drivers/net/usb/usbnet.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * USB Network driver infrastructure
   4  * Copyright (C) 2000-2005 by David Brownell
   5  * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   6  */
   7
   8 /*
   9  * This is a generic "USB networking" framework that works with several
  10  * kinds of full and high speed networking devices:  host-to-host cables,
  11  * smart usb peripherals, and actual Ethernet adapters.
  12  *
  13  * These devices usually differ in terms of control protocols (if they
  14  * even have one!) and sometimes they define new framing to wrap or batch
  15  * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  16  * so interface (un)binding, endpoint I/O queues, fault handling, and other
  17  * issues can usefully be addressed by this framework.
  18  */
  19
  20 // #define      DEBUG                   // error path messages, extra info
  21 // #define      VERBOSE                 // more; success messages
  22
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/etherdevice.h>
  27 #include <linux/ctype.h>
  28 #include <linux/ethtool.h>
  29 #include <linux/workqueue.h>
  30 #include <linux/mii.h>
  31 #include <linux/usb.h>
  32 #include <linux/usb/usbnet.h>
  33 #include <linux/slab.h>
  34 #include <linux/kernel.h>
  35 #include <linux/pm_runtime.h>
  36
  37 #define DRIVER_VERSION          "22-Aug-2005"
  38
  39
  40 /*-------------------------------------------------------------------------*/
  41
  42 /*
  43  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  44  * Several dozen bytes of IPv4 data can fit in two such transactions.
  45  * One maximum size Ethernet packet takes twenty four of them.
  46  * For high speed, each frame comfortably fits almost 36 max size
  47  * Ethernet packets (so queues should be bigger).
  48  *
  49  * The goal is to let the USB host controller be busy for 5msec or
  50  * more before an irq is required, under load.  Jumbograms change
  51  * the equation.
  52  */
  53 #define MAX_QUEUE_MEMORY        (60 * 1518)
  54 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  55 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  56
  57 // reawaken network queue this soon after stopping; else watchdog barks
  58 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  59
  60 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  61  * us (it polls at HZ/4 usually) before we report too many false errors.
  62  */
  63 #define THROTTLE_JIFFIES        (HZ/8)
  64
  65 // between wakeups
  66 #define UNLINK_TIMEOUT_MS       3
  67
  68 /*-------------------------------------------------------------------------*/
  69
  70 // randomly generated ethernet address
  71 static u8       node_id [ETH_ALEN];
  72
  73 /* use ethtool to change the level for any given device */
  74 static int msg_level = -1;
  75 module_param (msg_level, int, 0);
  76 MODULE_PARM_DESC (msg_level, "Override default message level");
  77
  78 /*-------------------------------------------------------------------------*/
  79
  80 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  81 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  82 {
  83         int                             tmp;
  84         struct usb_host_interface       *alt = NULL;
  85         struct usb_host_endpoint        *in = NULL, *out = NULL;
  86         struct usb_host_endpoint        *status = NULL;
  87
  88         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
  89                 unsigned        ep;
  90
  91                 in = out = status = NULL;
  92                 alt = intf->altsetting + tmp;
  93
  94                 /* take the first altsetting with in-bulk + out-bulk;
  95                  * remember any status endpoint, just in case;
  96                  * ignore other endpoints and altsettings.
  97                  */
  98                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
  99                         struct usb_host_endpoint        *e;
 100                         int                             intr = 0;
 101
 102                         e = alt->endpoint + ep;
 103
 104                         /* ignore endpoints which cannot transfer data */
 105                         if (!usb_endpoint_maxp(&e->desc))
 106                                 continue;
 107
 108                         switch (e->desc.bmAttributes) {
 109                         case USB_ENDPOINT_XFER_INT:
 110                                 if (!usb_endpoint_dir_in(&e->desc))
 111                                         continue;
 112                                 intr = 1;
 113                                 /* FALLTHROUGH */
 114                         case USB_ENDPOINT_XFER_BULK:
 115                                 break;
 116                         default:
 117                                 continue;
 118                         }
 119                         if (usb_endpoint_dir_in(&e->desc)) {
 120                                 if (!intr && !in)
 121                                         in = e;
 122                                 else if (intr && !status)
 123                                         status = e;
 124                         } else {
 125                                 if (!out)
 126                                         out = e;
 127                         }
 128                 }
 129                 if (in && out)
 130                         break;
 131         }
 132         if (!alt || !in || !out)
 133                 return -EINVAL;
 134
 135         if (alt->desc.bAlternateSetting != 0 ||
 136             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 137                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 138                                 alt->desc.bAlternateSetting);
 139                 if (tmp < 0)
 140                         return tmp;
 141         }
 142
 143         dev->in = usb_rcvbulkpipe (dev->udev,
 144                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 145         dev->out = usb_sndbulkpipe (dev->udev,
 146                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 147         dev->status = status;
 148         return 0;
 149 }
 150 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 151
 152 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 153 {
 154         int             tmp = -1, ret;
 155         unsigned char   buf [13];
 156
 157         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 158         if (ret == 12)
 159                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 160         if (tmp < 0) {
 161                 dev_dbg(&dev->udev->dev,
 162                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 163                 if (ret >= 0)
 164                         ret = -EINVAL;
 165                 return ret;
 166         }
 167         return 0;
 168 }
 169 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 170
 171 static void intr_complete (struct urb *urb)
 172 {
 173         struct usbnet   *dev = urb->context;
 174         int             status = urb->status;
 175
 176         switch (status) {
 177         /* success */
 178         case 0:
 179                 dev->driver_info->status(dev, urb);
 180                 break;
 181
 182         /* software-driven interface shutdown */
 183         case -ENOENT:           /* urb killed */
 184         case -ESHUTDOWN:        /* hardware gone */
 185                 netif_dbg(dev, ifdown, dev->net,
 186                           "intr shutdown, code %d\n", status);
 187                 return;
 188
 189         /* NOTE:  not throttling like RX/TX, since this endpoint
 190          * already polls infrequently
 191          */
 192         default:
 193                 netdev_dbg(dev->net, "intr status %d\n", status);
 194                 break;
 195         }
 196
 197         status = usb_submit_urb (urb, GFP_ATOMIC);
 198         if (status != 0)
 199                 netif_err(dev, timer, dev->net,
 200                           "intr resubmit --> %d\n", status);
 201 }
 202
 203 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 204 {
 205         char            *buf = NULL;
 206         unsigned        pipe = 0;
 207         unsigned        maxp;
 208         unsigned        period;
 209
 210         if (!dev->driver_info->status)
 211                 return 0;
 212
 213         pipe = usb_rcvintpipe (dev->udev,
 214                         dev->status->desc.bEndpointAddress
 215                                 & USB_ENDPOINT_NUMBER_MASK);
 216         maxp = usb_maxpacket (dev->udev, pipe, 0);
 217
 218         /* avoid 1 msec chatter:  min 8 msec poll rate */
 219         period = max ((int) dev->status->desc.bInterval,
 220                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 221
 222         buf = kmalloc (maxp, GFP_KERNEL);
 223         if (buf) {
 224                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 225                 if (!dev->interrupt) {
 226                         kfree (buf);
 227                         return -ENOMEM;
 228                 } else {
 229                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 230                                 buf, maxp, intr_complete, dev, period);
 231                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 232                         dev_dbg(&intf->dev,
 233                                 "status ep%din, %d bytes period %d\n",
 234                                 usb_pipeendpoint(pipe), maxp, period);
 235                 }
 236         }
 237         return 0;
 238 }
 239
 240 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 241 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 242 {
 243         int ret = 0;
 244
 245         WARN_ON_ONCE(dev->interrupt == NULL);
 246         if (dev->interrupt) {
 247                 mutex_lock(&dev->interrupt_mutex);
 248
 249                 if (++dev->interrupt_count == 1)
 250                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 251
 252                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 253                         dev->interrupt_count);
 254                 mutex_unlock(&dev->interrupt_mutex);
 255         }
 256         return ret;
 257 }
 258 EXPORT_SYMBOL_GPL(usbnet_status_start);
 259
 260 /* For resume; submit interrupt URB if previously submitted */
 261 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 262 {
 263         int ret = 0;
 264
 265         mutex_lock(&dev->interrupt_mutex);
 266         if (dev->interrupt_count) {
 267                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 268                 dev_dbg(&dev->udev->dev,
 269                         "submitted interrupt URB for resume\n");
 270         }
 271         mutex_unlock(&dev->interrupt_mutex);
 272         return ret;
 273 }
 274
 275 /* Kill the interrupt URB if all submitters want it killed */
 276 void usbnet_status_stop(struct usbnet *dev)
 277 {
 278         if (dev->interrupt) {
 279                 mutex_lock(&dev->interrupt_mutex);
 280                 WARN_ON(dev->interrupt_count == 0);
 281
 282                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 283                         usb_kill_urb(dev->interrupt);
 284
 285                 dev_dbg(&dev->udev->dev,
 286                         "decremented interrupt URB count to %d\n",
 287                         dev->interrupt_count);
 288                 mutex_unlock(&dev->interrupt_mutex);
 289         }
 290 }
 291 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 292
 293 /* For suspend; always kill interrupt URB */
 294 static void __usbnet_status_stop_force(struct usbnet *dev)
 295 {
 296         if (dev->interrupt) {
 297                 mutex_lock(&dev->interrupt_mutex);
 298                 usb_kill_urb(dev->interrupt);
 299                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 300                 mutex_unlock(&dev->interrupt_mutex);
 301         }
 302 }
 303
 304 /* Passes this packet up the stack, updating its accounting.
