drivers/net/usb/usbnet.c

   1 /*
   2  * USB Network driver infrastructure
   3  * Copyright (C) 2000-2005 by David Brownell
   4  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * This is a generic "USB networking" framework that works with several
  22  * kinds of full and high speed networking devices:  host-to-host cables,
  23  * smart usb peripherals, and actual Ethernet adapters.
  24  *
  25  * These devices usually differ in terms of control protocols (if they
  26  * even have one!) and sometimes they define new framing to wrap or batch
  27  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  28  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  29  * issues can usefully be addressed by this framework.
  30  */
  31
  32 // #define      DEBUG                   // error path messages, extra info
  33 // #define      VERBOSE                 // more; success messages
  34
  35 #include <linux/module.h>
  36 #include <linux/init.h>
  37 #include <linux/netdevice.h>
  38 #include <linux/etherdevice.h>
  39 #include <linux/ctype.h>
  40 #include <linux/ethtool.h>
  41 #include <linux/workqueue.h>
  42 #include <linux/mii.h>
  43 #include <linux/usb.h>
  44 #include <linux/usb/usbnet.h>
  45 #include <linux/slab.h>
  46 #include <linux/kernel.h>
  47 #include <linux/pm_runtime.h>
  48
  49 #define DRIVER_VERSION          "22-Aug-2005"
  50
  51
  52 /*-------------------------------------------------------------------------*/
  53
  54 /*
  55  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  56  * Several dozen bytes of IPv4 data can fit in two such transactions.
  57  * One maximum size Ethernet packet takes twenty four of them.
  58  * For high speed, each frame comfortably fits almost 36 max size
  59  * Ethernet packets (so queues should be bigger).
  60  *
  61  * The goal is to let the USB host controller be busy for 5msec or
  62  * more before an irq is required, under load.  Jumbograms change
  63  * the equation.
  64  */
  65 #define MAX_QUEUE_MEMORY        (60 * 1518)
  66 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  67 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  68
  69 // reawaken network queue this soon after stopping; else watchdog barks
  70 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  71
  72 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  73  * us (it polls at HZ/4 usually) before we report too many false errors.
  74  */
  75 #define THROTTLE_JIFFIES        (HZ/8)
  76
  77 // between wakeups
  78 #define UNLINK_TIMEOUT_MS       3
  79
  80 /*-------------------------------------------------------------------------*/
  81
  82 // randomly generated ethernet address
  83 static u8       node_id [ETH_ALEN];
  84
  85 static const char driver_name [] = "usbnet";
  86
  87 /* use ethtool to change the level for any given device */
  88 static int msg_level = -1;
  89 module_param (msg_level, int, 0);
  90 MODULE_PARM_DESC (msg_level, "Override default message level");
  91
  92 /*-------------------------------------------------------------------------*/
  93
  94 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  95 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  96 {
  97         int                             tmp;
  98         struct usb_host_interface       *alt = NULL;
  99         struct usb_host_endpoint        *in = NULL, *out = NULL;
 100         struct usb_host_endpoint        *status = NULL;
 101
 102         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 103                 unsigned        ep;
 104
 105                 in = out = status = NULL;
 106                 alt = intf->altsetting + tmp;
 107
 108                 /* take the first altsetting with in-bulk + out-bulk;
 109                  * remember any status endpoint, just in case;
 110                  * ignore other endpoints and altsettings.
 111                  */
 112                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 113                         struct usb_host_endpoint        *e;
 114                         int                             intr = 0;
 115
 116                         e = alt->endpoint + ep;
 117                         switch (e->desc.bmAttributes) {
 118                         case USB_ENDPOINT_XFER_INT:
 119                                 if (!usb_endpoint_dir_in(&e->desc))
 120                                         continue;
 121                                 intr = 1;
 122                                 /* FALLTHROUGH */
 123                         case USB_ENDPOINT_XFER_BULK:
 124                                 break;
 125                         default:
 126                                 continue;
 127                         }
 128                         if (usb_endpoint_dir_in(&e->desc)) {
 129                                 if (!intr && !in)
 130                                         in = e;
 131                                 else if (intr && !status)
 132                                         status = e;
 133                         } else {
 134                                 if (!out)
 135                                         out = e;
 136                         }
 137                 }
 138                 if (in && out)
 139                         break;
 140         }
 141         if (!alt || !in || !out)
 142                 return -EINVAL;
 143
 144         if (alt->desc.bAlternateSetting != 0 ||
 145             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 146                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 147                                 alt->desc.bAlternateSetting);
 148                 if (tmp < 0)
 149                         return tmp;
 150         }
 151
 152         dev->in = usb_rcvbulkpipe (dev->udev,
 153                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 154         dev->out = usb_sndbulkpipe (dev->udev,
 155                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156         dev->status = status;
 157         return 0;
 158 }
 159 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 160
 161 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 162 {
 163         int             tmp = -1, ret;
 164         unsigned char   buf [13];
 165
 166         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 167         if (ret == 12)
 168                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 169         if (tmp < 0) {
 170                 dev_dbg(&dev->udev->dev,
 171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172                 if (ret >= 0)
 173                         ret = -EINVAL;
 174                 return ret;
 175         }
 176         return 0;
 177 }
 178 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 179
 180 static void intr_complete (struct urb *urb)
 181 {
 182         struct usbnet   *dev = urb->context;
 183         int             status = urb->status;
 184
 185         switch (status) {
 186         /* success */
 187         case 0:
 188                 dev->driver_info->status(dev, urb);
 189                 break;
 190
 191         /* software-driven interface shutdown */
 192         case -ENOENT:           /* urb killed */
 193         case -ESHUTDOWN:        /* hardware gone */
 194                 netif_dbg(dev, ifdown, dev->net,
 195                           "intr shutdown, code %d\n", status);
 196                 return;
 197
 198         /* NOTE:  not throttling like RX/TX, since this endpoint
 199          * already polls infrequently
 200          */
 201         default:
 202                 netdev_dbg(dev->net, "intr status %d\n", status);
 203                 break;
 204         }
 205
 206         status = usb_submit_urb (urb, GFP_ATOMIC);
 207         if (status != 0)
 208                 netif_err(dev, timer, dev->net,
 209                           "intr resubmit --> %d\n", status);
 210 }
 211
 212 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 213 {
 214         char            *buf = NULL;
 215         unsigned        pipe = 0;
 216         unsigned        maxp;
 217         unsigned        period;
 218
 219         if (!dev->driver_info->status)
 220                 return 0;
 221
 222         pipe = usb_rcvintpipe (dev->udev,
 223                         dev->status->desc.bEndpointAddress
 224                                 & USB_ENDPOINT_NUMBER_MASK);
 225         maxp = usb_maxpacket (dev->udev, pipe, 0);
 226
 227         /* avoid 1 msec chatter:  min 8 msec poll rate */
 228         period = max ((int) dev->status->desc.bInterval,
 229                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 230
 231         buf = kmalloc (maxp, GFP_KERNEL);
 232         if (buf) {
 233                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 234                 if (!dev->interrupt) {
 235                         kfree (buf);
 236                         return -ENOMEM;
 237                 } else {
 238                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 239                                 buf, maxp, intr_complete, dev, period);
 240                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 241                         dev_dbg(&intf->dev,
 242                                 "status ep%din, %d bytes period %d\n",
 243                                 usb_pipeendpoint(pipe), maxp, period);
 244                 }
 245         }
 246         return 0;
 247 }
 248
 249 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 250 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 251 {
 252         int ret = 0;
 253
 254         WARN_ON_ONCE(dev->interrupt == NULL);
 255         if (dev->interrupt) {
 256                 mutex_lock(&dev->interrupt_mutex);
 257
 258                 if (++dev->interrupt_count == 1)
 259                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 260
 261                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 262                         dev->interrupt_count);
 263                 mutex_unlock(&dev->interrupt_mutex);
 264         }
 265         return ret;
 266 }
 267 EXPORT_SYMBOL_GPL(usbnet_status_start);
 268
 269 /* For resume; submit interrupt URB if previously submitted */
 270 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 271 {
 272         int ret = 0;
 273
 274         mutex_lock(&dev->interrupt_mutex);
 275         if (dev->interrupt_count) {
 276                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 277                 dev_dbg(&dev->udev->dev,
 278                         "submitted interrupt URB for resume\n");
 279         }
 280         mutex_unlock(&dev->interrupt_mutex);
 281         return ret;
 282 }
 283
 284 /* Kill the interrupt URB if all submitters want it killed */
 285 void usbnet_status_stop(struct usbnet *dev)
 286 {
 287         if (dev->interrupt) {
 288                 mutex_lock(&dev->interrupt_mutex);
 289                 WARN_ON(dev->interrupt_count == 0);
 290
 291                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 292                         usb_kill_urb(dev->interrupt);
 293
 294                 dev_dbg(&dev->udev->dev,
 295                         "decremented interrupt URB count to %d\n",
 296                         dev->interrupt_count);
 297                 mutex_unlock(&dev->interrupt_mutex);
 298         }
 299 }
 300 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 301
 302 /* For suspend; always kill interrupt URB */
 303 static void __usbnet_status_stop_force(struct usbnet *dev)
 304 {
 305         if (dev->interrupt) {
 306                 mutex_lock(&dev->interrupt_mutex);
 307                 usb_kill_urb(dev->interrupt);
 308                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 309                 mutex_unlock(&dev->interrupt_mutex);
 310         }
 311 }
 312
 313 /* Passes this packet up the stack, updating its accounting.
