
 820         usbnet_purge_paused_rxq(dev);
 821
 822         /* deferred work (task, timer, softirq) must also stop.
 823          * can't flush_scheduled_work() until we drop rtnl (later),
 824          * else workers could deadlock; so make workers a NOP.
 825          */
 826         dev->flags = 0;
 827         del_timer_sync (&dev->delay);
 828         tasklet_kill (&dev->bh);
 829         if (info->manage_power &&
 830             !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
 831                 info->manage_power(dev, 0);
 832         else
 833                 usb_autopm_put_interface(dev->intf);
 834
 835         return 0;
 836 }
 837 EXPORT_SYMBOL_GPL(usbnet_stop);
 838
 839 /*-------------------------------------------------------------------------*/
 840
 841 // posts reads, and enables write queuing
 842
 843 // precondition: never called in_interrupt
 844
 845 int usbnet_open (struct net_device *net)
 846 {
 847         struct usbnet           *dev = netdev_priv(net);
 848         int                     retval;
 849         struct driver_info      *info = dev->driver_info;
 850
 851         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 852                 netif_info(dev, ifup, dev->net,
 853                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 854                            retval,
 855                            dev->udev->bus->bus_name,
 856                            dev->udev->devpath,
 857                            info->description);
 858                 goto done_nopm;
 859         }
 860
 861         // put into "known safe" state
 862         if (info->reset && (retval = info->reset (dev)) < 0) {
 863                 netif_info(dev, ifup, dev->net,
 864                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 865                            retval,
 866                            dev->udev->bus->bus_name,
 867                            dev->udev->devpath,
 868                            info->description);
 869                 goto done;
 870         }
 871
 872         /* hard_mtu or rx_urb_size may change in reset() */
 873         usbnet_update_max_qlen(dev);
 874
 875         // insist peer be connected
 876         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 877                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 878                 goto done;
 879         }
 880
 881         /* start any status interrupt transfer */
 882         if (dev->interrupt) {
 883                 retval = usbnet_status_start(dev, GFP_KERNEL);
 884                 if (retval < 0) {
 885                         netif_err(dev, ifup, dev->net,
 886                                   "intr submit %d\n", retval);
 887                         goto done;
 888                 }
 889         }
 890
 891         set_bit(EVENT_DEV_OPEN, &dev->flags);
 892         netif_start_queue (net);
 893         netif_info(dev, ifup, dev->net,
 894                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 895                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 896                    dev->net->mtu,
 897                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 898                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 899                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 900                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 901                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 902                    "simple");
 903
 904         /* reset rx error state */
 905         dev->pkt_cnt = 0;
 906         dev->pkt_err = 0;
 907         clear_bit(EVENT_RX_KILL, &dev->flags);
 908
 909         // delay posting reads until we're fully open
 910         tasklet_schedule (&dev->bh);
 911         if (info->manage_power) {
 912                 retval = info->manage_power(dev, 1);
 913                 if (retval < 0) {
 914                         retval = 0;
 915                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 916                 } else {
 917                         usb_autopm_put_interface(dev->intf);
 918                 }
 919         }
 920         return retval;
 921 done:
 922         usb_autopm_put_interface(dev->intf);
 923 done_nopm:
 924         return retval;
 925 }
 926 EXPORT_SYMBOL_GPL(usbnet_open);
 927
 928 /*-------------------------------------------------------------------------*/
 929
 930 /* ethtool methods; minidrivers may need to add some more, but
 931  * they'll probably want to use this base set.