 305  * Some link protocols batch packets, so their rx_fixup paths
 306  * can return clones as well as just modify the original skb.
 307  */
 308 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 309 {
 310         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
 311         unsigned long flags;
 312         int     status;
 313
 314         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 315                 skb_queue_tail(&dev->rxq_pause, skb);
 316                 return;
 317         }
 318
 319         /* only update if unset to allow minidriver rx_fixup override */
 320         if (skb->protocol == 0)
 321                 skb->protocol = eth_type_trans (skb, dev->net);
 322
 323         flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 324         stats64->rx_packets++;
 325         stats64->rx_bytes += skb->len;
 326         u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 327
 328         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 329                   skb->len + sizeof (struct ethhdr), skb->protocol);
 330         memset (skb->cb, 0, sizeof (struct skb_data));
 331
 332         if (skb_defer_rx_timestamp(skb))
 333                 return;
 334
 335         status = netif_rx (skb);
 336         if (status != NET_RX_SUCCESS)
 337                 netif_dbg(dev, rx_err, dev->net,
 338                           "netif_rx status %d\n", status);
 339 }
 340 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 341
 342 /* must be called if hard_mtu or rx_urb_size changed */
 343 void usbnet_update_max_qlen(struct usbnet *dev)
 344 {
 345         enum usb_device_speed speed = dev->udev->speed;
 346
 347         if (!dev->rx_urb_size || !dev->hard_mtu)
 348                 goto insanity;
 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         case USB_SPEED_SUPER_PLUS:
 356                 /*
 357                  * Not take default 5ms qlen for super speed HC to
 358                  * save memory, and iperf tests show 2.5ms qlen can
 359                  * work well
 360                  */
 361                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 362                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 363                 break;
 364         default:
 365 insanity:
 366                 dev->rx_qlen = dev->tx_qlen = 4;
 367         }
 368 }
 369 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 370
 371 \f
 372 /*-------------------------------------------------------------------------
 373  *
 374  * Network Device Driver (peer link to "Host Device", from USB host)
 375  *
 376  *-------------------------------------------------------------------------*/
 377
 378 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 379 {
 380         struct usbnet   *dev = netdev_priv(net);
 381         int             ll_mtu = new_mtu + net->hard_header_len;
 382         int             old_hard_mtu = dev->hard_mtu;
 383         int             old_rx_urb_size = dev->rx_urb_size;
 384
 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_pause_rx(dev);
 395                         usbnet_unlink_rx_urbs(dev);
 396                         usbnet_resume_rx(dev);
 397                 }
 398         }
 399
 400         /* max qlen depend on hard_mtu and rx_urb_size */
 401         usbnet_update_max_qlen(dev);
 402
 403         return 0;
 404 }
 405 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 406
 407 /* The caller must hold list->lock */
 408 static void __usbnet_queue_skb(struct sk_buff_head *list,
 409                         struct sk_buff *newsk, enum skb_state state)
 410 {
 411         struct skb_data *entry = (struct skb_data *) newsk->cb;
 412
 413         __skb_queue_tail(list, newsk);
 414         entry->state = state;
 415 }
 416
 417 /*-------------------------------------------------------------------------*/
 418
 419 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 420  * completion callbacks.  2.5 should have fixed those bugs...
 421  */
 422
 423 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 424                 struct sk_buff_head *list, enum skb_state state)
 425 {
 426         unsigned long           flags;
 427         enum skb_state          old_state;
 428         struct skb_data *entry = (struct skb_data *) skb->cb;
 429
 430         spin_lock_irqsave(&list->lock, flags);
 431         old_state = entry->state;
 432         entry->state = state;
 433         __skb_unlink(skb, list);
 434
 435         /* defer_bh() is never called with list == &dev->done.
 436          * spin_lock_nested() tells lockdep that it is OK to take
 437          * dev->done.lock here with list->lock held.
 438          */
 439         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 440
 441         __skb_queue_tail(&dev->done, skb);
 442         if (dev->done.qlen == 1)
 443                 tasklet_schedule(&dev->bh);
 444         spin_unlock(&dev->done.lock);
 445         spin_unlock_irqrestore(&list->lock, flags);
 446         return old_state;
 447 }
 448
 449 /* some work can't be done in tasklets, so we use keventd
 450  *
 451  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 452  * but tasklet_schedule() doesn't.  hope the failure is rare.
 453  */
 454 void usbnet_defer_kevent (struct usbnet *dev, int work)
 455 {
 456         set_bit (work, &dev->flags);
 457         if (!schedule_work (&dev->kevent))
 458                 netdev_dbg(dev->net, "kevent %d may have been dropped\n", work);
 459         else
 460                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 461 }
 462 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 463
 464 /*-------------------------------------------------------------------------*/
 465
 466 static void rx_complete (struct urb *urb);
 467
 468 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 469 {
 470         struct sk_buff          *skb;
 471         struct skb_data         *entry;
 472         int                     retval = 0;
 473         unsigned long           lockflags;
 474         size_t                  size = dev->rx_urb_size;
 475
 476         /* prevent rx skb allocation when error ratio is high */
 477         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 478                 usb_free_urb(urb);
 479                 return -ENOLINK;
 480         }
 481
 482         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 483                 skb = __netdev_alloc_skb(dev->net, size, flags);
 484         else
 485                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 486         if (!skb) {
 487                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 488                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 489                 usb_free_urb (urb);
 490                 return -ENOMEM;
 491         }
 492
 493         entry = (struct skb_data *) skb->cb;
 494         entry->urb = urb;
 495         entry->dev = dev;
 496         entry->length = 0;
 497
 498         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 499                 skb->data, size, rx_complete, skb);
 500
 501         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 502
 503         if (netif_running (dev->net) &&
 504             netif_device_present (dev->net) &&
 505             test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 506             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 507             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 508                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 509                 case -EPIPE:
 510                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 511                         break;
 512                 case -ENOMEM:
 513                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 514                         break;
 515                 case -ENODEV:
 516                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 517                         netif_device_detach (dev->net);
 518                         break;
 519                 case -EHOSTUNREACH:
 520                         retval = -ENOLINK;
 521                         break;
 522                 default:
 523                         netif_dbg(dev, rx_err, dev->net,
 524                                   "rx submit, %d\n", retval);
 525                         tasklet_schedule (&dev->bh);
 526                         break;
 527                 case 0:
 528                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 529                 }
 530         } else {
 531                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 532                 retval = -ENOLINK;
 533         }
 534         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 535         if (retval) {
 536                 dev_kfree_skb_any (skb);
 537                 usb_free_urb (urb);
 538         }
 539         return retval;
 540 }
 541
 542
 543 /*-------------------------------------------------------------------------*/
 544
 545 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 546 {
 547         if (dev->driver_info->rx_fixup &&
 548             !dev->driver_info->rx_fixup (dev, skb)) {
 549                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 550                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 551                         dev->net->stats.rx_errors++;
 552                 goto done;
 553         }
 554         // else network stack removes extra byte if we forced a short packet
 555
 556         /* all data was already cloned from skb inside the driver */
 557         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 558                 goto done;
 559
 560         if (skb->len < ETH_HLEN) {
 561                 dev->net->stats.rx_errors++;
 562                 dev->net->stats.rx_length_errors++;
 563                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 564         } else {
 565                 usbnet_skb_return(dev, skb);
 566                 return;
 567         }
 568
 569 done:
 570         skb_queue_tail(&dev->done, skb);
 571 }
 572
 573 /*-------------------------------------------------------------------------*/
 574
 575 static void rx_complete (struct urb *urb)
 576 {
 577         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 578         struct skb_data         *entry = (struct skb_data *) skb->cb;
 579         struct usbnet           *dev = entry->dev;
 580         int                     urb_status = urb->status;
 581         enum skb_state          state;
 582
 583         skb_put (skb, urb->actual_length);
 584         state = rx_done;
 585         entry->urb = NULL;
 586
 587         switch (urb_status) {
 588         /* success */
 589         case 0:
 590                 break;
 591
 592         /* stalls need manual reset. this is rare ... except that
 593          * when going through USB 2.0 TTs, unplug appears this way.
