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 #include <linux/module.h>
  21 #include <linux/init.h>
  22 #include <linux/netdevice.h>
  23 #include <linux/etherdevice.h>
  24 #include <linux/ctype.h>
  25 #include <linux/ethtool.h>
  26 #include <linux/workqueue.h>
  27 #include <linux/mii.h>
  28 #include <linux/usb.h>
  29 #include <linux/usb/usbnet.h>
  30 #include <linux/slab.h>
  31 #include <linux/kernel.h>
  32 #include <linux/pm_runtime.h>
  33
  34 /*-------------------------------------------------------------------------*/
  35
  36 /*
  37  * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  38  * Several dozen bytes of IPv4 data can fit in two such transactions.
  39  * One maximum size Ethernet packet takes twenty four of them.
  40  * For high speed, each frame comfortably fits almost 36 max size
  41  * Ethernet packets (so queues should be bigger).
  42  *
  43  * The goal is to let the USB host controller be busy for 5msec or
  44  * more before an irq is required, under load.  Jumbograms change
  45  * the equation.
  46  */
  47 #define MAX_QUEUE_MEMORY        (60 * 1518)
  48 #define RX_QLEN(dev)            ((dev)->rx_qlen)
  49 #define TX_QLEN(dev)            ((dev)->tx_qlen)
  50
  51 // reawaken network queue this soon after stopping; else watchdog barks
  52 #define TX_TIMEOUT_JIFFIES      (5*HZ)
  53
  54 /* throttle rx/tx briefly after some faults, so hub_wq might disconnect()
  55  * us (it polls at HZ/4 usually) before we report too many false errors.
  56  */
  57 #define THROTTLE_JIFFIES        (HZ/8)
  58
  59 // between wakeups
  60 #define UNLINK_TIMEOUT_MS       3
  61
  62 /*-------------------------------------------------------------------------*/
  63
  64 /* use ethtool to change the level for any given device */
  65 static int msg_level = -1;
  66 module_param (msg_level, int, 0);
  67 MODULE_PARM_DESC (msg_level, "Override default message level");
  68
  69 /*-------------------------------------------------------------------------*/
  70
  71 static const char * const usbnet_event_names[] = {
  72         [EVENT_TX_HALT]            = "EVENT_TX_HALT",
  73         [EVENT_RX_HALT]            = "EVENT_RX_HALT",
  74         [EVENT_RX_MEMORY]          = "EVENT_RX_MEMORY",
  75         [EVENT_STS_SPLIT]          = "EVENT_STS_SPLIT",
  76         [EVENT_LINK_RESET]         = "EVENT_LINK_RESET",
  77         [EVENT_RX_PAUSED]          = "EVENT_RX_PAUSED",
  78         [EVENT_DEV_ASLEEP]         = "EVENT_DEV_ASLEEP",
  79         [EVENT_DEV_OPEN]           = "EVENT_DEV_OPEN",
  80         [EVENT_DEVICE_REPORT_IDLE] = "EVENT_DEVICE_REPORT_IDLE",
  81         [EVENT_NO_RUNTIME_PM]      = "EVENT_NO_RUNTIME_PM",
  82         [EVENT_RX_KILL]            = "EVENT_RX_KILL",
  83         [EVENT_LINK_CHANGE]        = "EVENT_LINK_CHANGE",
  84         [EVENT_SET_RX_MODE]        = "EVENT_SET_RX_MODE",
  85         [EVENT_NO_IP_ALIGN]        = "EVENT_NO_IP_ALIGN",
  86 };
  87
  88 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  89 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  90 {
  91         int                             tmp;
  92         struct usb_host_interface       *alt = NULL;
  93         struct usb_host_endpoint        *in = NULL, *out = NULL;
  94         struct usb_host_endpoint        *status = NULL;
  95
  96         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
  97                 unsigned        ep;
  98
  99                 in = out = status = NULL;
 100                 alt = intf->altsetting + tmp;
 101
 102                 /* take the first altsetting with in-bulk + out-bulk;
 103                  * remember any status endpoint, just in case;
 104                  * ignore other endpoints and altsettings.
 105                  */
 106                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 107                         struct usb_host_endpoint        *e;
 108                         int                             intr = 0;
 109
 110                         e = alt->endpoint + ep;
 111
 112                         /* ignore endpoints which cannot transfer data */
 113                         if (!usb_endpoint_maxp(&e->desc))
 114                                 continue;
 115
 116                         switch (e->desc.bmAttributes) {
 117                         case USB_ENDPOINT_XFER_INT:
 118                                 if (!usb_endpoint_dir_in(&e->desc))
 119                                         continue;
 120                                 intr = 1;
 121                                 fallthrough;
 122                         case USB_ENDPOINT_XFER_BULK:
 123                                 break;
 124                         default:
 125                                 continue;
 126                         }
 127                         if (usb_endpoint_dir_in(&e->desc)) {
 128                                 if (!intr && !in)
 129                                         in = e;
 130                                 else if (intr && !status)
 131                                         status = e;
 132                         } else {
 133                                 if (!out)
 134                                         out = e;
 135                         }
 136                 }
 137                 if (in && out)
 138                         break;
 139         }
 140         if (!alt || !in || !out)
 141                 return -EINVAL;
 142
 143         if (alt->desc.bAlternateSetting != 0 ||
 144             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 145                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 146                                 alt->desc.bAlternateSetting);
 147                 if (tmp < 0)
 148                         return tmp;
 149         }
 150
 151         dev->in = usb_rcvbulkpipe (dev->udev,
 152                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 153         dev->out = usb_sndbulkpipe (dev->udev,
 154                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 155         dev->status = status;
 156         return 0;
 157 }
 158 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 159
 160 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 161 {
 162         u8              addr[ETH_ALEN];
 163         int             tmp = -1, ret;
 164         unsigned char   buf [13];
 165
 166         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 167         if (ret == 12)
 168                 tmp = hex2bin(addr, buf, 6);
 169         if (tmp < 0) {
 170                 dev_dbg(&dev->udev->dev,
 171                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 172                 if (ret >= 0)
 173                         ret = -EINVAL;
 174                 return ret;
 175         }
 176         eth_hw_addr_set(dev->net, addr);
 177         return 0;
 178 }
 179 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 180
 181 static void intr_complete (struct urb *urb)
 182 {
 183         struct usbnet   *dev = urb->context;
 184         int             status = urb->status;
 185
 186         switch (status) {
 187         /* success */
 188         case 0:
 189                 dev->driver_info->status(dev, urb);
 190                 break;
 191
 192         /* software-driven interface shutdown */
 193         case -ENOENT:           /* urb killed */
 194         case -ESHUTDOWN:        /* hardware gone */
 195                 netif_dbg(dev, ifdown, dev->net,
 196                           "intr shutdown, code %d\n", status);
 197                 return;
 198
 199         /* NOTE:  not throttling like RX/TX, since this endpoint
 200          * already polls infrequently
 201          */
 202         default:
 203                 netdev_dbg(dev->net, "intr status %d\n", status);
 204                 break;
 205         }
 206
 207         status = usb_submit_urb (urb, GFP_ATOMIC);
 208         if (status != 0)
 209                 netif_err(dev, timer, dev->net,
 210                           "intr resubmit --> %d\n", status);
 211 }
 212
 213 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 214 {
 215         char            *buf = NULL;
 216         unsigned        pipe = 0;
 217         unsigned        maxp;
 218         unsigned        period;
 219
 220         if (!dev->driver_info->status)
 221                 return 0;
 222
 223         pipe = usb_rcvintpipe (dev->udev,
 224                         dev->status->desc.bEndpointAddress
 225                                 & USB_ENDPOINT_NUMBER_MASK);
 226         maxp = usb_maxpacket(dev->udev, pipe);
 227
 228         /* avoid 1 msec chatter:  min 8 msec poll rate */
 229         period = max ((int) dev->status->desc.bInterval,
 230                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 231
 232         buf = kmalloc (maxp, GFP_KERNEL);
 233         if (buf) {
 234                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 235                 if (!dev->interrupt) {
