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 <[email protected]>
   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 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 EXPORT_SYMBOL_GPL(usbnet_set_rx_mode);
1118
1119 static void __handle_set_rx_mode(struct usbnet *dev)
1120 {
1121         if (dev->driver_info->set_rx_mode)
1122                 (dev->driver_info->set_rx_mode)(dev);
1123
1124         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1125 }
1126
1127 /* work that cannot be done in interrupt context uses keventd.
1128  *
1129  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1130  * especially now that control transfers can be queued.
1131  */
1132 static void
1133 usbnet_deferred_kevent (struct work_struct *work)
1134 {
1135         struct usbnet           *dev =
1136                 container_of(work, struct usbnet, kevent);
1137         int                     status;
1138
1139         /* usb_clear_halt() needs a thread context */
1140         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1141                 unlink_urbs (dev, &dev->txq);
1142                 status = usb_autopm_get_interface(dev->intf);
1143                 if (status < 0)
1144                         goto fail_pipe;
1145                 status = usb_clear_halt (dev->udev, dev->out);
1146                 usb_autopm_put_interface(dev->intf);
1147                 if (status < 0 &&
1148                     status != -EPIPE &&
1149                     status != -ESHUTDOWN) {
1150                         if (netif_msg_tx_err (dev))
1151 fail_pipe:
1152                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1153                                            status);
1154                 } else {
1155                         clear_bit (EVENT_TX_HALT, &dev->flags);
1156                         if (status != -ESHUTDOWN)
1157                                 netif_wake_queue (dev->net);
1158                 }
1159         }
1160         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1161                 unlink_urbs (dev, &dev->rxq);
1162                 status = usb_autopm_get_interface(dev->intf);
1163                 if (status < 0)
1164                         goto fail_halt;
1165                 status = usb_clear_halt (dev->udev, dev->in);
1166                 usb_autopm_put_interface(dev->intf);
1167                 if (status < 0 &&
1168                     status != -EPIPE &&
1169                     status != -ESHUTDOWN) {
1170                         if (netif_msg_rx_err (dev))
1171 fail_halt:
1172                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1173                                            status);
1174                 } else {
1175                         clear_bit (EVENT_RX_HALT, &dev->flags);
1176                         tasklet_schedule (&dev->bh);
1177                 }
1178         }
1179
1180         /* tasklet could resubmit itself forever if memory is tight */
1181         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1182                 struct urb      *urb = NULL;
1183                 int resched = 1;
1184
1185                 if (netif_running (dev->net))
1186                         urb = usb_alloc_urb (0, GFP_KERNEL);
1187                 else
1188                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1189                 if (urb != NULL) {
1190                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1191                         status = usb_autopm_get_interface(dev->intf);
1192                         if (status < 0) {
1193                                 usb_free_urb(urb);
1194                                 goto fail_lowmem;
1195                         }
1196                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1197                                 resched = 0;
1198                         usb_autopm_put_interface(dev->intf);
1199 fail_lowmem:
1200                         if (resched)
1201                                 tasklet_schedule (&dev->bh);
1202                 }
1203         }
1204
1205         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1206                 const struct driver_info *info = dev->driver_info;
1207                 int                     retval = 0;
1208
1209                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1210                 status = usb_autopm_get_interface(dev->intf);
1211                 if (status < 0)
1212                         goto skip_reset;
1213                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1214                         usb_autopm_put_interface(dev->intf);
1215 skip_reset:
1216                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1217                                     retval,
1218                                     dev->udev->bus->bus_name,
1219                                     dev->udev->devpath,
1220                                     info->description);
1221                 } else {
1222                         usb_autopm_put_interface(dev->intf);
1223                 }
1224
1225                 /* handle link change from link resetting */
1226                 __handle_link_change(dev);
1227         }
1228
1229         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1230                 __handle_link_change(dev);
1231
1232         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1233                 __handle_set_rx_mode(dev);
1234
1235
1236         if (dev->flags)
1237                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1238 }
1239
1240 /*-------------------------------------------------------------------------*/
1241
1242 static void tx_complete (struct urb *urb)
1243 {
1244         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1245         struct skb_data         *entry = (struct skb_data *) skb->cb;
1246         struct usbnet           *dev = entry->dev;
1247
1248         if (urb->status == 0) {
1249                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->stats64);
1250                 unsigned long flags;
1251
1252                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1253                 stats64->tx_packets += entry->packets;
1254                 stats64->tx_bytes += entry->length;
1255                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1256         } else {
1257                 dev->net->stats.tx_errors++;
1258
1259                 switch (urb->status) {
1260                 case -EPIPE:
1261                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1262                         break;
1263
1264                 /* software-driven interface shutdown */
1265                 case -ECONNRESET:               // async unlink
1266                 case -ESHUTDOWN:                // hardware gone
1267                         break;
1268
1269                 /* like rx, tx gets controller i/o faults during hub_wq
1270                  * delays and so it uses the same throttling mechanism.
