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 /* use ethtool to change the level for any given device */
  86 static int msg_level = -1;
  87 module_param (msg_level, int, 0);
  88 MODULE_PARM_DESC (msg_level, "Override default message level");
  89
  90 /*-------------------------------------------------------------------------*/
  91
  92 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  93 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  94 {
  95         int                             tmp;
  96         struct usb_host_interface       *alt = NULL;
  97         struct usb_host_endpoint        *in = NULL, *out = NULL;
  98         struct usb_host_endpoint        *status = NULL;
  99
 100         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 101                 unsigned        ep;
 102
 103                 in = out = status = NULL;
 104                 alt = intf->altsetting + tmp;
 105
 106                 /* take the first altsetting with in-bulk + out-bulk;
 107                  * remember any status endpoint, just in case;
 108                  * ignore other endpoints and altsettings.
 109                  */
 110                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 111                         struct usb_host_endpoint        *e;
 112                         int                             intr = 0;
 113
 114                         e = alt->endpoint + ep;
 115                         switch (e->desc.bmAttributes) {
 116                         case USB_ENDPOINT_XFER_INT:
 117                                 if (!usb_endpoint_dir_in(&e->desc))
 118                                         continue;
 119                                 intr = 1;
 120                                 /* FALLTHROUGH */
 121                         case USB_ENDPOINT_XFER_BULK:
 122                                 break;
 123                         default:
 124                                 continue;
 125                         }
 126                         if (usb_endpoint_dir_in(&e->desc)) {
 127                                 if (!intr && !in)
 128                                         in = e;
 129                                 else if (intr && !status)
 130                                         status = e;
 131                         } else {
 132                                 if (!out)
 133                                         out = e;
 134                         }
 135                 }
 136                 if (in && out)
 137                         break;
 138         }
 139         if (!alt || !in || !out)
 140                 return -EINVAL;
 141
 142         if (alt->desc.bAlternateSetting != 0 ||
 143             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 144                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 145                                 alt->desc.bAlternateSetting);
 146                 if (tmp < 0)
 147                         return tmp;
 148         }
 149
 150         dev->in = usb_rcvbulkpipe (dev->udev,
 151                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 152         dev->out = usb_sndbulkpipe (dev->udev,
 153                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 154         dev->status = status;
 155         return 0;
 156 }
 157 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 158
 159 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 160 {
 161         int             tmp = -1, ret;
 162         unsigned char   buf [13];
 163
 164         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 165         if (ret == 12)
 166                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 167         if (tmp < 0) {
 168                 dev_dbg(&dev->udev->dev,
 169                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 170                 if (ret >= 0)
 171                         ret = -EINVAL;
 172                 return ret;
 173         }
 174         return 0;
 175 }
 176 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 177
 178 static void intr_complete (struct urb *urb)
 179 {
 180         struct usbnet   *dev = urb->context;
 181         int             status = urb->status;
 182
 183         switch (status) {
 184         /* success */
 185         case 0:
 186                 dev->driver_info->status(dev, urb);
 187                 break;
 188
 189         /* software-driven interface shutdown */
 190         case -ENOENT:           /* urb killed */
 191         case -ESHUTDOWN:        /* hardware gone */
 192                 netif_dbg(dev, ifdown, dev->net,
 193                           "intr shutdown, code %d\n", status);
 194                 return;
 195
 196         /* NOTE:  not throttling like RX/TX, since this endpoint
 197          * already polls infrequently
 198          */
 199         default:
 200                 netdev_dbg(dev->net, "intr status %d\n", status);
 201                 break;
 202         }
 203
 204         status = usb_submit_urb (urb, GFP_ATOMIC);
 205         if (status != 0)
 206                 netif_err(dev, timer, dev->net,
 207                           "intr resubmit --> %d\n", status);
 208 }
 209
 210 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 211 {
 212         char            *buf = NULL;
 213         unsigned        pipe = 0;
 214         unsigned        maxp;
 215         unsigned        period;
 216
 217         if (!dev->driver_info->status)
 218                 return 0;
 219
 220         pipe = usb_rcvintpipe (dev->udev,
 221                         dev->status->desc.bEndpointAddress
 222                                 & USB_ENDPOINT_NUMBER_MASK);
 223         maxp = usb_maxpacket (dev->udev, pipe, 0);
 224
 225         /* avoid 1 msec chatter:  min 8 msec poll rate */
 226         period = max ((int) dev->status->desc.bInterval,
 227                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 228
 229         buf = kmalloc (maxp, GFP_KERNEL);
 230         if (buf) {
 231                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 232                 if (!dev->interrupt) {
 233                         kfree (buf);
 234                         return -ENOMEM;
 235                 } else {
 236                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 237                                 buf, maxp, intr_complete, dev, period);
 238                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 239                         dev_dbg(&intf->dev,
 240                                 "status ep%din, %d bytes period %d\n",
 241                                 usb_pipeendpoint(pipe), maxp, period);
 242                 }
 243         }
 244         return 0;
 245 }
 246
 247 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 248 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 249 {
 250         int ret = 0;
 251
 252         WARN_ON_ONCE(dev->interrupt == NULL);
 253         if (dev->interrupt) {
 254                 mutex_lock(&dev->interrupt_mutex);
 255
 256                 if (++dev->interrupt_count == 1)
 257                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 258
 259                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 260                         dev->interrupt_count);
 261                 mutex_unlock(&dev->interrupt_mutex);
 262         }
 263         return ret;
 264 }
 265 EXPORT_SYMBOL_GPL(usbnet_status_start);
 266
 267 /* For resume; submit interrupt URB if previously submitted */
 268 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 269 {
 270         int ret = 0;
 271
 272         mutex_lock(&dev->interrupt_mutex);
 273         if (dev->interrupt_count) {
 274                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 275                 dev_dbg(&dev->udev->dev,
 276                         "submitted interrupt URB for resume\n");
 277         }
 278         mutex_unlock(&dev->interrupt_mutex);
 279         return ret;
 280 }
 281
 282 /* Kill the interrupt URB if all submitters want it killed */
 283 void usbnet_status_stop(struct usbnet *dev)
 284 {
 285         if (dev->interrupt) {
 286                 mutex_lock(&dev->interrupt_mutex);
 287                 WARN_ON(dev->interrupt_count == 0);
 288
 289                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 290                         usb_kill_urb(dev->interrupt);
 291
 292                 dev_dbg(&dev->udev->dev,
 293                         "decremented interrupt URB count to %d\n",
 294                         dev->interrupt_count);
 295                 mutex_unlock(&dev->interrupt_mutex);
 296         }
 297 }
 298 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 299
 300 /* For suspend; always kill interrupt URB */
 301 static void __usbnet_status_stop_force(struct usbnet *dev)
 302 {
 303         if (dev->interrupt) {
 304                 mutex_lock(&dev->interrupt_mutex);
 305                 usb_kill_urb(dev->interrupt);
 306                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 307                 mutex_unlock(&dev->interrupt_mutex);
 308         }
 309 }
 310
 311 /* Passes this packet up the stack, updating its accounting.
 312  * Some link protocols batch packets, so their rx_fixup paths
 313  * can return clones as well as just modify the original skb.