 594          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 595          * storm, recovering as needed.
 596          */
 597         case -EPIPE:
 598                 dev->net->stats.rx_errors++;
 599                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 600                 // FALLTHROUGH
 601
 602         /* software-driven interface shutdown */
 603         case -ECONNRESET:               /* async unlink */
 604         case -ESHUTDOWN:                /* hardware gone */
 605                 netif_dbg(dev, ifdown, dev->net,
 606                           "rx shutdown, code %d\n", urb_status);
 607                 goto block;
 608
 609         /* we get controller i/o faults during hub_wq disconnect() delays.
 610          * throttle down resubmits, to avoid log floods; just temporarily,
 611          * so we still recover when the fault isn't a hub_wq delay.
 612          */
 613         case -EPROTO:
 614         case -ETIME:
 615         case -EILSEQ:
 616                 dev->net->stats.rx_errors++;
 617                 if (!timer_pending (&dev->delay)) {
 618                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 619                         netif_dbg(dev, link, dev->net,
 620                                   "rx throttle %d\n", urb_status);
 621                 }
 622 block:
 623                 state = rx_cleanup;
 624                 entry->urb = urb;
 625                 urb = NULL;
 626                 break;
 627
 628         /* data overrun ... flush fifo? */
 629         case -EOVERFLOW:
 630                 dev->net->stats.rx_over_errors++;
 631                 // FALLTHROUGH
 632
 633         default:
 634                 state = rx_cleanup;
 635                 dev->net->stats.rx_errors++;
 636                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 637                 break;
 638         }
 639
 640         /* stop rx if packet error rate is high */
 641         if (++dev->pkt_cnt > 30) {
 642                 dev->pkt_cnt = 0;
 643                 dev->pkt_err = 0;
 644         } else {
 645                 if (state == rx_cleanup)
 646                         dev->pkt_err++;
 647                 if (dev->pkt_err > 20)
 648                         set_bit(EVENT_RX_KILL, &dev->flags);
 649         }
 650
 651         state = defer_bh(dev, skb, &dev->rxq, state);
 652
 653         if (urb) {
 654                 if (netif_running (dev->net) &&
 655                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 656                     state != unlink_start) {
 657                         rx_submit (dev, urb, GFP_ATOMIC);
 658                         usb_mark_last_busy(dev->udev);
 659                         return;
 660                 }
 661                 usb_free_urb (urb);
 662         }
 663         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 664 }
 665
 666 /*-------------------------------------------------------------------------*/
 667 void usbnet_pause_rx(struct usbnet *dev)
 668 {
 669         set_bit(EVENT_RX_PAUSED, &dev->flags);
 670
 671         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 672 }
 673 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 674
 675 void usbnet_resume_rx(struct usbnet *dev)
 676 {
 677         struct sk_buff *skb;
 678         int num = 0;
 679
 680         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 681
 682         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 683                 usbnet_skb_return(dev, skb);
 684                 num++;
 685         }
 686
 687         tasklet_schedule(&dev->bh);
 688
 689         netif_dbg(dev, rx_status, dev->net,
 690                   "paused rx queue disabled, %d skbs requeued\n", num);
 691 }
 692 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 693
 694 void usbnet_purge_paused_rxq(struct usbnet *dev)
 695 {
 696         skb_queue_purge(&dev->rxq_pause);
 697 }
 698 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 699
 700 /*-------------------------------------------------------------------------*/
 701
 702 // unlink pending rx/tx; completion handlers do all other cleanup
 703
 704 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 705 {
 706         unsigned long           flags;
 707         struct sk_buff          *skb;
 708         int                     count = 0;
 709
 710         spin_lock_irqsave (&q->lock, flags);
 711         while (!skb_queue_empty(q)) {
 712                 struct skb_data         *entry;
 713                 struct urb              *urb;
 714                 int                     retval;
 715
 716                 skb_queue_walk(q, skb) {
 717                         entry = (struct skb_data *) skb->cb;
 718                         if (entry->state != unlink_start)
 719                                 goto found;
 720                 }
 721                 break;
 722 found:
 723                 entry->state = unlink_start;
 724                 urb = entry->urb;
 725
 726                 /*
 727                  * Get reference count of the URB to avoid it to be
 728                  * freed during usb_unlink_urb, which may trigger
 729                  * use-after-free problem inside usb_unlink_urb since
 730                  * usb_unlink_urb is always racing with .complete
 731                  * handler(include defer_bh).
 732                  */
 733                 usb_get_urb(urb);
 734                 spin_unlock_irqrestore(&q->lock, flags);
 735                 // during some PM-driven resume scenarios,
 736                 // these (async) unlinks complete immediately
 737                 retval = usb_unlink_urb (urb);
 738                 if (retval != -EINPROGRESS && retval != 0)
 739                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 740                 else
 741                         count++;
 742                 usb_put_urb(urb);
 743                 spin_lock_irqsave(&q->lock, flags);
 744         }
 745         spin_unlock_irqrestore (&q->lock, flags);
 746         return count;
 747 }
 748
 749 // Flush all pending rx urbs
 750 // minidrivers may need to do this when the MTU changes
 751
 752 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 753 {
 754         if (netif_running(dev->net)) {
 755                 (void) unlink_urbs (dev, &dev->rxq);
 756                 tasklet_schedule(&dev->bh);
 757         }
 758 }
 759 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 760
 761 /*-------------------------------------------------------------------------*/
 762
 763 static void wait_skb_queue_empty(struct sk_buff_head *q)
 764 {
 765         unsigned long flags;
 766
 767         spin_lock_irqsave(&q->lock, flags);
 768         while (!skb_queue_empty(q)) {
 769                 spin_unlock_irqrestore(&q->lock, flags);
 770                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 771                 set_current_state(TASK_UNINTERRUPTIBLE);
 772                 spin_lock_irqsave(&q->lock, flags);
 773         }
 774         spin_unlock_irqrestore(&q->lock, flags);
 775 }
 776
 777 // precondition: never called in_interrupt
 778 static void usbnet_terminate_urbs(struct usbnet *dev)
 779 {
 780         DECLARE_WAITQUEUE(wait, current);
 781         int temp;
 782
 783         /* ensure there are no more active urbs */
 784         add_wait_queue(&dev->wait, &wait);
 785         set_current_state(TASK_UNINTERRUPTIBLE);
 786         temp = unlink_urbs(dev, &dev->txq) +
 787                 unlink_urbs(dev, &dev->rxq);
 788
 789         /* maybe wait for deletions to finish. */
 790         wait_skb_queue_empty(&dev->rxq);
 791         wait_skb_queue_empty(&dev->txq);
 792         wait_skb_queue_empty(&dev->done);
 793         netif_dbg(dev, ifdown, dev->net,
 794                   "waited for %d urb completions\n", temp);
 795         set_current_state(TASK_RUNNING);
 796         remove_wait_queue(&dev->wait, &wait);
 797 }
 798
 799 int usbnet_stop (struct net_device *net)
 800 {
 801         struct usbnet           *dev = netdev_priv(net);
 802         const struct driver_info *info = dev->driver_info;
 803         int                     retval, pm, mpn;
 804
 805         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 806         netif_stop_queue (net);
 807
 808         netif_info(dev, ifdown, dev->net,
 809                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 810                    net->stats.rx_packets, net->stats.tx_packets,
 811                    net->stats.rx_errors, net->stats.tx_errors);
 812
 813         /* to not race resume */
 814         pm = usb_autopm_get_interface(dev->intf);
 815         /* allow minidriver to stop correctly (wireless devices to turn off
 816          * radio etc) */
 817         if (info->stop) {
 818                 retval = info->stop(dev);
 819                 if (retval < 0)
 820                         netif_info(dev, ifdown, dev->net,
 821                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 822                                    retval,
 823                                    dev->udev->bus->bus_name, dev->udev->devpath,
 824                                    info->description);
 825         }
 826
 827         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 828                 usbnet_terminate_urbs(dev);
 829
 830         usbnet_status_stop(dev);
 831
 832         usbnet_purge_paused_rxq(dev);
 833
 834         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 835
 836         /* deferred work (task, timer, softirq) must also stop.