1271                  */
1272                 case -EPROTO:
1273                 case -ETIME:
1274                 case -EILSEQ:
1275                         usb_mark_last_busy(dev->udev);
1276                         if (!timer_pending (&dev->delay)) {
1277                                 mod_timer (&dev->delay,
1278                                         jiffies + THROTTLE_JIFFIES);
1279                                 netif_dbg(dev, link, dev->net,
1280                                           "tx throttle %d\n", urb->status);
1281                         }
1282                         netif_stop_queue (dev->net);
1283                         break;
1284                 default:
1285                         netif_dbg(dev, tx_err, dev->net,
1286                                   "tx err %d\n", entry->urb->status);
1287                         break;
1288                 }
1289         }
1290
1291         usb_autopm_put_interface_async(dev->intf);
1292         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1293 }
1294
1295 /*-------------------------------------------------------------------------*/
1296
1297 void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue)
1298 {
1299         struct usbnet           *dev = netdev_priv(net);
1300
1301         unlink_urbs (dev, &dev->txq);
1302         tasklet_schedule (&dev->bh);
1303         /* this needs to be handled individually because the generic layer
1304          * doesn't know what is sufficient and could not restore private
1305          * information if a remedy of an unconditional reset were used.
1306          */
1307         if (dev->driver_info->recover)
1308                 (dev->driver_info->recover)(dev);
1309 }
1310 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1311
1312 /*-------------------------------------------------------------------------*/
1313
1314 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1315 {
1316         unsigned num_sgs, total_len = 0;
1317         int i, s = 0;
1318
1319         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1320         if (num_sgs == 1)
1321                 return 0;
1322
1323         /* reserve one for zero packet */
1324         urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1325                                 GFP_ATOMIC);
1326         if (!urb->sg)
1327                 return -ENOMEM;
1328
1329         urb->num_sgs = num_sgs;
1330         sg_init_table(urb->sg, urb->num_sgs + 1);
1331
1332         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1333         total_len += skb_headlen(skb);
1334
1335         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1336                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1337
1338                 total_len += skb_frag_size(f);
1339                 sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1340                             skb_frag_off(f));
1341         }
1342         urb->transfer_buffer_length = total_len;
1343
1344         return 1;
1345 }
1346
1347 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1348                                      struct net_device *net)
1349 {
1350         struct usbnet           *dev = netdev_priv(net);
1351         unsigned int                    length;
1352         struct urb              *urb = NULL;
1353         struct skb_data         *entry;
1354         const struct driver_info *info = dev->driver_info;
1355         unsigned long           flags;
1356         int retval;
1357
1358         if (skb)
1359                 skb_tx_timestamp(skb);
1360
1361         // some devices want funky USB-level framing, for
1362         // win32 driver (usually) and/or hardware quirks
1363         if (info->tx_fixup) {
1364                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1365                 if (!skb) {
1366                         /* packet collected; minidriver waiting for more */
1367                         if (info->flags & FLAG_MULTI_PACKET)
1368                                 goto not_drop;
1369                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1370                         goto drop;
1371                 }
1372         }
1373
1374         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1375                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1376                 goto drop;
1377         }
1378
1379         entry = (struct skb_data *) skb->cb;
1380         entry->urb = urb;
1381         entry->dev = dev;
1382
1383         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1384                         skb->data, skb->len, tx_complete, skb);
1385         if (dev->can_dma_sg) {
1386                 if (build_dma_sg(skb, urb) < 0)
1387                         goto drop;
1388         }
1389         length = urb->transfer_buffer_length;
1390
1391         /* don't assume the hardware handles USB_ZERO_PACKET
1392          * NOTE:  strictly conforming cdc-ether devices should expect
1393          * the ZLP here, but ignore the one-byte packet.