 932  */
 933
 934 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 935 {
 936         struct usbnet *dev = netdev_priv(net);
 937
 938         if (!dev->mii.mdio_read)
 939                 return -EOPNOTSUPP;
 940
 941         return mii_ethtool_gset(&dev->mii, cmd);
 942 }
 943 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 944
 945 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 946 {
 947         struct usbnet *dev = netdev_priv(net);
 948         int retval;
 949
 950         if (!dev->mii.mdio_write)
 951                 return -EOPNOTSUPP;
 952
 953         retval = mii_ethtool_sset(&dev->mii, cmd);
 954
 955         /* link speed/duplex might have changed */
 956         if (dev->driver_info->link_reset)
 957                 dev->driver_info->link_reset(dev);
 958
 959         /* hard_mtu or rx_urb_size may change in link_reset() */
 960         usbnet_update_max_qlen(dev);
 961
 962         return retval;
 963
 964 }
 965 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 966
 967 u32 usbnet_get_link (struct net_device *net)
 968 {
 969         struct usbnet *dev = netdev_priv(net);
 970
 971         /* If a check_connect is defined, return its result */
 972         if (dev->driver_info->check_connect)
 973                 return dev->driver_info->check_connect (dev) == 0;
 974
 975         /* if the device has mii operations, use those */
 976         if (dev->mii.mdio_read)
 977                 return mii_link_ok(&dev->mii);
 978
 979         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 980         return ethtool_op_get_link(net);
 981 }
 982 EXPORT_SYMBOL_GPL(usbnet_get_link);
 983
 984 int usbnet_nway_reset(struct net_device *net)
 985 {
 986         struct usbnet *dev = netdev_priv(net);
 987
 988         if (!dev->mii.mdio_write)
 989                 return -EOPNOTSUPP;
 990
 991         return mii_nway_restart(&dev->mii);
 992 }
 993 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 994
 995 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 996 {
 997         struct usbnet *dev = netdev_priv(net);
 998
 999         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1000         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1001         strlcpy (info->fw_version, dev->driver_info->description,
1002                 sizeof info->fw_version);
1003         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1004 }
1005 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1006
1007 u32 usbnet_get_msglevel (struct net_device *net)
1008 {
1009         struct usbnet *dev = netdev_priv(net);
1010
1011         return dev->msg_enable;
1012 }
1013 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1014
1015 void usbnet_set_msglevel (struct net_device *net, u32 level)
1016 {
1017         struct usbnet *dev = netdev_priv(net);
1018
1019         dev->msg_enable = level;
1020 }
1021 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1022
1023 /* drivers may override default ethtool_ops in their bind() routine */
1024 static const struct ethtool_ops usbnet_ethtool_ops = {
1025         .get_settings           = usbnet_get_settings,
1026         .set_settings           = usbnet_set_settings,
1027         .get_link               = usbnet_get_link,
1028         .nway_reset             = usbnet_nway_reset,
1029         .get_drvinfo            = usbnet_get_drvinfo,
1030         .get_msglevel           = usbnet_get_msglevel,
1031         .set_msglevel           = usbnet_set_msglevel,
1032         .get_ts_info            = ethtool_op_get_ts_info,
1033 };
1034
1035 /*-------------------------------------------------------------------------*/
1036
1037 static void __handle_link_change(struct usbnet *dev)
1038 {
1039         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1040                 return;
1041
1042         if (!netif_carrier_ok(dev->net)) {
1043                 /* kill URBs for reading packets to save bus bandwidth */
1044                 unlink_urbs(dev, &dev->rxq);
1045
1046                 /*
1047                  * tx_timeout will unlink URBs for sending packets and
1048                  * tx queue is stopped by netcore after link becomes off
1049                  */
1050         } else {
1051                 /* submitting URBs for reading packets */
1052                 tasklet_schedule(&dev->bh);
1053         }
1054
1055         /* hard_mtu or rx_urb_size may change during link change */
1056         usbnet_update_max_qlen(dev);
1057
1058         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1059 }
1060
1061 /* work that cannot be done in interrupt context uses keventd.
1062  *
1063  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1064  * especially now that control transfers can be queued.