 314  */
 315 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 316 {
 317         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
 318         int     status;
 319
 320         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 321                 skb_queue_tail(&dev->rxq_pause, skb);
 322                 return;
 323         }
 324
 325         /* only update if unset to allow minidriver rx_fixup override */
 326         if (skb->protocol == 0)
 327                 skb->protocol = eth_type_trans (skb, dev->net);
 328
 329         u64_stats_update_begin(&stats64->syncp);
 330         stats64->rx_packets++;
 331         stats64->rx_bytes += skb->len;
 332         u64_stats_update_end(&stats64->syncp);
 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         case USB_SPEED_SUPER_PLUS:
 360                 /*
 361                  * Not take default 5ms qlen for super speed HC to
 362                  * save memory, and iperf tests show 2.5ms qlen can
 363                  * work well
 364                  */
 365                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 366                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 367                 break;
 368         default:
 369                 dev->rx_qlen = dev->tx_qlen = 4;
 370         }
 371 }
 372 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 373
 374 \f
 375 /*-------------------------------------------------------------------------
 376  *
 377  * Network Device Driver (peer link to "Host Device", from USB host)
 378  *
 379  *-------------------------------------------------------------------------*/
 380
 381 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 382 {
 383         struct usbnet   *dev = netdev_priv(net);
 384         int             ll_mtu = new_mtu + net->hard_header_len;
 385         int             old_hard_mtu = dev->hard_mtu;
 386         int             old_rx_urb_size = dev->rx_urb_size;
 387
 388         // no second zero-length packet read wanted after mtu-sized packets
 389         if ((ll_mtu % dev->maxpacket) == 0)
 390                 return -EDOM;
 391         net->mtu = new_mtu;
 392
 393         dev->hard_mtu = net->mtu + net->hard_header_len;
 394         if (dev->rx_urb_size == old_hard_mtu) {
 395                 dev->rx_urb_size = dev->hard_mtu;
 396                 if (dev->rx_urb_size > old_rx_urb_size) {
 397                         usbnet_pause_rx(dev);
 398                         usbnet_unlink_rx_urbs(dev);
 399                         usbnet_resume_rx(dev);
 400                 }
 401         }
 402
 403         /* max qlen depend on hard_mtu and rx_urb_size */
 404         usbnet_update_max_qlen(dev);
 405
 406         return 0;
 407 }
 408 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 409
 410 /* The caller must hold list->lock */
 411 static void __usbnet_queue_skb(struct sk_buff_head *list,
 412                         struct sk_buff *newsk, enum skb_state state)
 413 {
 414         struct skb_data *entry = (struct skb_data *) newsk->cb;
 415
 416         __skb_queue_tail(list, newsk);
 417         entry->state = state;
 418 }
 419
 420 /*-------------------------------------------------------------------------*/
 421
 422 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 423  * completion callbacks.  2.5 should have fixed those bugs...
 424  */
 425
 426 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 427                 struct sk_buff_head *list, enum skb_state state)
 428 {
 429         unsigned long           flags;
 430         enum skb_state          old_state;
 431         struct skb_data *entry = (struct skb_data *) skb->cb;
 432
 433         spin_lock_irqsave(&list->lock, flags);
 434         old_state = entry->state;
 435         entry->state = state;
 436         __skb_unlink(skb, list);
 437
 438         /* defer_bh() is never called with list == &dev->done.
 439          * spin_lock_nested() tells lockdep that it is OK to take
 440          * dev->done.lock here with list->lock held.
 441          */
 442         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 443
 444         __skb_queue_tail(&dev->done, skb);
 445         if (dev->done.qlen == 1)
 446                 tasklet_schedule(&dev->bh);
 447         spin_unlock(&dev->done.lock);
 448         spin_unlock_irqrestore(&list->lock, flags);
 449         return old_state;
 450 }
 451
 452 /* some work can't be done in tasklets, so we use keventd
 453  *
 454  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 455  * but tasklet_schedule() doesn't.  hope the failure is rare.
 456  */
 457 void usbnet_defer_kevent (struct usbnet *dev, int work)
 458 {
 459         set_bit (work, &dev->flags);
 460         if (!schedule_work (&dev->kevent)) {
 461                 if (net_ratelimit())
 462                         netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 463         } else {
 464                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 465         }
 466 }
 467 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 468
 469 /*-------------------------------------------------------------------------*/
 470
 471 static void rx_complete (struct urb *urb);
 472
 473 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 474 {
 475         struct sk_buff          *skb;
 476         struct skb_data         *entry;
 477         int                     retval = 0;
 478         unsigned long           lockflags;
 479         size_t                  size = dev->rx_urb_size;
 480
 481         /* prevent rx skb allocation when error ratio is high */
 482         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 483                 usb_free_urb(urb);
 484                 return -ENOLINK;
 485         }
 486
 487         skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 488         if (!skb) {
 489                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 490                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 491                 usb_free_urb (urb);
 492                 return -ENOMEM;
 493         }
 494
 495         entry = (struct skb_data *) skb->cb;
 496         entry->urb = urb;
 497         entry->dev = dev;
 498         entry->length = 0;
 499
 500         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 501                 skb->data, size, rx_complete, skb);
 502
 503         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 504
 505         if (netif_running (dev->net) &&
 506             netif_device_present (dev->net) &&
 507             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 508             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 509                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 510                 case -EPIPE:
 511                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 512                         break;
 513                 case -ENOMEM:
 514                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 515                         break;
 516                 case -ENODEV:
 517                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 518                         netif_device_detach (dev->net);
 519                         break;
 520                 case -EHOSTUNREACH:
 521                         retval = -ENOLINK;
 522                         break;
 523                 default:
 524                         netif_dbg(dev, rx_err, dev->net,
 525                                   "rx submit, %d\n", retval);
 526                         tasklet_schedule (&dev->bh);
 527                         break;
 528                 case 0:
 529                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 530                 }
 531         } else {
 532                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 533                 retval = -ENOLINK;
 534         }
 535         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 536         if (retval) {
 537                 dev_kfree_skb_any (skb);
 538                 usb_free_urb (urb);
 539         }
 540         return retval;
 541 }
 542
 543
 544 /*-------------------------------------------------------------------------*/
 545
 546 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 547 {
 548         if (dev->driver_info->rx_fixup &&
 549             !dev->driver_info->rx_fixup (dev, skb)) {
 550                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 551                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 552                         dev->net->stats.rx_errors++;
 553                 goto done;
 554         }
 555         // else network stack removes extra byte if we forced a short packet
 556
 557         /* all data was already cloned from skb inside the driver */
 558         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 559                 goto done;
 560
 561         if (skb->len < ETH_HLEN) {
 562                 dev->net->stats.rx_errors++;
 563                 dev->net->stats.rx_length_errors++;
 564                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 565         } else {
 566                 usbnet_skb_return(dev, skb);
 567                 return;
 568         }
 569
 570 done:
 571         skb_queue_tail(&dev->done, skb);
 572 }
 573
 574 /*-------------------------------------------------------------------------*/
 575
 576 static void rx_complete (struct urb *urb)
 577 {
 578         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 579         struct skb_data         *entry = (struct skb_data *) skb->cb;
 580         struct usbnet           *dev = entry->dev;
 581         int                     urb_status = urb->status;
 582         enum skb_state          state;
 583
 584         skb_put (skb, urb->actual_length);
 585         state = rx_done;
 586         entry->urb = NULL;
 587
 588         switch (urb_status) {
 589         /* success */
 590         case 0:
 591                 break;
 592
 593         /* stalls need manual reset. this is rare ... except that
 594          * when going through USB 2.0 TTs, unplug appears this way.
 595          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 596          * storm, recovering as needed.
 597          */
 598         case -EPIPE:
 599                 dev->net->stats.rx_errors++;
 600                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 601                 // FALLTHROUGH
 602
 603         /* software-driven interface shutdown */
 604         case -ECONNRESET:               /* async unlink */
 605         case -ESHUTDOWN:                /* hardware gone */
 606                 netif_dbg(dev, ifdown, dev->net,
 607                           "rx shutdown, code %d\n", urb_status);
 608                 goto block;
 609
 610         /* we get controller i/o faults during hub_wq disconnect() delays.
 611          * throttle down resubmits, to avoid log floods; just temporarily,
 612          * so we still recover when the fault isn't a hub_wq delay.