 837          * can't flush_scheduled_work() until we drop rtnl (later),
 838          * else workers could deadlock; so make workers a NOP.
 839          */
 840         dev->flags = 0;
 841         del_timer_sync (&dev->delay);
 842         tasklet_kill (&dev->bh);
 843         if (!pm)
 844                 usb_autopm_put_interface(dev->intf);
 845
 846         if (info->manage_power && mpn)
 847                 info->manage_power(dev, 0);
 848         else
 849                 usb_autopm_put_interface(dev->intf);
 850
 851         return 0;
 852 }
 853 EXPORT_SYMBOL_GPL(usbnet_stop);
 854
 855 /*-------------------------------------------------------------------------*/
 856
 857 // posts reads, and enables write queuing
 858
 859 // precondition: never called in_interrupt
 860
 861 int usbnet_open (struct net_device *net)
 862 {
 863         struct usbnet           *dev = netdev_priv(net);
 864         int                     retval;
 865         const struct driver_info *info = dev->driver_info;
 866
 867         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 868                 netif_info(dev, ifup, dev->net,
 869                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 870                            retval,
 871                            dev->udev->bus->bus_name,
 872                            dev->udev->devpath,
 873                            info->description);
 874                 goto done_nopm;
 875         }
 876
 877         // put into "known safe" state
 878         if (info->reset && (retval = info->reset (dev)) < 0) {
 879                 netif_info(dev, ifup, dev->net,
 880                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 881                            retval,
 882                            dev->udev->bus->bus_name,
 883                            dev->udev->devpath,
 884                            info->description);
 885                 goto done;
 886         }
 887
 888         /* hard_mtu or rx_urb_size may change in reset() */
 889         usbnet_update_max_qlen(dev);
 890
 891         // insist peer be connected
 892         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 893                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 894                 goto done;
 895         }
 896
 897         /* start any status interrupt transfer */
 898         if (dev->interrupt) {
 899                 retval = usbnet_status_start(dev, GFP_KERNEL);
 900                 if (retval < 0) {
 901                         netif_err(dev, ifup, dev->net,
 902                                   "intr submit %d\n", retval);
 903                         goto done;
 904                 }
 905         }
 906
 907         set_bit(EVENT_DEV_OPEN, &dev->flags);
 908         netif_start_queue (net);
 909         netif_info(dev, ifup, dev->net,
 910                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 911                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 912                    dev->net->mtu,
 913                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 914                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 915                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 916                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 917                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 918                    "simple");
 919
 920         /* reset rx error state */
 921         dev->pkt_cnt = 0;
 922         dev->pkt_err = 0;
 923         clear_bit(EVENT_RX_KILL, &dev->flags);
 924
 925         // delay posting reads until we're fully open
 926         tasklet_schedule (&dev->bh);
 927         if (info->manage_power) {
 928                 retval = info->manage_power(dev, 1);
 929                 if (retval < 0) {
 930                         retval = 0;
 931                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 932                 } else {
 933                         usb_autopm_put_interface(dev->intf);
 934                 }
 935         }
 936         return retval;
 937 done:
 938         usb_autopm_put_interface(dev->intf);
 939 done_nopm:
 940         return retval;
 941 }
 942 EXPORT_SYMBOL_GPL(usbnet_open);
 943
 944 /*-------------------------------------------------------------------------*/
 945
 946 /* ethtool methods; minidrivers may need to add some more, but
 947  * they'll probably want to use this base set.
 948  */
 949
 950 int usbnet_get_link_ksettings(struct net_device *net,
 951                               struct ethtool_link_ksettings *cmd)
 952 {
 953         struct usbnet *dev = netdev_priv(net);
 954
 955         if (!dev->mii.mdio_read)
 956                 return -EOPNOTSUPP;
 957
 958         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 959
 960         return 0;
 961 }
 962 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
 963
 964 int usbnet_set_link_ksettings(struct net_device *net,
 965                               const struct ethtool_link_ksettings *cmd)
 966 {
 967         struct usbnet *dev = netdev_priv(net);
 968         int retval;
 969
 970         if (!dev->mii.mdio_write)
 971                 return -EOPNOTSUPP;
 972
 973         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
 974
 975         /* link speed/duplex might have changed */
 976         if (dev->driver_info->link_reset)
 977                 dev->driver_info->link_reset(dev);
 978
 979         /* hard_mtu or rx_urb_size may change in link_reset() */
 980         usbnet_update_max_qlen(dev);
 981
 982         return retval;
 983 }
 984 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
 985
 986 void usbnet_get_stats64(struct net_device *net, struct rtnl_link_stats64 *stats)
 987 {
 988         struct usbnet *dev = netdev_priv(net);
 989         unsigned int start;
 990         int cpu;
 991
 992         netdev_stats_to_stats64(stats, &net->stats);
 993
 994         for_each_possible_cpu(cpu) {
 995                 struct pcpu_sw_netstats *stats64;
 996                 u64 rx_packets, rx_bytes;
 997                 u64 tx_packets, tx_bytes;
 998
 999                 stats64 = per_cpu_ptr(dev->stats64, cpu);
1000
1001                 do {
1002                         start = u64_stats_fetch_begin_irq(&stats64->syncp);
1003                         rx_packets = stats64->rx_packets;
1004                         rx_bytes = stats64->rx_bytes;
1005                         tx_packets = stats64->tx_packets;
1006                         tx_bytes = stats64->tx_bytes;
1007                 } while (u64_stats_fetch_retry_irq(&stats64->syncp, start));
1008
1009                 stats->rx_packets += rx_packets;
1010                 stats->rx_bytes += rx_bytes;
1011                 stats->tx_packets += tx_packets;
1012                 stats->tx_bytes += tx_bytes;
1013         }
1014 }
1015 EXPORT_SYMBOL_GPL(usbnet_get_stats64);
1016
1017 u32 usbnet_get_link (struct net_device *net)
1018 {
1019         struct usbnet *dev = netdev_priv(net);
1020
1021         /* If a check_connect is defined, return its result */
1022         if (dev->driver_info->check_connect)
1023                 return dev->driver_info->check_connect (dev) == 0;
1024
1025         /* if the device has mii operations, use those */
1026         if (dev->mii.mdio_read)
1027                 return mii_link_ok(&dev->mii);
1028
1029         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1030         return ethtool_op_get_link(net);
1031 }
1032 EXPORT_SYMBOL_GPL(usbnet_get_link);
1033
1034 int usbnet_nway_reset(struct net_device *net)
1035 {
1036         struct usbnet *dev = netdev_priv(net);
1037
1038         if (!dev->mii.mdio_write)
1039                 return -EOPNOTSUPP;
1040
1041         return mii_nway_restart(&dev->mii);
1042 }
1043 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1044
1045 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1046 {
1047         struct usbnet *dev = netdev_priv(net);
1048
1049         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1050         strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
1051         strlcpy (info->fw_version, dev->driver_info->description,
1052                 sizeof info->fw_version);
1053         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1054 }
1055 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1056
1057 u32 usbnet_get_msglevel (struct net_device *net)
1058 {
1059         struct usbnet *dev = netdev_priv(net);
1060
1061         return dev->msg_enable;
1062 }
1063 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1064
1065 void usbnet_set_msglevel (struct net_device *net, u32 level)
1066 {
1067         struct usbnet *dev = netdev_priv(net);
1068
1069         dev->msg_enable = level;
1070 }
1071 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1072
1073 /* drivers may override default ethtool_ops in their bind() routine */
1074 static const struct ethtool_ops usbnet_ethtool_ops = {
1075         .get_link               = usbnet_get_link,
1076         .nway_reset             = usbnet_nway_reset,
1077         .get_drvinfo            = usbnet_get_drvinfo,
1078         .get_msglevel           = usbnet_get_msglevel,
1079         .set_msglevel           = usbnet_set_msglevel,
1080         .get_ts_info            = ethtool_op_get_ts_info,
1081         .get_link_ksettings     = usbnet_get_link_ksettings,
1082         .set_link_ksettings     = usbnet_set_link_ksettings,
1083 };
1084
1085 /*-------------------------------------------------------------------------*/
1086
1087 static void __handle_link_change(struct usbnet *dev)
1088 {
1089         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1090                 return;
1091
1092         if (!netif_carrier_ok(dev->net)) {
1093                 /* kill URBs for reading packets to save bus bandwidth */
1094                 unlink_urbs(dev, &dev->rxq);
1095
1096                 /*
1097                  * tx_timeout will unlink URBs for sending packets and
1098                  * tx queue is stopped by netcore after link becomes off
1099                  */
1100         } else {
1101                 /* submitting URBs for reading packets */
1102                 tasklet_schedule(&dev->bh);
1103         }
1104
1105         /* hard_mtu or rx_urb_size may change during link change */
1106         usbnet_update_max_qlen(dev);
1107
1108         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1109 }
1110
1111 static void usbnet_set_rx_mode(struct net_device *net)
1112 {
1113         struct usbnet           *dev = netdev_priv(net);
1114
1115         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1116 }
1117
1118 static void __handle_set_rx_mode(struct usbnet *dev)
1119 {
1120         if (dev->driver_info->set_rx_mode)
1121                 (dev->driver_info->set_rx_mode)(dev);
1122
1123         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1124 }
1125
1126 /* work that cannot be done in interrupt context uses keventd.
