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 /*-------------------------------------------------------------------------*/
  38
  39 /*
  40  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  41  * Several dozen bytes of IPv4 data can fit in two such transactions.
  42  * One maximum size Ethernet packet takes twenty four of them.
  43  * For high speed, each frame comfortably fits almost 36 max size
  44  * Ethernet packets (so queues should be bigger).
  45  *
  46  * The goal is to let the USB host controller be busy for 5msec or
  47  * more before an irq is required, under load.  Jumbograms change
  48  * the equation.
  49  */
  50 #define MAX_QUEUE_MEMORY        (60 * 1518)
  51 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  52 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  53
  54 // reawaken network queue this soon after stopping; else watchdog barks
  55 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  56
  57 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  58  * us (it polls at HZ/4 usually) before we report too many false errors.
  59  */
  60 #define THROTTLE_JIFFIES        (HZ/8)
  61
  62 // between wakeups
  63 #define UNLINK_TIMEOUT_MS       3
  64
  65 /*-------------------------------------------------------------------------*/
  66
  67 // randomly generated ethernet address
  68 static u8       node_id [ETH_ALEN];
  69
  70 /* use ethtool to change the level for any given device */
  71 static int msg_level = -1;
  72 module_param (msg_level, int, 0);
  73 MODULE_PARM_DESC (msg_level, "Override default message level");
  74
  75 /*-------------------------------------------------------------------------*/
  76
  77 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  78 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  79 {
  80         int                             tmp;
  81         struct usb_host_interface       *alt = NULL;
  82         struct usb_host_endpoint        *in = NULL, *out = NULL;
  83         struct usb_host_endpoint        *status = NULL;
  84
  85         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
  86                 unsigned        ep;
  87
  88                 in = out = status = NULL;
  89                 alt = intf->altsetting + tmp;
  90
  91                 /* take the first altsetting with in-bulk + out-bulk;
  92                  * remember any status endpoint, just in case;
  93                  * ignore other endpoints and altsettings.
  94                  */
  95                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
  96                         struct usb_host_endpoint        *e;
  97                         int                             intr = 0;
  98
  99                         e = alt->endpoint + ep;
 100
 101                         /* ignore endpoints which cannot transfer data */
 102                         if (!usb_endpoint_maxp(&e->desc))
 103                                 continue;
 104
 105                         switch (e->desc.bmAttributes) {
 106                         case USB_ENDPOINT_XFER_INT:
 107                                 if (!usb_endpoint_dir_in(&e->desc))
 108                                         continue;
 109                                 intr = 1;
 110                                 fallthrough;
 111                         case USB_ENDPOINT_XFER_BULK:
 112                                 break;
 113                         default:
 114                                 continue;
 115                         }
 116                         if (usb_endpoint_dir_in(&e->desc)) {
 117                                 if (!intr && !in)
 118                                         in = e;
 119                                 else if (intr && !status)
 120                                         status = e;
 121                         } else {
 122                                 if (!out)
 123                                         out = e;
 124                         }
 125                 }
 126                 if (in && out)
 127                         break;
 128         }
 129         if (!alt || !in || !out)
 130                 return -EINVAL;
 131
 132         if (alt->desc.bAlternateSetting != 0 ||
 133             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 134                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 135                                 alt->desc.bAlternateSetting);
 136                 if (tmp < 0)
 137                         return tmp;
 138         }
 139
 140         dev->in = usb_rcvbulkpipe (dev->udev,
 141                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 142         dev->out = usb_sndbulkpipe (dev->udev,
 143                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 144         dev->status = status;
 145         return 0;
 146 }
 147 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 148
 149 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 150 {
 151         int             tmp = -1, ret;
 152         unsigned char   buf [13];
 153
 154         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 155         if (ret == 12)
 156                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 157         if (tmp < 0) {
 158                 dev_dbg(&dev->udev->dev,
 159                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 160                 if (ret >= 0)
 161                         ret = -EINVAL;
 162                 return ret;
 163         }
 164         return 0;
 165 }
 166 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 167
 168 static void intr_complete (struct urb *urb)
 169 {
 170         struct usbnet   *dev = urb->context;
 171         int             status = urb->status;
 172
 173         switch (status) {
 174         /* success */
 175         case 0:
 176                 dev->driver_info->status(dev, urb);
 177                 break;
 178
 179         /* software-driven interface shutdown */
 180         case -ENOENT:           /* urb killed */
 181         case -ESHUTDOWN:        /* hardware gone */
 182                 netif_dbg(dev, ifdown, dev->net,
 183                           "intr shutdown, code %d\n", status);
 184                 return;
 185
 186         /* NOTE:  not throttling like RX/TX, since this endpoint
 187          * already polls infrequently
 188          */
 189         default:
 190                 netdev_dbg(dev->net, "intr status %d\n", status);
 191                 break;
 192         }
 193
 194         status = usb_submit_urb (urb, GFP_ATOMIC);
 195         if (status != 0)
 196                 netif_err(dev, timer, dev->net,
 197                           "intr resubmit --> %d\n", status);
 198 }
 199
 200 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 201 {
 202         char            *buf = NULL;
 203         unsigned        pipe = 0;
 204         unsigned        maxp;
 205         unsigned        period;
 206
 207         if (!dev->driver_info->status)
 208                 return 0;
 209
 210         pipe = usb_rcvintpipe (dev->udev,
 211                         dev->status->desc.bEndpointAddress
 212                                 & USB_ENDPOINT_NUMBER_MASK);
 213         maxp = usb_maxpacket (dev->udev, pipe, 0);
 214
 215         /* avoid 1 msec chatter:  min 8 msec poll rate */
 216         period = max ((int) dev->status->desc.bInterval,
 217                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 218
 219         buf = kmalloc (maxp, GFP_KERNEL);
 220         if (buf) {
 221                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 222                 if (!dev->interrupt) {
 223                         kfree (buf);
 224                         return -ENOMEM;
 225                 } else {
 226                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 227                                 buf, maxp, intr_complete, dev, period);
 228                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 229                         dev_dbg(&intf->dev,
 230                                 "status ep%din, %d bytes period %d\n",
 231                                 usb_pipeendpoint(pipe), maxp, period);
 232                 }
 233         }
 234         return 0;
 235 }
 236
 237 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 238 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 239 {
 240         int ret = 0;
 241
 242         WARN_ON_ONCE(dev->interrupt == NULL);
 243         if (dev->interrupt) {
 244                 mutex_lock(&dev->interrupt_mutex);
 245
 246                 if (++dev->interrupt_count == 1)
 247                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 248
 249                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 250                         dev->interrupt_count);
 251                 mutex_unlock(&dev->interrupt_mutex);
 252         }
 253         return ret;
 254 }
 255 EXPORT_SYMBOL_GPL(usbnet_status_start);
 256
 257 /* For resume; submit interrupt URB if previously submitted */
 258 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 259 {
 260         int ret = 0;
 261
 262         mutex_lock(&dev->interrupt_mutex);
 263         if (dev->interrupt_count) {
 264                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 265                 dev_dbg(&dev->udev->dev,
 266                         "submitted interrupt URB for resume\n");
 267         }
 268         mutex_unlock(&dev->interrupt_mutex);
 269         return ret;
 270 }
 271
 272 /* Kill the interrupt URB if all submitters want it killed */
 273 void usbnet_status_stop(struct usbnet *dev)
 274 {
 275         if (dev->interrupt) {
 276                 mutex_lock(&dev->interrupt_mutex);
 277                 WARN_ON(dev->interrupt_count == 0);
 278
 279                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 280                         usb_kill_urb(dev->interrupt);
 281
 282                 dev_dbg(&dev->udev->dev,
 283                         "decremented interrupt URB count to %d\n",
 284                         dev->interrupt_count);
 285                 mutex_unlock(&dev->interrupt_mutex);
 286         }
 287 }
 288 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 289
 290 /* For suspend; always kill interrupt URB */
 291 static void __usbnet_status_stop_force(struct usbnet *dev)
 292 {
 293         if (dev->interrupt) {
 294                 mutex_lock(&dev->interrupt_mutex);
 295                 usb_kill_urb(dev->interrupt);
 296                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 297                 mutex_unlock(&dev->interrupt_mutex);
 298         }
 299 }
 300
 301 /* Passes this packet up the stack, updating its accounting.
 302  * Some link protocols batch packets, so their rx_fixup paths
 303  * can return clones as well as just modify the original skb.