 613          */
 614         case -EPROTO:
 615         case -ETIME:
 616         case -EILSEQ:
 617                 dev->net->stats.rx_errors++;
 618                 if (!timer_pending (&dev->delay)) {
 619                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 620                         netif_dbg(dev, link, dev->net,
 621                                   "rx throttle %d\n", urb_status);
 622                 }
 623 block:
 624                 state = rx_cleanup;
 625                 entry->urb = urb;
 626                 urb = NULL;
 627                 break;
 628
 629         /* data overrun ... flush fifo? */
 630         case -EOVERFLOW:
 631                 dev->net->stats.rx_over_errors++;
 632                 // FALLTHROUGH
 633
 634         default:
 635                 state = rx_cleanup;
 636                 dev->net->stats.rx_errors++;
 637                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 638                 break;
 639         }
 640
 641         /* stop rx if packet error rate is high */
 642         if (++dev->pkt_cnt > 30) {
 643                 dev->pkt_cnt = 0;
 644                 dev->pkt_err = 0;
 645         } else {
 646                 if (state == rx_cleanup)
 647                         dev->pkt_err++;
 648                 if (dev->pkt_err > 20)
 649                         set_bit(EVENT_RX_KILL, &dev->flags);
 650         }
 651
 652         state = defer_bh(dev, skb, &dev->rxq, state);
 653
 654         if (urb) {
 655                 if (netif_running (dev->net) &&
 656                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 657                     state != unlink_start) {
 658                         rx_submit (dev, urb, GFP_ATOMIC);
 659                         usb_mark_last_busy(dev->udev);
 660                         return;
 661                 }
 662                 usb_free_urb (urb);
 663         }
 664         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 665 }
 666
 667 /*-------------------------------------------------------------------------*/
 668 void usbnet_pause_rx(struct usbnet *dev)
 669 {
 670         set_bit(EVENT_RX_PAUSED, &dev->flags);
 671
 672         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 673 }
 674 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 675
 676 void usbnet_resume_rx(struct usbnet *dev)
 677 {
 678         struct sk_buff *skb;
 679         int num = 0;
 680
 681         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 682
 683         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 684                 usbnet_skb_return(dev, skb);
 685                 num++;
 686         }
 687
 688         tasklet_schedule(&dev->bh);
 689
 690         netif_dbg(dev, rx_status, dev->net,
 691                   "paused rx queue disabled, %d skbs requeued\n", num);
 692 }
 693 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 694
 695 void usbnet_purge_paused_rxq(struct usbnet *dev)
 696 {
 697         skb_queue_purge(&dev->rxq_pause);
 698 }
 699 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 700
 701 /*-------------------------------------------------------------------------*/
 702
 703 // unlink pending rx/tx; completion handlers do all other cleanup
 704
 705 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 706 {
 707         unsigned long           flags;
 708         struct sk_buff          *skb;
 709         int                     count = 0;
 710
 711         spin_lock_irqsave (&q->lock, flags);
 712         while (!skb_queue_empty(q)) {
 713                 struct skb_data         *entry;
 714                 struct urb              *urb;
 715                 int                     retval;
 716
 717                 skb_queue_walk(q, skb) {
 718                         entry = (struct skb_data *) skb->cb;
 719                         if (entry->state != unlink_start)
 720                                 goto found;
 721                 }
 722                 break;
 723 found:
 724                 entry->state = unlink_start;
 725                 urb = entry->urb;
 726
 727                 /*
 728                  * Get reference count of the URB to avoid it to be
 729                  * freed during usb_unlink_urb, which may trigger
 730                  * use-after-free problem inside usb_unlink_urb since
 731                  * usb_unlink_urb is always racing with .complete
 732                  * handler(include defer_bh).
 733                  */
 734                 usb_get_urb(urb);
 735                 spin_unlock_irqrestore(&q->lock, flags);
 736                 // during some PM-driven resume scenarios,
 737                 // these (async) unlinks complete immediately
 738                 retval = usb_unlink_urb (urb);
 739                 if (retval != -EINPROGRESS && retval != 0)
 740                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 741                 else
 742                         count++;
 743                 usb_put_urb(urb);
 744                 spin_lock_irqsave(&q->lock, flags);
 745         }
 746         spin_unlock_irqrestore (&q->lock, flags);
 747         return count;
 748 }
 749
 750 // Flush all pending rx urbs
 751 // minidrivers may need to do this when the MTU changes
 752
 753 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 754 {
 755         if (netif_running(dev->net)) {
 756                 (void) unlink_urbs (dev, &dev->rxq);
 757                 tasklet_schedule(&dev->bh);
 758         }
 759 }
 760 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 761
 762 /*-------------------------------------------------------------------------*/
 763
 764 static void wait_skb_queue_empty(struct sk_buff_head *q)
 765 {
 766         unsigned long flags;
 767
 768         spin_lock_irqsave(&q->lock, flags);
 769         while (!skb_queue_empty(q)) {
 770                 spin_unlock_irqrestore(&q->lock, flags);
 771                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 772                 set_current_state(TASK_UNINTERRUPTIBLE);
 773                 spin_lock_irqsave(&q->lock, flags);
 774         }
 775         spin_unlock_irqrestore(&q->lock, flags);
 776 }
 777
 778 // precondition: never called in_interrupt
 779 static void usbnet_terminate_urbs(struct usbnet *dev)
 780 {
 781         DECLARE_WAITQUEUE(wait, current);
 782         int temp;
 783
 784         /* ensure there are no more active urbs */
 785         add_wait_queue(&dev->wait, &wait);
 786         set_current_state(TASK_UNINTERRUPTIBLE);
 787         temp = unlink_urbs(dev, &dev->txq) +
 788                 unlink_urbs(dev, &dev->rxq);
 789
 790         /* maybe wait for deletions to finish. */
 791         wait_skb_queue_empty(&dev->rxq);
 792         wait_skb_queue_empty(&dev->txq);
 793         wait_skb_queue_empty(&dev->done);
 794         netif_dbg(dev, ifdown, dev->net,
 795                   "waited for %d urb completions\n", temp);
 796         set_current_state(TASK_RUNNING);
 797         remove_wait_queue(&dev->wait, &wait);
 798 }
 799
 800 int usbnet_stop (struct net_device *net)
 801 {
 802         struct usbnet           *dev = netdev_priv(net);
 803         struct driver_info      *info = dev->driver_info;
 804         int                     retval, pm, mpn;
 805
 806         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 807         netif_stop_queue (net);
 808
 809         netif_info(dev, ifdown, dev->net,
 810                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 811                    net->stats.rx_packets, net->stats.tx_packets,
 812                    net->stats.rx_errors, net->stats.tx_errors);
 813
 814         /* to not race resume */
 815         pm = usb_autopm_get_interface(dev->intf);
 816         /* allow minidriver to stop correctly (wireless devices to turn off
 817          * radio etc) */
 818         if (info->stop) {
 819                 retval = info->stop(dev);
 820                 if (retval < 0)
 821                         netif_info(dev, ifdown, dev->net,
 822                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 823                                    retval,
 824                                    dev->udev->bus->bus_name, dev->udev->devpath,
 825                                    info->description);
 826         }
 827
 828         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 829                 usbnet_terminate_urbs(dev);
 830
 831         usbnet_status_stop(dev);
 832
 833         usbnet_purge_paused_rxq(dev);
 834
 835         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 836
 837         /* deferred work (task, timer, softirq) must also stop.
 838          * can't flush_scheduled_work() until we drop rtnl (later),
 839          * else workers could deadlock; so make workers a NOP.