 314  * Some link protocols batch packets, so their rx_fixup paths
 315  * can return clones as well as just modify the original skb.
 316  */
 317 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 318 {
 319         int     status;
 320
 321         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 322                 skb_queue_tail(&dev->rxq_pause, skb);
 323                 return;
 324         }
 325
 326         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         /* all data was already cloned from skb inside the driver */
 546         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 547                 goto done;
 548
 549         if (skb->len < ETH_HLEN) {
 550                 dev->net->stats.rx_errors++;
 551                 dev->net->stats.rx_length_errors++;
 552                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 553         } else {
 554                 usbnet_skb_return(dev, skb);
 555                 return;
 556         }
 557
 558 done:
 559         skb_queue_tail(&dev->done, skb);
 560 }
 561
 562 /*-------------------------------------------------------------------------*/
 563
 564 static void rx_complete (struct urb *urb)
 565 {
 566         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 567         struct skb_data         *entry = (struct skb_data *) skb->cb;
 568         struct usbnet           *dev = entry->dev;
 569         int                     urb_status = urb->status;
 570         enum skb_state          state;
 571
 572         skb_put (skb, urb->actual_length);
 573         state = rx_done;
 574         entry->urb = NULL;
 575
 576         switch (urb_status) {
 577         /* success */
 578         case 0:
 579                 break;
 580
 581         /* stalls need manual reset. this is rare ... except that
 582          * when going through USB 2.0 TTs, unplug appears this way.
 583          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 584          * storm, recovering as needed.
 585          */
 586         case -EPIPE:
 587                 dev->net->stats.rx_errors++;
 588                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 589                 // FALLTHROUGH
 590
 591         /* software-driven interface shutdown */
 592         case -ECONNRESET:               /* async unlink */
 593         case -ESHUTDOWN:                /* hardware gone */
 594                 netif_dbg(dev, ifdown, dev->net,
 595                           "rx shutdown, code %d\n", urb_status);
 596                 goto block;
 597
 598         /* we get controller i/o faults during hub_wq disconnect() delays.
 599          * throttle down resubmits, to avoid log floods; just temporarily,
 600          * so we still recover when the fault isn't a hub_wq delay.
 601          */
 602         case -EPROTO:
 603         case -ETIME:
 604         case -EILSEQ:
 605                 dev->net->stats.rx_errors++;
 606                 if (!timer_pending (&dev->delay)) {
 607                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 608                         netif_dbg(dev, link, dev->net,
 609                                   "rx throttle %d\n", urb_status);
 610                 }
 611 block:
 612                 state = rx_cleanup;
 613                 entry->urb = urb;
 614                 urb = NULL;
 615                 break;
 616
 617         /* data overrun ... flush fifo? */
 618         case -EOVERFLOW:
 619                 dev->net->stats.rx_over_errors++;
 620                 // FALLTHROUGH
 621
 622         default:
 623                 state = rx_cleanup;
 624                 dev->net->stats.rx_errors++;
 625                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 626                 break;
 627         }
 628
 629         /* stop rx if packet error rate is high */
 630         if (++dev->pkt_cnt > 30) {
 631                 dev->pkt_cnt = 0;
 632                 dev->pkt_err = 0;
 633         } else {
 634                 if (state == rx_cleanup)
 635                         dev->pkt_err++;
 636                 if (dev->pkt_err > 20)
 637                         set_bit(EVENT_RX_KILL, &dev->flags);
 638         }
 639
 640         state = defer_bh(dev, skb, &dev->rxq, state);
 641
 642         if (urb) {
 643                 if (netif_running (dev->net) &&
 644                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 645                     state != unlink_start) {
 646                         rx_submit (dev, urb, GFP_ATOMIC);
 647                         usb_mark_last_busy(dev->udev);
 648                         return;
 649                 }
 650                 usb_free_urb (urb);
 651         }
 652         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 653 }
 654
 655 /*-------------------------------------------------------------------------*/
 656 void usbnet_pause_rx(struct usbnet *dev)
 657 {
 658         set_bit(EVENT_RX_PAUSED, &dev->flags);
 659
 660         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 661 }
 662 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 663
 664 void usbnet_resume_rx(struct usbnet *dev)
 665 {
 666         struct sk_buff *skb;
 667         int num = 0;
 668
 669         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 670
 671         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 672                 usbnet_skb_return(dev, skb);
 673                 num++;
 674         }
 675
 676         tasklet_schedule(&dev->bh);
 677
 678         netif_dbg(dev, rx_status, dev->net,
 679                   "paused rx queue disabled, %d skbs requeued\n", num);
 680 }
 681 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 682
 683 void usbnet_purge_paused_rxq(struct usbnet *dev)
 684 {
 685         skb_queue_purge(&dev->rxq_pause);
 686 }
 687 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 688
 689 /*-------------------------------------------------------------------------*/
 690
 691 // unlink pending rx/tx; completion handlers do all other cleanup
 692
 693 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 694 {
 695         unsigned long           flags;
 696         struct sk_buff          *skb;
 697         int                     count = 0;
 698
 699         spin_lock_irqsave (&q->lock, flags);
 700         while (!skb_queue_empty(q)) {
 701                 struct skb_data         *entry;
 702                 struct urb              *urb;
 703                 int                     retval;
 704
 705                 skb_queue_walk(q, skb) {
 706                         entry = (struct skb_data *) skb->cb;
 707                         if (entry->state != unlink_start)
 708                                 goto found;
 709                 }
 710                 break;
 711 found:
 712                 entry->state = unlink_start;
 713                 urb = entry->urb;
 714
 715                 /*
 716                  * Get reference count of the URB to avoid it to be
 717                  * freed during usb_unlink_urb, which may trigger
 718                  * use-after-free problem inside usb_unlink_urb since
 719                  * usb_unlink_urb is always racing with .complete
 720                  * handler(include defer_bh).