 236                         kfree (buf);
 237                         return -ENOMEM;
 238                 } else {
 239                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 240                                 buf, maxp, intr_complete, dev, period);
 241                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 242                         dev_dbg(&intf->dev,
 243                                 "status ep%din, %d bytes period %d\n",
 244                                 usb_pipeendpoint(pipe), maxp, period);
 245                 }
 246         }
 247         return 0;
 248 }
 249
 250 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 251 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 252 {
 253         int ret = 0;
 254
 255         WARN_ON_ONCE(dev->interrupt == NULL);
 256         if (dev->interrupt) {
 257                 mutex_lock(&dev->interrupt_mutex);
 258
 259                 if (++dev->interrupt_count == 1)
 260                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 261
 262                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 263                         dev->interrupt_count);
 264                 mutex_unlock(&dev->interrupt_mutex);
 265         }
 266         return ret;
 267 }
 268 EXPORT_SYMBOL_GPL(usbnet_status_start);
 269
 270 /* For resume; submit interrupt URB if previously submitted */
 271 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 272 {
 273         int ret = 0;
 274
 275         mutex_lock(&dev->interrupt_mutex);
 276         if (dev->interrupt_count) {
 277                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 278                 dev_dbg(&dev->udev->dev,
 279                         "submitted interrupt URB for resume\n");
 280         }
 281         mutex_unlock(&dev->interrupt_mutex);
 282         return ret;
 283 }
 284
 285 /* Kill the interrupt URB if all submitters want it killed */
 286 void usbnet_status_stop(struct usbnet *dev)
 287 {
 288         if (dev->interrupt) {
 289                 mutex_lock(&dev->interrupt_mutex);
 290                 WARN_ON(dev->interrupt_count == 0);
 291
 292                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 293                         usb_kill_urb(dev->interrupt);
 294
 295                 dev_dbg(&dev->udev->dev,
 296                         "decremented interrupt URB count to %d\n",
 297                         dev->interrupt_count);
 298                 mutex_unlock(&dev->interrupt_mutex);
 299         }
 300 }
 301 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 302
 303 /* For suspend; always kill interrupt URB */
 304 static void __usbnet_status_stop_force(struct usbnet *dev)
 305 {
 306         if (dev->interrupt) {
 307                 mutex_lock(&dev->interrupt_mutex);
 308                 usb_kill_urb(dev->interrupt);
 309                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 310                 mutex_unlock(&dev->interrupt_mutex);
 311         }
 312 }
 313
 314 /* Passes this packet up the stack, updating its accounting.
 315  * Some link protocols batch packets, so their rx_fixup paths
 316  * can return clones as well as just modify the original skb.
 317  */
 318 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 319 {
 320         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
 321         unsigned long flags;
 322         int     status;
 323
 324         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 325                 skb_queue_tail(&dev->rxq_pause, skb);
 326                 return;
 327         }
 328
 329         /* only update if unset to allow minidriver rx_fixup override */
 330         if (skb->protocol == 0)
 331                 skb->protocol = eth_type_trans (skb, dev->net);
 332
 333         flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 334         u64_stats_inc(&stats64->rx_packets);
 335         u64_stats_add(&stats64->rx_bytes, skb->len);
 336         u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 337
 338         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 339                   skb->len + sizeof (struct ethhdr), skb->protocol);
 340         memset (skb->cb, 0, sizeof (struct skb_data));
 341
 342         if (skb_defer_rx_timestamp(skb))
 343                 return;
 344
 345         status = netif_rx (skb);
 346         if (status != NET_RX_SUCCESS)
 347                 netif_dbg(dev, rx_err, dev->net,
 348                           "netif_rx status %d\n", status);
 349 }
 350 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 351
 352 /* must be called if hard_mtu or rx_urb_size changed */
 353 void usbnet_update_max_qlen(struct usbnet *dev)
 354 {
 355         enum usb_device_speed speed = dev->udev->speed;
 356
 357         if (!dev->rx_urb_size || !dev->hard_mtu)
 358                 goto insanity;
 359         switch (speed) {
 360         case USB_SPEED_HIGH:
 361                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 362                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 363                 break;
 364         case USB_SPEED_SUPER:
 365         case USB_SPEED_SUPER_PLUS:
 366                 /*
 367                  * Not take default 5ms qlen for super speed HC to
 368                  * save memory, and iperf tests show 2.5ms qlen can
 369                  * work well
 370                  */
 371                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 372                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 373                 break;
 374         default:
 375 insanity:
 376                 dev->rx_qlen = dev->tx_qlen = 4;
 377         }
 378 }
 379 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 380
 381
 382 /*-------------------------------------------------------------------------
 383  *
 384  * Network Device Driver (peer link to "Host Device", from USB host)
 385  *
 386  *-------------------------------------------------------------------------*/
 387
 388 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 389 {
 390         struct usbnet   *dev = netdev_priv(net);
 391         int             ll_mtu = new_mtu + net->hard_header_len;
 392         int             old_hard_mtu = dev->hard_mtu;
 393         int             old_rx_urb_size = dev->rx_urb_size;
 394
 395         // no second zero-length packet read wanted after mtu-sized packets
 396         if ((ll_mtu % dev->maxpacket) == 0)
 397                 return -EDOM;
 398         WRITE_ONCE(net->mtu, new_mtu);
 399
 400         dev->hard_mtu = net->mtu + net->hard_header_len;
 401         if (dev->rx_urb_size == old_hard_mtu) {
 402                 dev->rx_urb_size = dev->hard_mtu;
 403                 if (dev->rx_urb_size > old_rx_urb_size) {
 404                         usbnet_pause_rx(dev);
 405                         usbnet_unlink_rx_urbs(dev);
 406                         usbnet_resume_rx(dev);
 407                 }
 408         }
 409
 410         /* max qlen depend on hard_mtu and rx_urb_size */
 411         usbnet_update_max_qlen(dev);
 412
 413         return 0;
 414 }
 415 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 416
 417 /* The caller must hold list->lock */
 418 static void __usbnet_queue_skb(struct sk_buff_head *list,
 419                         struct sk_buff *newsk, enum skb_state state)
 420 {
 421         struct skb_data *entry = (struct skb_data *) newsk->cb;
 422
 423         __skb_queue_tail(list, newsk);
 424         entry->state = state;
 425 }
 426
 427 /*-------------------------------------------------------------------------*/
 428
 429 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 430  * completion callbacks.  2.5 should have fixed those bugs...
 431  */
 432
 433 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 434                 struct sk_buff_head *list, enum skb_state state)
 435 {
 436         unsigned long           flags;
 437         enum skb_state          old_state;
 438         struct skb_data *entry = (struct skb_data *) skb->cb;
 439
 440         spin_lock_irqsave(&list->lock, flags);
 441         old_state = entry->state;
 442         entry->state = state;
 443         __skb_unlink(skb, list);
 444
 445         /* defer_bh() is never called with list == &dev->done.
 446          * spin_lock_nested() tells lockdep that it is OK to take
 447          * dev->done.lock here with list->lock held.
 448          */
 449         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 450
 451         __skb_queue_tail(&dev->done, skb);
 452         if (dev->done.qlen == 1)
 453                 tasklet_schedule(&dev->bh);
 454         spin_unlock(&dev->done.lock);
 455         spin_unlock_irqrestore(&list->lock, flags);
 456         return old_state;
 457 }
 458
 459 /* some work can't be done in tasklets, so we use keventd
 460  *
 461  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 462  * but tasklet_schedule() doesn't.  hope the failure is rare.