 304  */
 305 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 306 {
 307         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
 308         unsigned long flags;
 309         int     status;
 310
 311         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 312                 skb_queue_tail(&dev->rxq_pause, skb);
 313                 return;
 314         }
 315
 316         /* only update if unset to allow minidriver rx_fixup override */
 317         if (skb->protocol == 0)
 318                 skb->protocol = eth_type_trans (skb, dev->net);
 319
 320         flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 321         stats64->rx_packets++;
 322         stats64->rx_bytes += skb->len;
 323         u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 324
 325         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 326                   skb->len + sizeof (struct ethhdr), skb->protocol);
 327         memset (skb->cb, 0, sizeof (struct skb_data));
 328
 329         if (skb_defer_rx_timestamp(skb))
 330                 return;
 331
 332         status = netif_rx (skb);
 333         if (status != NET_RX_SUCCESS)
 334                 netif_dbg(dev, rx_err, dev->net,
 335                           "netif_rx status %d\n", status);
 336 }
 337 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 338
 339 /* must be called if hard_mtu or rx_urb_size changed */
 340 void usbnet_update_max_qlen(struct usbnet *dev)
 341 {
 342         enum usb_device_speed speed = dev->udev->speed;
 343
 344         if (!dev->rx_urb_size || !dev->hard_mtu)
 345                 goto insanity;
 346         switch (speed) {
 347         case USB_SPEED_HIGH:
 348                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 349                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 350                 break;
 351         case USB_SPEED_SUPER:
 352         case USB_SPEED_SUPER_PLUS:
 353                 /*
 354                  * Not take default 5ms qlen for super speed HC to
 355                  * save memory, and iperf tests show 2.5ms qlen can
 356                  * work well
 357                  */
 358                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 359                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 360                 break;
 361         default:
 362 insanity:
 363                 dev->rx_qlen = dev->tx_qlen = 4;
 364         }
 365 }
 366 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 367
 368 \f
 369 /*-------------------------------------------------------------------------
 370  *
 371  * Network Device Driver (peer link to "Host Device", from USB host)
 372  *
 373  *-------------------------------------------------------------------------*/
 374
 375 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 376 {
 377         struct usbnet   *dev = netdev_priv(net);
 378         int             ll_mtu = new_mtu + net->hard_header_len;
 379         int             old_hard_mtu = dev->hard_mtu;
 380         int             old_rx_urb_size = dev->rx_urb_size;
 381
 382         // no second zero-length packet read wanted after mtu-sized packets
 383         if ((ll_mtu % dev->maxpacket) == 0)
 384                 return -EDOM;
 385         net->mtu = new_mtu;
 386
 387         dev->hard_mtu = net->mtu + net->hard_header_len;
 388         if (dev->rx_urb_size == old_hard_mtu) {
 389                 dev->rx_urb_size = dev->hard_mtu;
 390                 if (dev->rx_urb_size > old_rx_urb_size) {
 391                         usbnet_pause_rx(dev);
 392                         usbnet_unlink_rx_urbs(dev);
 393                         usbnet_resume_rx(dev);
 394                 }
 395         }
 396
 397         /* max qlen depend on hard_mtu and rx_urb_size */
 398         usbnet_update_max_qlen(dev);
 399
 400         return 0;
 401 }
 402 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 403
 404 /* The caller must hold list->lock */
 405 static void __usbnet_queue_skb(struct sk_buff_head *list,
 406                         struct sk_buff *newsk, enum skb_state state)
 407 {
 408         struct skb_data *entry = (struct skb_data *) newsk->cb;
 409
 410         __skb_queue_tail(list, newsk);
 411         entry->state = state;
 412 }
 413
 414 /*-------------------------------------------------------------------------*/
 415
 416 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 417  * completion callbacks.  2.5 should have fixed those bugs...
 418  */
 419
 420 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 421                 struct sk_buff_head *list, enum skb_state state)
 422 {
 423         unsigned long           flags;
 424         enum skb_state          old_state;
 425         struct skb_data *entry = (struct skb_data *) skb->cb;
 426
 427         spin_lock_irqsave(&list->lock, flags);
 428         old_state = entry->state;
 429         entry->state = state;
 430         __skb_unlink(skb, list);
 431
 432         /* defer_bh() is never called with list == &dev->done.
 433          * spin_lock_nested() tells lockdep that it is OK to take
 434          * dev->done.lock here with list->lock held.
 435          */
 436         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 437
 438         __skb_queue_tail(&dev->done, skb);
 439         if (dev->done.qlen == 1)
 440                 tasklet_schedule(&dev->bh);
 441         spin_unlock(&dev->done.lock);
 442         spin_unlock_irqrestore(&list->lock, flags);
 443         return old_state;
 444 }
 445
 446 /* some work can't be done in tasklets, so we use keventd
 447  *
 448  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 449  * but tasklet_schedule() doesn't.  hope the failure is rare.
 450  */
 451 void usbnet_defer_kevent (struct usbnet *dev, int work)
 452 {
 453         set_bit (work, &dev->flags);
 454         if (!schedule_work (&dev->kevent))
 455                 netdev_dbg(dev->net, "kevent %d may have been dropped\n", work);
 456         else
 457                 netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 458 }
 459 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 460
 461 /*-------------------------------------------------------------------------*/
 462
 463 static void rx_complete (struct urb *urb);
 464
 465 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 466 {
 467         struct sk_buff          *skb;
 468         struct skb_data         *entry;
 469         int                     retval = 0;
 470         unsigned long           lockflags;
 471         size_t                  size = dev->rx_urb_size;
 472
 473         /* prevent rx skb allocation when error ratio is high */
 474         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 475                 usb_free_urb(urb);
 476                 return -ENOLINK;
 477         }
 478
 479         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 480                 skb = __netdev_alloc_skb(dev->net, size, flags);
 481         else
 482                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 483         if (!skb) {
 484                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 485                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 486                 usb_free_urb (urb);
 487                 return -ENOMEM;
 488         }
 489
 490         entry = (struct skb_data *) skb->cb;
 491         entry->urb = urb;
 492         entry->dev = dev;
 493         entry->length = 0;
 494
 495         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 496                 skb->data, size, rx_complete, skb);
 497
 498         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 499
 500         if (netif_running (dev->net) &&
 501             netif_device_present (dev->net) &&
 502             test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 503             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 504             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 505                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 506                 case -EPIPE:
 507                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 508                         break;
 509                 case -ENOMEM:
 510                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 511                         break;
 512                 case -ENODEV:
 513                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 514                         netif_device_detach (dev->net);
 515                         break;
 516                 case -EHOSTUNREACH:
 517                         retval = -ENOLINK;
 518                         break;
 519                 default:
 520                         netif_dbg(dev, rx_err, dev->net,
 521                                   "rx submit, %d\n", retval);
 522                         tasklet_schedule (&dev->bh);
 523                         break;
 524                 case 0:
 525                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 526                 }
 527         } else {
 528                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 529                 retval = -ENOLINK;
 530         }
 531         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 532         if (retval) {
 533                 dev_kfree_skb_any (skb);
 534                 usb_free_urb (urb);
 535         }
 536         return retval;
 537 }
 538
 539
 540 /*-------------------------------------------------------------------------*/
 541
 542 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 543 {
 544         if (dev->driver_info->rx_fixup &&
 545             !dev->driver_info->rx_fixup (dev, skb)) {
 546                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 547                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 548                         dev->net->stats.rx_errors++;
 549                 goto done;
 550         }
 551         // else network stack removes extra byte if we forced a short packet
 552
 553         /* all data was already cloned from skb inside the driver */
 554         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 555                 goto done;
 556
 557         if (skb->len < ETH_HLEN) {
 558                 dev->net->stats.rx_errors++;
 559                 dev->net->stats.rx_length_errors++;
 560                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 561         } else {
 562                 usbnet_skb_return(dev, skb);
 563                 return;
 564         }
 565
 566 done:
 567         skb_queue_tail(&dev->done, skb);
 568 }
 569
 570 /*-------------------------------------------------------------------------*/
 571
 572 static void rx_complete (struct urb *urb)
 573 {
 574         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 575         struct skb_data         *entry = (struct skb_data *) skb->cb;
 576         struct usbnet           *dev = entry->dev;
 577         int                     urb_status = urb->status;
 578         enum skb_state          state;
 579
 580         skb_put (skb, urb->actual_length);
 581         state = rx_done;
 582         entry->urb = NULL;
 583
 584         switch (urb_status) {
 585         /* success */
 586         case 0:
 587                 break;
 588
 589         /* stalls need manual reset. this is rare ... except that
 590          * when going through USB 2.0 TTs, unplug appears this way.