 721                  */
 722                 usb_get_urb(urb);
 723                 spin_unlock_irqrestore(&q->lock, flags);
 724                 // during some PM-driven resume scenarios,
 725                 // these (async) unlinks complete immediately
 726                 retval = usb_unlink_urb (urb);
 727                 if (retval != -EINPROGRESS && retval != 0)
 728                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 729                 else
 730                         count++;
 731                 usb_put_urb(urb);
 732                 spin_lock_irqsave(&q->lock, flags);
 733         }
 734         spin_unlock_irqrestore (&q->lock, flags);
 735         return count;
 736 }
 737
 738 // Flush all pending rx urbs
 739 // minidrivers may need to do this when the MTU changes
 740
 741 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 742 {
 743         if (netif_running(dev->net)) {
 744                 (void) unlink_urbs (dev, &dev->rxq);
 745                 tasklet_schedule(&dev->bh);
 746         }
 747 }
 748 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 749
 750 /*-------------------------------------------------------------------------*/
 751
 752 // precondition: never called in_interrupt
 753 static void usbnet_terminate_urbs(struct usbnet *dev)
 754 {
 755         DECLARE_WAITQUEUE(wait, current);
 756         int temp;
 757
 758         /* ensure there are no more active urbs */
 759         add_wait_queue(&dev->wait, &wait);
 760         set_current_state(TASK_UNINTERRUPTIBLE);
 761         temp = unlink_urbs(dev, &dev->txq) +
 762                 unlink_urbs(dev, &dev->rxq);
 763
 764         /* maybe wait for deletions to finish. */
 765         while (!skb_queue_empty(&dev->rxq)
 766                 && !skb_queue_empty(&dev->txq)
 767                 && !skb_queue_empty(&dev->done)) {
 768                         schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 769                         set_current_state(TASK_UNINTERRUPTIBLE);
 770                         netif_dbg(dev, ifdown, dev->net,
 771                                   "waited for %d urb completions\n", temp);
 772         }
 773         set_current_state(TASK_RUNNING);
 774         remove_wait_queue(&dev->wait, &wait);
 775 }
 776
 777 int usbnet_stop (struct net_device *net)
 778 {
 779         struct usbnet           *dev = netdev_priv(net);
 780         struct driver_info      *info = dev->driver_info;
 781         int                     retval, pm;
 782
 783         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 784         netif_stop_queue (net);
 785
 786         netif_info(dev, ifdown, dev->net,
 787                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 788                    net->stats.rx_packets, net->stats.tx_packets,
 789                    net->stats.rx_errors, net->stats.tx_errors);
 790
 791         /* to not race resume */
 792         pm = usb_autopm_get_interface(dev->intf);
 793         /* allow minidriver to stop correctly (wireless devices to turn off
 794          * radio etc) */
 795         if (info->stop) {
 796                 retval = info->stop(dev);
 797                 if (retval < 0)
 798                         netif_info(dev, ifdown, dev->net,
 799                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 800                                    retval,
 801                                    dev->udev->bus->bus_name, dev->udev->devpath,
 802                                    info->description);
 803         }
 804
 805         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 806                 usbnet_terminate_urbs(dev);
 807
 808         usbnet_status_stop(dev);
 809
 810         usbnet_purge_paused_rxq(dev);
 811
 812         /* deferred work (task, timer, softirq) must also stop.
 813          * can't flush_scheduled_work() until we drop rtnl (later),
 814          * else workers could deadlock; so make workers a NOP.
 815          */
 816         dev->flags = 0;
 817         del_timer_sync (&dev->delay);
 818         tasklet_kill (&dev->bh);
 819         if (!pm)
 820                 usb_autopm_put_interface(dev->intf);
 821
 822         if (info->manage_power &&
 823             !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
 824                 info->manage_power(dev, 0);
 825         else
 826                 usb_autopm_put_interface(dev->intf);
 827
 828         return 0;
 829 }
 830 EXPORT_SYMBOL_GPL(usbnet_stop);
 831
 832 /*-------------------------------------------------------------------------*/
 833
 834 // posts reads, and enables write queuing
 835
 836 // precondition: never called in_interrupt
 837
 838 int usbnet_open (struct net_device *net)
 839 {
 840         struct usbnet           *dev = netdev_priv(net);
 841         int                     retval;
 842         struct driver_info      *info = dev->driver_info;
 843
 844         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 845                 netif_info(dev, ifup, dev->net,
 846                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 847                            retval,
 848                            dev->udev->bus->bus_name,
 849                            dev->udev->devpath,
 850                            info->description);
 851                 goto done_nopm;
 852         }
 853
 854         // put into "known safe" state
 855         if (info->reset && (retval = info->reset (dev)) < 0) {
 856                 netif_info(dev, ifup, dev->net,
 857                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 858                            retval,
 859                            dev->udev->bus->bus_name,
 860                            dev->udev->devpath,
 861                            info->description);
 862                 goto done;
 863         }
 864
 865         /* hard_mtu or rx_urb_size may change in reset() */
 866         usbnet_update_max_qlen(dev);
 867
 868         // insist peer be connected
 869         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 870                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 871                 goto done;
 872         }
 873
 874         /* start any status interrupt transfer */
 875         if (dev->interrupt) {
 876                 retval = usbnet_status_start(dev, GFP_KERNEL);
 877                 if (retval < 0) {
 878                         netif_err(dev, ifup, dev->net,
 879                                   "intr submit %d\n", retval);
 880                         goto done;
 881                 }
 882         }
 883
 884         set_bit(EVENT_DEV_OPEN, &dev->flags);
 885         netif_start_queue (net);
 886         netif_info(dev, ifup, dev->net,
 887                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 888                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 889                    dev->net->mtu,
 890                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 891                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 892                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 893                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 894                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 895                    "simple");
 896
 897         /* reset rx error state */
 898         dev->pkt_cnt = 0;
 899         dev->pkt_err = 0;
 900         clear_bit(EVENT_RX_KILL, &dev->flags);
 901
 902         // delay posting reads until we're fully open
 903         tasklet_schedule (&dev->bh);
 904         if (info->manage_power) {
 905                 retval = info->manage_power(dev, 1);
 906                 if (retval < 0) {
 907                         retval = 0;
 908                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 909                 } else {
 910                         usb_autopm_put_interface(dev->intf);
 911                 }
 912         }
 913         return retval;
 914 done:
 915         usb_autopm_put_interface(dev->intf);
 916 done_nopm:
 917         return retval;
 918 }
 919 EXPORT_SYMBOL_GPL(usbnet_open);
 920
 921 /*-------------------------------------------------------------------------*/
 922
 923 /* ethtool methods; minidrivers may need to add some more, but
 924  * they'll probably want to use this base set.