 463  */
 464 void usbnet_defer_kevent (struct usbnet *dev, int work)
 465 {
 466         set_bit (work, &dev->flags);
 467         if (!usbnet_going_away(dev)) {
 468                 if (!schedule_work(&dev->kevent))
 469                         netdev_dbg(dev->net,
 470                                    "kevent %s may have been dropped\n",
 471                                    usbnet_event_names[work]);
 472                 else
 473                         netdev_dbg(dev->net,
 474                                    "kevent %s scheduled\n", usbnet_event_names[work]);
 475         }
 476 }
 477 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 478
 479 /*-------------------------------------------------------------------------*/
 480
 481 static void rx_complete (struct urb *urb);
 482
 483 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 484 {
 485         struct sk_buff          *skb;
 486         struct skb_data         *entry;
 487         int                     retval = 0;
 488         unsigned long           lockflags;
 489         size_t                  size = dev->rx_urb_size;
 490
 491         /* prevent rx skb allocation when error ratio is high */
 492         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 493                 usb_free_urb(urb);
 494                 return -ENOLINK;
 495         }
 496
 497         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 498                 skb = __netdev_alloc_skb(dev->net, size, flags);
 499         else
 500                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 501         if (!skb) {
 502                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 503                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 504                 usb_free_urb (urb);
 505                 return -ENOMEM;
 506         }
 507
 508         entry = (struct skb_data *) skb->cb;
 509         entry->urb = urb;
 510         entry->dev = dev;
 511         entry->length = 0;
 512
 513         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 514                 skb->data, size, rx_complete, skb);
 515
 516         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 517
 518         if (netif_running (dev->net) &&
 519             netif_device_present (dev->net) &&
 520             test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 521             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 522             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 523                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 524                 case -EPIPE:
 525                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 526                         break;
 527                 case -ENOMEM:
 528                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 529                         break;
 530                 case -ENODEV:
 531                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 532                         netif_device_detach (dev->net);
 533                         break;
 534                 case -EHOSTUNREACH:
 535                         retval = -ENOLINK;
 536                         break;
 537                 default:
 538                         netif_dbg(dev, rx_err, dev->net,
 539                                   "rx submit, %d\n", retval);
 540                         tasklet_schedule (&dev->bh);
 541                         break;
 542                 case 0:
 543                         if (!usbnet_going_away(dev))
 544                                 __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 545                 }
 546         } else {
 547                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 548                 retval = -ENOLINK;
 549         }
 550         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 551         if (retval) {
 552                 dev_kfree_skb_any (skb);
 553                 usb_free_urb (urb);
 554         }
 555         return retval;
 556 }
 557
 558
 559 /*-------------------------------------------------------------------------*/
 560
 561 static inline int rx_process(struct usbnet *dev, struct sk_buff *skb)
 562 {
 563         if (dev->driver_info->rx_fixup &&
 564             !dev->driver_info->rx_fixup (dev, skb)) {
 565                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 566                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 567                         dev->net->stats.rx_errors++;
 568                 return -EPROTO;
 569         }
 570         // else network stack removes extra byte if we forced a short packet
 571
 572         /* all data was already cloned from skb inside the driver */
 573         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 574                 return -EALREADY;
 575
 576         if (skb->len < ETH_HLEN) {
 577                 dev->net->stats.rx_errors++;
 578                 dev->net->stats.rx_length_errors++;
 579                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 580                 return -EPROTO;
 581         }
 582
 583         usbnet_skb_return(dev, skb);
 584         return 0;
 585 }
 586
 587 /*-------------------------------------------------------------------------*/
 588
 589 static void rx_complete (struct urb *urb)
 590 {
 591         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 592         struct skb_data         *entry = (struct skb_data *) skb->cb;
 593         struct usbnet           *dev = entry->dev;
 594         int                     urb_status = urb->status;
 595         enum skb_state          state;
 596
 597         skb_put (skb, urb->actual_length);
 598         state = rx_done;
 599         entry->urb = NULL;
 600
 601         switch (urb_status) {
 602         /* success */
 603         case 0:
 604                 break;
 605
 606         /* stalls need manual reset. this is rare ... except that
 607          * when going through USB 2.0 TTs, unplug appears this way.
 608          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 609          * storm, recovering as needed.
 610          */
 611         case -EPIPE:
 612                 dev->net->stats.rx_errors++;
 613                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 614                 fallthrough;
 615
 616         /* software-driven interface shutdown */
 617         case -ECONNRESET:               /* async unlink */
 618         case -ESHUTDOWN:                /* hardware gone */
 619                 netif_dbg(dev, ifdown, dev->net,
 620                           "rx shutdown, code %d\n", urb_status);
 621                 goto block;
 622
 623         /* we get controller i/o faults during hub_wq disconnect() delays.
 624          * throttle down resubmits, to avoid log floods; just temporarily,
 625          * so we still recover when the fault isn't a hub_wq delay.
 626          */
 627         case -EPROTO:
 628         case -ETIME:
 629         case -EILSEQ:
 630                 dev->net->stats.rx_errors++;
 631                 if (!timer_pending (&dev->delay)) {
 632                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 633                         netif_dbg(dev, link, dev->net,
 634                                   "rx throttle %d\n", urb_status);
 635                 }
 636 block:
 637                 state = rx_cleanup;
 638                 entry->urb = urb;
 639                 urb = NULL;
 640                 break;
 641
 642         /* data overrun ... flush fifo? */
 643         case -EOVERFLOW:
 644                 dev->net->stats.rx_over_errors++;
 645                 fallthrough;
 646
 647         default:
 648                 state = rx_cleanup;
 649                 dev->net->stats.rx_errors++;
 650                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 651                 break;
 652         }
 653
 654         /* stop rx if packet error rate is high */
 655         if (++dev->pkt_cnt > 30) {
 656                 dev->pkt_cnt = 0;
 657                 dev->pkt_err = 0;
 658         } else {
 659                 if (state == rx_cleanup)
 660                         dev->pkt_err++;
 661                 if (dev->pkt_err > 20)
 662                         set_bit(EVENT_RX_KILL, &dev->flags);
 663         }
 664
 665         state = defer_bh(dev, skb, &dev->rxq, state);
 666
 667         if (urb) {
 668                 if (netif_running (dev->net) &&
 669                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 670                     state != unlink_start) {
 671                         rx_submit (dev, urb, GFP_ATOMIC);
 672                         usb_mark_last_busy(dev->udev);
 673                         return;
 674                 }
 675                 usb_free_urb (urb);
 676         }
 677         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 678 }
 679
 680 /*-------------------------------------------------------------------------*/
 681 void usbnet_pause_rx(struct usbnet *dev)
 682 {
 683         set_bit(EVENT_RX_PAUSED, &dev->flags);
 684
 685         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 686 }
 687 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 688
 689 void usbnet_resume_rx(struct usbnet *dev)
 690 {
 691         struct sk_buff *skb;
 692         int num = 0;
 693
 694         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 695
 696         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 697                 usbnet_skb_return(dev, skb);
 698                 num++;
 699         }
 700
 701         tasklet_schedule(&dev->bh);
 702
 703         netif_dbg(dev, rx_status, dev->net,
 704                   "paused rx queue disabled, %d skbs requeued\n", num);
 705 }
 706 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 707
 708 void usbnet_purge_paused_rxq(struct usbnet *dev)
 709 {
 710         skb_queue_purge(&dev->rxq_pause);
 711 }
 712 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 713
 714 /*-------------------------------------------------------------------------*/
 715
 716 // unlink pending rx/tx; completion handlers do all other cleanup
 717
 718 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 719 {
 720         unsigned long           flags;
 721         struct sk_buff          *skb;
 722         int                     count = 0;
 723
 724         spin_lock_irqsave (&q->lock, flags);
 725         while (!skb_queue_empty(q)) {
 726                 struct skb_data         *entry;
 727                 struct urb              *urb;
 728                 int                     retval;
 729
 730                 skb_queue_walk(q, skb) {
 731                         entry = (struct skb_data *) skb->cb;
 732                         if (entry->state != unlink_start)
 733                                 goto found;
 734                 }
 735                 break;
 736 found:
 737                 entry->state = unlink_start;
 738                 urb = entry->urb;
 739
 740                 /*
 741                  * Get reference count of the URB to avoid it to be
 742                  * freed during usb_unlink_urb, which may trigger
 743                  * use-after-free problem inside usb_unlink_urb since
 744                  * usb_unlink_urb is always racing with .complete
 745                  * handler(include defer_bh).