 840          */
 841         dev->flags = 0;
 842         del_timer_sync (&dev->delay);
 843         tasklet_kill (&dev->bh);
 844         if (!pm)
 845                 usb_autopm_put_interface(dev->intf);
 846
 847         if (info->manage_power && mpn)
 848                 info->manage_power(dev, 0);
 849         else
 850                 usb_autopm_put_interface(dev->intf);
 851
 852         return 0;
 853 }
 854 EXPORT_SYMBOL_GPL(usbnet_stop);
 855
 856 /*-------------------------------------------------------------------------*/
 857
 858 // posts reads, and enables write queuing
 859
 860 // precondition: never called in_interrupt
 861
 862 int usbnet_open (struct net_device *net)
 863 {
 864         struct usbnet           *dev = netdev_priv(net);
 865         int                     retval;
 866         struct driver_info      *info = dev->driver_info;
 867
 868         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 869                 netif_info(dev, ifup, dev->net,
 870                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 871                            retval,
 872                            dev->udev->bus->bus_name,
 873                            dev->udev->devpath,
 874                            info->description);
 875                 goto done_nopm;
 876         }
 877
 878         // put into "known safe" state
 879         if (info->reset && (retval = info->reset (dev)) < 0) {
 880                 netif_info(dev, ifup, dev->net,
 881                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 882                            retval,
 883                            dev->udev->bus->bus_name,
 884                            dev->udev->devpath,
 885                            info->description);
 886                 goto done;
 887         }
 888
 889         /* hard_mtu or rx_urb_size may change in reset() */
 890         usbnet_update_max_qlen(dev);
 891
 892         // insist peer be connected
 893         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 894                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 895                 goto done;
 896         }
 897
 898         /* start any status interrupt transfer */
 899         if (dev->interrupt) {
 900                 retval = usbnet_status_start(dev, GFP_KERNEL);
 901                 if (retval < 0) {
 902                         netif_err(dev, ifup, dev->net,
 903                                   "intr submit %d\n", retval);
 904                         goto done;
 905                 }
 906         }
 907
 908         set_bit(EVENT_DEV_OPEN, &dev->flags);
 909         netif_start_queue (net);
 910         netif_info(dev, ifup, dev->net,
 911                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 912                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 913                    dev->net->mtu,
 914                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 915                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 916                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 917                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 918                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 919                    "simple");
 920
 921         /* reset rx error state */
 922         dev->pkt_cnt = 0;
 923         dev->pkt_err = 0;
 924         clear_bit(EVENT_RX_KILL, &dev->flags);
 925
 926         // delay posting reads until we're fully open
 927         tasklet_schedule (&dev->bh);
 928         if (info->manage_power) {
 929                 retval = info->manage_power(dev, 1);
 930                 if (retval < 0) {
 931                         retval = 0;
 932                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 933                 } else {
 934                         usb_autopm_put_interface(dev->intf);
 935                 }
 936         }
 937         return retval;
 938 done:
 939         usb_autopm_put_interface(dev->intf);
 940 done_nopm:
 941         return retval;
 942 }
 943 EXPORT_SYMBOL_GPL(usbnet_open);
 944
 945 /*-------------------------------------------------------------------------*/
 946
 947 /* ethtool methods; minidrivers may need to add some more, but
 948  * they'll probably want to use this base set.
 949  */
 950
 951 int usbnet_get_link_ksettings(struct net_device *net,
 952                               struct ethtool_link_ksettings *cmd)
 953 {
 954         struct usbnet *dev = netdev_priv(net);
 955
 956         if (!dev->mii.mdio_read)
 957                 return -EOPNOTSUPP;
 958
 959         return mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 960 }
 961 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
 962
 963 int usbnet_set_link_ksettings(struct net_device *net,
 964                               const struct ethtool_link_ksettings *cmd)
 965 {
 966         struct usbnet *dev = netdev_priv(net);
 967         int retval;
 968
 969         if (!dev->mii.mdio_write)
 970                 return -EOPNOTSUPP;
 971
 972         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
 973
 974         /* link speed/duplex might have changed */
 975         if (dev->driver_info->link_reset)
 976                 dev->driver_info->link_reset(dev);
 977
 978         /* hard_mtu or rx_urb_size may change in link_reset() */
 979         usbnet_update_max_qlen(dev);
 980
 981         return retval;
 982 }
 983 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
 984
 985 void usbnet_get_stats64(struct net_device *net, struct rtnl_link_stats64 *stats)
 986 {
 987         struct usbnet *dev = netdev_priv(net);
 988         unsigned int start;
 989         int cpu;
 990
 991         netdev_stats_to_stats64(stats, &net->stats);
 992
 993         for_each_possible_cpu(cpu) {
 994                 struct pcpu_sw_netstats *stats64;
 995                 u64 rx_packets, rx_bytes;
 996                 u64 tx_packets, tx_bytes;
 997
 998                 stats64 = per_cpu_ptr(dev->stats64, cpu);
 999
1000                 do {
1001                         start = u64_stats_fetch_begin_irq(&stats64->syncp);
1002                         rx_packets = stats64->rx_packets;
1003                         rx_bytes = stats64->rx_bytes;
1004                         tx_packets = stats64->tx_packets;
1005                         tx_bytes = stats64->tx_bytes;
1006                 } while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
1007
1008                 stats->rx_packets += rx_packets;
1009                 stats->rx_bytes += rx_bytes;
1010                 stats->tx_packets += tx_packets;
1011                 stats->tx_bytes += tx_bytes;
1012         }
1013 }
1014 EXPORT_SYMBOL_GPL(usbnet_get_stats64);
1015
1016 u32 usbnet_get_link (struct net_device *net)
1017 {
1018         struct usbnet *dev = netdev_priv(net);
1019
1020         /* If a check_connect is defined, return its result */
1021         if (dev->driver_info->check_connect)
1022                 return dev->driver_info->check_connect (dev) == 0;
1023
1024         /* if the device has mii operations, use those */
1025         if (dev->mii.mdio_read)
1026                 return mii_link_ok(&dev->mii);
1027
1028         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1029         return ethtool_op_get_link(net);
1030 }
1031 EXPORT_SYMBOL_GPL(usbnet_get_link);
1032
1033 int usbnet_nway_reset(struct net_device *net)
1034 {
1035         struct usbnet *dev = netdev_priv(net);
1036
1037         if (!dev->mii.mdio_write)
1038                 return -EOPNOTSUPP;
1039
1040         return mii_nway_restart(&dev->mii);
1041 }
1042 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1043
1044 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1045 {
1046         struct usbnet *dev = netdev_priv(net);
1047
1048         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1049         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1050         strlcpy (info->fw_version, dev->driver_info->description,
1051                 sizeof info->fw_version);
1052         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1053 }
1054 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1055
1056 u32 usbnet_get_msglevel (struct net_device *net)
1057 {
1058         struct usbnet *dev = netdev_priv(net);
1059
1060         return dev->msg_enable;
1061 }
1062 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1063
1064 void usbnet_set_msglevel (struct net_device *net, u32 level)
1065 {
1066         struct usbnet *dev = netdev_priv(net);
1067
1068         dev->msg_enable = level;
1069 }
1070 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1071
1072 /* drivers may override default ethtool_ops in their bind() routine */
1073 static const struct ethtool_ops usbnet_ethtool_ops = {
1074         .get_link               = usbnet_get_link,
1075         .nway_reset             = usbnet_nway_reset,
1076         .get_drvinfo            = usbnet_get_drvinfo,
1077         .get_msglevel           = usbnet_get_msglevel,
1078         .set_msglevel           = usbnet_set_msglevel,
1079         .get_ts_info            = ethtool_op_get_ts_info,
1080         .get_link_ksettings     = usbnet_get_link_ksettings,
1081         .set_link_ksettings     = usbnet_set_link_ksettings,
1082 };
1083
1084 /*-------------------------------------------------------------------------*/
1085
1086 static void __handle_link_change(struct usbnet *dev)
1087 {
1088         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1089                 return;
1090
1091         if (!netif_carrier_ok(dev->net)) {
1092                 /* kill URBs for reading packets to save bus bandwidth */
1093                 unlink_urbs(dev, &dev->rxq);
1094
1095                 /*
1096                  * tx_timeout will unlink URBs for sending packets and
1097                  * tx queue is stopped by netcore after link becomes off
1098                  */
1099         } else {
1100                 /* submitting URBs for reading packets */
1101                 tasklet_schedule(&dev->bh);
1102         }
1103
1104         /* hard_mtu or rx_urb_size may change during link change */
1105         usbnet_update_max_qlen(dev);
1106
1107         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1108 }
1109
1110 static void usbnet_set_rx_mode(struct net_device *net)
1111 {
1112         struct usbnet           *dev = netdev_priv(net);
1113
1114         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1115 }
1116
1117 static void __handle_set_rx_mode(struct usbnet *dev)
1118 {
1119         if (dev->driver_info->set_rx_mode)
1120                 (dev->driver_info->set_rx_mode)(dev);
1121
1122         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1123 }
1124
1125 /* work that cannot be done in interrupt context uses keventd.
1126  *
1127  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1128  * especially now that control transfers can be queued.