 925  */
 926
 927 int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 928 {
 929         struct usbnet *dev = netdev_priv(net);
 930
 931         if (!dev->mii.mdio_read)
 932                 return -EOPNOTSUPP;
 933
 934         return mii_ethtool_gset(&dev->mii, cmd);
 935 }
 936 EXPORT_SYMBOL_GPL(usbnet_get_settings);
 937
 938 int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 939 {
 940         struct usbnet *dev = netdev_priv(net);
 941         int retval;
 942
 943         if (!dev->mii.mdio_write)
 944                 return -EOPNOTSUPP;
 945
 946         retval = mii_ethtool_sset(&dev->mii, cmd);
 947
 948         /* link speed/duplex might have changed */
 949         if (dev->driver_info->link_reset)
 950                 dev->driver_info->link_reset(dev);
 951
 952         /* hard_mtu or rx_urb_size may change in link_reset() */
 953         usbnet_update_max_qlen(dev);
 954
 955         return retval;
 956
 957 }
 958 EXPORT_SYMBOL_GPL(usbnet_set_settings);
 959
 960 u32 usbnet_get_link (struct net_device *net)
 961 {
 962         struct usbnet *dev = netdev_priv(net);
 963
 964         /* If a check_connect is defined, return its result */
 965         if (dev->driver_info->check_connect)
 966                 return dev->driver_info->check_connect (dev) == 0;
 967
 968         /* if the device has mii operations, use those */
 969         if (dev->mii.mdio_read)
 970                 return mii_link_ok(&dev->mii);
 971
 972         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 973         return ethtool_op_get_link(net);
 974 }
 975 EXPORT_SYMBOL_GPL(usbnet_get_link);
 976
 977 int usbnet_nway_reset(struct net_device *net)
 978 {
 979         struct usbnet *dev = netdev_priv(net);
 980
 981         if (!dev->mii.mdio_write)
 982                 return -EOPNOTSUPP;
 983
 984         return mii_nway_restart(&dev->mii);
 985 }
 986 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 987
 988 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 989 {
 990         struct usbnet *dev = netdev_priv(net);
 991
 992         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 993         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 994         strlcpy (info->fw_version, dev->driver_info->description,
 995                 sizeof info->fw_version);
 996         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 997 }
 998 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 999
1000 u32 usbnet_get_msglevel (struct net_device *net)
1001 {
1002         struct usbnet *dev = netdev_priv(net);
1003
1004         return dev->msg_enable;
1005 }
1006 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1007
1008 void usbnet_set_msglevel (struct net_device *net, u32 level)
1009 {
1010         struct usbnet *dev = netdev_priv(net);
1011
1012         dev->msg_enable = level;
1013 }
1014 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1015
1016 /* drivers may override default ethtool_ops in their bind() routine */
1017 static const struct ethtool_ops usbnet_ethtool_ops = {
1018         .get_settings           = usbnet_get_settings,
1019         .set_settings           = usbnet_set_settings,
1020         .get_link               = usbnet_get_link,
1021         .nway_reset             = usbnet_nway_reset,
1022         .get_drvinfo            = usbnet_get_drvinfo,
1023         .get_msglevel           = usbnet_get_msglevel,
1024         .set_msglevel           = usbnet_set_msglevel,
1025         .get_ts_info            = ethtool_op_get_ts_info,
1026 };
1027
1028 /*-------------------------------------------------------------------------*/
1029
1030 static void __handle_link_change(struct usbnet *dev)
1031 {
1032         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1033                 return;
1034
1035         if (!netif_carrier_ok(dev->net)) {
1036                 /* kill URBs for reading packets to save bus bandwidth */
1037                 unlink_urbs(dev, &dev->rxq);
1038
1039                 /*
1040                  * tx_timeout will unlink URBs for sending packets and
1041                  * tx queue is stopped by netcore after link becomes off
1042                  */
1043         } else {
1044                 /* submitting URBs for reading packets */
1045                 tasklet_schedule(&dev->bh);
1046         }
1047
1048         /* hard_mtu or rx_urb_size may change during link change */
1049         usbnet_update_max_qlen(dev);
1050
1051         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1052 }
1053
1054 static void usbnet_set_rx_mode(struct net_device *net)
1055 {
1056         struct usbnet           *dev = netdev_priv(net);
1057
1058         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1059 }
1060
1061 static void __handle_set_rx_mode(struct usbnet *dev)
1062 {
1063         if (dev->driver_info->set_rx_mode)
1064                 (dev->driver_info->set_rx_mode)(dev);
1065
1066         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1067 }
1068
1069 /* work that cannot be done in interrupt context uses keventd.
1070  *
1071  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1072  * especially now that control transfers can be queued.
1073  */
1074 static void
1075 kevent (struct work_struct *work)
1076 {
1077         struct usbnet           *dev =
1078                 container_of(work, struct usbnet, kevent);
1079         int                     status;
1080
1081         /* usb_clear_halt() needs a thread context */
1082         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1083                 unlink_urbs (dev, &dev->txq);
1084                 status = usb_autopm_get_interface(dev->intf);
1085                 if (status < 0)
1086                         goto fail_pipe;
1087                 status = usb_clear_halt (dev->udev, dev->out);
1088                 usb_autopm_put_interface(dev->intf);
1089                 if (status < 0 &&
1090                     status != -EPIPE &&
1091                     status != -ESHUTDOWN) {
1092                         if (netif_msg_tx_err (dev))
1093 fail_pipe:
1094                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1095                                            status);
1096                 } else {
1097                         clear_bit (EVENT_TX_HALT, &dev->flags);
1098                         if (status != -ESHUTDOWN)
1099                                 netif_wake_queue (dev->net);
1100                 }
1101         }
1102         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1103                 unlink_urbs (dev, &dev->rxq);
1104                 status = usb_autopm_get_interface(dev->intf);
1105                 if (status < 0)
1106                         goto fail_halt;
1107                 status = usb_clear_halt (dev->udev, dev->in);
1108                 usb_autopm_put_interface(dev->intf);
1109                 if (status < 0 &&
1110                     status != -EPIPE &&
1111                     status != -ESHUTDOWN) {
1112                         if (netif_msg_rx_err (dev))
1113 fail_halt:
1114                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1115                                            status);
1116                 } else {
1117                         clear_bit (EVENT_RX_HALT, &dev->flags);
1118                         tasklet_schedule (&dev->bh);
1119                 }
1120         }
1121
1122         /* tasklet could resubmit itself forever if memory is tight */
1123         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1124                 struct urb      *urb = NULL;
1125                 int resched = 1;
1126
1127                 if (netif_running (dev->net))
1128                         urb = usb_alloc_urb (0, GFP_KERNEL);
1129                 else
1130                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1131                 if (urb != NULL) {
1132                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1133                         status = usb_autopm_get_interface(dev->intf);
1134                         if (status < 0) {
1135                                 usb_free_urb(urb);
1136                                 goto fail_lowmem;
1137                         }
1138                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1139                                 resched = 0;
1140                         usb_autopm_put_interface(dev->intf);
1141 fail_lowmem:
1142                         if (resched)
1143                                 tasklet_schedule (&dev->bh);
1144                 }
1145         }
1146
1147         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1148                 struct driver_info      *info = dev->driver_info;
1149                 int                     retval = 0;
1150
1151                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1152                 status = usb_autopm_get_interface(dev->intf);
1153                 if (status < 0)
1154                         goto skip_reset;
1155                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1156                         usb_autopm_put_interface(dev->intf);
1157 skip_reset:
1158                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1159                                     retval,
1160                                     dev->udev->bus->bus_name,
1161                                     dev->udev->devpath,
1162                                     info->description);
1163                 } else {
1164                         usb_autopm_put_interface(dev->intf);
1165                 }
1166
1167                 /* handle link change from link resetting */
1168                 __handle_link_change(dev);
1169         }
1170
1171         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1172                 __handle_link_change(dev);
1173
1174         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1175                 __handle_set_rx_mode(dev);
1176
1177
1178         if (dev->flags)
1179                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1180 }
1181
1182 /*-------------------------------------------------------------------------*/
1183
1184 static void tx_complete (struct urb *urb)
1185 {
1186         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1187         struct skb_data         *entry = (struct skb_data *) skb->cb;
1188         struct usbnet           *dev = entry->dev;
1189
1190         if (urb->status == 0) {
1191                 dev->net->stats.tx_packets += entry->packets;
1192                 dev->net->stats.tx_bytes += entry->length;
1193         } else {
1194                 dev->net->stats.tx_errors++;
1195
1196                 switch (urb->status) {
1197                 case -EPIPE:
1198                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1199                         break;
1200
1201                 /* software-driven interface shutdown */
1202                 case -ECONNRESET:               // async unlink
1203                 case -ESHUTDOWN:                // hardware gone
1204                         break;
1205
1206                 /* like rx, tx gets controller i/o faults during hub_wq
1207                  * delays and so it uses the same throttling mechanism.