1065  */
1066 static void
1067 kevent (struct work_struct *work)
1068 {
1069         struct usbnet           *dev =
1070                 container_of(work, struct usbnet, kevent);
1071         int                     status;
1072
1073         /* usb_clear_halt() needs a thread context */
1074         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1075                 unlink_urbs (dev, &dev->txq);
1076                 status = usb_autopm_get_interface(dev->intf);
1077                 if (status < 0)
1078                         goto fail_pipe;
1079                 status = usb_clear_halt (dev->udev, dev->out);
1080                 usb_autopm_put_interface(dev->intf);
1081                 if (status < 0 &&
1082                     status != -EPIPE &&
1083                     status != -ESHUTDOWN) {
1084                         if (netif_msg_tx_err (dev))
1085 fail_pipe:
1086                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1087                                            status);
1088                 } else {
1089                         clear_bit (EVENT_TX_HALT, &dev->flags);
1090                         if (status != -ESHUTDOWN)
1091                                 netif_wake_queue (dev->net);
1092                 }
1093         }
1094         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1095                 unlink_urbs (dev, &dev->rxq);
1096                 status = usb_autopm_get_interface(dev->intf);
1097                 if (status < 0)
1098                         goto fail_halt;
1099                 status = usb_clear_halt (dev->udev, dev->in);
1100                 usb_autopm_put_interface(dev->intf);
1101                 if (status < 0 &&
1102                     status != -EPIPE &&
1103                     status != -ESHUTDOWN) {
1104                         if (netif_msg_rx_err (dev))
1105 fail_halt:
1106                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1107                                            status);
1108                 } else {
1109                         clear_bit (EVENT_RX_HALT, &dev->flags);
1110                         tasklet_schedule (&dev->bh);
1111                 }
1112         }
1113
1114         /* tasklet could resubmit itself forever if memory is tight */
1115         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1116                 struct urb      *urb = NULL;
1117                 int resched = 1;
1118
1119                 if (netif_running (dev->net))
1120                         urb = usb_alloc_urb (0, GFP_KERNEL);
1121                 else
1122                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1123                 if (urb != NULL) {
1124                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1125                         status = usb_autopm_get_interface(dev->intf);
1126                         if (status < 0) {
1127                                 usb_free_urb(urb);
1128                                 goto fail_lowmem;
1129                         }
1130                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1131                                 resched = 0;
1132                         usb_autopm_put_interface(dev->intf);
1133 fail_lowmem:
1134                         if (resched)
1135                                 tasklet_schedule (&dev->bh);
1136                 }
1137         }
1138
1139         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1140                 struct driver_info      *info = dev->driver_info;
1141                 int                     retval = 0;
1142
1143                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1144                 status = usb_autopm_get_interface(dev->intf);
1145                 if (status < 0)
1146                         goto skip_reset;
1147                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1148                         usb_autopm_put_interface(dev->intf);
1149 skip_reset:
1150                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1151                                     retval,
1152                                     dev->udev->bus->bus_name,
1153                                     dev->udev->devpath,
1154                                     info->description);
1155                 } else {
1156                         usb_autopm_put_interface(dev->intf);
1157                 }
1158
1159                 /* handle link change from link resetting */
1160                 __handle_link_change(dev);
1161         }
1162
1163         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1164                 __handle_link_change(dev);
1165
1166         if (dev->flags)
1167                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1168 }
1169
1170 /*-------------------------------------------------------------------------*/
1171
1172 static void tx_complete (struct urb *urb)
1173 {
1174         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1175         struct skb_data         *entry = (struct skb_data *) skb->cb;
1176         struct usbnet           *dev = entry->dev;
1177
1178         if (urb->status == 0) {
1179                 if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1180                         dev->net->stats.tx_packets++;
1181                 dev->net->stats.tx_bytes += entry->length;
1182         } else {
1183                 dev->net->stats.tx_errors++;
1184
1185                 switch (urb->status) {
1186                 case -EPIPE:
1187                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1188                         break;
1189
1190                 /* software-driven interface shutdown */
1191                 case -ECONNRESET:               // async unlink
1192                 case -ESHUTDOWN:                // hardware gone
1193                         break;
1194
1195                 // like rx, tx gets controller i/o faults during khubd delays
1196                 // and so it uses the same throttling mechanism.
1197                 case -EPROTO:
1198                 case -ETIME:
1199                 case -EILSEQ:
1200                         usb_mark_last_busy(dev->udev);
1201                         if (!timer_pending (&dev->delay)) {
1202                                 mod_timer (&dev->delay,
1203                                         jiffies + THROTTLE_JIFFIES);
1204                                 netif_dbg(dev, link, dev->net,
1205                                           "tx throttle %d\n", urb->status);
1206                         }
1207                         netif_stop_queue (dev->net);
1208                         break;
1209                 default:
1210                         netif_dbg(dev, tx_err, dev->net,
1211                                   "tx err %d\n", entry->urb->status);
1212                         break;
1213                 }
1214         }
1215
1216         usb_autopm_put_interface_async(dev->intf);
1217         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1218 }
1219
1220 /*-------------------------------------------------------------------------*/
1221
1222 void usbnet_tx_timeout (struct net_device *net)
1223 {
1224         struct usbnet           *dev = netdev_priv(net);
1225
1226         unlink_urbs (dev, &dev->txq);
1227         tasklet_schedule (&dev->bh);
1228
1229         // FIXME: device recovery -- reset?