1394          * NOTE2: CDC NCM specification is different from CDC ECM when
1395          * handling ZLP/short packets, so cdc_ncm driver will make short
1396          * packet itself if needed.
1397          */
1398         if (length % dev->maxpacket == 0) {
1399                 if (!(info->flags & FLAG_SEND_ZLP)) {
1400                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1401                                 length++;
1402                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1403                                         skb->data[skb->len] = 0;
1404                                         __skb_put(skb, 1);
1405                                 } else if (urb->num_sgs)
1406                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1407                                                         dev->padding_pkt, 1);
1408                         }
1409                 } else
1410                         urb->transfer_flags |= URB_ZERO_PACKET;
1411         }
1412         urb->transfer_buffer_length = length;
1413
1414         if (info->flags & FLAG_MULTI_PACKET) {
1415                 /* Driver has set number of packets and a length delta.
1416                  * Calculate the complete length and ensure that it's
1417                  * positive.
1418                  */
1419                 entry->length += length;
1420                 if (WARN_ON_ONCE(entry->length <= 0))
1421                         entry->length = length;
1422         } else {
1423                 usbnet_set_skb_tx_stats(skb, 1, length);
1424         }
1425
1426         spin_lock_irqsave(&dev->txq.lock, flags);
1427         retval = usb_autopm_get_interface_async(dev->intf);
1428         if (retval < 0) {
1429                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1430                 goto drop;
1431         }
1432         if (netif_queue_stopped(net)) {
1433                 usb_autopm_put_interface_async(dev->intf);
1434                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1435                 goto drop;
1436         }
1437
1438 #ifdef CONFIG_PM
1439         /* if this triggers the device is still a sleep */
1440         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1441                 /* transmission will be done in resume */
1442                 usb_anchor_urb(urb, &dev->deferred);
1443                 /* no use to process more packets */
1444                 netif_stop_queue(net);
1445                 usb_put_urb(urb);
1446                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1447                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1448                 goto deferred;
1449         }
1450 #endif
1451
1452         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1453         case -EPIPE:
1454                 netif_stop_queue (net);
1455                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1456                 usb_autopm_put_interface_async(dev->intf);
1457                 break;
1458         default:
1459                 usb_autopm_put_interface_async(dev->intf);
1460                 netif_dbg(dev, tx_err, dev->net,
1461                           "tx: submit urb err %d\n", retval);
1462                 break;
1463         case 0:
1464                 netif_trans_update(net);
1465                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1466                 if (dev->txq.qlen >= TX_QLEN (dev))
1467                         netif_stop_queue (net);
1468         }
1469         spin_unlock_irqrestore (&dev->txq.lock, flags);
1470
1471         if (retval) {
1472                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1473 drop:
1474                 dev->net->stats.tx_dropped++;
1475 not_drop:
1476                 if (skb)
1477                         dev_kfree_skb_any (skb);
1478                 if (urb) {
1479                         kfree(urb->sg);
1480                         usb_free_urb(urb);
1481                 }
1482         } else
1483                 netif_dbg(dev, tx_queued, dev->net,
1484                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1485 #ifdef CONFIG_PM
1486 deferred:
1487 #endif
1488         return NETDEV_TX_OK;
1489 }
1490 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1491
1492 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1493 {
1494         struct urb      *urb;
1495         int             i;
1496         int             ret = 0;
1497
1498         /* don't refill the queue all at once */
1499         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1500                 urb = usb_alloc_urb(0, flags);
1501                 if (urb != NULL) {
1502                         ret = rx_submit(dev, urb, flags);
1503                         if (ret)
1504                                 goto err;
1505                 } else {
1506                         ret = -ENOMEM;
1507                         goto err;
1508                 }
1509         }
1510 err:
1511         return ret;
1512 }
1513
1514 /*-------------------------------------------------------------------------*/
1515
1516 // tasklet (work deferred from completions, in_irq) or timer
1517
1518 static void usbnet_bh (struct timer_list *t)
1519 {
1520         struct usbnet           *dev = from_timer(dev, t, delay);
1521         struct sk_buff          *skb;
1522         struct skb_data         *entry;
1523
1524         while ((skb = skb_dequeue (&dev->done))) {
1525                 entry = (struct skb_data *) skb->cb;
1526                 switch (entry->state) {
1527                 case rx_done:
1528                         entry->state = rx_cleanup;
1529                         rx_process (dev, skb);
1530                         continue;
1531                 case tx_done:
1532                         kfree(entry->urb->sg);
1533                         /* fall through */
1534                 case rx_cleanup:
1535                         usb_free_urb (entry->urb);
1536                         dev_kfree_skb (skb);
1537                         continue;
1538                 default:
1539                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1540                 }
1541         }
1542
1543         /* restart RX again after disabling due to high error rate */
1544         clear_bit(EVENT_RX_KILL, &dev->flags);
1545
1546         /* waiting for all pending urbs to complete?