1208                  */
1209                 case -EPROTO:
1210                 case -ETIME:
1211                 case -EILSEQ:
1212                         usb_mark_last_busy(dev->udev);
1213                         if (!timer_pending (&dev->delay)) {
1214                                 mod_timer (&dev->delay,
1215                                         jiffies + THROTTLE_JIFFIES);
1216                                 netif_dbg(dev, link, dev->net,
1217                                           "tx throttle %d\n", urb->status);
1218                         }
1219                         netif_stop_queue (dev->net);
1220                         break;
1221                 default:
1222                         netif_dbg(dev, tx_err, dev->net,
1223                                   "tx err %d\n", entry->urb->status);
1224                         break;
1225                 }
1226         }
1227
1228         usb_autopm_put_interface_async(dev->intf);
1229         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1230 }
1231
1232 /*-------------------------------------------------------------------------*/
1233
1234 void usbnet_tx_timeout (struct net_device *net)
1235 {
1236         struct usbnet           *dev = netdev_priv(net);
1237
1238         unlink_urbs (dev, &dev->txq);
1239         tasklet_schedule (&dev->bh);
1240         /* this needs to be handled individually because the generic layer
1241          * doesn't know what is sufficient and could not restore private
1242          * information if a remedy of an unconditional reset were used.
1243          */
1244         if (dev->driver_info->recover)
1245                 (dev->driver_info->recover)(dev);
1246 }
1247 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1248
1249 /*-------------------------------------------------------------------------*/
1250
1251 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1252 {
1253         unsigned num_sgs, total_len = 0;
1254         int i, s = 0;
1255
1256         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1257         if (num_sgs == 1)
1258                 return 0;
1259
1260         /* reserve one for zero packet */
1261         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1262                           GFP_ATOMIC);
1263         if (!urb->sg)
1264                 return -ENOMEM;
1265
1266         urb->num_sgs = num_sgs;
1267         sg_init_table(urb->sg, urb->num_sgs + 1);
1268
1269         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1270         total_len += skb_headlen(skb);
1271
1272         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1273                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1274
1275                 total_len += skb_frag_size(f);
1276                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1277                                 f->page_offset);
1278         }
1279         urb->transfer_buffer_length = total_len;
1280
1281         return 1;
1282 }
1283
1284 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1285                                      struct net_device *net)
1286 {
1287         struct usbnet           *dev = netdev_priv(net);
1288         int                     length;
1289         struct urb              *urb = NULL;
1290         struct skb_data         *entry;
1291         struct driver_info      *info = dev->driver_info;
1292         unsigned long           flags;
1293         int retval;
1294
1295         if (skb)
1296                 skb_tx_timestamp(skb);
1297
1298         // some devices want funky USB-level framing, for
1299         // win32 driver (usually) and/or hardware quirks
1300         if (info->tx_fixup) {
1301                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1302                 if (!skb) {
1303                         /* packet collected; minidriver waiting for more */
1304                         if (info->flags & FLAG_MULTI_PACKET)
1305                                 goto not_drop;
1306                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1307                         goto drop;
1308                 }
1309         }
1310
1311         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1312                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1313                 goto drop;
1314         }
1315
1316         entry = (struct skb_data *) skb->cb;
1317         entry->urb = urb;
1318         entry->dev = dev;
1319
1320         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1321                         skb->data, skb->len, tx_complete, skb);
1322         if (dev->can_dma_sg) {
1323                 if (build_dma_sg(skb, urb) < 0)
1324                         goto drop;
1325         }
1326         length = urb->transfer_buffer_length;
1327
1328         /* don't assume the hardware handles USB_ZERO_PACKET
1329          * NOTE:  strictly conforming cdc-ether devices should expect
1330          * the ZLP here, but ignore the one-byte packet.
1331          * NOTE2: CDC NCM specification is different from CDC ECM when
1332          * handling ZLP/short packets, so cdc_ncm driver will make short
1333          * packet itself if needed.