 591          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 592          * storm, recovering as needed.
 593          */
 594         case -EPIPE:
 595                 dev->net->stats.rx_errors++;
 596                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 597                 fallthrough;
 598
 599         /* software-driven interface shutdown */
 600         case -ECONNRESET:               /* async unlink */
 601         case -ESHUTDOWN:                /* hardware gone */
 602                 netif_dbg(dev, ifdown, dev->net,
 603                           "rx shutdown, code %d\n", urb_status);
 604                 goto block;
 605
 606         /* we get controller i/o faults during hub_wq disconnect() delays.
 607          * throttle down resubmits, to avoid log floods; just temporarily,
 608          * so we still recover when the fault isn't a hub_wq delay.
 609          */
 610         case -EPROTO:
 611         case -ETIME:
 612         case -EILSEQ:
 613                 dev->net->stats.rx_errors++;
 614                 if (!timer_pending (&dev->delay)) {
 615                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 616                         netif_dbg(dev, link, dev->net,
 617                                   "rx throttle %d\n", urb_status);
 618                 }
 619 block:
 620                 state = rx_cleanup;
 621                 entry->urb = urb;
 622                 urb = NULL;
 623                 break;
 624
 625         /* data overrun ... flush fifo? */
 626         case -EOVERFLOW:
 627                 dev->net->stats.rx_over_errors++;
 628                 fallthrough;
 629
 630         default:
 631                 state = rx_cleanup;
 632                 dev->net->stats.rx_errors++;
 633                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 634                 break;
 635         }
 636
 637         /* stop rx if packet error rate is high */
 638         if (++dev->pkt_cnt > 30) {
 639                 dev->pkt_cnt = 0;
 640                 dev->pkt_err = 0;
 641         } else {
 642                 if (state == rx_cleanup)
 643                         dev->pkt_err++;
 644                 if (dev->pkt_err > 20)
 645                         set_bit(EVENT_RX_KILL, &dev->flags);
 646         }
 647
 648         state = defer_bh(dev, skb, &dev->rxq, state);
 649
 650         if (urb) {
 651                 if (netif_running (dev->net) &&
 652                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 653                     state != unlink_start) {
 654                         rx_submit (dev, urb, GFP_ATOMIC);
 655                         usb_mark_last_busy(dev->udev);
 656                         return;
 657                 }
 658                 usb_free_urb (urb);
 659         }
 660         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 661 }
 662
 663 /*-------------------------------------------------------------------------*/
 664 void usbnet_pause_rx(struct usbnet *dev)
 665 {
 666         set_bit(EVENT_RX_PAUSED, &dev->flags);
 667
 668         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 669 }
 670 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 671
 672 void usbnet_resume_rx(struct usbnet *dev)
 673 {
 674         struct sk_buff *skb;
 675         int num = 0;
 676
 677         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 678
 679         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 680                 usbnet_skb_return(dev, skb);
 681                 num++;
 682         }
 683
 684         tasklet_schedule(&dev->bh);
 685
 686         netif_dbg(dev, rx_status, dev->net,
 687                   "paused rx queue disabled, %d skbs requeued\n", num);
 688 }
 689 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 690
 691 void usbnet_purge_paused_rxq(struct usbnet *dev)
 692 {
 693         skb_queue_purge(&dev->rxq_pause);
 694 }
 695 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 696
 697 /*-------------------------------------------------------------------------*/
 698
 699 // unlink pending rx/tx; completion handlers do all other cleanup
 700
 701 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 702 {
 703         unsigned long           flags;
 704         struct sk_buff          *skb;
 705         int                     count = 0;
 706
 707         spin_lock_irqsave (&q->lock, flags);
 708         while (!skb_queue_empty(q)) {
 709                 struct skb_data         *entry;
 710                 struct urb              *urb;
 711                 int                     retval;
 712
 713                 skb_queue_walk(q, skb) {
 714                         entry = (struct skb_data *) skb->cb;
 715                         if (entry->state != unlink_start)
 716                                 goto found;
 717                 }
 718                 break;
 719 found:
 720                 entry->state = unlink_start;
 721                 urb = entry->urb;
 722
 723                 /*
 724                  * Get reference count of the URB to avoid it to be
 725                  * freed during usb_unlink_urb, which may trigger
 726                  * use-after-free problem inside usb_unlink_urb since
 727                  * usb_unlink_urb is always racing with .complete
 728                  * handler(include defer_bh).
 729                  */
 730                 usb_get_urb(urb);
 731                 spin_unlock_irqrestore(&q->lock, flags);
 732                 // during some PM-driven resume scenarios,
 733                 // these (async) unlinks complete immediately
 734                 retval = usb_unlink_urb (urb);
 735                 if (retval != -EINPROGRESS && retval != 0)
 736                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 737                 else
 738                         count++;
 739                 usb_put_urb(urb);
 740                 spin_lock_irqsave(&q->lock, flags);
 741         }
 742         spin_unlock_irqrestore (&q->lock, flags);
 743         return count;
 744 }
 745
 746 // Flush all pending rx urbs
 747 // minidrivers may need to do this when the MTU changes
 748
 749 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 750 {
 751         if (netif_running(dev->net)) {
 752                 (void) unlink_urbs (dev, &dev->rxq);
 753                 tasklet_schedule(&dev->bh);
 754         }
 755 }
 756 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 757
 758 /*-------------------------------------------------------------------------*/
 759
 760 static void wait_skb_queue_empty(struct sk_buff_head *q)
 761 {
 762         unsigned long flags;
 763
 764         spin_lock_irqsave(&q->lock, flags);
 765         while (!skb_queue_empty(q)) {
 766                 spin_unlock_irqrestore(&q->lock, flags);
 767                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 768                 set_current_state(TASK_UNINTERRUPTIBLE);
 769                 spin_lock_irqsave(&q->lock, flags);
 770         }
 771         spin_unlock_irqrestore(&q->lock, flags);
 772 }
 773
 774 // precondition: never called in_interrupt
 775 static void usbnet_terminate_urbs(struct usbnet *dev)
 776 {
 777         DECLARE_WAITQUEUE(wait, current);
 778         int temp;
 779
 780         /* ensure there are no more active urbs */
 781         add_wait_queue(&dev->wait, &wait);
 782         set_current_state(TASK_UNINTERRUPTIBLE);
 783         temp = unlink_urbs(dev, &dev->txq) +
 784                 unlink_urbs(dev, &dev->rxq);
 785
 786         /* maybe wait for deletions to finish. */
 787         wait_skb_queue_empty(&dev->rxq);
 788         wait_skb_queue_empty(&dev->txq);
 789         wait_skb_queue_empty(&dev->done);
 790         netif_dbg(dev, ifdown, dev->net,
 791                   "waited for %d urb completions\n", temp);
 792         set_current_state(TASK_RUNNING);
 793         remove_wait_queue(&dev->wait, &wait);
 794 }
 795
 796 int usbnet_stop (struct net_device *net)
 797 {
 798         struct usbnet           *dev = netdev_priv(net);
 799         const struct driver_info *info = dev->driver_info;
 800         int                     retval, pm, mpn;
 801
 802         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 803         netif_stop_queue (net);
 804
 805         netif_info(dev, ifdown, dev->net,
 806                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 807                    net->stats.rx_packets, net->stats.tx_packets,
 808                    net->stats.rx_errors, net->stats.tx_errors);
 809
 810         /* to not race resume */
 811         pm = usb_autopm_get_interface(dev->intf);
 812         /* allow minidriver to stop correctly (wireless devices to turn off
 813          * radio etc) */
 814         if (info->stop) {
 815                 retval = info->stop(dev);
 816                 if (retval < 0)
 817                         netif_info(dev, ifdown, dev->net,
 818                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 819                                    retval,
 820                                    dev->udev->bus->bus_name, dev->udev->devpath,
 821                                    info->description);
 822         }
 823
 824         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 825                 usbnet_terminate_urbs(dev);
 826
 827         usbnet_status_stop(dev);
 828
 829         usbnet_purge_paused_rxq(dev);
 830
 831         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 832
 833         /* deferred work (task, timer, softirq) must also stop.