1230 }
1231 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1232
1233 /*-------------------------------------------------------------------------*/
1234
1235 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1236 {
1237         unsigned num_sgs, total_len = 0;
1238         int i, s = 0;
1239
1240         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1241         if (num_sgs == 1)
1242                 return 0;
1243
1244         /* reserve one for zero packet */
1245         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1246                           GFP_ATOMIC);
1247         if (!urb->sg)
1248                 return -ENOMEM;
1249
1250         urb->num_sgs = num_sgs;
1251         sg_init_table(urb->sg, urb->num_sgs);
1252
1253         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1254         total_len += skb_headlen(skb);
1255
1256         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1257                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1258
1259                 total_len += skb_frag_size(f);
1260                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1261                                 f->page_offset);
1262         }
1263         urb->transfer_buffer_length = total_len;
1264
1265         return 1;
1266 }
1267
1268 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1269                                      struct net_device *net)
1270 {
1271         struct usbnet           *dev = netdev_priv(net);
1272         int                     length;
1273         struct urb              *urb = NULL;
1274         struct skb_data         *entry;
1275         struct driver_info      *info = dev->driver_info;
1276         unsigned long           flags;
1277         int retval;
1278
1279         if (skb)
1280                 skb_tx_timestamp(skb);
1281
1282         // some devices want funky USB-level framing, for
1283         // win32 driver (usually) and/or hardware quirks
1284         if (info->tx_fixup) {
1285                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1286                 if (!skb) {
1287                         /* packet collected; minidriver waiting for more */
1288                         if (info->flags & FLAG_MULTI_PACKET)
1289                                 goto not_drop;
1290                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1291                         goto drop;
1292                 }
1293         }
1294
1295         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1296                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1297                 goto drop;
1298         }
1299
1300         entry = (struct skb_data *) skb->cb;
1301         entry->urb = urb;
1302         entry->dev = dev;
1303
1304         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1305                         skb->data, skb->len, tx_complete, skb);
1306         if (dev->can_dma_sg) {
1307                 if (build_dma_sg(skb, urb) < 0)
1308                         goto drop;
1309         }
1310         length = urb->transfer_buffer_length;
1311
1312         /* don't assume the hardware handles USB_ZERO_PACKET
1313          * NOTE:  strictly conforming cdc-ether devices should expect
1314          * the ZLP here, but ignore the one-byte packet.
1315          * NOTE2: CDC NCM specification is different from CDC ECM when
1316          * handling ZLP/short packets, so cdc_ncm driver will make short
1317          * packet itself if needed.
1318          */
1319         if (length % dev->maxpacket == 0) {
1320                 if (!(info->flags & FLAG_SEND_ZLP)) {
1321                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1322                                 length++;
1323                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1324                                         skb->data[skb->len] = 0;
1325                                         __skb_put(skb, 1);
1326                                 } else if (urb->num_sgs)
1327                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1328                                                         dev->padding_pkt, 1);
1329                         }
1330                 } else
1331                         urb->transfer_flags |= URB_ZERO_PACKET;
1332         }
1333         entry->length = urb->transfer_buffer_length = length;
1334
1335         spin_lock_irqsave(&dev->txq.lock, flags);
1336         retval = usb_autopm_get_interface_async(dev->intf);
1337         if (retval < 0) {
1338                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1339                 goto drop;
1340         }
1341
1342 #ifdef CONFIG_PM
1343         /* if this triggers the device is still a sleep */
1344         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1345                 /* transmission will be done in resume */
1346                 usb_anchor_urb(urb, &dev->deferred);
1347                 /* no use to process more packets */
1348                 netif_stop_queue(net);
1349                 usb_put_urb(urb);
1350                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1351                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1352                 goto deferred;
1353         }
1354 #endif
1355
1356         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1357         case -EPIPE:
1358                 netif_stop_queue (net);
1359                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1360                 usb_autopm_put_interface_async(dev->intf);