1547          * only then can we forgo submitting anew
1548          */
1549         if (waitqueue_active(&dev->wait)) {
1550                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1551                         wake_up_all(&dev->wait);
1552
1553         // or are we maybe short a few urbs?
1554         } else if (netif_running (dev->net) &&
1555                    netif_device_present (dev->net) &&
1556                    netif_carrier_ok(dev->net) &&
1557                    !timer_pending(&dev->delay) &&
1558                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1559                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1560                 int     temp = dev->rxq.qlen;
1561
1562                 if (temp < RX_QLEN(dev)) {
1563                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1564                                 return;
1565                         if (temp != dev->rxq.qlen)
1566                                 netif_dbg(dev, link, dev->net,
1567                                           "rxqlen %d --> %d\n",
1568                                           temp, dev->rxq.qlen);
1569                         if (dev->rxq.qlen < RX_QLEN(dev))
1570                                 tasklet_schedule (&dev->bh);
1571                 }
1572                 if (dev->txq.qlen < TX_QLEN (dev))
1573                         netif_wake_queue (dev->net);
1574         }
1575 }
1576
1577 static void usbnet_bh_tasklet(unsigned long data)
1578 {
1579         struct timer_list *t = (struct timer_list *)data;
1580
1581         usbnet_bh(t);
1582 }
1583
1584
1585 /*-------------------------------------------------------------------------
1586  *
1587  * USB Device Driver support
1588  *
1589  *-------------------------------------------------------------------------*/
1590
1591 // precondition: never called in_interrupt
1592
1593 void usbnet_disconnect (struct usb_interface *intf)
1594 {
1595         struct usbnet           *dev;
1596         struct usb_device       *xdev;
1597         struct net_device       *net;
1598
1599         dev = usb_get_intfdata(intf);
1600         usb_set_intfdata(intf, NULL);
1601         if (!dev)
1602                 return;
1603
1604         xdev = interface_to_usbdev (intf);
1605
1606         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1607                    intf->dev.driver->name,
1608                    xdev->bus->bus_name, xdev->devpath,
1609                    dev->driver_info->description);
1610
1611         net = dev->net;
1612         unregister_netdev (net);
1613
1614         cancel_work_sync(&dev->kevent);
1615
1616         usb_scuttle_anchored_urbs(&dev->deferred);
1617
1618         if (dev->driver_info->unbind)
1619                 dev->driver_info->unbind (dev, intf);
1620
1621         usb_kill_urb(dev->interrupt);
1622         usb_free_urb(dev->interrupt);
1623         kfree(dev->padding_pkt);
1624
1625         free_percpu(dev->stats64);
1626         free_netdev(net);
1627 }
1628 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1629
1630 static const struct net_device_ops usbnet_netdev_ops = {
1631         .ndo_open               = usbnet_open,
1632         .ndo_stop               = usbnet_stop,
1633         .ndo_start_xmit         = usbnet_start_xmit,
1634         .ndo_tx_timeout         = usbnet_tx_timeout,
1635         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1636         .ndo_change_mtu         = usbnet_change_mtu,
1637         .ndo_get_stats64        = usbnet_get_stats64,
1638         .ndo_set_mac_address    = eth_mac_addr,
1639         .ndo_validate_addr      = eth_validate_addr,
1640 };
1641
1642 /*-------------------------------------------------------------------------*/
1643
1644 // precondition: never called in_interrupt
1645
1646 static struct device_type wlan_type = {
1647         .name   = "wlan",
1648 };
1649
1650 static struct device_type wwan_type = {
1651         .name   = "wwan",
1652 };
1653
1654 int
1655 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1656 {
1657         struct usbnet                   *dev;
1658         struct net_device               *net;
1659         struct usb_host_interface       *interface;
1660         const struct driver_info        *info;
1661         struct usb_device               *xdev;
1662         int                             status;
1663         const char                      *name;
1664         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1665
1666         /* usbnet already took usb runtime pm, so have to enable the feature
1667          * for usb interface, otherwise usb_autopm_get_interface may return
1668          * failure if RUNTIME_PM is enabled.