1127  *
1128  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1129  * especially now that control transfers can be queued.
1130  */
1131 static void
1132 usbnet_deferred_kevent (struct work_struct *work)
1133 {
1134         struct usbnet           *dev =
1135                 container_of(work, struct usbnet, kevent);
1136         int                     status;
1137
1138         /* usb_clear_halt() needs a thread context */
1139         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1140                 unlink_urbs (dev, &dev->txq);
1141                 status = usb_autopm_get_interface(dev->intf);
1142                 if (status < 0)
1143                         goto fail_pipe;
1144                 status = usb_clear_halt (dev->udev, dev->out);
1145                 usb_autopm_put_interface(dev->intf);
1146                 if (status < 0 &&
1147                     status != -EPIPE &&
1148                     status != -ESHUTDOWN) {
1149                         if (netif_msg_tx_err (dev))
1150 fail_pipe:
1151                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1152                                            status);
1153                 } else {
1154                         clear_bit (EVENT_TX_HALT, &dev->flags);
1155                         if (status != -ESHUTDOWN)
1156                                 netif_wake_queue (dev->net);
1157                 }
1158         }
1159         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1160                 unlink_urbs (dev, &dev->rxq);
1161                 status = usb_autopm_get_interface(dev->intf);
1162                 if (status < 0)
1163                         goto fail_halt;
1164                 status = usb_clear_halt (dev->udev, dev->in);
1165                 usb_autopm_put_interface(dev->intf);
1166                 if (status < 0 &&
1167                     status != -EPIPE &&
1168                     status != -ESHUTDOWN) {
1169                         if (netif_msg_rx_err (dev))
1170 fail_halt:
1171                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1172                                            status);
1173                 } else {
1174                         clear_bit (EVENT_RX_HALT, &dev->flags);
1175                         tasklet_schedule (&dev->bh);
1176                 }
1177         }
1178
1179         /* tasklet could resubmit itself forever if memory is tight */
1180         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1181                 struct urb      *urb = NULL;
1182                 int resched = 1;
1183
1184                 if (netif_running (dev->net))
1185                         urb = usb_alloc_urb (0, GFP_KERNEL);
1186                 else
1187                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1188                 if (urb != NULL) {
1189                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1190                         status = usb_autopm_get_interface(dev->intf);
1191                         if (status < 0) {
1192                                 usb_free_urb(urb);
1193                                 goto fail_lowmem;
1194                         }
1195                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1196                                 resched = 0;
1197                         usb_autopm_put_interface(dev->intf);
1198 fail_lowmem:
1199                         if (resched)
1200                                 tasklet_schedule (&dev->bh);
1201                 }
1202         }
1203
1204         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1205                 const struct driver_info *info = dev->driver_info;
1206                 int                     retval = 0;
1207
1208                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1209                 status = usb_autopm_get_interface(dev->intf);
1210                 if (status < 0)
1211                         goto skip_reset;
1212                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1213                         usb_autopm_put_interface(dev->intf);
1214 skip_reset:
1215                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1216                                     retval,
1217                                     dev->udev->bus->bus_name,
1218                                     dev->udev->devpath,
1219                                     info->description);
1220                 } else {
1221                         usb_autopm_put_interface(dev->intf);
1222                 }
1223
1224                 /* handle link change from link resetting */
1225                 __handle_link_change(dev);
1226         }
1227
1228         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1229                 __handle_link_change(dev);
1230
1231         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1232                 __handle_set_rx_mode(dev);
1233
1234
1235         if (dev->flags)
1236                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1237 }
1238
1239 /*-------------------------------------------------------------------------*/
1240
1241 static void tx_complete (struct urb *urb)
1242 {
1243         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1244         struct skb_data         *entry = (struct skb_data *) skb->cb;
1245         struct usbnet           *dev = entry->dev;
1246
1247         if (urb->status == 0) {
1248                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1249                 unsigned long flags;
1250
1251                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1252                 stats64->tx_packets += entry->packets;
1253                 stats64->tx_bytes += entry->length;
1254                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1255         } else {
1256                 dev->net->stats.tx_errors++;
1257
1258                 switch (urb->status) {
1259                 case -EPIPE:
1260                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1261                         break;
1262
1263                 /* software-driven interface shutdown */
1264                 case -ECONNRESET:               // async unlink
1265                 case -ESHUTDOWN:                // hardware gone
1266                         break;
1267
1268                 /* like rx, tx gets controller i/o faults during hub_wq
1269                  * delays and so it uses the same throttling mechanism.
1270                  */
1271                 case -EPROTO:
1272                 case -ETIME:
1273                 case -EILSEQ:
1274                         usb_mark_last_busy(dev->udev);
1275                         if (!timer_pending (&dev->delay)) {
1276                                 mod_timer (&dev->delay,
1277                                         jiffies + THROTTLE_JIFFIES);
1278                                 netif_dbg(dev, link, dev->net,
1279                                           "tx throttle %d\n", urb->status);
1280                         }
1281                         netif_stop_queue (dev->net);
1282                         break;
1283                 default:
1284                         netif_dbg(dev, tx_err, dev->net,
1285                                   "tx err %d\n", entry->urb->status);
1286                         break;
1287                 }
1288         }
1289
1290         usb_autopm_put_interface_async(dev->intf);
1291         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1292 }
1293
1294 /*-------------------------------------------------------------------------*/
1295
1296 void usbnet_tx_timeout (struct net_device *net)
1297 {
1298         struct usbnet           *dev = netdev_priv(net);
1299
1300         unlink_urbs (dev, &dev->txq);
1301         tasklet_schedule (&dev->bh);
1302         /* this needs to be handled individually because the generic layer
1303          * doesn't know what is sufficient and could not restore private
1304          * information if a remedy of an unconditional reset were used.
1305          */
1306         if (dev->driver_info->recover)
1307                 (dev->driver_info->recover)(dev);
1308 }
1309 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1310
1311 /*-------------------------------------------------------------------------*/
1312
1313 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1314 {
1315         unsigned num_sgs, total_len = 0;
1316         int i, s = 0;
1317
1318         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1319         if (num_sgs == 1)
1320                 return 0;
1321
1322         /* reserve one for zero packet */
1323         urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1324                                 GFP_ATOMIC);
1325         if (!urb->sg)
1326                 return -ENOMEM;
1327
1328         urb->num_sgs = num_sgs;
1329         sg_init_table(urb->sg, urb->num_sgs + 1);
1330
1331         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1332         total_len += skb_headlen(skb);
1333
1334         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1335                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1336
1337                 total_len += skb_frag_size(f);
1338                 sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1339                             skb_frag_off(f));
1340         }
1341         urb->transfer_buffer_length = total_len;
1342
1343         return 1;
1344 }
1345
1346 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1347                                      struct net_device *net)
1348 {
1349         struct usbnet           *dev = netdev_priv(net);
1350         unsigned int                    length;
1351         struct urb              *urb = NULL;
1352         struct skb_data         *entry;
1353         const struct driver_info *info = dev->driver_info;
1354         unsigned long           flags;
1355         int retval;
1356
1357         if (skb)
1358                 skb_tx_timestamp(skb);
1359
1360         // some devices want funky USB-level framing, for
1361         // win32 driver (usually) and/or hardware quirks
1362         if (info->tx_fixup) {
1363                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1364                 if (!skb) {
1365                         /* packet collected; minidriver waiting for more */
1366                         if (info->flags & FLAG_MULTI_PACKET)
1367                                 goto not_drop;
1368                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1369                         goto drop;
1370                 }
1371         }
1372
1373         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1374                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1375                 goto drop;
1376         }
1377
1378         entry = (struct skb_data *) skb->cb;
1379         entry->urb = urb;
1380         entry->dev = dev;
1381
1382         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1383                         skb->data, skb->len, tx_complete, skb);
1384         if (dev->can_dma_sg) {
1385                 if (build_dma_sg(skb, urb) < 0)
1386                         goto drop;
1387         }
1388         length = urb->transfer_buffer_length;
1389
1390         /* don't assume the hardware handles USB_ZERO_PACKET
1391          * NOTE:  strictly conforming cdc-ether devices should expect
1392          * the ZLP here, but ignore the one-byte packet.