1361                 break;
1362         default:
1363                 usb_autopm_put_interface_async(dev->intf);
1364                 netif_dbg(dev, tx_err, dev->net,
1365                           "tx: submit urb err %d\n", retval);
1366                 break;
1367         case 0:
1368                 net->trans_start = jiffies;
1369                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1370                 if (dev->txq.qlen >= TX_QLEN (dev))
1371                         netif_stop_queue (net);
1372         }
1373         spin_unlock_irqrestore (&dev->txq.lock, flags);
1374
1375         if (retval) {
1376                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1377 drop:
1378                 dev->net->stats.tx_dropped++;
1379 not_drop:
1380                 if (skb)
1381                         dev_kfree_skb_any (skb);
1382                 if (urb) {
1383                         kfree(urb->sg);
1384                         usb_free_urb(urb);
1385                 }
1386         } else
1387                 netif_dbg(dev, tx_queued, dev->net,
1388                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1389 #ifdef CONFIG_PM
1390 deferred:
1391 #endif
1392         return NETDEV_TX_OK;
1393 }
1394 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1395
1396 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1397 {
1398         struct urb      *urb;
1399         int             i;
1400         int             ret = 0;
1401
1402         /* don't refill the queue all at once */
1403         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1404                 urb = usb_alloc_urb(0, flags);
1405                 if (urb != NULL) {
1406                         ret = rx_submit(dev, urb, flags);
1407                         if (ret)
1408                                 goto err;
1409                 } else {
1410                         ret = -ENOMEM;
1411                         goto err;
1412                 }
1413         }
1414 err:
1415         return ret;
1416 }
1417
1418 /*-------------------------------------------------------------------------*/
1419
1420 // tasklet (work deferred from completions, in_irq) or timer
1421
1422 static void usbnet_bh (unsigned long param)
1423 {
1424         struct usbnet           *dev = (struct usbnet *) param;
1425         struct sk_buff          *skb;
1426         struct skb_data         *entry;
1427
1428         while ((skb = skb_dequeue (&dev->done))) {
1429                 entry = (struct skb_data *) skb->cb;
1430                 switch (entry->state) {
1431                 case rx_done:
1432                         entry->state = rx_cleanup;
1433                         rx_process (dev, skb);
1434                         continue;
1435                 case tx_done:
1436                         kfree(entry->urb->sg);
1437                 case rx_cleanup:
1438                         usb_free_urb (entry->urb);
1439                         dev_kfree_skb (skb);
1440                         continue;
1441                 default:
1442                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1443                 }
1444         }
1445
1446         /* restart RX again after disabling due to high error rate */
1447         clear_bit(EVENT_RX_KILL, &dev->flags);
1448
1449         // waiting for all pending urbs to complete?
1450         if (dev->wait) {
1451                 if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
1452                         wake_up (dev->wait);
1453                 }
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         skb_queue_head_init (&dev->rxq);
1593         skb_queue_head_init (&dev->txq);
1594         skb_queue_head_init (&dev->done);
1595         skb_queue_head_init(&dev->rxq_pause);
1596         dev->bh.func = usbnet_bh;
1597         dev->bh.data = (unsigned long) dev;
1598         INIT_WORK (&dev->kevent, kevent);
1599         init_usb_anchor(&dev->deferred);
1600         dev->delay.function = usbnet_bh;
1601         dev->delay.data = (unsigned long) dev;
1602         init_timer (&dev->delay);
1603         mutex_init (&dev->phy_mutex);
1604         mutex_init(&dev->interrupt_mutex);
1605         dev->interrupt_count = 0;
1606
1607         dev->net = net;
1608         strcpy (net->name, "usb%d");
1609         memcpy (net->dev_addr, node_id, sizeof node_id);
1610
1611         /* rx and tx sides can use different message sizes;
1612          * bind() should set rx_urb_size in that case.
1613          */
1614         dev->hard_mtu = net->mtu + net->hard_header_len;
1615 #if 0
1616 // dma_supported() is deeply broken on almost all architectures
1617         // possible with some EHCI controllers
1618         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1619                 net->features |= NETIF_F_HIGHDMA;
1620 #endif
1621
1622         net->netdev_ops = &usbnet_netdev_ops;
1623         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1624         net->ethtool_ops = &usbnet_ethtool_ops;
1625
1626         // allow device-specific bind/init procedures
1627         // NOTE net->name still not usable ...
1628         if (info->bind) {
1629                 status = info->bind (dev, udev);
1630                 if (status < 0)
1631                         goto out1;
1632
1633                 // heuristic:  "usb%d" for links we know are two-host,
1634                 // else "eth%d" when there's reasonable doubt.  userspace
1635                 // can rename the link if it knows better.