1669          */
1670         if (!driver->supports_autosuspend) {
1671                 driver->supports_autosuspend = 1;
1672                 pm_runtime_enable(&udev->dev);
1673         }
1674
1675         name = udev->dev.driver->name;
1676         info = (const struct driver_info *) prod->driver_info;
1677         if (!info) {
1678                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1679                 return -ENODEV;
1680         }
1681         xdev = interface_to_usbdev (udev);
1682         interface = udev->cur_altsetting;
1683
1684         status = -ENOMEM;
1685
1686         // set up our own records
1687         net = alloc_etherdev(sizeof(*dev));
1688         if (!net)
1689                 goto out;
1690
1691         /* netdev_printk() needs this so do it as early as possible */
1692         SET_NETDEV_DEV(net, &udev->dev);
1693
1694         dev = netdev_priv(net);
1695         dev->udev = xdev;
1696         dev->intf = udev;
1697         dev->driver_info = info;
1698         dev->driver_name = name;
1699
1700         dev->stats64 = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1701         if (!dev->stats64)
1702                 goto out0;
1703
1704         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1705                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1706         init_waitqueue_head(&dev->wait);
1707         skb_queue_head_init (&dev->rxq);
1708         skb_queue_head_init (&dev->txq);
1709         skb_queue_head_init (&dev->done);
1710         skb_queue_head_init(&dev->rxq_pause);
1711         dev->bh.func = usbnet_bh_tasklet;
1712         dev->bh.data = (unsigned long)&dev->delay;
1713         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1714         init_usb_anchor(&dev->deferred);
1715         timer_setup(&dev->delay, usbnet_bh, 0);
1716         mutex_init (&dev->phy_mutex);
1717         mutex_init(&dev->interrupt_mutex);
1718         dev->interrupt_count = 0;
1719
1720         dev->net = net;
1721         strcpy (net->name, "usb%d");
1722         memcpy (net->dev_addr, node_id, sizeof node_id);
1723
1724         /* rx and tx sides can use different message sizes;
1725          * bind() should set rx_urb_size in that case.
1726          */
1727         dev->hard_mtu = net->mtu + net->hard_header_len;
1728         net->min_mtu = 0;
1729         net->max_mtu = ETH_MAX_MTU;
1730
1731         net->netdev_ops = &usbnet_netdev_ops;
1732         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1733         net->ethtool_ops = &usbnet_ethtool_ops;
1734
1735         // allow device-specific bind/init procedures
1736         // NOTE net->name still not usable ...
1737         if (info->bind) {
1738                 status = info->bind (dev, udev);
1739                 if (status < 0)
1740                         goto out1;
1741
1742                 // heuristic:  "usb%d" for links we know are two-host,
1743                 // else "eth%d" when there's reasonable doubt.  userspace
1744                 // can rename the link if it knows better.