1129  */
1130 static void
1131 usbnet_deferred_kevent (struct work_struct *work)
1132 {
1133         struct usbnet           *dev =
1134                 container_of(work, struct usbnet, kevent);
1135         int                     status;
1136
1137         /* usb_clear_halt() needs a thread context */
1138         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1139                 unlink_urbs (dev, &dev->txq);
1140                 status = usb_autopm_get_interface(dev->intf);
1141                 if (status < 0)
1142                         goto fail_pipe;
1143                 status = usb_clear_halt (dev->udev, dev->out);
1144                 usb_autopm_put_interface(dev->intf);
1145                 if (status < 0 &&
1146                     status != -EPIPE &&
1147                     status != -ESHUTDOWN) {
1148                         if (netif_msg_tx_err (dev))
1149 fail_pipe:
1150                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1151                                            status);
1152                 } else {
1153                         clear_bit (EVENT_TX_HALT, &dev->flags);
1154                         if (status != -ESHUTDOWN)
1155                                 netif_wake_queue (dev->net);
1156                 }
1157         }
1158         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1159                 unlink_urbs (dev, &dev->rxq);
1160                 status = usb_autopm_get_interface(dev->intf);
1161                 if (status < 0)
1162                         goto fail_halt;
1163                 status = usb_clear_halt (dev->udev, dev->in);
1164                 usb_autopm_put_interface(dev->intf);
1165                 if (status < 0 &&
1166                     status != -EPIPE &&
1167                     status != -ESHUTDOWN) {
1168                         if (netif_msg_rx_err (dev))
1169 fail_halt:
1170                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1171                                            status);
1172                 } else {
1173                         clear_bit (EVENT_RX_HALT, &dev->flags);
1174                         tasklet_schedule (&dev->bh);
1175                 }
1176         }
1177
1178         /* tasklet could resubmit itself forever if memory is tight */
1179         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1180                 struct urb      *urb = NULL;
1181                 int resched = 1;
1182
1183                 if (netif_running (dev->net))
1184                         urb = usb_alloc_urb (0, GFP_KERNEL);
1185                 else
1186                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1187                 if (urb != NULL) {
1188                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1189                         status = usb_autopm_get_interface(dev->intf);
1190                         if (status < 0) {
1191                                 usb_free_urb(urb);
1192                                 goto fail_lowmem;
1193                         }
1194                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1195                                 resched = 0;
1196                         usb_autopm_put_interface(dev->intf);
1197 fail_lowmem:
1198                         if (resched)
1199                                 tasklet_schedule (&dev->bh);
1200                 }
1201         }
1202
1203         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1204                 struct driver_info      *info = dev->driver_info;
1205                 int                     retval = 0;
1206
1207                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1208                 status = usb_autopm_get_interface(dev->intf);
1209                 if (status < 0)
1210                         goto skip_reset;
1211                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1212                         usb_autopm_put_interface(dev->intf);
1213 skip_reset:
1214                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1215                                     retval,
1216                                     dev->udev->bus->bus_name,
1217                                     dev->udev->devpath,
1218                                     info->description);
1219                 } else {
1220                         usb_autopm_put_interface(dev->intf);
1221                 }
1222
1223                 /* handle link change from link resetting */
1224                 __handle_link_change(dev);
1225         }
1226
1227         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1228                 __handle_link_change(dev);
1229
1230         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1231                 __handle_set_rx_mode(dev);
1232
1233
1234         if (dev->flags)
1235                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1236 }
1237
1238 /*-------------------------------------------------------------------------*/
1239
1240 static void tx_complete (struct urb *urb)
1241 {
1242         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1243         struct skb_data         *entry = (struct skb_data *) skb->cb;
1244         struct usbnet           *dev = entry->dev;
1245
1246         if (urb->status == 0) {
1247                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1248
1249                 u64_stats_update_begin(&stats64->syncp);
1250                 stats64->tx_packets += entry->packets;
1251                 stats64->tx_bytes += entry->length;
1252                 u64_stats_update_end(&stats64->syncp);
1253         } else {
1254                 dev->net->stats.tx_errors++;
1255
1256                 switch (urb->status) {
1257                 case -EPIPE:
1258                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1259                         break;
1260
1261                 /* software-driven interface shutdown */
1262                 case -ECONNRESET:               // async unlink
1263                 case -ESHUTDOWN:                // hardware gone
1264                         break;
1265
1266                 /* like rx, tx gets controller i/o faults during hub_wq
1267                  * delays and so it uses the same throttling mechanism.
1268                  */
1269                 case -EPROTO:
1270                 case -ETIME:
1271                 case -EILSEQ:
1272                         usb_mark_last_busy(dev->udev);
1273                         if (!timer_pending (&dev->delay)) {
1274                                 mod_timer (&dev->delay,
1275                                         jiffies + THROTTLE_JIFFIES);
1276                                 netif_dbg(dev, link, dev->net,
1277                                           "tx throttle %d\n", urb->status);
1278                         }
1279                         netif_stop_queue (dev->net);
1280                         break;
1281                 default:
1282                         netif_dbg(dev, tx_err, dev->net,
1283                                   "tx err %d\n", entry->urb->status);
1284                         break;
1285                 }
1286         }
1287
1288         usb_autopm_put_interface_async(dev->intf);
1289         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1290 }
1291
1292 /*-------------------------------------------------------------------------*/
1293
1294 void usbnet_tx_timeout (struct net_device *net)
1295 {
1296         struct usbnet           *dev = netdev_priv(net);
1297
1298         unlink_urbs (dev, &dev->txq);
1299         tasklet_schedule (&dev->bh);
1300         /* this needs to be handled individually because the generic layer
1301          * doesn't know what is sufficient and could not restore private
1302          * information if a remedy of an unconditional reset were used.
1303          */
1304         if (dev->driver_info->recover)
1305                 (dev->driver_info->recover)(dev);
1306 }
1307 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1308
1309 /*-------------------------------------------------------------------------*/
1310
1311 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1312 {
1313         unsigned num_sgs, total_len = 0;
1314         int i, s = 0;
1315
1316         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1317         if (num_sgs == 1)
1318                 return 0;
1319
1320         /* reserve one for zero packet */
1321         urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1322                           GFP_ATOMIC);
1323         if (!urb->sg)
1324                 return -ENOMEM;
1325
1326         urb->num_sgs = num_sgs;
1327         sg_init_table(urb->sg, urb->num_sgs + 1);
1328
1329         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1330         total_len += skb_headlen(skb);
1331
1332         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1333                 struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1334
1335                 total_len += skb_frag_size(f);
1336                 sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1337                                 f->page_offset);
1338         }
1339         urb->transfer_buffer_length = total_len;
1340
1341         return 1;
1342 }
1343
1344 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1345                                      struct net_device *net)
1346 {
1347         struct usbnet           *dev = netdev_priv(net);
1348         unsigned int                    length;
1349         struct urb              *urb = NULL;
1350         struct skb_data         *entry;
1351         struct driver_info      *info = dev->driver_info;
1352         unsigned long           flags;
1353         int retval;
1354
1355         if (skb)
1356                 skb_tx_timestamp(skb);
1357
1358         // some devices want funky USB-level framing, for
1359         // win32 driver (usually) and/or hardware quirks
1360         if (info->tx_fixup) {
1361                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1362                 if (!skb) {
1363                         /* packet collected; minidriver waiting for more */
1364                         if (info->flags & FLAG_MULTI_PACKET)
1365                                 goto not_drop;
1366                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1367                         goto drop;
1368                 }
1369         }
1370
1371         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1372                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1373                 goto drop;
1374         }
1375
1376         entry = (struct skb_data *) skb->cb;
1377         entry->urb = urb;
1378         entry->dev = dev;
1379
1380         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1381                         skb->data, skb->len, tx_complete, skb);
1382         if (dev->can_dma_sg) {
1383                 if (build_dma_sg(skb, urb) < 0)
1384                         goto drop;
1385         }
1386         length = urb->transfer_buffer_length;
1387
1388         /* don't assume the hardware handles USB_ZERO_PACKET
1389          * NOTE:  strictly conforming cdc-ether devices should expect
1390          * the ZLP here, but ignore the one-byte packet.
1391          * NOTE2: CDC NCM specification is different from CDC ECM when
1392          * handling ZLP/short packets, so cdc_ncm driver will make short
1393          * packet itself if needed.