 834          * can't flush_scheduled_work() until we drop rtnl (later),
 835          * else workers could deadlock; so make workers a NOP.
 836          */
 837         dev->flags = 0;
 838         del_timer_sync (&dev->delay);
 839         tasklet_kill (&dev->bh);
 840         if (!pm)
 841                 usb_autopm_put_interface(dev->intf);
 842
 843         if (info->manage_power && mpn)
 844                 info->manage_power(dev, 0);
 845         else
 846                 usb_autopm_put_interface(dev->intf);
 847
 848         return 0;
 849 }
 850 EXPORT_SYMBOL_GPL(usbnet_stop);
 851
 852 /*-------------------------------------------------------------------------*/
 853
 854 // posts reads, and enables write queuing
 855
 856 // precondition: never called in_interrupt
 857
 858 int usbnet_open (struct net_device *net)
 859 {
 860         struct usbnet           *dev = netdev_priv(net);
 861         int                     retval;
 862         const struct driver_info *info = dev->driver_info;
 863
 864         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 865                 netif_info(dev, ifup, dev->net,
 866                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 867                            retval,
 868                            dev->udev->bus->bus_name,
 869                            dev->udev->devpath,
 870                            info->description);
 871                 goto done_nopm;
 872         }
 873
 874         // put into "known safe" state
 875         if (info->reset && (retval = info->reset (dev)) < 0) {
 876                 netif_info(dev, ifup, dev->net,
 877                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 878                            retval,
 879                            dev->udev->bus->bus_name,
 880                            dev->udev->devpath,
 881                            info->description);
 882                 goto done;
 883         }
 884
 885         /* hard_mtu or rx_urb_size may change in reset() */
 886         usbnet_update_max_qlen(dev);
 887
 888         // insist peer be connected
 889         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 890                 netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 891                 goto done;
 892         }
 893
 894         /* start any status interrupt transfer */
 895         if (dev->interrupt) {
 896                 retval = usbnet_status_start(dev, GFP_KERNEL);
 897                 if (retval < 0) {
 898                         netif_err(dev, ifup, dev->net,
 899                                   "intr submit %d\n", retval);
 900                         goto done;
 901                 }
 902         }
 903
 904         set_bit(EVENT_DEV_OPEN, &dev->flags);
 905         netif_start_queue (net);
 906         netif_info(dev, ifup, dev->net,
 907                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 908                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 909                    dev->net->mtu,
 910                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 911                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 912                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 913                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 914                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 915                    "simple");
 916
 917         /* reset rx error state */
 918         dev->pkt_cnt = 0;
 919         dev->pkt_err = 0;
 920         clear_bit(EVENT_RX_KILL, &dev->flags);
 921
 922         // delay posting reads until we're fully open
 923         tasklet_schedule (&dev->bh);
 924         if (info->manage_power) {
 925                 retval = info->manage_power(dev, 1);
 926                 if (retval < 0) {
 927                         retval = 0;
 928                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 929                 } else {
 930                         usb_autopm_put_interface(dev->intf);
 931                 }
 932         }
 933         return retval;
 934 done:
 935         usb_autopm_put_interface(dev->intf);
 936 done_nopm:
 937         return retval;
 938 }
 939 EXPORT_SYMBOL_GPL(usbnet_open);
 940
 941 /*-------------------------------------------------------------------------*/
 942
 943 /* ethtool methods; minidrivers may need to add some more, but
 944  * they'll probably want to use this base set.
 945  */
 946
 947 int usbnet_get_link_ksettings(struct net_device *net,
 948                               struct ethtool_link_ksettings *cmd)
 949 {
 950         struct usbnet *dev = netdev_priv(net);
 951
 952         if (!dev->mii.mdio_read)
 953                 return -EOPNOTSUPP;
 954
 955         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 956
 957         return 0;
 958 }
 959 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings);
 960
 961 int usbnet_set_link_ksettings(struct net_device *net,
 962                               const struct ethtool_link_ksettings *cmd)
 963 {
 964         struct usbnet *dev = netdev_priv(net);
 965         int retval;
 966
 967         if (!dev->mii.mdio_write)
 968                 return -EOPNOTSUPP;
 969
 970         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
 971
 972         /* link speed/duplex might have changed */
 973         if (dev->driver_info->link_reset)
 974                 dev->driver_info->link_reset(dev);
 975
 976         /* hard_mtu or rx_urb_size may change in link_reset() */
 977         usbnet_update_max_qlen(dev);
 978
 979         return retval;
 980 }
 981 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings);
 982
 983 u32 usbnet_get_link (struct net_device *net)
 984 {
 985         struct usbnet *dev = netdev_priv(net);
 986
 987         /* If a check_connect is defined, return its result */
 988         if (dev->driver_info->check_connect)
 989                 return dev->driver_info->check_connect (dev) == 0;
 990
 991         /* if the device has mii operations, use those */
 992         if (dev->mii.mdio_read)
 993                 return mii_link_ok(&dev->mii);
 994
 995         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 996         return ethtool_op_get_link(net);
 997 }
 998 EXPORT_SYMBOL_GPL(usbnet_get_link);
 999
1000 int usbnet_nway_reset(struct net_device *net)
1001 {
1002         struct usbnet *dev = netdev_priv(net);
1003
1004         if (!dev->mii.mdio_write)
1005                 return -EOPNOTSUPP;
1006
1007         return mii_nway_restart(&dev->mii);
1008 }
1009 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1010
1011 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1012 {
1013         struct usbnet *dev = netdev_priv(net);
1014
1015         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1016         strlcpy (info->fw_version, dev->driver_info->description,
1017                 sizeof info->fw_version);
1018         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1019 }
1020 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1021
1022 u32 usbnet_get_msglevel (struct net_device *net)
1023 {
1024         struct usbnet *dev = netdev_priv(net);
1025
1026         return dev->msg_enable;
1027 }
1028 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1029
1030 void usbnet_set_msglevel (struct net_device *net, u32 level)
1031 {
1032         struct usbnet *dev = netdev_priv(net);
1033
1034         dev->msg_enable = level;
1035 }
1036 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1037
1038 /* drivers may override default ethtool_ops in their bind() routine */
1039 static const struct ethtool_ops usbnet_ethtool_ops = {
1040         .get_link               = usbnet_get_link,
1041         .nway_reset             = usbnet_nway_reset,
1042         .get_drvinfo            = usbnet_get_drvinfo,
1043         .get_msglevel           = usbnet_get_msglevel,
1044         .set_msglevel           = usbnet_set_msglevel,
1045         .get_ts_info            = ethtool_op_get_ts_info,
1046         .get_link_ksettings     = usbnet_get_link_ksettings,
1047         .set_link_ksettings     = usbnet_set_link_ksettings,
1048 };
1049
1050 /*-------------------------------------------------------------------------*/
1051
1052 static void __handle_link_change(struct usbnet *dev)
1053 {
1054         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1055                 return;
1056
1057         if (!netif_carrier_ok(dev->net)) {
1058                 /* kill URBs for reading packets to save bus bandwidth */
1059                 unlink_urbs(dev, &dev->rxq);
1060
1061                 /*
1062                  * tx_timeout will unlink URBs for sending packets and
1063                  * tx queue is stopped by netcore after link becomes off
1064                  */
1065         } else {
1066                 /* submitting URBs for reading packets */
1067                 tasklet_schedule(&dev->bh);
1068         }
1069
1070         /* hard_mtu or rx_urb_size may change during link change */
1071         usbnet_update_max_qlen(dev);
1072
1073         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1074 }
1075
1076 void usbnet_set_rx_mode(struct net_device *net)
1077 {
1078         struct usbnet           *dev = netdev_priv(net);
1079
1080         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1081 }
1082 EXPORT_SYMBOL_GPL(usbnet_set_rx_mode);
1083
1084 static void __handle_set_rx_mode(struct usbnet *dev)
1085 {
1086         if (dev->driver_info->set_rx_mode)
1087                 (dev->driver_info->set_rx_mode)(dev);
1088
1089         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1090 }
1091
1092 /* work that cannot be done in interrupt context uses keventd.
1093  *
1094  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1095  * especially now that control transfers can be queued.