 746                  */
 747                 usb_get_urb(urb);
 748                 spin_unlock_irqrestore(&q->lock, flags);
 749                 // during some PM-driven resume scenarios,
 750                 // these (async) unlinks complete immediately
 751                 retval = usb_unlink_urb (urb);
 752                 if (retval != -EINPROGRESS && retval != 0)
 753                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 754                 else
 755                         count++;
 756                 usb_put_urb(urb);
 757                 spin_lock_irqsave(&q->lock, flags);
 758         }
 759         spin_unlock_irqrestore (&q->lock, flags);
 760         return count;
 761 }
 762
 763 // Flush all pending rx urbs
 764 // minidrivers may need to do this when the MTU changes
 765
 766 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 767 {
 768         if (netif_running(dev->net)) {
 769                 (void) unlink_urbs (dev, &dev->rxq);
 770                 tasklet_schedule(&dev->bh);
 771         }
 772 }
 773 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 774
 775 /*-------------------------------------------------------------------------*/
 776
 777 static void wait_skb_queue_empty(struct sk_buff_head *q)
 778 {
 779         unsigned long flags;
 780
 781         spin_lock_irqsave(&q->lock, flags);
 782         while (!skb_queue_empty(q)) {
 783                 spin_unlock_irqrestore(&q->lock, flags);
 784                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 785                 set_current_state(TASK_UNINTERRUPTIBLE);
 786                 spin_lock_irqsave(&q->lock, flags);
 787         }
 788         spin_unlock_irqrestore(&q->lock, flags);
 789 }
 790
 791 // precondition: never called in_interrupt
 792 static void usbnet_terminate_urbs(struct usbnet *dev)
 793 {
 794         DECLARE_WAITQUEUE(wait, current);
 795         int temp;
 796
 797         /* ensure there are no more active urbs */
 798         add_wait_queue(&dev->wait, &wait);
 799         set_current_state(TASK_UNINTERRUPTIBLE);
 800         temp = unlink_urbs(dev, &dev->txq) +
 801                 unlink_urbs(dev, &dev->rxq);
 802
 803         /* maybe wait for deletions to finish. */
 804         wait_skb_queue_empty(&dev->rxq);
 805         wait_skb_queue_empty(&dev->txq);
 806         wait_skb_queue_empty(&dev->done);
 807         netif_dbg(dev, ifdown, dev->net,
 808                   "waited for %d urb completions\n", temp);
 809         set_current_state(TASK_RUNNING);
 810         remove_wait_queue(&dev->wait, &wait);
 811 }
 812
 813 int usbnet_stop (struct net_device *net)
 814 {
 815         struct usbnet           *dev = netdev_priv(net);
 816         const struct driver_info *info = dev->driver_info;
 817         int                     retval, pm, mpn;
 818
 819         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 820         netif_stop_queue (net);
 821
 822         netif_info(dev, ifdown, dev->net,
 823                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 824                    net->stats.rx_packets, net->stats.tx_packets,
 825                    net->stats.rx_errors, net->stats.tx_errors);
 826
 827         /* to not race resume */
 828         pm = usb_autopm_get_interface(dev->intf);
 829         /* allow minidriver to stop correctly (wireless devices to turn off
 830          * radio etc) */
 831         if (info->stop) {
 832                 retval = info->stop(dev);
 833                 if (retval < 0)
 834                         netif_info(dev, ifdown, dev->net,
 835                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 836                                    retval,
 837                                    dev->udev->bus->bus_name, dev->udev->devpath,
 838                                    info->description);
 839         }
 840
 841         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 842                 usbnet_terminate_urbs(dev);
 843
 844         usbnet_status_stop(dev);
 845
 846         usbnet_purge_paused_rxq(dev);
 847
 848         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 849
 850         /* deferred work (timer, softirq, task) must also stop */
 851         dev->flags = 0;
 852         del_timer_sync(&dev->delay);
 853         tasklet_kill(&dev->bh);
 854         cancel_work_sync(&dev->kevent);
 855
 856         /* We have cyclic dependencies. Those calls are needed
 857          * to break a cycle. We cannot fall into the gaps because
 858          * we have a flag
 859          */
 860         tasklet_kill(&dev->bh);
 861         del_timer_sync(&dev->delay);
 862         cancel_work_sync(&dev->kevent);
 863
 864         if (!pm)
 865                 usb_autopm_put_interface(dev->intf);
 866
 867         if (info->manage_power && mpn)
 868                 info->manage_power(dev, 0);
 869         else
 870                 usb_autopm_put_interface(dev->intf);
 871
 872         return 0;
 873 }
 874 EXPORT_SYMBOL_GPL(usbnet_stop);
 875
 876 /*-------------------------------------------------------------------------*/
 877
 878 // posts reads, and enables write queuing
 879
 880 // precondition: never called in_interrupt
 881
 882 int usbnet_open (struct net_device *net)
 883 {
 884         struct usbnet           *dev = netdev_priv(net);
 885         int                     retval;
 886         const struct driver_info *info = dev->driver_info;
 887
 888         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 889                 netif_info(dev, ifup, dev->net,
 890                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 891                            retval,
 892                            dev->udev->bus->bus_name,
 893                            dev->udev->devpath,
 894                            info->description);
 895                 goto done_nopm;
 896         }
 897
 898         // put into "known safe" state
 899         if (info->reset && (retval = info->reset (dev)) < 0) {
 900                 netif_info(dev, ifup, dev->net,
 901                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 902                            retval,
 903                            dev->udev->bus->bus_name,
 904                            dev->udev->devpath,
 905                            info->description);
 906                 goto done;
 907         }
 908
 909         /* hard_mtu or rx_urb_size may change in reset() */
 910         usbnet_update_max_qlen(dev);
 911
 912         // insist peer be connected
 913         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 914                 netif_err(dev, ifup, dev->net, "can't open; %d\n", retval);
 915                 goto done;
 916         }
 917
 918         /* start any status interrupt transfer */
 919         if (dev->interrupt) {
 920                 retval = usbnet_status_start(dev, GFP_KERNEL);
 921                 if (retval < 0) {
 922                         netif_err(dev, ifup, dev->net,
 923                                   "intr submit %d\n", retval);
 924                         goto done;
 925                 }
 926         }
 927
 928         set_bit(EVENT_DEV_OPEN, &dev->flags);
 929         netif_start_queue (net);
 930         netif_info(dev, ifup, dev->net,
 931                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 932                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 933                    dev->net->mtu,
 934                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 935                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 936                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 937                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 938                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 939                    "simple");
 940
 941         /* reset rx error state */
 942         dev->pkt_cnt = 0;
 943         dev->pkt_err = 0;
 944         clear_bit(EVENT_RX_KILL, &dev->flags);
 945
 946         // delay posting reads until we're fully open
 947         tasklet_schedule (&dev->bh);
 948         if (info->manage_power) {
 949                 retval = info->manage_power(dev, 1);
 950                 if (retval < 0) {
 951                         retval = 0;
 952                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 953                 } else {
 954                         usb_autopm_put_interface(dev->intf);
 955                 }
 956         }
 957         return retval;
 958 done:
 959         usb_autopm_put_interface(dev->intf);
 960 done_nopm:
 961         return retval;
 962 }
 963 EXPORT_SYMBOL_GPL(usbnet_open);
 964
 965 /*-------------------------------------------------------------------------*/
 966
 967 /* ethtool methods; minidrivers may need to add some more, but
 968  * they'll probably want to use this base set.