1334          */
1335         if (length % dev->maxpacket == 0) {
1336                 if (!(info->flags & FLAG_SEND_ZLP)) {
1337                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1338                                 length++;
1339                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1340                                         skb->data[skb->len] = 0;
1341                                         __skb_put(skb, 1);
1342                                 } else if (urb->num_sgs)
1343                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1344                                                         dev->padding_pkt, 1);
1345                         }
1346                 } else
1347                         urb->transfer_flags |= URB_ZERO_PACKET;
1348         }
1349         entry->length = urb->transfer_buffer_length = length;
1350         if (!(info->flags & FLAG_MULTI_PACKET))
1351                 usbnet_set_skb_tx_stats(skb, 1);
1352
1353         spin_lock_irqsave(&dev->txq.lock, flags);
1354         retval = usb_autopm_get_interface_async(dev->intf);
1355         if (retval < 0) {
1356                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1357                 goto drop;
1358         }
1359
1360 #ifdef CONFIG_PM
1361         /* if this triggers the device is still a sleep */
1362         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1363                 /* transmission will be done in resume */
1364                 usb_anchor_urb(urb, &dev->deferred);
1365                 /* no use to process more packets */
1366                 netif_stop_queue(net);
1367                 usb_put_urb(urb);
1368                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1369                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1370                 goto deferred;
1371         }
1372 #endif
1373
1374         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1375         case -EPIPE:
1376                 netif_stop_queue (net);
1377                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1378                 usb_autopm_put_interface_async(dev->intf);
1379                 break;
1380         default:
1381                 usb_autopm_put_interface_async(dev->intf);
1382                 netif_dbg(dev, tx_err, dev->net,
1383                           "tx: submit urb err %d\n", retval);
1384                 break;
1385         case 0:
1386                 net->trans_start = jiffies;
1387                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1388                 if (dev->txq.qlen >= TX_QLEN (dev))
1389                         netif_stop_queue (net);
1390         }
1391         spin_unlock_irqrestore (&dev->txq.lock, flags);
1392
1393         if (retval) {
1394                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1395 drop:
1396                 dev->net->stats.tx_dropped++;
1397 not_drop:
1398                 if (skb)
1399                         dev_kfree_skb_any (skb);
1400                 if (urb) {
1401                         kfree(urb->sg);
1402                         usb_free_urb(urb);
1403                 }
1404         } else
1405                 netif_dbg(dev, tx_queued, dev->net,
1406                           "> tx, len %d, type 0x%x\n", length, skb->protocol);
1407 #ifdef CONFIG_PM
1408 deferred:
1409 #endif
1410         return NETDEV_TX_OK;
1411 }
1412 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1413
1414 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1415 {
1416         struct urb      *urb;
1417         int             i;
1418         int             ret = 0;
1419
1420         /* don't refill the queue all at once */
1421         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1422                 urb = usb_alloc_urb(0, flags);
1423                 if (urb != NULL) {
1424                         ret = rx_submit(dev, urb, flags);
1425                         if (ret)
1426                                 goto err;
1427                 } else {
1428                         ret = -ENOMEM;
1429                         goto err;
1430                 }
1431         }
1432 err:
1433         return ret;
1434 }
1435
1436 /*-------------------------------------------------------------------------*/
1437
1438 // tasklet (work deferred from completions, in_irq) or timer
1439
1440 static void usbnet_bh (unsigned long param)
1441 {
1442         struct usbnet           *dev = (struct usbnet *) param;
1443         struct sk_buff          *skb;
1444         struct skb_data         *entry;
1445
1446         while ((skb = skb_dequeue (&dev->done))) {
1447                 entry = (struct skb_data *) skb->cb;
1448                 switch (entry->state) {
1449                 case rx_done:
1450                         entry->state = rx_cleanup;
1451                         rx_process (dev, skb);
1452                         continue;
1453                 case tx_done:
1454                         kfree(entry->urb->sg);
1455                 case rx_cleanup:
1456                         usb_free_urb (entry->urb);
1457                         dev_kfree_skb (skb);
1458                         continue;
1459                 default:
1460                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1461                 }
1462         }
1463
1464         /* restart RX again after disabling due to high error rate */
1465         clear_bit(EVENT_RX_KILL, &dev->flags);
1466
1467         /* waiting for all pending urbs to complete?
1468          * only then can we forgo submitting anew
1469          */
1470         if (waitqueue_active(&dev->wait)) {
1471                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1472                         wake_up_all(&dev->wait);
1473
1474         // or are we maybe short a few urbs?
1475         } else if (netif_running (dev->net) &&
1476                    netif_device_present (dev->net) &&
1477                    netif_carrier_ok(dev->net) &&
1478                    !timer_pending (&dev->delay) &&
1479                    !test_bit (EVENT_RX_HALT, &dev->flags)) {
1480                 int     temp = dev->rxq.qlen;
1481
1482                 if (temp < RX_QLEN(dev)) {
1483                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1484                                 return;
1485                         if (temp != dev->rxq.qlen)
1486                                 netif_dbg(dev, link, dev->net,
1487                                           "rxqlen %d --> %d\n",
1488                                           temp, dev->rxq.qlen);
1489                         if (dev->rxq.qlen < RX_QLEN(dev))
1490                                 tasklet_schedule (&dev->bh);
1491                 }
1492                 if (dev->txq.qlen < TX_QLEN (dev))
1493                         netif_wake_queue (dev->net);
1494         }
1495 }
1496
1497
1498 /*-------------------------------------------------------------------------
1499  *
1500  * USB Device Driver support
1501  *
1502  *-------------------------------------------------------------------------*/
1503
1504 // precondition: never called in_interrupt
1505
1506 void usbnet_disconnect (struct usb_interface *intf)
1507 {
1508         struct usbnet           *dev;
1509         struct usb_device       *xdev;
1510         struct net_device       *net;
1511
1512         dev = usb_get_intfdata(intf);
1513         usb_set_intfdata(intf, NULL);
1514         if (!dev)
1515                 return;
1516
1517         xdev = interface_to_usbdev (intf);
1518
1519         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1520                    intf->dev.driver->name,
1521                    xdev->bus->bus_name, xdev->devpath,
1522                    dev->driver_info->description);
1523
1524         net = dev->net;
1525         unregister_netdev (net);
1526
1527         cancel_work_sync(&dev->kevent);
1528
1529         usb_scuttle_anchored_urbs(&dev->deferred);
1530
1531         if (dev->driver_info->unbind)
1532                 dev->driver_info->unbind (dev, intf);
1533
1534         usb_kill_urb(dev->interrupt);
1535         usb_free_urb(dev->interrupt);
1536         kfree(dev->padding_pkt);
1537
1538         free_netdev(net);
1539 }
1540 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1541
1542 static const struct net_device_ops usbnet_netdev_ops = {
1543         .ndo_open               = usbnet_open,
1544         .ndo_stop               = usbnet_stop,
1545         .ndo_start_xmit         = usbnet_start_xmit,
1546         .ndo_tx_timeout         = usbnet_tx_timeout,
1547         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1548         .ndo_change_mtu         = usbnet_change_mtu,
1549         .ndo_set_mac_address    = eth_mac_addr,
1550         .ndo_validate_addr      = eth_validate_addr,
1551 };
1552
1553 /*-------------------------------------------------------------------------*/
1554
1555 // precondition: never called in_interrupt
1556
1557 static struct device_type wlan_type = {
1558         .name   = "wlan",
1559 };
1560
1561 static struct device_type wwan_type = {
1562         .name   = "wwan",
1563 };
1564
1565 int
1566 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1567 {
1568         struct usbnet                   *dev;
1569         struct net_device               *net;
1570         struct usb_host_interface       *interface;
1571         struct driver_info              *info;
1572         struct usb_device               *xdev;
1573         int                             status;
1574         const char                      *name;
1575         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1576
1577         /* usbnet already took usb runtime pm, so have to enable the feature
1578          * for usb interface, otherwise usb_autopm_get_interface may return
1579          * failure if RUNTIME_PM is enabled.
1580          */
1581         if (!driver->supports_autosuspend) {
1582                 driver->supports_autosuspend = 1;
1583                 pm_runtime_enable(&udev->dev);
1584         }
1585
1586         name = udev->dev.driver->name;
1587         info = (struct driver_info *) prod->driver_info;
1588         if (!info) {
1589                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1590                 return -ENODEV;
1591         }
1592         xdev = interface_to_usbdev (udev);
1593         interface = udev->cur_altsetting;
1594
1595         status = -ENOMEM;
1596
1597         // set up our own records
1598         net = alloc_etherdev(sizeof(*dev));
1599         if (!net)
1600                 goto out;
1601
1602         /* netdev_printk() needs this so do it as early as possible */
1603         SET_NETDEV_DEV(net, &udev->dev);
1604
1605         dev = netdev_priv(net);
1606         dev->udev = xdev;
1607         dev->intf = udev;
1608         dev->driver_info = info;
1609         dev->driver_name = name;
1610         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1611                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1612         init_waitqueue_head(&dev->wait);
1613         skb_queue_head_init (&dev->rxq);
1614         skb_queue_head_init (&dev->txq);
1615         skb_queue_head_init (&dev->done);
1616         skb_queue_head_init(&dev->rxq_pause);
1617         dev->bh.func = usbnet_bh;
1618         dev->bh.data = (unsigned long) dev;
1619         INIT_WORK (&dev->kevent, kevent);
1620         init_usb_anchor(&dev->deferred);
1621         dev->delay.function = usbnet_bh;
1622         dev->delay.data = (unsigned long) dev;
1623         init_timer (&dev->delay);
1624         mutex_init (&dev->phy_mutex);
1625         mutex_init(&dev->interrupt_mutex);
1626         dev->interrupt_count = 0;
1627
1628         dev->net = net;
1629         strcpy (net->name, "usb%d");
1630         memcpy (net->dev_addr, node_id, sizeof node_id);
1631
1632         /* rx and tx sides can use different message sizes;
1633          * bind() should set rx_urb_size in that case.