1636                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1637                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1638                      (net->dev_addr [0] & 0x02) == 0))
1639                         strcpy (net->name, "eth%d");
1640                 /* WLAN devices should always be named "wlan%d" */
1641                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1642                         strcpy(net->name, "wlan%d");
1643                 /* WWAN devices should always be named "wwan%d" */
1644                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1645                         strcpy(net->name, "wwan%d");
1646
1647                 /* devices that cannot do ARP */
1648                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1649                         net->flags |= IFF_NOARP;
1650
1651                 /* maybe the remote can't receive an Ethernet MTU */
1652                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1653                         net->mtu = dev->hard_mtu - net->hard_header_len;
1654         } else if (!info->in || !info->out)
1655                 status = usbnet_get_endpoints (dev, udev);
1656         else {
1657                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1658                 dev->out = usb_sndbulkpipe (xdev, info->out);
1659                 if (!(info->flags & FLAG_NO_SETINT))
1660                         status = usb_set_interface (xdev,
1661                                 interface->desc.bInterfaceNumber,
1662                                 interface->desc.bAlternateSetting);
1663                 else
1664                         status = 0;
1665
1666         }
1667         if (status >= 0 && dev->status)
1668                 status = init_status (dev, udev);
1669         if (status < 0)
1670                 goto out3;
1671
1672         if (!dev->rx_urb_size)
1673                 dev->rx_urb_size = dev->hard_mtu;
1674         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1675
1676         /* let userspace know we have a random address */
1677         if (ether_addr_equal(net->dev_addr, node_id))
1678                 net->addr_assign_type = NET_ADDR_RANDOM;
1679
1680         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1681                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1682         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1683                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1684
1685         /* initialize max rx_qlen and tx_qlen */
1686         usbnet_update_max_qlen(dev);
1687
1688         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1689                 !(info->flags & FLAG_MULTI_PACKET)) {
1690                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1691                 if (!dev->padding_pkt) {
1692                         status = -ENOMEM;
1693                         goto out4;
1694                 }
1695         }
1696
1697         status = register_netdev (net);
1698         if (status)
1699                 goto out5;
1700         netif_info(dev, probe, dev->net,
1701                    "register '%s' at usb-%s-%s, %s, %pM\n",
1702                    udev->dev.driver->name,
1703                    xdev->bus->bus_name, xdev->devpath,
1704                    dev->driver_info->description,
1705                    net->dev_addr);
1706
1707         // ok, it's ready to go.
1708         usb_set_intfdata (udev, dev);
1709
1710         netif_device_attach (net);
1711
1712         if (dev->driver_info->flags & FLAG_LINK_INTR)
1713                 usbnet_link_change(dev, 0, 0);
1714
1715         return 0;
1716
1717 out5:
1718         kfree(dev->padding_pkt);
1719 out4:
1720         usb_free_urb(dev->interrupt);
1721 out3:
1722         if (info->unbind)
1723                 info->unbind (dev, udev);
1724 out1:
1725         free_netdev(net);
1726 out:
1727         return status;
1728 }
1729 EXPORT_SYMBOL_GPL(usbnet_probe);
1730
1731 /*-------------------------------------------------------------------------*/
1732
1733 /*
1734  * suspend the whole driver as soon as the first interface is suspended
1735  * resume only when the last interface is resumed
1736  */
1737
1738 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1739 {
1740         struct usbnet           *dev = usb_get_intfdata(intf);
1741
1742         if (!dev->suspend_count++) {
1743                 spin_lock_irq(&dev->txq.lock);
1744                 /* don't autosuspend while transmitting */
1745                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1746                         dev->suspend_count--;
1747                         spin_unlock_irq(&dev->txq.lock);
1748                         return -EBUSY;
1749                 } else {
1750                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1751                         spin_unlock_irq(&dev->txq.lock);
1752                 }
1753                 /*
1754                  * accelerate emptying of the rx and queues, to avoid
1755                  * having everything error out.