1393          * NOTE2: CDC NCM specification is different from CDC ECM when
1394          * handling ZLP/short packets, so cdc_ncm driver will make short
1395          * packet itself if needed.
1396          */
1397         if (length % dev->maxpacket == 0) {
1398                 if (!(info->flags & FLAG_SEND_ZLP)) {
1399                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1400                                 length++;
1401                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1402                                         skb->data[skb->len] = 0;
1403                                         __skb_put(skb, 1);
1404                                 } else if (urb->num_sgs)
1405                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1406                                                         dev->padding_pkt, 1);
1407                         }
1408                 } else
1409                         urb->transfer_flags |= URB_ZERO_PACKET;
1410         }
1411         urb->transfer_buffer_length = length;
1412
1413         if (info->flags & FLAG_MULTI_PACKET) {
1414                 /* Driver has set number of packets and a length delta.
1415                  * Calculate the complete length and ensure that it's
1416                  * positive.
1417                  */
1418                 entry->length += length;
1419                 if (WARN_ON_ONCE(entry->length <= 0))
1420                         entry->length = length;
1421         } else {
1422                 usbnet_set_skb_tx_stats(skb, 1, length);
1423         }
1424
1425         spin_lock_irqsave(&dev->txq.lock, flags);
1426         retval = usb_autopm_get_interface_async(dev->intf);
1427         if (retval < 0) {
1428                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1429                 goto drop;
1430         }
1431         if (netif_queue_stopped(net)) {
1432                 usb_autopm_put_interface_async(dev->intf);
1433                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1434                 goto drop;
1435         }
1436
1437 #ifdef CONFIG_PM
1438         /* if this triggers the device is still a sleep */
1439         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1440                 /* transmission will be done in resume */
1441                 usb_anchor_urb(urb, &dev->deferred);
1442                 /* no use to process more packets */
1443                 netif_stop_queue(net);
1444                 usb_put_urb(urb);
1445                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1446                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1447                 goto deferred;
1448         }
1449 #endif
1450
1451         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1452         case -EPIPE:
1453                 netif_stop_queue (net);
1454                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1455                 usb_autopm_put_interface_async(dev->intf);
1456                 break;
1457         default:
1458                 usb_autopm_put_interface_async(dev->intf);
1459                 netif_dbg(dev, tx_err, dev->net,
1460                           "tx: submit urb err %d\n", retval);
1461                 break;
1462         case 0:
1463                 netif_trans_update(net);
1464                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1465                 if (dev->txq.qlen >= TX_QLEN (dev))
1466                         netif_stop_queue (net);
1467         }
1468         spin_unlock_irqrestore (&dev->txq.lock, flags);
1469
1470         if (retval) {
1471                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1472 drop:
1473                 dev->net->stats.tx_dropped++;
1474 not_drop:
1475                 if (skb)
1476                         dev_kfree_skb_any (skb);
1477                 if (urb) {
1478                         kfree(urb->sg);
1479                         usb_free_urb(urb);
1480                 }
1481         } else
1482                 netif_dbg(dev, tx_queued, dev->net,
1483                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1484 #ifdef CONFIG_PM
1485 deferred:
1486 #endif
1487         return NETDEV_TX_OK;
1488 }
1489 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1490
1491 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1492 {
1493         struct urb      *urb;
1494         int             i;
1495         int             ret = 0;
1496
1497         /* don't refill the queue all at once */
1498         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1499                 urb = usb_alloc_urb(0, flags);
1500                 if (urb != NULL) {
1501                         ret = rx_submit(dev, urb, flags);
1502                         if (ret)
1503                                 goto err;
1504                 } else {
1505                         ret = -ENOMEM;
1506                         goto err;
1507                 }
1508         }
1509 err:
1510         return ret;
1511 }
1512
1513 /*-------------------------------------------------------------------------*/
1514
1515 // tasklet (work deferred from completions, in_irq) or timer
1516
1517 static void usbnet_bh (struct timer_list *t)
1518 {
1519         struct usbnet           *dev = from_timer(dev, t, delay);
1520         struct sk_buff          *skb;
1521         struct skb_data         *entry;
1522
1523         while ((skb = skb_dequeue (&dev->done))) {
1524                 entry = (struct skb_data *) skb->cb;
1525                 switch (entry->state) {
1526                 case rx_done:
1527                         entry->state = rx_cleanup;
1528                         rx_process (dev, skb);
1529                         continue;
1530                 case tx_done:
1531                         kfree(entry->urb->sg);
1532                         /* fall through */
1533                 case rx_cleanup:
1534                         usb_free_urb (entry->urb);
1535                         dev_kfree_skb (skb);
1536                         continue;
1537                 default:
1538                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1539                 }
1540         }
1541
1542         /* restart RX again after disabling due to high error rate */
1543         clear_bit(EVENT_RX_KILL, &dev->flags);
1544
1545         /* waiting for all pending urbs to complete?
1546          * only then can we forgo submitting anew
1547          */
1548         if (waitqueue_active(&dev->wait)) {
1549                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1550                         wake_up_all(&dev->wait);
1551
1552         // or are we maybe short a few urbs?
1553         } else if (netif_running (dev->net) &&
1554                    netif_device_present (dev->net) &&
1555                    netif_carrier_ok(dev->net) &&
1556                    !timer_pending(&dev->delay) &&
1557                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1558                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1559                 int     temp = dev->rxq.qlen;
1560
1561                 if (temp < RX_QLEN(dev)) {
1562                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1563                                 return;
1564                         if (temp != dev->rxq.qlen)
1565                                 netif_dbg(dev, link, dev->net,
1566                                           "rxqlen %d --> %d\n",
1567                                           temp, dev->rxq.qlen);
1568                         if (dev->rxq.qlen < RX_QLEN(dev))
1569                                 tasklet_schedule (&dev->bh);
1570                 }
1571                 if (dev->txq.qlen < TX_QLEN (dev))
1572                         netif_wake_queue (dev->net);
1573         }
1574 }
1575
1576
1577 /*-------------------------------------------------------------------------
1578  *
1579  * USB Device Driver support
1580  *
1581  *-------------------------------------------------------------------------*/
1582
1583 // precondition: never called in_interrupt
1584
1585 void usbnet_disconnect (struct usb_interface *intf)
1586 {
1587         struct usbnet           *dev;
1588         struct usb_device       *xdev;
1589         struct net_device       *net;
1590
1591         dev = usb_get_intfdata(intf);
1592         usb_set_intfdata(intf, NULL);
1593         if (!dev)
1594                 return;
1595
1596         xdev = interface_to_usbdev (intf);
1597
1598         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1599                    intf->dev.driver->name,
1600                    xdev->bus->bus_name, xdev->devpath,
1601                    dev->driver_info->description);
1602
1603         net = dev->net;
1604         unregister_netdev (net);
1605
1606         cancel_work_sync(&dev->kevent);
1607
1608         usb_scuttle_anchored_urbs(&dev->deferred);
1609
1610         if (dev->driver_info->unbind)
1611                 dev->driver_info->unbind (dev, intf);
1612
1613         usb_kill_urb(dev->interrupt);
1614         usb_free_urb(dev->interrupt);
1615         kfree(dev->padding_pkt);
1616
1617         free_percpu(dev->stats64);
1618         free_netdev(net);
1619 }
1620 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1621
1622 static const struct net_device_ops usbnet_netdev_ops = {
1623         .ndo_open               = usbnet_open,
1624         .ndo_stop               = usbnet_stop,
1625         .ndo_start_xmit         = usbnet_start_xmit,
1626         .ndo_tx_timeout         = usbnet_tx_timeout,
1627         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1628         .ndo_change_mtu         = usbnet_change_mtu,
1629         .ndo_get_stats64        = usbnet_get_stats64,
1630         .ndo_set_mac_address    = eth_mac_addr,
1631         .ndo_validate_addr      = eth_validate_addr,
1632 };
1633
1634 /*-------------------------------------------------------------------------*/
1635
1636 // precondition: never called in_interrupt
1637
1638 static struct device_type wlan_type = {
1639         .name   = "wlan",
1640 };
1641
1642 static struct device_type wwan_type = {
1643         .name   = "wwan",
1644 };
1645
1646 int
1647 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1648 {
1649         struct usbnet                   *dev;
1650         struct net_device               *net;
1651         struct usb_host_interface       *interface;
1652         const struct driver_info        *info;
1653         struct usb_device               *xdev;
1654         int                             status;
1655         const char                      *name;
1656         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1657
1658         /* usbnet already took usb runtime pm, so have to enable the feature
1659          * for usb interface, otherwise usb_autopm_get_interface may return
1660          * failure if RUNTIME_PM is enabled.