 969  */
 970
 971 /* These methods are written on the assumption that the device
 972  * uses MII
 973  */
 974 int usbnet_get_link_ksettings_mii(struct net_device *net,
 975                               struct ethtool_link_ksettings *cmd)
 976 {
 977         struct usbnet *dev = netdev_priv(net);
 978
 979         if (!dev->mii.mdio_read)
 980                 return -EOPNOTSUPP;
 981
 982         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 983
 984         return 0;
 985 }
 986 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_mii);
 987
 988 int usbnet_get_link_ksettings_internal(struct net_device *net,
 989                                         struct ethtool_link_ksettings *cmd)
 990 {
 991         struct usbnet *dev = netdev_priv(net);
 992
 993         /* the assumption that speed is equal on tx and rx
 994          * is deeply engrained into the networking layer.
 995          * For wireless stuff it is not true.
 996          * We assume that rx_speed matters more.
 997          */
 998         if (dev->rx_speed != SPEED_UNSET)
 999                 cmd->base.speed = dev->rx_speed / 1000000;
1000         else if (dev->tx_speed != SPEED_UNSET)
1001                 cmd->base.speed = dev->tx_speed / 1000000;
1002         else
1003                 cmd->base.speed = SPEED_UNKNOWN;
1004
1005         return 0;
1006 }
1007 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_internal);
1008
1009 int usbnet_set_link_ksettings_mii(struct net_device *net,
1010                               const struct ethtool_link_ksettings *cmd)
1011 {
1012         struct usbnet *dev = netdev_priv(net);
1013         int retval;
1014
1015         if (!dev->mii.mdio_write)
1016                 return -EOPNOTSUPP;
1017
1018         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
1019
1020         /* link speed/duplex might have changed */
1021         if (dev->driver_info->link_reset)
1022                 dev->driver_info->link_reset(dev);
1023
1024         /* hard_mtu or rx_urb_size may change in link_reset() */
1025         usbnet_update_max_qlen(dev);
1026
1027         return retval;
1028 }
1029 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings_mii);
1030
1031 u32 usbnet_get_link (struct net_device *net)
1032 {
1033         struct usbnet *dev = netdev_priv(net);
1034
1035         /* If a check_connect is defined, return its result */
1036         if (dev->driver_info->check_connect)
1037                 return dev->driver_info->check_connect (dev) == 0;
1038
1039         /* if the device has mii operations, use those */
1040         if (dev->mii.mdio_read)
1041                 return mii_link_ok(&dev->mii);
1042
1043         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1044         return ethtool_op_get_link(net);
1045 }
1046 EXPORT_SYMBOL_GPL(usbnet_get_link);
1047
1048 int usbnet_nway_reset(struct net_device *net)
1049 {
1050         struct usbnet *dev = netdev_priv(net);
1051
1052         if (!dev->mii.mdio_write)
1053                 return -EOPNOTSUPP;
1054
1055         return mii_nway_restart(&dev->mii);
1056 }
1057 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1058
1059 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1060 {
1061         struct usbnet *dev = netdev_priv(net);
1062
1063         strscpy(info->driver, dev->driver_name, sizeof(info->driver));
1064         strscpy(info->fw_version, dev->driver_info->description,
1065                 sizeof(info->fw_version));
1066         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1067 }
1068 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1069
1070 u32 usbnet_get_msglevel (struct net_device *net)
1071 {
1072         struct usbnet *dev = netdev_priv(net);
1073
1074         return dev->msg_enable;
1075 }
1076 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1077
1078 void usbnet_set_msglevel (struct net_device *net, u32 level)
1079 {
1080         struct usbnet *dev = netdev_priv(net);
1081
1082         dev->msg_enable = level;
1083 }
1084 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1085
1086 /* drivers may override default ethtool_ops in their bind() routine */
1087 static const struct ethtool_ops usbnet_ethtool_ops = {
1088         .get_link               = usbnet_get_link,
1089         .nway_reset             = usbnet_nway_reset,
1090         .get_drvinfo            = usbnet_get_drvinfo,
1091         .get_msglevel           = usbnet_get_msglevel,
1092         .set_msglevel           = usbnet_set_msglevel,
1093         .get_ts_info            = ethtool_op_get_ts_info,
1094         .get_link_ksettings     = usbnet_get_link_ksettings_mii,
1095         .set_link_ksettings     = usbnet_set_link_ksettings_mii,
1096 };
1097
1098 /*-------------------------------------------------------------------------*/
1099
1100 static void __handle_link_change(struct usbnet *dev)
1101 {
1102         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1103                 return;
1104
1105         if (!netif_carrier_ok(dev->net)) {
1106                 /* kill URBs for reading packets to save bus bandwidth */
1107                 unlink_urbs(dev, &dev->rxq);
1108
1109                 /*
1110                  * tx_timeout will unlink URBs for sending packets and
1111                  * tx queue is stopped by netcore after link becomes off
1112                  */
1113         } else {
1114                 /* submitting URBs for reading packets */
1115                 tasklet_schedule(&dev->bh);
1116         }
1117
1118         /* hard_mtu or rx_urb_size may change during link change */
1119         usbnet_update_max_qlen(dev);
1120
1121         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1122 }
1123
1124 void usbnet_set_rx_mode(struct net_device *net)
1125 {
1126         struct usbnet           *dev = netdev_priv(net);
1127
1128         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1129 }
1130 EXPORT_SYMBOL_GPL(usbnet_set_rx_mode);
1131
1132 static void __handle_set_rx_mode(struct usbnet *dev)
1133 {
1134         if (dev->driver_info->set_rx_mode)
1135                 (dev->driver_info->set_rx_mode)(dev);
1136
1137         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1138 }
1139
1140 /* work that cannot be done in interrupt context uses keventd.
1141  *
1142  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1143  * especially now that control transfers can be queued.