1096  */
1097 static void
1098 usbnet_deferred_kevent (struct work_struct *work)
1099 {
1100         struct usbnet           *dev =
1101                 container_of(work, struct usbnet, kevent);
1102         int                     status;
1103
1104         /* usb_clear_halt() needs a thread context */
1105         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1106                 unlink_urbs (dev, &dev->txq);
1107                 status = usb_autopm_get_interface(dev->intf);
1108                 if (status < 0)
1109                         goto fail_pipe;
1110                 status = usb_clear_halt (dev->udev, dev->out);
1111                 usb_autopm_put_interface(dev->intf);
1112                 if (status < 0 &&
1113                     status != -EPIPE &&
1114                     status != -ESHUTDOWN) {
1115                         if (netif_msg_tx_err (dev))
1116 fail_pipe:
1117                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1118                                            status);
1119                 } else {
1120                         clear_bit (EVENT_TX_HALT, &dev->flags);
1121                         if (status != -ESHUTDOWN)
1122                                 netif_wake_queue (dev->net);
1123                 }
1124         }
1125         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1126                 unlink_urbs (dev, &dev->rxq);
1127                 status = usb_autopm_get_interface(dev->intf);
1128                 if (status < 0)
1129                         goto fail_halt;
1130                 status = usb_clear_halt (dev->udev, dev->in);
1131                 usb_autopm_put_interface(dev->intf);
1132                 if (status < 0 &&
1133                     status != -EPIPE &&
1134                     status != -ESHUTDOWN) {
1135                         if (netif_msg_rx_err (dev))
1136 fail_halt:
1137                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1138                                            status);
1139                 } else {
1140                         clear_bit (EVENT_RX_HALT, &dev->flags);
1141                         tasklet_schedule (&dev->bh);
1142                 }
1143         }
1144
1145         /* tasklet could resubmit itself forever if memory is tight */
1146         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1147                 struct urb      *urb = NULL;
1148                 int resched = 1;
1149
1150                 if (netif_running (dev->net))
1151                         urb = usb_alloc_urb (0, GFP_KERNEL);
1152                 else
1153                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1154                 if (urb != NULL) {
1155                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1156                         status = usb_autopm_get_interface(dev->intf);
1157                         if (status < 0) {
1158                                 usb_free_urb(urb);
1159                                 goto fail_lowmem;
1160                         }
1161                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1162                                 resched = 0;
1163                         usb_autopm_put_interface(dev->intf);
1164 fail_lowmem:
1165                         if (resched)
1166                                 tasklet_schedule (&dev->bh);
1167                 }
1168         }
1169
1170         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1171                 const struct driver_info *info = dev->driver_info;
1172                 int                     retval = 0;
1173
1174                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1175                 status = usb_autopm_get_interface(dev->intf);
1176                 if (status < 0)
1177                         goto skip_reset;
1178                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1179                         usb_autopm_put_interface(dev->intf);
1180 skip_reset:
1181                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1182                                     retval,
1183                                     dev->udev->bus->bus_name,
1184                                     dev->udev->devpath,
1185                                     info->description);
1186                 } else {
1187                         usb_autopm_put_interface(dev->intf);
1188                 }
1189
1190                 /* handle link change from link resetting */
1191                 __handle_link_change(dev);
1192         }
1193
1194         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1195                 __handle_link_change(dev);
1196
1197         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1198                 __handle_set_rx_mode(dev);
1199
1200
1201         if (dev->flags)
1202                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1203 }
1204
1205 /*-------------------------------------------------------------------------*/
1206
1207 static void tx_complete (struct urb *urb)
1208 {
1209         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1210         struct skb_data         *entry = (struct skb_data *) skb->cb;
1211         struct usbnet           *dev = entry->dev;
1212
1213         if (urb->status == 0) {
1214                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
1215                 unsigned long flags;
1216
1217                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1218                 stats64->tx_packets += entry->packets;
1219                 stats64->tx_bytes += entry->length;
1220                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1221         } else {
1222                 dev->net->stats.tx_errors++;
1223
1224                 switch (urb->status) {
1225                 case -EPIPE:
1226                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1227                         break;
1228
1229                 /* software-driven interface shutdown */
1230                 case -ECONNRESET:               // async unlink
1231                 case -ESHUTDOWN:                // hardware gone
1232                         break;
1233
1234                 /* like rx, tx gets controller i/o faults during hub_wq
1235                  * delays and so it uses the same throttling mechanism.
1236                  */
1237                 case -EPROTO:
1238                 case -ETIME:
1239                 case -EILSEQ:
1240                         usb_mark_last_busy(dev->udev);
1241                         if (!timer_pending (&dev->delay)) {
1242                                 mod_timer (&dev->delay,
1243                                         jiffies + THROTTLE_JIFFIES);
1244                                 netif_dbg(dev, link, dev->net,
1245                                           "tx throttle %d\n", urb->status);
1246                         }
1247                         netif_stop_queue (dev->net);
1248                         break;
1249                 default:
1250                         netif_dbg(dev, tx_err, dev->net,
1251                                   "tx err %d\n", entry->urb->status);
1252                         break;
1253                 }
1254         }
1255
1256         usb_autopm_put_interface_async(dev->intf);
1257         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1258 }
1259
1260 /*-------------------------------------------------------------------------*/
1261
1262 void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue)
1263 {
1264         struct usbnet           *dev = netdev_priv(net);
1265
1266         unlink_urbs (dev, &dev->txq);
1267         tasklet_schedule (&dev->bh);
1268         /* this needs to be handled individually because the generic layer
1269          * doesn't know what is sufficient and could not restore private
1270          * information if a remedy of an unconditional reset were used.
1271          */
1272         if (dev->driver_info->recover)
1273                 (dev->driver_info->recover)(dev);
1274 }
1275 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1276
1277 /*-------------------------------------------------------------------------*/
1278
1279 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1280 {
1281         unsigned num_sgs, total_len = 0;
1282         int i, s = 0;
1283
1284         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1285         if (num_sgs == 1)
1286                 return 0;
1287
1288         /* reserve one for zero packet */
1289         urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1290                                 GFP_ATOMIC);
1291         if (!urb->sg)
1292                 return -ENOMEM;
1293
1294         urb->num_sgs = num_sgs;
1295         sg_init_table(urb->sg, urb->num_sgs + 1);
1296
1297         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1298         total_len += skb_headlen(skb);
1299
1300         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1301                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1302
1303                 total_len += skb_frag_size(f);
1304                 sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1305                             skb_frag_off(f));
1306         }
1307         urb->transfer_buffer_length = total_len;
1308
1309         return 1;
1310 }
1311
1312 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1313                                      struct net_device *net)
1314 {
1315         struct usbnet           *dev = netdev_priv(net);
1316         unsigned int                    length;
1317         struct urb              *urb = NULL;
1318         struct skb_data         *entry;
1319         const struct driver_info *info = dev->driver_info;
1320         unsigned long           flags;
1321         int retval;
1322
1323         if (skb)
1324                 skb_tx_timestamp(skb);
1325
1326         // some devices want funky USB-level framing, for
1327         // win32 driver (usually) and/or hardware quirks
1328         if (info->tx_fixup) {
1329                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1330                 if (!skb) {
1331                         /* packet collected; minidriver waiting for more */
1332                         if (info->flags & FLAG_MULTI_PACKET)
1333                                 goto not_drop;
1334                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1335                         goto drop;
1336                 }
1337         }
1338
1339         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1340                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1341                 goto drop;
1342         }
1343
1344         entry = (struct skb_data *) skb->cb;
1345         entry->urb = urb;
1346         entry->dev = dev;
1347
1348         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1349                         skb->data, skb->len, tx_complete, skb);
1350         if (dev->can_dma_sg) {
1351                 if (build_dma_sg(skb, urb) < 0)
1352                         goto drop;
1353         }
1354         length = urb->transfer_buffer_length;
1355
1356         /* don't assume the hardware handles USB_ZERO_PACKET
1357          * NOTE:  strictly conforming cdc-ether devices should expect
1358          * the ZLP here, but ignore the one-byte packet.
1359          * NOTE2: CDC NCM specification is different from CDC ECM when
1360          * handling ZLP/short packets, so cdc_ncm driver will make short
1361          * packet itself if needed.