1634          */
1635         dev->hard_mtu = net->mtu + net->hard_header_len;
1636 #if 0
1637 // dma_supported() is deeply broken on almost all architectures
1638         // possible with some EHCI controllers
1639         if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1640                 net->features |= NETIF_F_HIGHDMA;
1641 #endif
1642
1643         net->netdev_ops = &usbnet_netdev_ops;
1644         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1645         net->ethtool_ops = &usbnet_ethtool_ops;
1646
1647         // allow device-specific bind/init procedures
1648         // NOTE net->name still not usable ...
1649         if (info->bind) {
1650                 status = info->bind (dev, udev);
1651                 if (status < 0)
1652                         goto out1;
1653
1654                 // heuristic:  "usb%d" for links we know are two-host,
1655                 // else "eth%d" when there's reasonable doubt.  userspace
1656                 // can rename the link if it knows better.
1657                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1658                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1659                      (net->dev_addr [0] & 0x02) == 0))
1660                         strcpy (net->name, "eth%d");
1661                 /* WLAN devices should always be named "wlan%d" */
1662                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1663                         strcpy(net->name, "wlan%d");
1664                 /* WWAN devices should always be named "wwan%d" */
1665                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1666                         strcpy(net->name, "wwan%d");
1667
1668                 /* devices that cannot do ARP */
1669                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1670                         net->flags |= IFF_NOARP;
1671
1672                 /* maybe the remote can't receive an Ethernet MTU */
1673                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1674                         net->mtu = dev->hard_mtu - net->hard_header_len;
1675         } else if (!info->in || !info->out)
1676                 status = usbnet_get_endpoints (dev, udev);
1677         else {
1678                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1679                 dev->out = usb_sndbulkpipe (xdev, info->out);
1680                 if (!(info->flags & FLAG_NO_SETINT))
1681                         status = usb_set_interface (xdev,
1682                                 interface->desc.bInterfaceNumber,
1683                                 interface->desc.bAlternateSetting);
1684                 else
1685                         status = 0;
1686
1687         }
1688         if (status >= 0 && dev->status)
1689                 status = init_status (dev, udev);
1690         if (status < 0)
1691                 goto out3;
1692
1693         if (!dev->rx_urb_size)
1694                 dev->rx_urb_size = dev->hard_mtu;
1695         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1696
1697         /* let userspace know we have a random address */
1698         if (ether_addr_equal(net->dev_addr, node_id))
1699                 net->addr_assign_type = NET_ADDR_RANDOM;
1700
1701         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1702                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1703         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1704                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1705
1706         /* initialize max rx_qlen and tx_qlen */
1707         usbnet_update_max_qlen(dev);
1708
1709         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1710                 !(info->flags & FLAG_MULTI_PACKET)) {
1711                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1712                 if (!dev->padding_pkt) {
1713                         status = -ENOMEM;
1714                         goto out4;
1715                 }
1716         }
1717
1718         status = register_netdev (net);
1719         if (status)
1720                 goto out5;
1721         netif_info(dev, probe, dev->net,
1722                    "register '%s' at usb-%s-%s, %s, %pM\n",
1723                    udev->dev.driver->name,
1724                    xdev->bus->bus_name, xdev->devpath,
1725                    dev->driver_info->description,
1726                    net->dev_addr);
1727
1728         // ok, it's ready to go.
1729         usb_set_intfdata (udev, dev);
1730
1731         netif_device_attach (net);
1732
1733         if (dev->driver_info->flags & FLAG_LINK_INTR)
1734                 usbnet_link_change(dev, 0, 0);
1735
1736         return 0;
1737
1738 out5:
1739         kfree(dev->padding_pkt);
1740 out4:
1741         usb_free_urb(dev->interrupt);
1742 out3:
1743         if (info->unbind)
1744                 info->unbind (dev, udev);
1745 out1:
1746         free_netdev(net);
1747 out:
1748         return status;
1749 }
1750 EXPORT_SYMBOL_GPL(usbnet_probe);
1751
1752 /*-------------------------------------------------------------------------*/
1753
1754 /*
1755  * suspend the whole driver as soon as the first interface is suspended
1756  * resume only when the last interface is resumed
1757  */
1758
1759 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1760 {
1761         struct usbnet           *dev = usb_get_intfdata(intf);
1762
1763         if (!dev->suspend_count++) {
1764                 spin_lock_irq(&dev->txq.lock);
1765                 /* don't autosuspend while transmitting */
1766                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1767                         dev->suspend_count--;
1768                         spin_unlock_irq(&dev->txq.lock);
1769                         return -EBUSY;
1770                 } else {
1771                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1772                         spin_unlock_irq(&dev->txq.lock);
1773                 }
1774                 /*
1775                  * accelerate emptying of the rx and queues, to avoid
1776                  * having everything error out.