1394          */
1395         if (length % dev->maxpacket == 0) {
1396                 if (!(info->flags & FLAG_SEND_ZLP)) {
1397                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1398                                 length++;
1399                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1400                                         skb->data[skb->len] = 0;
1401                                         __skb_put(skb, 1);
1402                                 } else if (urb->num_sgs)
1403                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1404                                                         dev->padding_pkt, 1);
1405                         }
1406                 } else
1407                         urb->transfer_flags |= URB_ZERO_PACKET;
1408         }
1409         urb->transfer_buffer_length = length;
1410
1411         if (info->flags & FLAG_MULTI_PACKET) {
1412                 /* Driver has set number of packets and a length delta.
1413                  * Calculate the complete length and ensure that it's
1414                  * positive.
1415                  */
1416                 entry->length += length;
1417                 if (WARN_ON_ONCE(entry->length <= 0))
1418                         entry->length = length;
1419         } else {
1420                 usbnet_set_skb_tx_stats(skb, 1, length);
1421         }
1422
1423         spin_lock_irqsave(&dev->txq.lock, flags);
1424         retval = usb_autopm_get_interface_async(dev->intf);
1425         if (retval < 0) {
1426                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1427                 goto drop;
1428         }
1429
1430 #ifdef CONFIG_PM
1431         /* if this triggers the device is still a sleep */
1432         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1433                 /* transmission will be done in resume */
1434                 usb_anchor_urb(urb, &dev->deferred);
1435                 /* no use to process more packets */
1436                 netif_stop_queue(net);
1437                 usb_put_urb(urb);
1438                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1439                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1440                 goto deferred;
1441         }
1442 #endif
1443
1444         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1445         case -EPIPE:
1446                 netif_stop_queue (net);
1447                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1448                 usb_autopm_put_interface_async(dev->intf);
1449                 break;
1450         default:
1451                 usb_autopm_put_interface_async(dev->intf);
1452                 netif_dbg(dev, tx_err, dev->net,
1453                           "tx: submit urb err %d\n", retval);
1454                 break;
1455         case 0:
1456                 netif_trans_update(net);
1457                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1458                 if (dev->txq.qlen >= TX_QLEN (dev))
1459                         netif_stop_queue (net);
1460         }
1461         spin_unlock_irqrestore (&dev->txq.lock, flags);
1462
1463         if (retval) {
1464                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1465 drop:
1466                 dev->net->stats.tx_dropped++;
1467 not_drop:
1468                 if (skb)
1469                         dev_kfree_skb_any (skb);
1470                 if (urb) {
1471                         kfree(urb->sg);
1472                         usb_free_urb(urb);
1473                 }
1474         } else
1475                 netif_dbg(dev, tx_queued, dev->net,
1476                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1477 #ifdef CONFIG_PM
1478 deferred:
1479 #endif
1480         return NETDEV_TX_OK;
1481 }
1482 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1483
1484 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1485 {
1486         struct urb      *urb;
1487         int             i;
1488         int             ret = 0;
1489
1490         /* don't refill the queue all at once */
1491         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1492                 urb = usb_alloc_urb(0, flags);
1493                 if (urb != NULL) {
1494                         ret = rx_submit(dev, urb, flags);
1495                         if (ret)
1496                                 goto err;
1497                 } else {
1498                         ret = -ENOMEM;
1499                         goto err;
1500                 }
1501         }
1502 err:
1503         return ret;
1504 }
1505
1506 /*-------------------------------------------------------------------------*/
1507
1508 // tasklet (work deferred from completions, in_irq) or timer
1509
1510 static void usbnet_bh (unsigned long param)
1511 {
1512         struct usbnet           *dev = (struct usbnet *) param;
1513         struct sk_buff          *skb;
1514         struct skb_data         *entry;
1515
1516         while ((skb = skb_dequeue (&dev->done))) {
1517                 entry = (struct skb_data *) skb->cb;
1518                 switch (entry->state) {
1519                 case rx_done:
1520                         entry->state = rx_cleanup;
1521                         rx_process (dev, skb);
1522                         continue;
1523                 case tx_done:
1524                         kfree(entry->urb->sg);
1525                 case rx_cleanup:
1526                         usb_free_urb (entry->urb);
1527                         dev_kfree_skb (skb);
1528                         continue;
1529                 default:
1530                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1531                 }
1532         }
1533
1534         /* restart RX again after disabling due to high error rate */
1535         clear_bit(EVENT_RX_KILL, &dev->flags);
1536
1537         /* waiting for all pending urbs to complete?
1538          * only then can we forgo submitting anew
1539          */
1540         if (waitqueue_active(&dev->wait)) {
1541                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1542                         wake_up_all(&dev->wait);
1543
1544         // or are we maybe short a few urbs?
1545         } else if (netif_running (dev->net) &&
1546                    netif_device_present (dev->net) &&
1547                    netif_carrier_ok(dev->net) &&
1548                    !timer_pending(&dev->delay) &&
1549                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1550                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1551                 int     temp = dev->rxq.qlen;
1552
1553                 if (temp < RX_QLEN(dev)) {
1554                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1555                                 return;
1556                         if (temp != dev->rxq.qlen)
1557                                 netif_dbg(dev, link, dev->net,
1558                                           "rxqlen %d --> %d\n",
1559                                           temp, dev->rxq.qlen);
1560                         if (dev->rxq.qlen < RX_QLEN(dev))
1561                                 tasklet_schedule (&dev->bh);
1562                 }
1563                 if (dev->txq.qlen < TX_QLEN (dev))
1564                         netif_wake_queue (dev->net);
1565         }
1566 }
1567
1568
1569 /*-------------------------------------------------------------------------
1570  *
1571  * USB Device Driver support
1572  *
1573  *-------------------------------------------------------------------------*/
1574
1575 // precondition: never called in_interrupt
1576
1577 void usbnet_disconnect (struct usb_interface *intf)
1578 {
1579         struct usbnet           *dev;
1580         struct usb_device       *xdev;
1581         struct net_device       *net;
1582
1583         dev = usb_get_intfdata(intf);
1584         usb_set_intfdata(intf, NULL);
1585         if (!dev)
1586                 return;
1587
1588         xdev = interface_to_usbdev (intf);
1589
1590         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1591                    intf->dev.driver->name,
1592                    xdev->bus->bus_name, xdev->devpath,
1593                    dev->driver_info->description);
1594
1595         net = dev->net;
1596         unregister_netdev (net);
1597
1598         cancel_work_sync(&dev->kevent);
1599
1600         usb_scuttle_anchored_urbs(&dev->deferred);
1601
1602         if (dev->driver_info->unbind)
1603                 dev->driver_info->unbind (dev, intf);
1604
1605         usb_kill_urb(dev->interrupt);
1606         usb_free_urb(dev->interrupt);
1607         kfree(dev->padding_pkt);
1608
1609         free_percpu(dev->stats64);
1610         free_netdev(net);
1611 }
1612 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1613
1614 static const struct net_device_ops usbnet_netdev_ops = {
1615         .ndo_open               = usbnet_open,
1616         .ndo_stop               = usbnet_stop,
1617         .ndo_start_xmit         = usbnet_start_xmit,
1618         .ndo_tx_timeout         = usbnet_tx_timeout,
1619         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1620         .ndo_change_mtu         = usbnet_change_mtu,
1621         .ndo_get_stats64        = usbnet_get_stats64,
1622         .ndo_set_mac_address    = eth_mac_addr,
1623         .ndo_validate_addr      = eth_validate_addr,
1624 };
1625
1626 /*-------------------------------------------------------------------------*/
1627
1628 // precondition: never called in_interrupt
1629
1630 static struct device_type wlan_type = {
1631         .name   = "wlan",
1632 };
1633
1634 static struct device_type wwan_type = {
1635         .name   = "wwan",
1636 };
1637
1638 int
1639 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1640 {
1641         struct usbnet                   *dev;
1642         struct net_device               *net;
1643         struct usb_host_interface       *interface;
1644         struct driver_info              *info;
1645         struct usb_device               *xdev;
1646         int                             status;
1647         const char                      *name;
1648         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1649
1650         /* usbnet already took usb runtime pm, so have to enable the feature
1651          * for usb interface, otherwise usb_autopm_get_interface may return
1652          * failure if RUNTIME_PM is enabled.