1661          */
1662         if (!driver->supports_autosuspend) {
1663                 driver->supports_autosuspend = 1;
1664                 pm_runtime_enable(&udev->dev);
1665         }
1666
1667         name = udev->dev.driver->name;
1668         info = (const struct driver_info *) prod->driver_info;
1669         if (!info) {
1670                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1671                 return -ENODEV;
1672         }
1673         xdev = interface_to_usbdev (udev);
1674         interface = udev->cur_altsetting;
1675
1676         status = -ENOMEM;
1677
1678         // set up our own records
1679         net = alloc_etherdev(sizeof(*dev));
1680         if (!net)
1681                 goto out;
1682
1683         /* netdev_printk() needs this so do it as early as possible */
1684         SET_NETDEV_DEV(net, &udev->dev);
1685
1686         dev = netdev_priv(net);
1687         dev->udev = xdev;
1688         dev->intf = udev;
1689         dev->driver_info = info;
1690         dev->driver_name = name;
1691
1692         dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1693         if (!dev->stats64)
1694                 goto out0;
1695
1696         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1697                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1698         init_waitqueue_head(&dev->wait);
1699         skb_queue_head_init (&dev->rxq);
1700         skb_queue_head_init (&dev->txq);
1701         skb_queue_head_init (&dev->done);
1702         skb_queue_head_init(&dev->rxq_pause);
1703         dev->bh.func = (void (*)(unsigned long))usbnet_bh;
1704         dev->bh.data = (unsigned long)&dev->delay;
1705         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1706         init_usb_anchor(&dev->deferred);
1707         timer_setup(&dev->delay, usbnet_bh, 0);
1708         mutex_init (&dev->phy_mutex);
1709         mutex_init(&dev->interrupt_mutex);
1710         dev->interrupt_count = 0;
1711
1712         dev->net = net;
1713         strcpy (net->name, "usb%d");
1714         memcpy (net->dev_addr, node_id, sizeof node_id);
1715
1716         /* rx and tx sides can use different message sizes;
1717          * bind() should set rx_urb_size in that case.
1718          */
1719         dev->hard_mtu = net->mtu + net->hard_header_len;
1720         net->min_mtu = 0;
1721         net->max_mtu = ETH_MAX_MTU;
1722
1723         net->netdev_ops = &usbnet_netdev_ops;
1724         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1725         net->ethtool_ops = &usbnet_ethtool_ops;
1726
1727         // allow device-specific bind/init procedures
1728         // NOTE net->name still not usable ...
1729         if (info->bind) {
1730                 status = info->bind (dev, udev);
1731                 if (status < 0)
1732                         goto out1;
1733
1734                 // heuristic:  "usb%d" for links we know are two-host,
1735                 // else "eth%d" when there's reasonable doubt.  userspace
1736                 // can rename the link if it knows better.
1737                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1738                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1739                      (net->dev_addr [0] & 0x02) == 0))
1740                         strcpy (net->name, "eth%d");
1741                 /* WLAN devices should always be named "wlan%d" */
1742                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1743                         strcpy(net->name, "wlan%d");
1744                 /* WWAN devices should always be named "wwan%d" */
1745                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1746                         strcpy(net->name, "wwan%d");
1747
1748                 /* devices that cannot do ARP */
1749                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1750                         net->flags |= IFF_NOARP;
1751
1752                 /* maybe the remote can't receive an Ethernet MTU */
1753                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1754                         net->mtu = dev->hard_mtu - net->hard_header_len;
1755         } else if (!info->in || !info->out)
1756                 status = usbnet_get_endpoints (dev, udev);
1757         else {
1758                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1759                 dev->out = usb_sndbulkpipe (xdev, info->out);
1760                 if (!(info->flags & FLAG_NO_SETINT))
1761                         status = usb_set_interface (xdev,
1762                                 interface->desc.bInterfaceNumber,
1763                                 interface->desc.bAlternateSetting);
1764                 else
1765                         status = 0;
1766
1767         }
1768         if (status >= 0 && dev->status)
1769                 status = init_status (dev, udev);
1770         if (status < 0)
1771                 goto out3;
1772
1773         if (!dev->rx_urb_size)
1774                 dev->rx_urb_size = dev->hard_mtu;
1775         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1776
1777         /* let userspace know we have a random address */
1778         if (ether_addr_equal(net->dev_addr, node_id))
1779                 net->addr_assign_type = NET_ADDR_RANDOM;
1780
1781         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1782                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1783         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1784                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1785
1786         /* initialize max rx_qlen and tx_qlen */
1787         usbnet_update_max_qlen(dev);
1788
1789         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1790                 !(info->flags & FLAG_MULTI_PACKET)) {
1791                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1792                 if (!dev->padding_pkt) {
1793                         status = -ENOMEM;
1794                         goto out4;
1795                 }
1796         }
1797
1798         status = register_netdev (net);
1799         if (status)
1800                 goto out5;
1801         netif_info(dev, probe, dev->net,
1802                    "register '%s' at usb-%s-%s, %s, %pM\n",
1803                    udev->dev.driver->name,
1804                    xdev->bus->bus_name, xdev->devpath,
1805                    dev->driver_info->description,
1806                    net->dev_addr);
1807
1808         // ok, it's ready to go.
1809         usb_set_intfdata (udev, dev);
1810
1811         netif_device_attach (net);
1812
1813         if (dev->driver_info->flags & FLAG_LINK_INTR)
1814                 usbnet_link_change(dev, 0, 0);
1815
1816         return 0;
1817
1818 out5:
1819         kfree(dev->padding_pkt);
1820 out4:
1821         usb_free_urb(dev->interrupt);
1822 out3:
1823         if (info->unbind)
1824                 info->unbind (dev, udev);
1825 out1:
1826         /* subdrivers must undo all they did in bind() if they
1827          * fail it, but we may fail later and a deferred kevent
1828          * may trigger an error resubmitting itself and, worse,
1829          * schedule a timer. So we kill it all just in case.
1830          */
1831         cancel_work_sync(&dev->kevent);
1832         del_timer_sync(&dev->delay);
1833         free_percpu(dev->stats64);
1834 out0:
1835         free_netdev(net);
1836 out:
1837         return status;
1838 }
1839 EXPORT_SYMBOL_GPL(usbnet_probe);
1840
1841 /*-------------------------------------------------------------------------*/
1842
1843 /*
1844  * suspend the whole driver as soon as the first interface is suspended
1845  * resume only when the last interface is resumed
1846  */
1847
1848 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1849 {
1850         struct usbnet           *dev = usb_get_intfdata(intf);
1851
1852         if (!dev->suspend_count++) {
1853                 spin_lock_irq(&dev->txq.lock);
1854                 /* don't autosuspend while transmitting */
1855                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1856                         dev->suspend_count--;
1857                         spin_unlock_irq(&dev->txq.lock);
1858                         return -EBUSY;
1859                 } else {
1860                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1861                         spin_unlock_irq(&dev->txq.lock);
1862                 }
1863                 /*
1864                  * accelerate emptying of the rx and queues, to avoid
1865                  * having everything error out.