1756                  */
1757                 netif_device_detach (dev->net);
1758                 usbnet_terminate_urbs(dev);
1759                 __usbnet_status_stop_force(dev);
1760
1761                 /*
1762                  * reattach so runtime management can use and
1763                  * wake the device
1764                  */
1765                 netif_device_attach (dev->net);
1766         }
1767         return 0;
1768 }
1769 EXPORT_SYMBOL_GPL(usbnet_suspend);
1770
1771 int usbnet_resume (struct usb_interface *intf)
1772 {
1773         struct usbnet           *dev = usb_get_intfdata(intf);
1774         struct sk_buff          *skb;
1775         struct urb              *res;
1776         int                     retval;
1777
1778         if (!--dev->suspend_count) {
1779                 /* resume interrupt URB if it was previously submitted */
1780                 __usbnet_status_start_force(dev, GFP_NOIO);
1781
1782                 spin_lock_irq(&dev->txq.lock);
1783                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1784
1785                         skb = (struct sk_buff *)res->context;
1786                         retval = usb_submit_urb(res, GFP_ATOMIC);
1787                         if (retval < 0) {
1788                                 dev_kfree_skb_any(skb);
1789                                 kfree(res->sg);
1790                                 usb_free_urb(res);
1791                                 usb_autopm_put_interface_async(dev->intf);
1792                         } else {
1793                                 dev->net->trans_start = jiffies;
1794                                 __skb_queue_tail(&dev->txq, skb);
1795                         }
1796                 }
1797
1798                 smp_mb();
1799                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1800                 spin_unlock_irq(&dev->txq.lock);
1801
1802                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1803                         /* handle remote wakeup ASAP */
1804                         if (!dev->wait &&
1805                                 netif_device_present(dev->net) &&
1806                                 !timer_pending(&dev->delay) &&
1807                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1808                                         rx_alloc_submit(dev, GFP_NOIO);
1809
1810                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1811                                 netif_tx_wake_all_queues(dev->net);
1812                         tasklet_schedule (&dev->bh);
1813                 }
1814         }
1815
1816         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1817                 usb_autopm_get_interface_no_resume(intf);
1818
1819         return 0;
1820 }
1821 EXPORT_SYMBOL_GPL(usbnet_resume);
1822
1823 /*
1824  * Either a subdriver implements manage_power, then it is assumed to always
1825  * be ready to be suspended or it reports the readiness to be suspended
1826  * explicitly
1827  */
1828 void usbnet_device_suggests_idle(struct usbnet *dev)
1829 {
1830         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1831                 dev->intf->needs_remote_wakeup = 1;
1832                 usb_autopm_put_interface_async(dev->intf);
1833         }
1834 }
1835 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1836
1837 /*
1838  * For devices that can do without special commands
1839  */
1840 int usbnet_manage_power(struct usbnet *dev, int on)
1841 {
1842         dev->intf->needs_remote_wakeup = on;
1843         return 0;
1844 }
1845 EXPORT_SYMBOL(usbnet_manage_power);
1846
1847 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1848 {
1849         /* update link after link is reseted */
1850         if (link && !need_reset)
1851                 netif_carrier_on(dev->net);
1852         else
1853                 netif_carrier_off(dev->net);
1854
1855         if (need_reset && link)
1856                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1857         else
1858                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1859 }
1860 EXPORT_SYMBOL(usbnet_link_change);
1861
1862 /*-------------------------------------------------------------------------*/
1863 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1864                              u16 value, u16 index, void *data, u16 size)
1865 {
1866         void *buf = NULL;
1867         int err = -ENOMEM;
1868
1869         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1870                    " value=0x%04x index=0x%04x size=%d\n",
1871                    cmd, reqtype, value, index, size);
1872
1873         if (data) {
1874                 buf = kmalloc(size, GFP_KERNEL);
1875                 if (!buf)
1876                         goto out;
1877         }
1878
1879         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1880                               cmd, reqtype, value, index, buf, size,
1881                               USB_CTRL_GET_TIMEOUT);
1882         if (err > 0 && err <= size)
1883                 memcpy(data, buf, err);
1884         kfree(buf);
1885 out:
1886         return err;
1887 }
1888
1889 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1890                               u16 value, u16 index, const void *data,
1891                               u16 size)
1892 {
1893         void *buf = NULL;
1894         int err = -ENOMEM;
1895
1896         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1897                    " value=0x%04x index=0x%04x size=%d\n",
1898                    cmd, reqtype, value, index, size);
1899
1900         if (data) {
1901                 buf = kmemdup(data, size, GFP_KERNEL);
1902                 if (!buf)
1903                         goto out;
1904         }
1905
1906         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1907                               cmd, reqtype, value, index, buf, size,
1908                               USB_CTRL_SET_TIMEOUT);
1909         kfree(buf);
1910
1911 out:
1912         return err;
1913 }
1914
1915 /*
1916  * The function can't be called inside suspend/resume callback,
1917  * otherwise deadlock will be caused.