1745                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1746                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1747                      (net->dev_addr [0] & 0x02) == 0))
1748                         strcpy (net->name, "eth%d");
1749                 /* WLAN devices should always be named "wlan%d" */
1750                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1751                         strcpy(net->name, "wlan%d");
1752                 /* WWAN devices should always be named "wwan%d" */
1753                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1754                         strcpy(net->name, "wwan%d");
1755
1756                 /* devices that cannot do ARP */
1757                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1758                         net->flags |= IFF_NOARP;
1759
1760                 /* maybe the remote can't receive an Ethernet MTU */
1761                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1762                         net->mtu = dev->hard_mtu - net->hard_header_len;
1763         } else if (!info->in || !info->out)
1764                 status = usbnet_get_endpoints (dev, udev);
1765         else {
1766                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1767                 dev->out = usb_sndbulkpipe (xdev, info->out);
1768                 if (!(info->flags & FLAG_NO_SETINT))
1769                         status = usb_set_interface (xdev,
1770                                 interface->desc.bInterfaceNumber,
1771                                 interface->desc.bAlternateSetting);
1772                 else
1773                         status = 0;
1774
1775         }
1776         if (status >= 0 && dev->status)
1777                 status = init_status (dev, udev);
1778         if (status < 0)
1779                 goto out3;
1780
1781         if (!dev->rx_urb_size)
1782                 dev->rx_urb_size = dev->hard_mtu;
1783         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1784
1785         /* let userspace know we have a random address */
1786         if (ether_addr_equal(net->dev_addr, node_id))
1787                 net->addr_assign_type = NET_ADDR_RANDOM;
1788
1789         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1790                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1791         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1792                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1793
1794         /* initialize max rx_qlen and tx_qlen */
1795         usbnet_update_max_qlen(dev);
1796
1797         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1798                 !(info->flags & FLAG_MULTI_PACKET)) {
1799                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1800                 if (!dev->padding_pkt) {
1801                         status = -ENOMEM;
1802                         goto out4;
1803                 }
1804         }
1805
1806         status = register_netdev (net);
1807         if (status)
1808                 goto out5;
1809         netif_info(dev, probe, dev->net,
1810                    "register '%s' at usb-%s-%s, %s, %pM\n",
1811                    udev->dev.driver->name,
1812                    xdev->bus->bus_name, xdev->devpath,
1813                    dev->driver_info->description,
1814                    net->dev_addr);
1815
1816         // ok, it's ready to go.
1817         usb_set_intfdata (udev, dev);
1818
1819         netif_device_attach (net);
1820
1821         if (dev->driver_info->flags & FLAG_LINK_INTR)
1822                 usbnet_link_change(dev, 0, 0);
1823
1824         return 0;
1825
1826 out5:
1827         kfree(dev->padding_pkt);
1828 out4:
1829         usb_free_urb(dev->interrupt);
1830 out3:
1831         if (info->unbind)
1832                 info->unbind (dev, udev);
1833 out1:
1834         /* subdrivers must undo all they did in bind() if they
1835          * fail it, but we may fail later and a deferred kevent
1836          * may trigger an error resubmitting itself and, worse,
1837          * schedule a timer. So we kill it all just in case.
1838          */
1839         cancel_work_sync(&dev->kevent);
1840         del_timer_sync(&dev->delay);
1841         free_percpu(dev->stats64);
1842 out0:
1843         free_netdev(net);
1844 out:
1845         return status;
1846 }
1847 EXPORT_SYMBOL_GPL(usbnet_probe);
1848
1849 /*-------------------------------------------------------------------------*/
1850
1851 /*
1852  * suspend the whole driver as soon as the first interface is suspended
1853  * resume only when the last interface is resumed
1854  */
1855
1856 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1857 {
1858         struct usbnet           *dev = usb_get_intfdata(intf);
1859
1860         if (!dev->suspend_count++) {
1861                 spin_lock_irq(&dev->txq.lock);
1862                 /* don't autosuspend while transmitting */
1863                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1864                         dev->suspend_count--;
1865                         spin_unlock_irq(&dev->txq.lock);
1866                         return -EBUSY;
1867                 } else {
1868                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1869                         spin_unlock_irq(&dev->txq.lock);
1870                 }
1871                 /*
1872                  * accelerate emptying of the rx and queues, to avoid
1873                  * having everything error out.