1362          */
1363         if (length % dev->maxpacket == 0) {
1364                 if (!(info->flags & FLAG_SEND_ZLP)) {
1365                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1366                                 length++;
1367                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1368                                         skb->data[skb->len] = 0;
1369                                         __skb_put(skb, 1);
1370                                 } else if (urb->num_sgs)
1371                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1372                                                         dev->padding_pkt, 1);
1373                         }
1374                 } else
1375                         urb->transfer_flags |= URB_ZERO_PACKET;
1376         }
1377         urb->transfer_buffer_length = length;
1378
1379         if (info->flags & FLAG_MULTI_PACKET) {
1380                 /* Driver has set number of packets and a length delta.
1381                  * Calculate the complete length and ensure that it's
1382                  * positive.
1383                  */
1384                 entry->length += length;
1385                 if (WARN_ON_ONCE(entry->length <= 0))
1386                         entry->length = length;
1387         } else {
1388                 usbnet_set_skb_tx_stats(skb, 1, length);
1389         }
1390
1391         spin_lock_irqsave(&dev->txq.lock, flags);
1392         retval = usb_autopm_get_interface_async(dev->intf);
1393         if (retval < 0) {
1394                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1395                 goto drop;
1396         }
1397         if (netif_queue_stopped(net)) {
1398                 usb_autopm_put_interface_async(dev->intf);
1399                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1400                 goto drop;
1401         }
1402
1403 #ifdef CONFIG_PM
1404         /* if this triggers the device is still a sleep */
1405         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1406                 /* transmission will be done in resume */
1407                 usb_anchor_urb(urb, &dev->deferred);
1408                 /* no use to process more packets */
1409                 netif_stop_queue(net);
1410                 usb_put_urb(urb);
1411                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1412                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1413                 goto deferred;
1414         }
1415 #endif
1416
1417         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1418         case -EPIPE:
1419                 netif_stop_queue (net);
1420                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1421                 usb_autopm_put_interface_async(dev->intf);
1422                 break;
1423         default:
1424                 usb_autopm_put_interface_async(dev->intf);
1425                 netif_dbg(dev, tx_err, dev->net,
1426                           "tx: submit urb err %d\n", retval);
1427                 break;
1428         case 0:
1429                 netif_trans_update(net);
1430                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1431                 if (dev->txq.qlen >= TX_QLEN (dev))
1432                         netif_stop_queue (net);
1433         }
1434         spin_unlock_irqrestore (&dev->txq.lock, flags);
1435
1436         if (retval) {
1437                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1438 drop:
1439                 dev->net->stats.tx_dropped++;
1440 not_drop:
1441                 if (skb)
1442                         dev_kfree_skb_any (skb);
1443                 if (urb) {
1444                         kfree(urb->sg);
1445                         usb_free_urb(urb);
1446                 }
1447         } else
1448                 netif_dbg(dev, tx_queued, dev->net,
1449                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1450 #ifdef CONFIG_PM
1451 deferred:
1452 #endif
1453         return NETDEV_TX_OK;
1454 }
1455 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1456
1457 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1458 {
1459         struct urb      *urb;
1460         int             i;
1461         int             ret = 0;
1462
1463         /* don't refill the queue all at once */
1464         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1465                 urb = usb_alloc_urb(0, flags);
1466                 if (urb != NULL) {
1467                         ret = rx_submit(dev, urb, flags);
1468                         if (ret)
1469                                 goto err;
1470                 } else {
1471                         ret = -ENOMEM;
1472                         goto err;
1473                 }
1474         }
1475 err:
1476         return ret;
1477 }
1478
1479 /*-------------------------------------------------------------------------*/
1480
1481 // tasklet (work deferred from completions, in_irq) or timer
1482
1483 static void usbnet_bh (struct timer_list *t)
1484 {
1485         struct usbnet           *dev = from_timer(dev, t, delay);
1486         struct sk_buff          *skb;
1487         struct skb_data         *entry;
1488
1489         while ((skb = skb_dequeue (&dev->done))) {
1490                 entry = (struct skb_data *) skb->cb;
1491                 switch (entry->state) {
1492                 case rx_done:
1493                         entry->state = rx_cleanup;
1494                         rx_process (dev, skb);
1495                         continue;
1496                 case tx_done:
1497                         kfree(entry->urb->sg);
1498                         fallthrough;
1499                 case rx_cleanup:
1500                         usb_free_urb (entry->urb);
1501                         dev_kfree_skb (skb);
1502                         continue;
1503                 default:
1504                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1505                 }
1506         }
1507
1508         /* restart RX again after disabling due to high error rate */
1509         clear_bit(EVENT_RX_KILL, &dev->flags);
1510
1511         /* waiting for all pending urbs to complete?
1512          * only then can we forgo submitting anew
1513          */
1514         if (waitqueue_active(&dev->wait)) {
1515                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1516                         wake_up_all(&dev->wait);
1517
1518         // or are we maybe short a few urbs?
1519         } else if (netif_running (dev->net) &&
1520                    netif_device_present (dev->net) &&
1521                    netif_carrier_ok(dev->net) &&
1522                    !timer_pending(&dev->delay) &&
1523                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1524                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1525                 int     temp = dev->rxq.qlen;
1526
1527                 if (temp < RX_QLEN(dev)) {
1528                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1529                                 return;
1530                         if (temp != dev->rxq.qlen)
1531                                 netif_dbg(dev, link, dev->net,
1532                                           "rxqlen %d --> %d\n",
1533                                           temp, dev->rxq.qlen);
1534                         if (dev->rxq.qlen < RX_QLEN(dev))
1535                                 tasklet_schedule (&dev->bh);
1536                 }
1537                 if (dev->txq.qlen < TX_QLEN (dev))
1538                         netif_wake_queue (dev->net);
1539         }
1540 }
1541
1542 static void usbnet_bh_tasklet(unsigned long data)
1543 {
1544         struct timer_list *t = (struct timer_list *)data;
1545
1546         usbnet_bh(t);
1547 }
1548
1549
1550 /*-------------------------------------------------------------------------
1551  *
1552  * USB Device Driver support
1553  *
1554  *-------------------------------------------------------------------------*/
1555
1556 // precondition: never called in_interrupt
1557
1558 void usbnet_disconnect (struct usb_interface *intf)
1559 {
1560         struct usbnet           *dev;
1561         struct usb_device       *xdev;
1562         struct net_device       *net;
1563
1564         dev = usb_get_intfdata(intf);
1565         usb_set_intfdata(intf, NULL);
1566         if (!dev)
1567                 return;
1568
1569         xdev = interface_to_usbdev (intf);
1570
1571         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1572                    intf->dev.driver->name,
1573                    xdev->bus->bus_name, xdev->devpath,
1574                    dev->driver_info->description);
1575
1576         net = dev->net;
1577         unregister_netdev (net);
1578
1579         cancel_work_sync(&dev->kevent);
1580
1581         usb_scuttle_anchored_urbs(&dev->deferred);
1582
1583         if (dev->driver_info->unbind)
1584                 dev->driver_info->unbind (dev, intf);
1585
1586         usb_kill_urb(dev->interrupt);
1587         usb_free_urb(dev->interrupt);
1588         kfree(dev->padding_pkt);
1589
1590         free_percpu(net->tstats);
1591         free_netdev(net);
1592 }
1593 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1594
1595 static const struct net_device_ops usbnet_netdev_ops = {
1596         .ndo_open               = usbnet_open,
1597         .ndo_stop               = usbnet_stop,
1598         .ndo_start_xmit         = usbnet_start_xmit,
1599         .ndo_tx_timeout         = usbnet_tx_timeout,
1600         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1601         .ndo_change_mtu         = usbnet_change_mtu,
1602         .ndo_get_stats64        = dev_get_tstats64,
1603         .ndo_set_mac_address    = eth_mac_addr,
1604         .ndo_validate_addr      = eth_validate_addr,
1605 };
1606
1607 /*-------------------------------------------------------------------------*/
1608
1609 // precondition: never called in_interrupt
1610
1611 static struct device_type wlan_type = {
1612         .name   = "wlan",
1613 };
1614
1615 static struct device_type wwan_type = {
1616         .name   = "wwan",
1617 };
1618
1619 int
1620 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1621 {
1622         struct usbnet                   *dev;
1623         struct net_device               *net;
1624         struct usb_host_interface       *interface;
1625         const struct driver_info        *info;
1626         struct usb_device               *xdev;
1627         int                             status;
1628         const char                      *name;
1629         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1630
1631         /* usbnet already took usb runtime pm, so have to enable the feature
1632          * for usb interface, otherwise usb_autopm_get_interface may return
1633          * failure if RUNTIME_PM is enabled.