1653          */
1654         if (!driver->supports_autosuspend) {
1655                 driver->supports_autosuspend = 1;
1656                 pm_runtime_enable(&udev->dev);
1657         }
1658
1659         name = udev->dev.driver->name;
1660         info = (struct driver_info *) prod->driver_info;
1661         if (!info) {
1662                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1663                 return -ENODEV;
1664         }
1665         xdev = interface_to_usbdev (udev);
1666         interface = udev->cur_altsetting;
1667
1668         status = -ENOMEM;
1669
1670         // set up our own records
1671         net = alloc_etherdev(sizeof(*dev));
1672         if (!net)
1673                 goto out;
1674
1675         /* netdev_printk() needs this so do it as early as possible */
1676         SET_NETDEV_DEV(net, &udev->dev);
1677
1678         dev = netdev_priv(net);
1679         dev->udev = xdev;
1680         dev->intf = udev;
1681         dev->driver_info = info;
1682         dev->driver_name = name;
1683
1684         dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1685         if (!dev->stats64)
1686                 goto out0;
1687
1688         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1689                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1690         init_waitqueue_head(&dev->wait);
1691         skb_queue_head_init (&dev->rxq);
1692         skb_queue_head_init (&dev->txq);
1693         skb_queue_head_init (&dev->done);
1694         skb_queue_head_init(&dev->rxq_pause);
1695         dev->bh.func = usbnet_bh;
1696         dev->bh.data = (unsigned long) dev;
1697         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1698         init_usb_anchor(&dev->deferred);
1699         dev->delay.function = usbnet_bh;
1700         dev->delay.data = (unsigned long) dev;
1701         init_timer (&dev->delay);
1702         mutex_init (&dev->phy_mutex);
1703         mutex_init(&dev->interrupt_mutex);
1704         dev->interrupt_count = 0;
1705
1706         dev->net = net;
1707         strcpy (net->name, "usb%d");
1708         memcpy (net->dev_addr, node_id, sizeof node_id);
1709
1710         /* rx and tx sides can use different message sizes;
1711          * bind() should set rx_urb_size in that case.
1712          */
1713         dev->hard_mtu = net->mtu + net->hard_header_len;
1714         net->min_mtu = 0;
1715         net->max_mtu = ETH_MAX_MTU;
1716
1717         net->netdev_ops = &usbnet_netdev_ops;
1718         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1719         net->ethtool_ops = &usbnet_ethtool_ops;
1720
1721         // allow device-specific bind/init procedures
1722         // NOTE net->name still not usable ...
1723         if (info->bind) {
1724                 status = info->bind (dev, udev);
1725                 if (status < 0)
1726                         goto out1;
1727
1728                 // heuristic:  "usb%d" for links we know are two-host,
1729                 // else "eth%d" when there's reasonable doubt.  userspace
1730                 // can rename the link if it knows better.
1731                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1732                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1733                      (net->dev_addr [0] & 0x02) == 0))
1734                         strcpy (net->name, "eth%d");
1735                 /* WLAN devices should always be named "wlan%d" */
1736                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1737                         strcpy(net->name, "wlan%d");
1738                 /* WWAN devices should always be named "wwan%d" */
1739                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1740                         strcpy(net->name, "wwan%d");
1741
1742                 /* devices that cannot do ARP */
1743                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1744                         net->flags |= IFF_NOARP;
1745
1746                 /* maybe the remote can't receive an Ethernet MTU */
1747                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1748                         net->mtu = dev->hard_mtu - net->hard_header_len;
1749         } else if (!info->in || !info->out)
1750                 status = usbnet_get_endpoints (dev, udev);
1751         else {
1752                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1753                 dev->out = usb_sndbulkpipe (xdev, info->out);
1754                 if (!(info->flags & FLAG_NO_SETINT))
1755                         status = usb_set_interface (xdev,
1756                                 interface->desc.bInterfaceNumber,
1757                                 interface->desc.bAlternateSetting);
1758                 else
1759                         status = 0;
1760
1761         }
1762         if (status >= 0 && dev->status)
1763                 status = init_status (dev, udev);
1764         if (status < 0)
1765                 goto out3;
1766
1767         if (!dev->rx_urb_size)
1768                 dev->rx_urb_size = dev->hard_mtu;
1769         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1770
1771         /* let userspace know we have a random address */
1772         if (ether_addr_equal(net->dev_addr, node_id))
1773                 net->addr_assign_type = NET_ADDR_RANDOM;
1774
1775         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1776                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1777         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1778                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1779
1780         /* initialize max rx_qlen and tx_qlen */
1781         usbnet_update_max_qlen(dev);
1782
1783         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1784                 !(info->flags & FLAG_MULTI_PACKET)) {
1785                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1786                 if (!dev->padding_pkt) {
1787                         status = -ENOMEM;
1788                         goto out4;
1789                 }
1790         }
1791
1792         status = register_netdev (net);
1793         if (status)
1794                 goto out5;
1795         netif_info(dev, probe, dev->net,
1796                    "register '%s' at usb-%s-%s, %s, %pM\n",
1797                    udev->dev.driver->name,
1798                    xdev->bus->bus_name, xdev->devpath,
1799                    dev->driver_info->description,
1800                    net->dev_addr);
1801
1802         // ok, it's ready to go.
1803         usb_set_intfdata (udev, dev);
1804
1805         netif_device_attach (net);
1806
1807         if (dev->driver_info->flags & FLAG_LINK_INTR)
1808                 usbnet_link_change(dev, 0, 0);
1809
1810         return 0;
1811
1812 out5:
1813         kfree(dev->padding_pkt);
1814 out4:
1815         usb_free_urb(dev->interrupt);
1816 out3:
1817         if (info->unbind)
1818                 info->unbind (dev, udev);
1819 out1:
1820         /* subdrivers must undo all they did in bind() if they
1821          * fail it, but we may fail later and a deferred kevent
1822          * may trigger an error resubmitting itself and, worse,
1823          * schedule a timer. So we kill it all just in case.
1824          */
1825         cancel_work_sync(&dev->kevent);
1826         del_timer_sync(&dev->delay);
1827         free_percpu(dev->stats64);
1828 out0:
1829         free_netdev(net);
1830 out:
1831         return status;
1832 }
1833 EXPORT_SYMBOL_GPL(usbnet_probe);
1834
1835 /*-------------------------------------------------------------------------*/
1836
1837 /*
1838  * suspend the whole driver as soon as the first interface is suspended
1839  * resume only when the last interface is resumed
1840  */
1841
1842 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1843 {
1844         struct usbnet           *dev = usb_get_intfdata(intf);
1845
1846         if (!dev->suspend_count++) {
1847                 spin_lock_irq(&dev->txq.lock);
1848                 /* don't autosuspend while transmitting */
1849                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1850                         dev->suspend_count--;
1851                         spin_unlock_irq(&dev->txq.lock);
1852                         return -EBUSY;
1853                 } else {
1854                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1855                         spin_unlock_irq(&dev->txq.lock);
1856                 }
1857                 /*
1858                  * accelerate emptying of the rx and queues, to avoid
1859                  * having everything error out.