1918  */
1919 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1920                     u16 value, u16 index, void *data, u16 size)
1921 {
1922         int ret;
1923
1924         if (usb_autopm_get_interface(dev->intf) < 0)
1925                 return -ENODEV;
1926         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1927                                 data, size);
1928         usb_autopm_put_interface(dev->intf);
1929         return ret;
1930 }
1931 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1932
1933 /*
1934  * The function can't be called inside suspend/resume callback,
1935  * otherwise deadlock will be caused.
1936  */
1937 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1938                      u16 value, u16 index, const void *data, u16 size)
1939 {
1940         int ret;
1941
1942         if (usb_autopm_get_interface(dev->intf) < 0)
1943                 return -ENODEV;
1944         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1945                                  data, size);
1946         usb_autopm_put_interface(dev->intf);
1947         return ret;
1948 }
1949 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1950
1951 /*
1952  * The function can be called inside suspend/resume callback safely
1953  * and should only be called by suspend/resume callback generally.
1954  */
1955 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1956                           u16 value, u16 index, void *data, u16 size)
1957 {
1958         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1959                                  data, size);
1960 }
1961 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1962
1963 /*
1964  * The function can be called inside suspend/resume callback safely
1965  * and should only be called by suspend/resume callback generally.
1966  */
1967 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1968                           u16 value, u16 index, const void *data,
1969                           u16 size)
1970 {
1971         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1972                                   data, size);
1973 }
1974 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1975
1976 static void usbnet_async_cmd_cb(struct urb *urb)
1977 {
1978         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
1979         int status = urb->status;
1980
1981         if (status < 0)
1982                 dev_dbg(&urb->dev->dev, "%s failed with %d",
1983                         __func__, status);
1984
1985         kfree(req);
1986         usb_free_urb(urb);
1987 }
1988
1989 /*
1990  * The caller must make sure that device can't be put into suspend
1991  * state until the control URB completes.
1992  */
1993 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
1994                            u16 value, u16 index, const void *data, u16 size)
1995 {
1996         struct usb_ctrlrequest *req = NULL;
1997         struct urb *urb;
1998         int err = -ENOMEM;
1999         void *buf = NULL;
2000
2001         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2002                    " value=0x%04x index=0x%04x size=%d\n",
2003                    cmd, reqtype, value, index, size);
2004
2005         urb = usb_alloc_urb(0, GFP_ATOMIC);
2006         if (!urb) {
2007                 netdev_err(dev->net, "Error allocating URB in"
2008                            " %s!\n", __func__);
2009                 goto fail;
2010         }
2011
2012         if (data) {
2013                 buf = kmemdup(data, size, GFP_ATOMIC);
2014                 if (!buf) {
2015                         netdev_err(dev->net, "Error allocating buffer"
2016                                    " in %s!\n", __func__);
2017                         goto fail_free;
2018                 }
2019         }
2020
2021         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2022         if (!req)
2023                 goto fail_free_buf;
2024
2025         req->bRequestType = reqtype;
2026         req->bRequest = cmd;
2027         req->wValue = cpu_to_le16(value);
2028         req->wIndex = cpu_to_le16(index);
2029         req->wLength = cpu_to_le16(size);
2030
2031         usb_fill_control_urb(urb, dev->udev,
2032                              usb_sndctrlpipe(dev->udev, 0),
2033                              (void *)req, buf, size,
2034                              usbnet_async_cmd_cb, req);
2035         urb->transfer_flags |= URB_FREE_BUFFER;
2036
2037         err = usb_submit_urb(urb, GFP_ATOMIC);
2038         if (err < 0) {
2039                 netdev_err(dev->net, "Error submitting the control"
2040                            " message: status=%d\n", err);
2041                 goto fail_free;
2042         }
2043         return 0;
2044
2045 fail_free_buf:
2046         kfree(buf);
2047 fail_free:
2048         kfree(req);
2049         usb_free_urb(urb);
2050 fail:
2051         return err;
2052
2053 }
2054 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2055 /*-------------------------------------------------------------------------*/
2056
2057 static int __init usbnet_init(void)
2058 {
2059         /* Compiler should optimize this out. */
2060         BUILD_BUG_ON(
2061                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2062
2063         eth_random_addr(node_id);
2064         return 0;
2065 }
2066 module_init(usbnet_init);
2067
2068 static void __exit usbnet_exit(void)
2069 {
2070 }
2071 module_exit(usbnet_exit);
2072
2073 MODULE_AUTHOR("David Brownell");
2074 MODULE_DESCRIPTION("USB network driver framework");
2075 MODULE_LICENSE("GPL");