1634          */
1635         if (!driver->supports_autosuspend) {
1636                 driver->supports_autosuspend = 1;
1637                 pm_runtime_enable(&udev->dev);
1638         }
1639
1640         name = udev->dev.driver->name;
1641         info = (const struct driver_info *) prod->driver_info;
1642         if (!info) {
1643                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1644                 return -ENODEV;
1645         }
1646         xdev = interface_to_usbdev (udev);
1647         interface = udev->cur_altsetting;
1648
1649         status = -ENOMEM;
1650
1651         // set up our own records
1652         net = alloc_etherdev(sizeof(*dev));
1653         if (!net)
1654                 goto out;
1655
1656         /* netdev_printk() needs this so do it as early as possible */
1657         SET_NETDEV_DEV(net, &udev->dev);
1658
1659         dev = netdev_priv(net);
1660         dev->udev = xdev;
1661         dev->intf = udev;
1662         dev->driver_info = info;
1663         dev->driver_name = name;
1664
1665         net->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1666         if (!net->tstats)
1667                 goto out0;
1668
1669         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1670                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1671         init_waitqueue_head(&dev->wait);
1672         skb_queue_head_init (&dev->rxq);
1673         skb_queue_head_init (&dev->txq);
1674         skb_queue_head_init (&dev->done);
1675         skb_queue_head_init(&dev->rxq_pause);
1676         dev->bh.func = usbnet_bh_tasklet;
1677         dev->bh.data = (unsigned long)&dev->delay;
1678         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1679         init_usb_anchor(&dev->deferred);
1680         timer_setup(&dev->delay, usbnet_bh, 0);
1681         mutex_init (&dev->phy_mutex);
1682         mutex_init(&dev->interrupt_mutex);
1683         dev->interrupt_count = 0;
1684
1685         dev->net = net;
1686         strcpy (net->name, "usb%d");
1687         memcpy (net->dev_addr, node_id, sizeof node_id);
1688
1689         /* rx and tx sides can use different message sizes;
1690          * bind() should set rx_urb_size in that case.
1691          */
1692         dev->hard_mtu = net->mtu + net->hard_header_len;
1693         net->min_mtu = 0;
1694         net->max_mtu = ETH_MAX_MTU;
1695
1696         net->netdev_ops = &usbnet_netdev_ops;
1697         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1698         net->ethtool_ops = &usbnet_ethtool_ops;
1699
1700         // allow device-specific bind/init procedures
1701         // NOTE net->name still not usable ...
1702         if (info->bind) {
1703                 status = info->bind (dev, udev);
1704                 if (status < 0)
1705                         goto out1;
1706
1707                 // heuristic:  "usb%d" for links we know are two-host,
1708                 // else "eth%d" when there's reasonable doubt.  userspace
1709                 // can rename the link if it knows better.
1710                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1711                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1712                      (net->dev_addr [0] & 0x02) == 0))
1713                         strcpy (net->name, "eth%d");
1714                 /* WLAN devices should always be named "wlan%d" */
1715                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1716                         strcpy(net->name, "wlan%d");
1717                 /* WWAN devices should always be named "wwan%d" */
1718                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1719                         strcpy(net->name, "wwan%d");
1720
1721                 /* devices that cannot do ARP */
1722                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1723                         net->flags |= IFF_NOARP;
1724
1725                 /* maybe the remote can't receive an Ethernet MTU */
1726                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1727                         net->mtu = dev->hard_mtu - net->hard_header_len;
1728         } else if (!info->in || !info->out)
1729                 status = usbnet_get_endpoints (dev, udev);
1730         else {
1731                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1732                 dev->out = usb_sndbulkpipe (xdev, info->out);
1733                 if (!(info->flags & FLAG_NO_SETINT))
1734                         status = usb_set_interface (xdev,
1735                                 interface->desc.bInterfaceNumber,
1736                                 interface->desc.bAlternateSetting);
1737                 else
1738                         status = 0;
1739
1740         }
1741         if (status >= 0 && dev->status)
1742                 status = init_status (dev, udev);
1743         if (status < 0)
1744                 goto out3;
1745
1746         if (!dev->rx_urb_size)
1747                 dev->rx_urb_size = dev->hard_mtu;
1748         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1749
1750         /* let userspace know we have a random address */
1751         if (ether_addr_equal(net->dev_addr, node_id))
1752                 net->addr_assign_type = NET_ADDR_RANDOM;
1753
1754         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1755                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1756         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1757                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1758
1759         /* initialize max rx_qlen and tx_qlen */
1760         usbnet_update_max_qlen(dev);
1761
1762         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1763                 !(info->flags & FLAG_MULTI_PACKET)) {
1764                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1765                 if (!dev->padding_pkt) {
1766                         status = -ENOMEM;
1767                         goto out4;
1768                 }
1769         }
1770
1771         status = register_netdev (net);
1772         if (status)
1773                 goto out5;
1774         netif_info(dev, probe, dev->net,
1775                    "register '%s' at usb-%s-%s, %s, %pM\n",
1776                    udev->dev.driver->name,
1777                    xdev->bus->bus_name, xdev->devpath,
1778                    dev->driver_info->description,
1779                    net->dev_addr);
1780
1781         // ok, it's ready to go.
1782         usb_set_intfdata (udev, dev);
1783
1784         netif_device_attach (net);
1785
1786         if (dev->driver_info->flags & FLAG_LINK_INTR)
1787                 usbnet_link_change(dev, 0, 0);
1788
1789         return 0;
1790
1791 out5:
1792         kfree(dev->padding_pkt);
1793 out4:
1794         usb_free_urb(dev->interrupt);
1795 out3:
1796         if (info->unbind)
1797                 info->unbind (dev, udev);
1798 out1:
1799         /* subdrivers must undo all they did in bind() if they
1800          * fail it, but we may fail later and a deferred kevent
1801          * may trigger an error resubmitting itself and, worse,
1802          * schedule a timer. So we kill it all just in case.
1803          */
1804         cancel_work_sync(&dev->kevent);
1805         del_timer_sync(&dev->delay);
1806         free_percpu(net->tstats);
1807 out0:
1808         free_netdev(net);
1809 out:
1810         return status;
1811 }
1812 EXPORT_SYMBOL_GPL(usbnet_probe);
1813
1814 /*-------------------------------------------------------------------------*/
1815
1816 /*
1817  * suspend the whole driver as soon as the first interface is suspended
1818  * resume only when the last interface is resumed
1819  */
1820
1821 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1822 {
1823         struct usbnet           *dev = usb_get_intfdata(intf);
1824
1825         if (!dev->suspend_count++) {
1826                 spin_lock_irq(&dev->txq.lock);
1827                 /* don't autosuspend while transmitting */
1828                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1829                         dev->suspend_count--;
1830                         spin_unlock_irq(&dev->txq.lock);
1831                         return -EBUSY;
1832                 } else {
1833                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1834                         spin_unlock_irq(&dev->txq.lock);
1835                 }
1836                 /*
1837                  * accelerate emptying of the rx and queues, to avoid
1838                  * having everything error out.