1874                  */
1875                 netif_device_detach (dev->net);
1876                 usbnet_terminate_urbs(dev);
1877                 __usbnet_status_stop_force(dev);
1878
1879                 /*
1880                  * reattach so runtime management can use and
1881                  * wake the device
1882                  */
1883                 netif_device_attach (dev->net);
1884         }
1885         return 0;
1886 }
1887 EXPORT_SYMBOL_GPL(usbnet_suspend);
1888
1889 int usbnet_resume (struct usb_interface *intf)
1890 {
1891         struct usbnet           *dev = usb_get_intfdata(intf);
1892         struct sk_buff          *skb;
1893         struct urb              *res;
1894         int                     retval;
1895
1896         if (!--dev->suspend_count) {
1897                 /* resume interrupt URB if it was previously submitted */
1898                 __usbnet_status_start_force(dev, GFP_NOIO);
1899
1900                 spin_lock_irq(&dev->txq.lock);
1901                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1902
1903                         skb = (struct sk_buff *)res->context;
1904                         retval = usb_submit_urb(res, GFP_ATOMIC);
1905                         if (retval < 0) {
1906                                 dev_kfree_skb_any(skb);
1907                                 kfree(res->sg);
1908                                 usb_free_urb(res);
1909                                 usb_autopm_put_interface_async(dev->intf);
1910                         } else {
1911                                 netif_trans_update(dev->net);
1912                                 __skb_queue_tail(&dev->txq, skb);
1913                         }
1914                 }
1915
1916                 smp_mb();
1917                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1918                 spin_unlock_irq(&dev->txq.lock);
1919
1920                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1921                         /* handle remote wakeup ASAP
1922                          * we cannot race against stop
1923                          */
1924                         if (netif_device_present(dev->net) &&
1925                                 !timer_pending(&dev->delay) &&
1926                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1927                                         rx_alloc_submit(dev, GFP_NOIO);
1928
1929                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1930                                 netif_tx_wake_all_queues(dev->net);
1931                         tasklet_schedule (&dev->bh);
1932                 }
1933         }
1934
1935         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1936                 usb_autopm_get_interface_no_resume(intf);
1937
1938         return 0;
1939 }
1940 EXPORT_SYMBOL_GPL(usbnet_resume);
1941
1942 /*
1943  * Either a subdriver implements manage_power, then it is assumed to always
1944  * be ready to be suspended or it reports the readiness to be suspended
1945  * explicitly
1946  */
1947 void usbnet_device_suggests_idle(struct usbnet *dev)
1948 {
1949         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1950                 dev->intf->needs_remote_wakeup = 1;
1951                 usb_autopm_put_interface_async(dev->intf);
1952         }
1953 }
1954 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1955
1956 /*
1957  * For devices that can do without special commands
1958  */
1959 int usbnet_manage_power(struct usbnet *dev, int on)
1960 {
1961         dev->intf->needs_remote_wakeup = on;
1962         return 0;
1963 }
1964 EXPORT_SYMBOL(usbnet_manage_power);
1965
1966 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1967 {
1968         /* update link after link is reseted */
1969         if (link && !need_reset)
1970                 netif_carrier_on(dev->net);
1971         else
1972                 netif_carrier_off(dev->net);
1973
1974         if (need_reset && link)
1975                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1976         else
1977                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1978 }
1979 EXPORT_SYMBOL(usbnet_link_change);
1980
1981 /*-------------------------------------------------------------------------*/
1982 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1983                              u16 value, u16 index, void *data, u16 size)
1984 {
1985         void *buf = NULL;
1986         int err = -ENOMEM;
1987
1988         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1989                    " value=0x%04x index=0x%04x size=%d\n",
1990                    cmd, reqtype, value, index, size);
1991
1992         if (size) {
1993                 buf = kmalloc(size, GFP_KERNEL);
1994                 if (!buf)
1995                         goto out;
1996         }
1997
1998         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1999                               cmd, reqtype, value, index, buf, size,
2000                               USB_CTRL_GET_TIMEOUT);
2001         if (err > 0 && err <= size) {
2002         if (data)
2003             memcpy(data, buf, err);
2004         else
2005             netdev_dbg(dev->net,
2006                 "Huh? Data requested but thrown away.\n");
2007     }
2008         kfree(buf);
2009 out:
2010         return err;
2011 }
2012
2013 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2014                               u16 value, u16 index, const void *data,
2015                               u16 size)
2016 {
2017         void *buf = NULL;
2018         int err = -ENOMEM;
2019
2020         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2021                    " value=0x%04x index=0x%04x size=%d\n",
2022                    cmd, reqtype, value, index, size);
2023
2024         if (data) {
2025                 buf = kmemdup(data, size, GFP_KERNEL);
2026                 if (!buf)
2027                         goto out;
2028         } else {
2029         if (size) {
2030             WARN_ON_ONCE(1);
2031             err = -EINVAL;
2032             goto out;
2033         }
2034     }
2035
2036         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2037                               cmd, reqtype, value, index, buf, size,
2038                               USB_CTRL_SET_TIMEOUT);
2039         kfree(buf);
2040
2041 out:
2042         return err;
2043 }
2044
2045 /*
2046  * The function can't be called inside suspend/resume callback,
2047  * otherwise deadlock will be caused.