1144  */
1145 static void
1146 usbnet_deferred_kevent (struct work_struct *work)
1147 {
1148         struct usbnet           *dev =
1149                 container_of(work, struct usbnet, kevent);
1150         int                     status;
1151
1152         /* usb_clear_halt() needs a thread context */
1153         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1154                 unlink_urbs (dev, &dev->txq);
1155                 status = usb_autopm_get_interface(dev->intf);
1156                 if (status < 0)
1157                         goto fail_pipe;
1158                 status = usb_clear_halt (dev->udev, dev->out);
1159                 usb_autopm_put_interface(dev->intf);
1160                 if (status < 0 &&
1161                     status != -EPIPE &&
1162                     status != -ESHUTDOWN) {
1163                         if (netif_msg_tx_err (dev))
1164 fail_pipe:
1165                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1166                                            status);
1167                 } else {
1168                         clear_bit (EVENT_TX_HALT, &dev->flags);
1169                         if (status != -ESHUTDOWN)
1170                                 netif_wake_queue (dev->net);
1171                 }
1172         }
1173         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1174                 unlink_urbs (dev, &dev->rxq);
1175                 status = usb_autopm_get_interface(dev->intf);
1176                 if (status < 0)
1177                         goto fail_halt;
1178                 status = usb_clear_halt (dev->udev, dev->in);
1179                 usb_autopm_put_interface(dev->intf);
1180                 if (status < 0 &&
1181                     status != -EPIPE &&
1182                     status != -ESHUTDOWN) {
1183                         if (netif_msg_rx_err (dev))
1184 fail_halt:
1185                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1186                                            status);
1187                 } else {
1188                         clear_bit (EVENT_RX_HALT, &dev->flags);
1189                         if (!usbnet_going_away(dev))
1190                                 tasklet_schedule(&dev->bh);
1191                 }
1192         }
1193
1194         /* tasklet could resubmit itself forever if memory is tight */
1195         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1196                 struct urb      *urb = NULL;
1197                 int resched = 1;
1198
1199                 if (netif_running (dev->net))
1200                         urb = usb_alloc_urb (0, GFP_KERNEL);
1201                 else
1202                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1203                 if (urb != NULL) {
1204                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1205                         status = usb_autopm_get_interface(dev->intf);
1206                         if (status < 0) {
1207                                 usb_free_urb(urb);
1208                                 goto fail_lowmem;
1209                         }
1210                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1211                                 resched = 0;
1212                         usb_autopm_put_interface(dev->intf);
1213 fail_lowmem:
1214                         if (resched)
1215                                 if (!usbnet_going_away(dev))
1216                                         tasklet_schedule(&dev->bh);
1217                 }
1218         }
1219
1220         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1221                 const struct driver_info *info = dev->driver_info;
1222                 int                     retval = 0;
1223
1224                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1225                 status = usb_autopm_get_interface(dev->intf);
1226                 if (status < 0)
1227                         goto skip_reset;
1228                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1229                         usb_autopm_put_interface(dev->intf);
1230 skip_reset:
1231                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1232                                     retval,
1233                                     dev->udev->bus->bus_name,
1234                                     dev->udev->devpath,
1235                                     info->description);
1236                 } else {
1237                         usb_autopm_put_interface(dev->intf);
1238                 }
1239
1240                 /* handle link change from link resetting */
1241                 __handle_link_change(dev);
1242         }
1243
1244         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1245                 __handle_link_change(dev);
1246
1247         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1248                 __handle_set_rx_mode(dev);
1249
1250
1251         if (dev->flags)
1252                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1253 }
1254
1255 /*-------------------------------------------------------------------------*/
1256
1257 static void tx_complete (struct urb *urb)
1258 {
1259         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1260         struct skb_data         *entry = (struct skb_data *) skb->cb;
1261         struct usbnet           *dev = entry->dev;
1262
1263         if (urb->status == 0) {
1264                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
1265                 unsigned long flags;
1266
1267                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1268                 u64_stats_add(&stats64->tx_packets, entry->packets);
1269                 u64_stats_add(&stats64->tx_bytes, entry->length);
1270                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1271         } else {
1272                 dev->net->stats.tx_errors++;
1273
1274                 switch (urb->status) {
1275                 case -EPIPE:
1276                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1277                         break;
1278
1279                 /* software-driven interface shutdown */
1280                 case -ECONNRESET:               // async unlink
1281                 case -ESHUTDOWN:                // hardware gone
1282                         break;
1283
1284                 /* like rx, tx gets controller i/o faults during hub_wq
1285                  * delays and so it uses the same throttling mechanism.
1286                  */
1287                 case -EPROTO:
1288                 case -ETIME:
1289                 case -EILSEQ:
1290                         usb_mark_last_busy(dev->udev);
1291                         if (!timer_pending (&dev->delay)) {
1292                                 mod_timer (&dev->delay,
1293                                         jiffies + THROTTLE_JIFFIES);
1294                                 netif_dbg(dev, link, dev->net,
1295                                           "tx throttle %d\n", urb->status);
1296                         }
1297                         netif_stop_queue (dev->net);
1298                         break;
1299                 default:
1300                         netif_dbg(dev, tx_err, dev->net,
1301                                   "tx err %d\n", entry->urb->status);
1302                         break;
1303                 }
1304         }
1305
1306         usb_autopm_put_interface_async(dev->intf);
1307         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1308 }
1309
1310 /*-------------------------------------------------------------------------*/
1311
1312 void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue)
1313 {
1314         struct usbnet           *dev = netdev_priv(net);
1315
1316         unlink_urbs (dev, &dev->txq);
1317         tasklet_schedule (&dev->bh);
1318         /* this needs to be handled individually because the generic layer
1319          * doesn't know what is sufficient and could not restore private
1320          * information if a remedy of an unconditional reset were used.
1321          */
1322         if (dev->driver_info->recover)
1323                 (dev->driver_info->recover)(dev);
1324 }
1325 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1326
1327 /*-------------------------------------------------------------------------*/
1328
1329 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1330 {
1331         unsigned num_sgs, total_len = 0;
1332         int i, s = 0;
1333
1334         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1335         if (num_sgs == 1)
1336                 return 0;
1337
1338         /* reserve one for zero packet */
1339         urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1340                                 GFP_ATOMIC);
1341         if (!urb->sg)
1342                 return -ENOMEM;
1343
1344         urb->num_sgs = num_sgs;
1345         sg_init_table(urb->sg, urb->num_sgs + 1);
1346
1347         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1348         total_len += skb_headlen(skb);
1349
1350         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1351                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1352
1353                 total_len += skb_frag_size(f);
1354                 sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1355                             skb_frag_off(f));
1356         }
1357         urb->transfer_buffer_length = total_len;
1358
1359         return 1;
1360 }
1361
1362 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1363                                      struct net_device *net)
1364 {
1365         struct usbnet           *dev = netdev_priv(net);
1366         unsigned int                    length;
1367         struct urb              *urb = NULL;
1368         struct skb_data         *entry;
1369         const struct driver_info *info = dev->driver_info;
1370         unsigned long           flags;
1371         int retval;
1372
1373         if (skb)
1374                 skb_tx_timestamp(skb);
1375
1376         // some devices want funky USB-level framing, for
1377         // win32 driver (usually) and/or hardware quirks
1378         if (info->tx_fixup) {
1379                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1380                 if (!skb) {
1381                         /* packet collected; minidriver waiting for more */
1382                         if (info->flags & FLAG_MULTI_PACKET)
1383                                 goto not_drop;
1384                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1385                         goto drop;
1386                 }
1387         }
1388
1389         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1390                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1391                 goto drop;
1392         }
1393
1394         entry = (struct skb_data *) skb->cb;
1395         entry->urb = urb;
1396         entry->dev = dev;
1397
1398         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1399                         skb->data, skb->len, tx_complete, skb);
1400         if (dev->can_dma_sg) {
1401                 if (build_dma_sg(skb, urb) < 0)
1402                         goto drop;
1403         }
1404         length = urb->transfer_buffer_length;
1405
1406         /* don't assume the hardware handles USB_ZERO_PACKET
1407          * NOTE:  strictly conforming cdc-ether devices should expect
1408          * the ZLP here, but ignore the one-byte packet.
1409          * NOTE2: CDC NCM specification is different from CDC ECM when
1410          * handling ZLP/short packets, so cdc_ncm driver will make short
1411          * packet itself if needed.
1412          */
1413         if (length % dev->maxpacket == 0) {
1414                 if (!(info->flags & FLAG_SEND_ZLP)) {
1415                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1416                                 length++;
1417                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1418                                         skb->data[skb->len] = 0;
1419                                         __skb_put(skb, 1);
1420                                 } else if (urb->num_sgs)
1421                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1422                                                         dev->padding_pkt, 1);
1423                         }
1424                 } else
1425                         urb->transfer_flags |= URB_ZERO_PACKET;
1426         }
1427         urb->transfer_buffer_length = length;
1428
1429         if (info->flags & FLAG_MULTI_PACKET) {
1430                 /* Driver has set number of packets and a length delta.