1839                  */
1840                 netif_device_detach (dev->net);
1841                 usbnet_terminate_urbs(dev);
1842                 __usbnet_status_stop_force(dev);
1843
1844                 /*
1845                  * reattach so runtime management can use and
1846                  * wake the device
1847                  */
1848                 netif_device_attach (dev->net);
1849         }
1850         return 0;
1851 }
1852 EXPORT_SYMBOL_GPL(usbnet_suspend);
1853
1854 int usbnet_resume (struct usb_interface *intf)
1855 {
1856         struct usbnet           *dev = usb_get_intfdata(intf);
1857         struct sk_buff          *skb;
1858         struct urb              *res;
1859         int                     retval;
1860
1861         if (!--dev->suspend_count) {
1862                 /* resume interrupt URB if it was previously submitted */
1863                 __usbnet_status_start_force(dev, GFP_NOIO);
1864
1865                 spin_lock_irq(&dev->txq.lock);
1866                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1867
1868                         skb = (struct sk_buff *)res->context;
1869                         retval = usb_submit_urb(res, GFP_ATOMIC);
1870                         if (retval < 0) {
1871                                 dev_kfree_skb_any(skb);
1872                                 kfree(res->sg);
1873                                 usb_free_urb(res);
1874                                 usb_autopm_put_interface_async(dev->intf);
1875                         } else {
1876                                 netif_trans_update(dev->net);
1877                                 __skb_queue_tail(&dev->txq, skb);
1878                         }
1879                 }
1880
1881                 smp_mb();
1882                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1883                 spin_unlock_irq(&dev->txq.lock);
1884
1885                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1886                         /* handle remote wakeup ASAP
1887                          * we cannot race against stop
1888                          */
1889                         if (netif_device_present(dev->net) &&
1890                                 !timer_pending(&dev->delay) &&
1891                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1892                                         rx_alloc_submit(dev, GFP_NOIO);
1893
1894                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1895                                 netif_tx_wake_all_queues(dev->net);
1896                         tasklet_schedule (&dev->bh);
1897                 }
1898         }
1899
1900         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1901                 usb_autopm_get_interface_no_resume(intf);
1902
1903         return 0;
1904 }
1905 EXPORT_SYMBOL_GPL(usbnet_resume);
1906
1907 /*
1908  * Either a subdriver implements manage_power, then it is assumed to always
1909  * be ready to be suspended or it reports the readiness to be suspended
1910  * explicitly
1911  */
1912 void usbnet_device_suggests_idle(struct usbnet *dev)
1913 {
1914         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1915                 dev->intf->needs_remote_wakeup = 1;
1916                 usb_autopm_put_interface_async(dev->intf);
1917         }
1918 }
1919 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1920
1921 /*
1922  * For devices that can do without special commands
1923  */
1924 int usbnet_manage_power(struct usbnet *dev, int on)
1925 {
1926         dev->intf->needs_remote_wakeup = on;
1927         return 0;
1928 }
1929 EXPORT_SYMBOL(usbnet_manage_power);
1930
1931 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1932 {
1933         /* update link after link is reseted */
1934         if (link && !need_reset)
1935                 netif_carrier_on(dev->net);
1936         else
1937                 netif_carrier_off(dev->net);
1938
1939         if (need_reset && link)
1940                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1941         else
1942                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1943 }
1944 EXPORT_SYMBOL(usbnet_link_change);
1945
1946 /*-------------------------------------------------------------------------*/
1947 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1948                              u16 value, u16 index, void *data, u16 size)
1949 {
1950         void *buf = NULL;
1951         int err = -ENOMEM;
1952
1953         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1954                    " value=0x%04x index=0x%04x size=%d\n",
1955                    cmd, reqtype, value, index, size);
1956
1957         if (size) {
1958                 buf = kmalloc(size, GFP_KERNEL);
1959                 if (!buf)
1960                         goto out;
1961         }
1962
1963         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1964                               cmd, reqtype, value, index, buf, size,
1965                               USB_CTRL_GET_TIMEOUT);
1966         if (err > 0 && err <= size) {
1967         if (data)
1968             memcpy(data, buf, err);
1969         else
1970             netdev_dbg(dev->net,
1971                 "Huh? Data requested but thrown away.\n");
1972     }
1973         kfree(buf);
1974 out:
1975         return err;
1976 }
1977
1978 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1979                               u16 value, u16 index, const void *data,
1980                               u16 size)
1981 {
1982         void *buf = NULL;
1983         int err = -ENOMEM;
1984
1985         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1986                    " value=0x%04x index=0x%04x size=%d\n",
1987                    cmd, reqtype, value, index, size);
1988
1989         if (data) {
1990                 buf = kmemdup(data, size, GFP_KERNEL);
1991                 if (!buf)
1992                         goto out;
1993         } else {
1994         if (size) {
1995             WARN_ON_ONCE(1);
1996             err = -EINVAL;
1997             goto out;
1998         }
1999     }
2000
2001         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2002                               cmd, reqtype, value, index, buf, size,
2003                               USB_CTRL_SET_TIMEOUT);
2004         kfree(buf);
2005
2006 out:
2007         return err;
2008 }
2009
2010 /*
2011  * The function can't be called inside suspend/resume callback,
2012  * otherwise deadlock will be caused.
2013  */
2014 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2015                     u16 value, u16 index, void *data, u16 size)
2016 {
2017         int ret;
2018
2019         if (usb_autopm_get_interface(dev->intf) < 0)
2020                 return -ENODEV;
2021         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2022                                 data, size);
2023         usb_autopm_put_interface(dev->intf);
2024         return ret;
2025 }
2026 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2027
2028 /*
2029  * The function can't be called inside suspend/resume callback,
2030  * otherwise deadlock will be caused.
2031  */
2032 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2033                      u16 value, u16 index, const void *data, u16 size)
2034 {
2035         int ret;
2036
2037         if (usb_autopm_get_interface(dev->intf) < 0)
2038                 return -ENODEV;
2039         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2040                                  data, size);
2041         usb_autopm_put_interface(dev->intf);
2042         return ret;
2043 }
2044 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2045
2046 /*
2047  * The function can be called inside suspend/resume callback safely
2048  * and should only be called by suspend/resume callback generally.
2049  */
2050 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2051                           u16 value, u16 index, void *data, u16 size)
2052 {
2053         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2054                                  data, size);
2055 }
2056 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2057
2058 /*
2059  * The function can be called inside suspend/resume callback safely
2060  * and should only be called by suspend/resume callback generally.
2061  */
2062 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2063                           u16 value, u16 index, const void *data,
2064                           u16 size)
2065 {
2066         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2067                                   data, size);
2068 }
2069 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2070
2071 static void usbnet_async_cmd_cb(struct urb *urb)
2072 {
2073         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2074         int status = urb->status;
2075
2076         if (status < 0)
2077                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2078                         __func__, status);
2079
2080         kfree(req);
2081         usb_free_urb(urb);
2082 }
2083
2084 /*
2085  * The caller must make sure that device can't be put into suspend
2086  * state until the control URB completes.
2087  */
2088 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2089                            u16 value, u16 index, const void *data, u16 size)
2090 {
2091         struct usb_ctrlrequest *req = NULL;
2092         struct urb *urb;
2093         int err = -ENOMEM;
2094         void *buf = NULL;
2095
2096         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2097                    " value=0x%04x index=0x%04x size=%d\n",
2098                    cmd, reqtype, value, index, size);
2099
2100         urb = usb_alloc_urb(0, GFP_ATOMIC);
2101         if (!urb)
2102                 goto fail;
2103
2104         if (data) {
2105                 buf = kmemdup(data, size, GFP_ATOMIC);
2106                 if (!buf) {
2107                         netdev_err(dev->net, "Error allocating buffer"
2108                                    " in %s!\n", __func__);
2109                         goto fail_free;
2110                 }
2111         }
2112
2113         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2114         if (!req)
2115                 goto fail_free_buf;
2116
2117         req->bRequestType = reqtype;
2118         req->bRequest = cmd;
2119         req->wValue = cpu_to_le16(value);
2120         req->wIndex = cpu_to_le16(index);
2121         req->wLength = cpu_to_le16(size);
2122
2123         usb_fill_control_urb(urb, dev->udev,
2124                              usb_sndctrlpipe(dev->udev, 0),
2125                              (void *)req, buf, size,
2126                              usbnet_async_cmd_cb, req);
2127         urb->transfer_flags |= URB_FREE_BUFFER;
2128
2129         err = usb_submit_urb(urb, GFP_ATOMIC);
2130         if (err < 0) {
2131                 netdev_err(dev->net, "Error submitting the control"
2132                            " message: status=%d\n", err);
2133                 goto fail_free;
2134         }
2135         return 0;
2136
2137 fail_free_buf:
2138         kfree(buf);
2139 fail_free:
2140         kfree(req);
2141         usb_free_urb(urb);
2142 fail:
2143         return err;
2144
2145 }
2146 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2147 /*-------------------------------------------------------------------------*/
2148
2149 static int __init usbnet_init(void)
2150 {
2151         /* Compiler should optimize this out. */
2152         BUILD_BUG_ON(
2153                 sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data));
2154
2155         eth_random_addr(node_id);
2156         return 0;
2157 }
2158 module_init(usbnet_init);
2159
2160 static void __exit usbnet_exit(void)
2161 {
2162 }
2163 module_exit(usbnet_exit);
2164
2165 MODULE_AUTHOR("David Brownell");
2166 MODULE_DESCRIPTION("USB network driver framework");
2167 MODULE_LICENSE("GPL");