2048  */
2049 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2050                     u16 value, u16 index, void *data, u16 size)
2051 {
2052         int ret;
2053
2054         if (usb_autopm_get_interface(dev->intf) < 0)
2055                 return -ENODEV;
2056         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2057                                 data, size);
2058         usb_autopm_put_interface(dev->intf);
2059         return ret;
2060 }
2061 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2062
2063 /*
2064  * The function can't be called inside suspend/resume callback,
2065  * otherwise deadlock will be caused.
2066  */
2067 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2068                      u16 value, u16 index, const void *data, u16 size)
2069 {
2070         int ret;
2071
2072         if (usb_autopm_get_interface(dev->intf) < 0)
2073                 return -ENODEV;
2074         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2075                                  data, size);
2076         usb_autopm_put_interface(dev->intf);
2077         return ret;
2078 }
2079 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2080
2081 /*
2082  * The function can be called inside suspend/resume callback safely
2083  * and should only be called by suspend/resume callback generally.
2084  */
2085 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2086                           u16 value, u16 index, void *data, u16 size)
2087 {
2088         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2089                                  data, size);
2090 }
2091 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2092
2093 /*
2094  * The function can be called inside suspend/resume callback safely
2095  * and should only be called by suspend/resume callback generally.
2096  */
2097 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2098                           u16 value, u16 index, const void *data,
2099                           u16 size)
2100 {
2101         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2102                                   data, size);
2103 }
2104 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2105
2106 static void usbnet_async_cmd_cb(struct urb *urb)
2107 {
2108         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2109         int status = urb->status;
2110
2111         if (status < 0)
2112                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2113                         __func__, status);
2114
2115         kfree(req);
2116         usb_free_urb(urb);
2117 }
2118
2119 /*
2120  * The caller must make sure that device can't be put into suspend
2121  * state until the control URB completes.
2122  */
2123 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2124                            u16 value, u16 index, const void *data, u16 size)
2125 {
2126         struct usb_ctrlrequest *req = NULL;
2127         struct urb *urb;
2128         int err = -ENOMEM;
2129         void *buf = NULL;
2130
2131         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2132                    " value=0x%04x index=0x%04x size=%d\n",
2133                    cmd, reqtype, value, index, size);
2134
2135         urb = usb_alloc_urb(0, GFP_ATOMIC);
2136         if (!urb)
2137                 goto fail;
2138
2139         if (data) {
2140                 buf = kmemdup(data, size, GFP_ATOMIC);
2141                 if (!buf) {
2142                         netdev_err(dev->net, "Error allocating buffer"
2143                                    " in %s!\n", __func__);
2144                         goto fail_free;
2145                 }
2146         }
2147
2148         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2149         if (!req)
2150                 goto fail_free_buf;
2151
2152         req->bRequestType = reqtype;
2153         req->bRequest = cmd;
2154         req->wValue = cpu_to_le16(value);
2155         req->wIndex = cpu_to_le16(index);
2156         req->wLength = cpu_to_le16(size);
2157
2158         usb_fill_control_urb(urb, dev->udev,
2159                              usb_sndctrlpipe(dev->udev, 0),
2160                              (void *)req, buf, size,
2161                              usbnet_async_cmd_cb, req);
2162         urb->transfer_flags |= URB_FREE_BUFFER;
2163
2164         err = usb_submit_urb(urb, GFP_ATOMIC);
2165         if (err < 0) {
2166                 netdev_err(dev->net, "Error submitting the control"
2167                            " message: status=%d\n", err);
2168                 goto fail_free;
2169         }
2170         return 0;
2171
2172 fail_free_buf:
2173         kfree(buf);
2174 fail_free:
2175         kfree(req);
2176         usb_free_urb(urb);
2177 fail:
2178         return err;
2179
2180 }
2181 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2182 /*-------------------------------------------------------------------------*/
2183
2184 static int __init usbnet_init(void)
2185 {
2186         /* Compiler should optimize this out. */
2187         BUILD_BUG_ON(
2188                 sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data));
2189
2190         eth_random_addr(node_id);
2191         return 0;
2192 }
2193 module_init(usbnet_init);
2194
2195 static void __exit usbnet_exit(void)
2196 {
2197 }
2198 module_exit(usbnet_exit);
2199
2200 MODULE_AUTHOR("David Brownell");
2201 MODULE_DESCRIPTION("USB network driver framework");
2202 MODULE_LICENSE("GPL");