1431                  * Calculate the complete length and ensure that it's
1432                  * positive.
1433                  */
1434                 entry->length += length;
1435                 if (WARN_ON_ONCE(entry->length <= 0))
1436                         entry->length = length;
1437         } else {
1438                 usbnet_set_skb_tx_stats(skb, 1, length);
1439         }
1440
1441         spin_lock_irqsave(&dev->txq.lock, flags);
1442         retval = usb_autopm_get_interface_async(dev->intf);
1443         if (retval < 0) {
1444                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1445                 goto drop;
1446         }
1447         if (netif_queue_stopped(net)) {
1448                 usb_autopm_put_interface_async(dev->intf);
1449                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1450                 goto drop;
1451         }
1452
1453 #ifdef CONFIG_PM
1454         /* if this triggers the device is still a sleep */
1455         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1456                 /* transmission will be done in resume */
1457                 usb_anchor_urb(urb, &dev->deferred);
1458                 /* no use to process more packets */
1459                 netif_stop_queue(net);
1460                 usb_put_urb(urb);
1461                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1462                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1463                 goto deferred;
1464         }
1465 #endif
1466
1467         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1468         case -EPIPE:
1469                 netif_stop_queue (net);
1470                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1471                 usb_autopm_put_interface_async(dev->intf);
1472                 break;
1473         default:
1474                 usb_autopm_put_interface_async(dev->intf);
1475                 netif_dbg(dev, tx_err, dev->net,
1476                           "tx: submit urb err %d\n", retval);
1477                 break;
1478         case 0:
1479                 netif_trans_update(net);
1480                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1481                 if (dev->txq.qlen >= TX_QLEN (dev))
1482                         netif_stop_queue (net);
1483         }
1484         spin_unlock_irqrestore (&dev->txq.lock, flags);
1485
1486         if (retval) {
1487                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1488 drop:
1489                 dev->net->stats.tx_dropped++;
1490 not_drop:
1491                 if (skb)
1492                         dev_kfree_skb_any (skb);
1493                 if (urb) {
1494                         kfree(urb->sg);
1495                         usb_free_urb(urb);
1496                 }
1497         } else
1498                 netif_dbg(dev, tx_queued, dev->net,
1499                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1500 #ifdef CONFIG_PM
1501 deferred:
1502 #endif
1503         return NETDEV_TX_OK;
1504 }
1505 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1506
1507 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1508 {
1509         struct urb      *urb;
1510         int             i;
1511         int             ret = 0;
1512
1513         /* don't refill the queue all at once */
1514         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1515                 urb = usb_alloc_urb(0, flags);
1516                 if (urb != NULL) {
1517                         ret = rx_submit(dev, urb, flags);
1518                         if (ret)
1519                                 goto err;
1520                 } else {
1521                         ret = -ENOMEM;
1522                         goto err;
1523                 }
1524         }
1525 err:
1526         return ret;
1527 }
1528
1529 static inline void usb_free_skb(struct sk_buff *skb)
1530 {
1531         struct skb_data *entry = (struct skb_data *)skb->cb;
1532
1533         usb_free_urb(entry->urb);
1534         dev_kfree_skb(skb);
1535 }
1536
1537 /*-------------------------------------------------------------------------*/
1538
1539 // tasklet (work deferred from completions, in_irq) or timer
1540
1541 static void usbnet_bh (struct timer_list *t)
1542 {
1543         struct usbnet           *dev = from_timer(dev, t, delay);
1544         struct sk_buff          *skb;
1545         struct skb_data         *entry;
1546
1547         while ((skb = skb_dequeue (&dev->done))) {
1548                 entry = (struct skb_data *) skb->cb;
1549                 switch (entry->state) {
1550                 case rx_done:
1551                         if (rx_process(dev, skb))
1552                                 usb_free_skb(skb);
1553                         continue;
1554                 case tx_done:
1555                         kfree(entry->urb->sg);
1556                         fallthrough;
1557                 case rx_cleanup:
1558                         usb_free_skb(skb);
1559                         continue;
1560                 default:
1561                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1562                 }
1563         }
1564
1565         /* restart RX again after disabling due to high error rate */
1566         clear_bit(EVENT_RX_KILL, &dev->flags);
1567
1568         /* waiting for all pending urbs to complete?
1569          * only then can we forgo submitting anew
1570          */
1571         if (waitqueue_active(&dev->wait)) {
1572                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1573                         wake_up_all(&dev->wait);
1574
1575         // or are we maybe short a few urbs?
1576         } else if (netif_running (dev->net) &&
1577                    netif_device_present (dev->net) &&
1578                    netif_carrier_ok(dev->net) &&
1579                    !usbnet_going_away(dev) &&
1580                    !timer_pending(&dev->delay) &&
1581                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1582                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1583                 int     temp = dev->rxq.qlen;
1584
1585                 if (temp < RX_QLEN(dev)) {
1586                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1587                                 return;
1588                         if (temp != dev->rxq.qlen)
1589                                 netif_dbg(dev, link, dev->net,
1590                                           "rxqlen %d --> %d\n",
1591                                           temp, dev->rxq.qlen);
1592                         if (dev->rxq.qlen < RX_QLEN(dev))
1593                                 tasklet_schedule (&dev->bh);
1594                 }
1595                 if (dev->txq.qlen < TX_QLEN (dev))
1596                         netif_wake_queue (dev->net);
1597         }
1598 }
1599
1600 static void usbnet_bh_tasklet(struct tasklet_struct *t)
1601 {
1602         struct usbnet *dev = from_tasklet(dev, t, bh);
1603
1604         usbnet_bh(&dev->delay);
1605 }
1606
1607
1608 /*-------------------------------------------------------------------------
1609  *
1610  * USB Device Driver support
1611  *
1612  *-------------------------------------------------------------------------*/
1613
1614 // precondition: never called in_interrupt
1615
1616 void usbnet_disconnect (struct usb_interface *intf)
1617 {
1618         struct usbnet           *dev;
1619         struct usb_device       *xdev;
1620         struct net_device       *net;
1621         struct urb              *urb;
1622
1623         dev = usb_get_intfdata(intf);
1624         usb_set_intfdata(intf, NULL);
1625         if (!dev)
1626                 return;
1627         usbnet_mark_going_away(dev);
1628
1629         xdev = interface_to_usbdev (intf);
1630
1631         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1632                    intf->dev.driver->name,
1633                    xdev->bus->bus_name, xdev->devpath,
1634                    dev->driver_info->description);
1635
1636         net = dev->net;
1637         unregister_netdev (net);
1638
1639         while ((urb = usb_get_from_anchor(&dev->deferred))) {
1640                 dev_kfree_skb(urb->context);
1641                 kfree(urb->sg);
1642                 usb_free_urb(urb);
1643         }
1644
1645         if (dev->driver_info->unbind)
1646                 dev->driver_info->unbind(dev, intf);
1647
1648         usb_kill_urb(dev->interrupt);
1649         usb_free_urb(dev->interrupt);
1650         kfree(dev->padding_pkt);
1651
1652         free_netdev(net);
1653 }
1654 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1655
1656 static const struct net_device_ops usbnet_netdev_ops = {
1657         .ndo_open               = usbnet_open,
1658         .ndo_stop               = usbnet_stop,
1659         .ndo_start_xmit         = usbnet_start_xmit,
1660         .ndo_tx_timeout         = usbnet_tx_timeout,
1661         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1662         .ndo_change_mtu         = usbnet_change_mtu,
1663         .ndo_set_mac_address    = eth_mac_addr,
1664         .ndo_validate_addr      = eth_validate_addr,
1665 };
1666
1667 /*-------------------------------------------------------------------------*/
1668
1669 // precondition: never called in_interrupt
1670
1671 static const struct device_type wlan_type = {
1672         .name   = "wlan",
1673 };
1674
1675 static const struct device_type wwan_type = {
1676         .name   = "wwan",
1677 };
1678
1679 int
1680 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1681 {
1682         struct usbnet                   *dev;
1683         struct net_device               *net;
1684         struct usb_host_interface       *interface;
1685         const struct driver_info        *info;
1686         struct usb_device               *xdev;
1687         int                             status;
1688         const char                      *name;
1689         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1690
1691         /* usbnet already took usb runtime pm, so have to enable the feature
1692          * for usb interface, otherwise usb_autopm_get_interface may return
1693          * failure if RUNTIME_PM is enabled.