1866                  */
1867                 netif_device_detach (dev->net);
1868                 usbnet_terminate_urbs(dev);
1869                 __usbnet_status_stop_force(dev);
1870
1871                 /*
1872                  * reattach so runtime management can use and
1873                  * wake the device
1874                  */
1875                 netif_device_attach (dev->net);
1876         }
1877         return 0;
1878 }
1879 EXPORT_SYMBOL_GPL(usbnet_suspend);
1880
1881 int usbnet_resume (struct usb_interface *intf)
1882 {
1883         struct usbnet           *dev = usb_get_intfdata(intf);
1884         struct sk_buff          *skb;
1885         struct urb              *res;
1886         int                     retval;
1887
1888         if (!--dev->suspend_count) {
1889                 /* resume interrupt URB if it was previously submitted */
1890                 __usbnet_status_start_force(dev, GFP_NOIO);
1891
1892                 spin_lock_irq(&dev->txq.lock);
1893                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1894
1895                         skb = (struct sk_buff *)res->context;
1896                         retval = usb_submit_urb(res, GFP_ATOMIC);
1897                         if (retval < 0) {
1898                                 dev_kfree_skb_any(skb);
1899                                 kfree(res->sg);
1900                                 usb_free_urb(res);
1901                                 usb_autopm_put_interface_async(dev->intf);
1902                         } else {
1903                                 netif_trans_update(dev->net);
1904                                 __skb_queue_tail(&dev->txq, skb);
1905                         }
1906                 }
1907
1908                 smp_mb();
1909                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1910                 spin_unlock_irq(&dev->txq.lock);
1911
1912                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1913                         /* handle remote wakeup ASAP
1914                          * we cannot race against stop
1915                          */
1916                         if (netif_device_present(dev->net) &&
1917                                 !timer_pending(&dev->delay) &&
1918                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1919                                         rx_alloc_submit(dev, GFP_NOIO);
1920
1921                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1922                                 netif_tx_wake_all_queues(dev->net);
1923                         tasklet_schedule (&dev->bh);
1924                 }
1925         }
1926
1927         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1928                 usb_autopm_get_interface_no_resume(intf);
1929
1930         return 0;
1931 }
1932 EXPORT_SYMBOL_GPL(usbnet_resume);
1933
1934 /*
1935  * Either a subdriver implements manage_power, then it is assumed to always
1936  * be ready to be suspended or it reports the readiness to be suspended
1937  * explicitly
1938  */
1939 void usbnet_device_suggests_idle(struct usbnet *dev)
1940 {
1941         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1942                 dev->intf->needs_remote_wakeup = 1;
1943                 usb_autopm_put_interface_async(dev->intf);
1944         }
1945 }
1946 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1947
1948 /*
1949  * For devices that can do without special commands
1950  */
1951 int usbnet_manage_power(struct usbnet *dev, int on)
1952 {
1953         dev->intf->needs_remote_wakeup = on;
1954         return 0;
1955 }
1956 EXPORT_SYMBOL(usbnet_manage_power);
1957
1958 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1959 {
1960         /* update link after link is reseted */
1961         if (link && !need_reset)
1962                 netif_carrier_on(dev->net);
1963         else
1964                 netif_carrier_off(dev->net);
1965
1966         if (need_reset && link)
1967                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1968         else
1969                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1970 }
1971 EXPORT_SYMBOL(usbnet_link_change);
1972
1973 /*-------------------------------------------------------------------------*/
1974 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1975                              u16 value, u16 index, void *data, u16 size)
1976 {
1977         void *buf = NULL;
1978         int err = -ENOMEM;
1979
1980         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1981                    " value=0x%04x index=0x%04x size=%d\n",
1982                    cmd, reqtype, value, index, size);
1983
1984         if (size) {
1985                 buf = kmalloc(size, GFP_KERNEL);
1986                 if (!buf)
1987                         goto out;
1988         }
1989
1990         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1991                               cmd, reqtype, value, index, buf, size,
1992                               USB_CTRL_GET_TIMEOUT);
1993         if (err > 0 && err <= size) {
1994         if (data)
1995             memcpy(data, buf, err);
1996         else
1997             netdev_dbg(dev->net,
1998                 "Huh? Data requested but thrown away.\n");
1999     }
2000         kfree(buf);
2001 out:
2002         return err;
2003 }
2004
2005 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2006                               u16 value, u16 index, const void *data,
2007                               u16 size)
2008 {
2009         void *buf = NULL;
2010         int err = -ENOMEM;
2011
2012         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2013                    " value=0x%04x index=0x%04x size=%d\n",
2014                    cmd, reqtype, value, index, size);
2015
2016         if (data) {
2017                 buf = kmemdup(data, size, GFP_KERNEL);
2018                 if (!buf)
2019                         goto out;
2020         } else {
2021         if (size) {
2022             WARN_ON_ONCE(1);
2023             err = -EINVAL;
2024             goto out;
2025         }
2026     }
2027
2028         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2029                               cmd, reqtype, value, index, buf, size,
2030                               USB_CTRL_SET_TIMEOUT);
2031         kfree(buf);
2032
2033 out:
2034         return err;
2035 }
2036
2037 /*
2038  * The function can't be called inside suspend/resume callback,
2039  * otherwise deadlock will be caused.
2040  */
2041 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2042                     u16 value, u16 index, void *data, u16 size)
2043 {
2044         int ret;
2045
2046         if (usb_autopm_get_interface(dev->intf) < 0)
2047                 return -ENODEV;
2048         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2049                                 data, size);
2050         usb_autopm_put_interface(dev->intf);
2051         return ret;
2052 }
2053 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2054
2055 /*
2056  * The function can't be called inside suspend/resume callback,
2057  * otherwise deadlock will be caused.
2058  */
2059 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2060                      u16 value, u16 index, const void *data, u16 size)
2061 {
2062         int ret;
2063
2064         if (usb_autopm_get_interface(dev->intf) < 0)
2065                 return -ENODEV;
2066         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2067                                  data, size);
2068         usb_autopm_put_interface(dev->intf);
2069         return ret;
2070 }
2071 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2072
2073 /*
2074  * The function can be called inside suspend/resume callback safely
2075  * and should only be called by suspend/resume callback generally.
2076  */
2077 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2078                           u16 value, u16 index, void *data, u16 size)
2079 {
2080         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2081                                  data, size);
2082 }
2083 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2084
2085 /*
2086  * The function can be called inside suspend/resume callback safely
2087  * and should only be called by suspend/resume callback generally.
2088  */
2089 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2090                           u16 value, u16 index, const void *data,
2091                           u16 size)
2092 {
2093         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2094                                   data, size);
2095 }
2096 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2097
2098 static void usbnet_async_cmd_cb(struct urb *urb)
2099 {
2100         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2101         int status = urb->status;
2102
2103         if (status < 0)
2104                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2105                         __func__, status);
2106
2107         kfree(req);
2108         usb_free_urb(urb);
2109 }
2110
2111 /*
2112  * The caller must make sure that device can't be put into suspend
2113  * state until the control URB completes.
2114  */
2115 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2116                            u16 value, u16 index, const void *data, u16 size)
2117 {
2118         struct usb_ctrlrequest *req = NULL;
2119         struct urb *urb;
2120         int err = -ENOMEM;
2121         void *buf = NULL;
2122
2123         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2124                    " value=0x%04x index=0x%04x size=%d\n",
2125                    cmd, reqtype, value, index, size);
2126
2127         urb = usb_alloc_urb(0, GFP_ATOMIC);
2128         if (!urb)
2129                 goto fail;
2130
2131         if (data) {
2132                 buf = kmemdup(data, size, GFP_ATOMIC);
2133                 if (!buf) {
2134                         netdev_err(dev->net, "Error allocating buffer"
2135                                    " in %s!\n", __func__);
2136                         goto fail_free;
2137                 }
2138         }
2139
2140         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2141         if (!req)
2142                 goto fail_free_buf;
2143
2144         req->bRequestType = reqtype;
2145         req->bRequest = cmd;
2146         req->wValue = cpu_to_le16(value);
2147         req->wIndex = cpu_to_le16(index);
2148         req->wLength = cpu_to_le16(size);
2149
2150         usb_fill_control_urb(urb, dev->udev,
2151                              usb_sndctrlpipe(dev->udev, 0),
2152                              (void *)req, buf, size,
2153                              usbnet_async_cmd_cb, req);
2154         urb->transfer_flags |= URB_FREE_BUFFER;
2155
2156         err = usb_submit_urb(urb, GFP_ATOMIC);
2157         if (err < 0) {
2158                 netdev_err(dev->net, "Error submitting the control"
2159                            " message: status=%d\n", err);
2160                 goto fail_free;
2161         }
2162         return 0;
2163
2164 fail_free_buf:
2165         kfree(buf);
2166 fail_free:
2167         kfree(req);
2168         usb_free_urb(urb);
2169 fail:
2170         return err;
2171
2172 }
2173 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2174 /*-------------------------------------------------------------------------*/
2175
2176 static int __init usbnet_init(void)
2177 {
2178         /* Compiler should optimize this out. */
2179         BUILD_BUG_ON(
2180                 FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2181
2182         eth_random_addr(node_id);
2183         return 0;
2184 }
2185 module_init(usbnet_init);
2186
2187 static void __exit usbnet_exit(void)
2188 {
2189 }
2190 module_exit(usbnet_exit);
2191
2192 MODULE_AUTHOR("David Brownell");
2193 MODULE_DESCRIPTION("USB network driver framework");
2194 MODULE_LICENSE("GPL");