1777                  */
1778                 netif_device_detach (dev->net);
1779                 usbnet_terminate_urbs(dev);
1780                 __usbnet_status_stop_force(dev);
1781
1782                 /*
1783                  * reattach so runtime management can use and
1784                  * wake the device
1785                  */
1786                 netif_device_attach (dev->net);
1787         }
1788         return 0;
1789 }
1790 EXPORT_SYMBOL_GPL(usbnet_suspend);
1791
1792 int usbnet_resume (struct usb_interface *intf)
1793 {
1794         struct usbnet           *dev = usb_get_intfdata(intf);
1795         struct sk_buff          *skb;
1796         struct urb              *res;
1797         int                     retval;
1798
1799         if (!--dev->suspend_count) {
1800                 /* resume interrupt URB if it was previously submitted */
1801                 __usbnet_status_start_force(dev, GFP_NOIO);
1802
1803                 spin_lock_irq(&dev->txq.lock);
1804                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1805
1806                         skb = (struct sk_buff *)res->context;
1807                         retval = usb_submit_urb(res, GFP_ATOMIC);
1808                         if (retval < 0) {
1809                                 dev_kfree_skb_any(skb);
1810                                 kfree(res->sg);
1811                                 usb_free_urb(res);
1812                                 usb_autopm_put_interface_async(dev->intf);
1813                         } else {
1814                                 dev->net->trans_start = jiffies;
1815                                 __skb_queue_tail(&dev->txq, skb);
1816                         }
1817                 }
1818
1819                 smp_mb();
1820                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1821                 spin_unlock_irq(&dev->txq.lock);
1822
1823                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1824                         /* handle remote wakeup ASAP
1825                          * we cannot race against stop
1826                          */
1827                         if (netif_device_present(dev->net) &&
1828                                 !timer_pending(&dev->delay) &&
1829                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1830                                         rx_alloc_submit(dev, GFP_NOIO);
1831
1832                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1833                                 netif_tx_wake_all_queues(dev->net);
1834                         tasklet_schedule (&dev->bh);
1835                 }
1836         }
1837
1838         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1839                 usb_autopm_get_interface_no_resume(intf);
1840
1841         return 0;
1842 }
1843 EXPORT_SYMBOL_GPL(usbnet_resume);
1844
1845 /*
1846  * Either a subdriver implements manage_power, then it is assumed to always
1847  * be ready to be suspended or it reports the readiness to be suspended
1848  * explicitly
1849  */
1850 void usbnet_device_suggests_idle(struct usbnet *dev)
1851 {
1852         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1853                 dev->intf->needs_remote_wakeup = 1;
1854                 usb_autopm_put_interface_async(dev->intf);
1855         }
1856 }
1857 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1858
1859 /*
1860  * For devices that can do without special commands
1861  */
1862 int usbnet_manage_power(struct usbnet *dev, int on)
1863 {
1864         dev->intf->needs_remote_wakeup = on;
1865         return 0;
1866 }
1867 EXPORT_SYMBOL(usbnet_manage_power);
1868
1869 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1870 {
1871         /* update link after link is reseted */
1872         if (link && !need_reset)
1873                 netif_carrier_on(dev->net);
1874         else
1875                 netif_carrier_off(dev->net);
1876
1877         if (need_reset && link)
1878                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1879         else
1880                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1881 }
1882 EXPORT_SYMBOL(usbnet_link_change);
1883
1884 /*-------------------------------------------------------------------------*/
1885 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1886                              u16 value, u16 index, void *data, u16 size)
1887 {
1888         void *buf = NULL;
1889         int err = -ENOMEM;
1890
1891         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1892                    " value=0x%04x index=0x%04x size=%d\n",
1893                    cmd, reqtype, value, index, size);
1894
1895         if (data) {
1896                 buf = kmalloc(size, GFP_KERNEL);
1897                 if (!buf)
1898                         goto out;
1899         }
1900
1901         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1902                               cmd, reqtype, value, index, buf, size,
1903                               USB_CTRL_GET_TIMEOUT);
1904         if (err > 0 && err <= size)
1905                 memcpy(data, buf, err);
1906         kfree(buf);
1907 out:
1908         return err;
1909 }
1910
1911 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1912                               u16 value, u16 index, const void *data,
1913                               u16 size)
1914 {
1915         void *buf = NULL;
1916         int err = -ENOMEM;
1917
1918         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1919                    " value=0x%04x index=0x%04x size=%d\n",
1920                    cmd, reqtype, value, index, size);
1921
1922         if (data) {
1923                 buf = kmemdup(data, size, GFP_KERNEL);
1924                 if (!buf)
1925                         goto out;
1926         }
1927
1928         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1929                               cmd, reqtype, value, index, buf, size,
1930                               USB_CTRL_SET_TIMEOUT);
1931         kfree(buf);
1932
1933 out:
1934         return err;
1935 }
1936
1937 /*
1938  * The function can't be called inside suspend/resume callback,
1939  * otherwise deadlock will be caused.
1940  */
1941 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1942                     u16 value, u16 index, void *data, u16 size)
1943 {
1944         int ret;
1945
1946         if (usb_autopm_get_interface(dev->intf) < 0)
1947                 return -ENODEV;
1948         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1949                                 data, size);
1950         usb_autopm_put_interface(dev->intf);
1951         return ret;
1952 }
1953 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1954
1955 /*
1956  * The function can't be called inside suspend/resume callback,
1957  * otherwise deadlock will be caused.
1958  */
1959 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1960                      u16 value, u16 index, const void *data, u16 size)
1961 {
1962         int ret;
1963
1964         if (usb_autopm_get_interface(dev->intf) < 0)
1965                 return -ENODEV;
1966         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1967                                  data, size);
1968         usb_autopm_put_interface(dev->intf);
1969         return ret;
1970 }
1971 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1972
1973 /*
1974  * The function can be called inside suspend/resume callback safely
1975  * and should only be called by suspend/resume callback generally.
1976  */
1977 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1978                           u16 value, u16 index, void *data, u16 size)
1979 {
1980         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1981                                  data, size);
1982 }
1983 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1984
1985 /*
1986  * The function can be called inside suspend/resume callback safely
1987  * and should only be called by suspend/resume callback generally.
1988  */
1989 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1990                           u16 value, u16 index, const void *data,
1991                           u16 size)
1992 {
1993         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1994                                   data, size);
1995 }
1996 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1997
1998 static void usbnet_async_cmd_cb(struct urb *urb)
1999 {
2000         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2001         int status = urb->status;
2002
2003         if (status < 0)
2004                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2005                         __func__, status);
2006
2007         kfree(req);
2008         usb_free_urb(urb);
2009 }
2010
2011 /*
2012  * The caller must make sure that device can't be put into suspend
2013  * state until the control URB completes.
2014  */
2015 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2016                            u16 value, u16 index, const void *data, u16 size)
2017 {
2018         struct usb_ctrlrequest *req = NULL;
2019         struct urb *urb;
2020         int err = -ENOMEM;
2021         void *buf = NULL;
2022
2023         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2024                    " value=0x%04x index=0x%04x size=%d\n",
2025                    cmd, reqtype, value, index, size);
2026
2027         urb = usb_alloc_urb(0, GFP_ATOMIC);
2028         if (!urb) {
2029                 netdev_err(dev->net, "Error allocating URB in"
2030                            " %s!\n", __func__);
2031                 goto fail;
2032         }
2033
2034         if (data) {
2035                 buf = kmemdup(data, size, GFP_ATOMIC);
2036                 if (!buf) {
2037                         netdev_err(dev->net, "Error allocating buffer"
2038                                    " in %s!\n", __func__);
2039                         goto fail_free;
2040                 }
2041         }
2042
2043         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2044         if (!req)
2045                 goto fail_free_buf;
2046
2047         req->bRequestType = reqtype;
2048         req->bRequest = cmd;
2049         req->wValue = cpu_to_le16(value);
2050         req->wIndex = cpu_to_le16(index);
2051         req->wLength = cpu_to_le16(size);
2052
2053         usb_fill_control_urb(urb, dev->udev,
2054                              usb_sndctrlpipe(dev->udev, 0),
2055                              (void *)req, buf, size,
2056                              usbnet_async_cmd_cb, req);
2057         urb->transfer_flags |= URB_FREE_BUFFER;
2058
2059         err = usb_submit_urb(urb, GFP_ATOMIC);
2060         if (err < 0) {
2061                 netdev_err(dev->net, "Error submitting the control"
2062                            " message: status=%d\n", err);
2063                 goto fail_free;
2064         }
2065         return 0;
2066
2067 fail_free_buf:
2068         kfree(buf);
2069 fail_free:
2070         kfree(req);
2071         usb_free_urb(urb);
2072 fail:
2073         return err;
2074
2075 }
2076 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2077 /*-------------------------------------------------------------------------*/
2078
2079 static int __init usbnet_init(void)
2080 {
2081         /* Compiler should optimize this out. */
2082         BUILD_BUG_ON(
2083                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2084
2085         eth_random_addr(node_id);
2086         return 0;
2087 }
2088 module_init(usbnet_init);
2089
2090 static void __exit usbnet_exit(void)
2091 {
2092 }
2093 module_exit(usbnet_exit);
2094
2095 MODULE_AUTHOR("David Brownell");
2096 MODULE_DESCRIPTION("USB network driver framework");
2097 MODULE_LICENSE("GPL");