1860                  */
1861                 netif_device_detach (dev->net);
1862                 usbnet_terminate_urbs(dev);
1863                 __usbnet_status_stop_force(dev);
1864
1865                 /*
1866                  * reattach so runtime management can use and
1867                  * wake the device
1868                  */
1869                 netif_device_attach (dev->net);
1870         }
1871         return 0;
1872 }
1873 EXPORT_SYMBOL_GPL(usbnet_suspend);
1874
1875 int usbnet_resume (struct usb_interface *intf)
1876 {
1877         struct usbnet           *dev = usb_get_intfdata(intf);
1878         struct sk_buff          *skb;
1879         struct urb              *res;
1880         int                     retval;
1881
1882         if (!--dev->suspend_count) {
1883                 /* resume interrupt URB if it was previously submitted */
1884                 __usbnet_status_start_force(dev, GFP_NOIO);
1885
1886                 spin_lock_irq(&dev->txq.lock);
1887                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1888
1889                         skb = (struct sk_buff *)res->context;
1890                         retval = usb_submit_urb(res, GFP_ATOMIC);
1891                         if (retval < 0) {
1892                                 dev_kfree_skb_any(skb);
1893                                 kfree(res->sg);
1894                                 usb_free_urb(res);
1895                                 usb_autopm_put_interface_async(dev->intf);
1896                         } else {
1897                                 netif_trans_update(dev->net);
1898                                 __skb_queue_tail(&dev->txq, skb);
1899                         }
1900                 }
1901
1902                 smp_mb();
1903                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1904                 spin_unlock_irq(&dev->txq.lock);
1905
1906                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1907                         /* handle remote wakeup ASAP
1908                          * we cannot race against stop
1909                          */
1910                         if (netif_device_present(dev->net) &&
1911                                 !timer_pending(&dev->delay) &&
1912                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1913                                         rx_alloc_submit(dev, GFP_NOIO);
1914
1915                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1916                                 netif_tx_wake_all_queues(dev->net);
1917                         tasklet_schedule (&dev->bh);
1918                 }
1919         }
1920
1921         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1922                 usb_autopm_get_interface_no_resume(intf);
1923
1924         return 0;
1925 }
1926 EXPORT_SYMBOL_GPL(usbnet_resume);
1927
1928 /*
1929  * Either a subdriver implements manage_power, then it is assumed to always
1930  * be ready to be suspended or it reports the readiness to be suspended
1931  * explicitly
1932  */
1933 void usbnet_device_suggests_idle(struct usbnet *dev)
1934 {
1935         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1936                 dev->intf->needs_remote_wakeup = 1;
1937                 usb_autopm_put_interface_async(dev->intf);
1938         }
1939 }
1940 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1941
1942 /*
1943  * For devices that can do without special commands
1944  */
1945 int usbnet_manage_power(struct usbnet *dev, int on)
1946 {
1947         dev->intf->needs_remote_wakeup = on;
1948         return 0;
1949 }
1950 EXPORT_SYMBOL(usbnet_manage_power);
1951
1952 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1953 {
1954         /* update link after link is reseted */
1955         if (link && !need_reset)
1956                 netif_carrier_on(dev->net);
1957         else
1958                 netif_carrier_off(dev->net);
1959
1960         if (need_reset && link)
1961                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1962         else
1963                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1964 }
1965 EXPORT_SYMBOL(usbnet_link_change);
1966
1967 /*-------------------------------------------------------------------------*/
1968 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1969                              u16 value, u16 index, void *data, u16 size)
1970 {
1971         void *buf = NULL;
1972         int err = -ENOMEM;
1973
1974         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1975                    " value=0x%04x index=0x%04x size=%d\n",
1976                    cmd, reqtype, value, index, size);
1977
1978         if (data) {
1979                 buf = kmalloc(size, GFP_KERNEL);
1980                 if (!buf)
1981                         goto out;
1982         }
1983
1984         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1985                               cmd, reqtype, value, index, buf, size,
1986                               USB_CTRL_GET_TIMEOUT);
1987         if (err > 0 && err <= size)
1988                 memcpy(data, buf, err);
1989         kfree(buf);
1990 out:
1991         return err;
1992 }
1993
1994 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1995                               u16 value, u16 index, const void *data,
1996                               u16 size)
1997 {
1998         void *buf = NULL;
1999         int err = -ENOMEM;
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         if (data) {
2006                 buf = kmemdup(data, size, GFP_KERNEL);
2007                 if (!buf)
2008                         goto out;
2009         }
2010
2011         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2012                               cmd, reqtype, value, index, buf, size,
2013                               USB_CTRL_SET_TIMEOUT);
2014         kfree(buf);
2015
2016 out:
2017         return err;
2018 }
2019
2020 /*
2021  * The function can't be called inside suspend/resume callback,
2022  * otherwise deadlock will be caused.
2023  */
2024 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2025                     u16 value, u16 index, void *data, u16 size)
2026 {
2027         int ret;
2028
2029         if (usb_autopm_get_interface(dev->intf) < 0)
2030                 return -ENODEV;
2031         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2032                                 data, size);
2033         usb_autopm_put_interface(dev->intf);
2034         return ret;
2035 }
2036 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2037
2038 /*
2039  * The function can't be called inside suspend/resume callback,
2040  * otherwise deadlock will be caused.
2041  */
2042 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2043                      u16 value, u16 index, const void *data, u16 size)
2044 {
2045         int ret;
2046
2047         if (usb_autopm_get_interface(dev->intf) < 0)
2048                 return -ENODEV;
2049         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2050                                  data, size);
2051         usb_autopm_put_interface(dev->intf);
2052         return ret;
2053 }
2054 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2055
2056 /*
2057  * The function can be called inside suspend/resume callback safely
2058  * and should only be called by suspend/resume callback generally.
2059  */
2060 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2061                           u16 value, u16 index, void *data, u16 size)
2062 {
2063         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2064                                  data, size);
2065 }
2066 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2067
2068 /*
2069  * The function can be called inside suspend/resume callback safely
2070  * and should only be called by suspend/resume callback generally.
2071  */
2072 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2073                           u16 value, u16 index, const void *data,
2074                           u16 size)
2075 {
2076         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2077                                   data, size);
2078 }
2079 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2080
2081 static void usbnet_async_cmd_cb(struct urb *urb)
2082 {
2083         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2084         int status = urb->status;
2085
2086         if (status < 0)
2087                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2088                         __func__, status);
2089
2090         kfree(req);
2091         usb_free_urb(urb);
2092 }
2093
2094 /*
2095  * The caller must make sure that device can't be put into suspend
2096  * state until the control URB completes.
2097  */
2098 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2099                            u16 value, u16 index, const void *data, u16 size)
2100 {
2101         struct usb_ctrlrequest *req = NULL;
2102         struct urb *urb;
2103         int err = -ENOMEM;
2104         void *buf = NULL;
2105
2106         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2107                    " value=0x%04x index=0x%04x size=%d\n",
2108                    cmd, reqtype, value, index, size);
2109
2110         urb = usb_alloc_urb(0, GFP_ATOMIC);
2111         if (!urb)
2112                 goto fail;
2113
2114         if (data) {
2115                 buf = kmemdup(data, size, GFP_ATOMIC);
2116                 if (!buf) {
2117                         netdev_err(dev->net, "Error allocating buffer"
2118                                    " in %s!\n", __func__);
2119                         goto fail_free;
2120                 }
2121         }
2122
2123         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2124         if (!req)
2125                 goto fail_free_buf;
2126
2127         req->bRequestType = reqtype;
2128         req->bRequest = cmd;
2129         req->wValue = cpu_to_le16(value);
2130         req->wIndex = cpu_to_le16(index);
2131         req->wLength = cpu_to_le16(size);
2132
2133         usb_fill_control_urb(urb, dev->udev,
2134                              usb_sndctrlpipe(dev->udev, 0),
2135                              (void *)req, buf, size,
2136                              usbnet_async_cmd_cb, req);
2137         urb->transfer_flags |= URB_FREE_BUFFER;
2138
2139         err = usb_submit_urb(urb, GFP_ATOMIC);
2140         if (err < 0) {
2141                 netdev_err(dev->net, "Error submitting the control"
2142                            " message: status=%d\n", err);
2143                 goto fail_free;
2144         }
2145         return 0;
2146
2147 fail_free_buf:
2148         kfree(buf);
2149 fail_free:
2150         kfree(req);
2151         usb_free_urb(urb);
2152 fail:
2153         return err;
2154
2155 }
2156 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2157 /*-------------------------------------------------------------------------*/
2158
2159 static int __init usbnet_init(void)
2160 {
2161         /* Compiler should optimize this out. */
2162         BUILD_BUG_ON(
2163                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2164
2165         eth_random_addr(node_id);
2166         return 0;
2167 }
2168 module_init(usbnet_init);
2169
2170 static void __exit usbnet_exit(void)
2171 {
2172 }
2173 module_exit(usbnet_exit);
2174
2175 MODULE_AUTHOR("David Brownell");
2176 MODULE_DESCRIPTION("USB network driver framework");
2177 MODULE_LICENSE("GPL");