1694          */
1695         if (!driver->supports_autosuspend) {
1696                 driver->supports_autosuspend = 1;
1697                 pm_runtime_enable(&udev->dev);
1698         }
1699
1700         name = udev->dev.driver->name;
1701         info = (const struct driver_info *) prod->driver_info;
1702         if (!info) {
1703                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1704                 return -ENODEV;
1705         }
1706         xdev = interface_to_usbdev (udev);
1707         interface = udev->cur_altsetting;
1708
1709         status = -ENOMEM;
1710
1711         // set up our own records
1712         net = alloc_etherdev(sizeof(*dev));
1713         if (!net)
1714                 goto out;
1715
1716         /* netdev_printk() needs this so do it as early as possible */
1717         SET_NETDEV_DEV(net, &udev->dev);
1718
1719         dev = netdev_priv(net);
1720         dev->udev = xdev;
1721         dev->intf = udev;
1722         dev->driver_info = info;
1723         dev->driver_name = name;
1724         dev->rx_speed = SPEED_UNSET;
1725         dev->tx_speed = SPEED_UNSET;
1726
1727         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1728                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1729         init_waitqueue_head(&dev->wait);
1730         skb_queue_head_init (&dev->rxq);
1731         skb_queue_head_init (&dev->txq);
1732         skb_queue_head_init (&dev->done);
1733         skb_queue_head_init(&dev->rxq_pause);
1734         tasklet_setup(&dev->bh, usbnet_bh_tasklet);
1735         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1736         init_usb_anchor(&dev->deferred);
1737         timer_setup(&dev->delay, usbnet_bh, 0);
1738         mutex_init (&dev->phy_mutex);
1739         mutex_init(&dev->interrupt_mutex);
1740         dev->interrupt_count = 0;
1741
1742         dev->net = net;
1743         strscpy(net->name, "usb%d", sizeof(net->name));
1744
1745         /* rx and tx sides can use different message sizes;
1746          * bind() should set rx_urb_size in that case.
1747          */
1748         dev->hard_mtu = net->mtu + net->hard_header_len;
1749         net->min_mtu = 0;
1750         net->max_mtu = ETH_MAX_MTU;
1751         net->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1752
1753         net->netdev_ops = &usbnet_netdev_ops;
1754         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1755         net->ethtool_ops = &usbnet_ethtool_ops;
1756         net->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1757
1758         // allow device-specific bind/init procedures
1759         // NOTE net->name still not usable ...
1760         if (info->bind) {
1761                 status = info->bind (dev, udev);
1762                 if (status < 0)
1763                         goto out1;
1764
1765                 // heuristic:  "usb%d" for links we know are two-host,
1766                 // else "eth%d" when there's reasonable doubt.  userspace
1767                 // can rename the link if it knows better.
1768                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1769                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1770                      (net->dev_addr [0] & 0x02) == 0))
1771                         strscpy(net->name, "eth%d", sizeof(net->name));
1772                 /* WLAN devices should always be named "wlan%d" */
1773                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1774                         strscpy(net->name, "wlan%d", sizeof(net->name));
1775                 /* WWAN devices should always be named "wwan%d" */
1776                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1777                         strscpy(net->name, "wwan%d", sizeof(net->name));
1778
1779                 /* devices that cannot do ARP */
1780                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1781                         net->flags |= IFF_NOARP;
1782
1783                 /* maybe the remote can't receive an Ethernet MTU */
1784                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1785                         net->mtu = dev->hard_mtu - net->hard_header_len;
1786         } else if (!info->in || !info->out)
1787                 status = usbnet_get_endpoints (dev, udev);
1788         else {
1789                 u8 ep_addrs[3] = {
1790                         info->in + USB_DIR_IN, info->out + USB_DIR_OUT, 0
1791                 };
1792
1793                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1794                 dev->out = usb_sndbulkpipe (xdev, info->out);
1795                 if (!(info->flags & FLAG_NO_SETINT))
1796                         status = usb_set_interface (xdev,
1797                                 interface->desc.bInterfaceNumber,
1798                                 interface->desc.bAlternateSetting);
1799                 else
1800                         status = 0;
1801
1802                 if (status == 0 && !usb_check_bulk_endpoints(udev, ep_addrs))
1803                         status = -EINVAL;
1804         }
1805         if (status >= 0 && dev->status)
1806                 status = init_status (dev, udev);
1807         if (status < 0)
1808                 goto out3;
1809
1810         if (!dev->rx_urb_size)
1811                 dev->rx_urb_size = dev->hard_mtu;
1812         dev->maxpacket = usb_maxpacket(dev->udev, dev->out);
1813         if (dev->maxpacket == 0) {
1814                 /* that is a broken device */
1815                 status = -ENODEV;
1816                 goto out4;
1817         }
1818
1819         /* this flags the device for user space */
1820         if (!is_valid_ether_addr(net->dev_addr))
1821                 eth_hw_addr_random(net);
1822
1823         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1824                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1825         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1826                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1827
1828         /* initialize max rx_qlen and tx_qlen */
1829         usbnet_update_max_qlen(dev);
1830
1831         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1832                 !(info->flags & FLAG_MULTI_PACKET)) {
1833                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1834                 if (!dev->padding_pkt) {
1835                         status = -ENOMEM;
1836                         goto out4;
1837                 }
1838         }
1839
1840         status = register_netdev (net);
1841         if (status)
1842                 goto out5;
1843         netif_info(dev, probe, dev->net,
1844                    "register '%s' at usb-%s-%s, %s, %pM\n",
1845                    udev->dev.driver->name,
1846                    xdev->bus->bus_name, xdev->devpath,
1847                    dev->driver_info->description,
1848                    net->dev_addr);
1849
1850         // ok, it's ready to go.
1851         usb_set_intfdata (udev, dev);
1852
1853         netif_device_attach (net);
1854
1855         if (dev->driver_info->flags & FLAG_LINK_INTR)
1856                 usbnet_link_change(dev, 0, 0);
1857
1858         return 0;
1859
1860 out5:
1861         kfree(dev->padding_pkt);
1862 out4:
1863         usb_free_urb(dev->interrupt);
1864 out3:
1865         if (info->unbind)
1866                 info->unbind (dev, udev);
1867 out1:
1868         /* subdrivers must undo all they did in bind() if they
1869          * fail it, but we may fail later and a deferred kevent
1870          * may trigger an error resubmitting itself and, worse,
1871          * schedule a timer. So we kill it all just in case.
1872          */
1873         cancel_work_sync(&dev->kevent);
1874         del_timer_sync(&dev->delay);
1875         free_netdev(net);
1876 out:
1877         return status;
1878 }
1879 EXPORT_SYMBOL_GPL(usbnet_probe);
1880
1881 /*-------------------------------------------------------------------------*/
1882
1883 /*
1884  * suspend the whole driver as soon as the first interface is suspended
1885  * resume only when the last interface is resumed
1886  */
1887
1888 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1889 {
1890         struct usbnet           *dev = usb_get_intfdata(intf);
1891
1892         if (!dev->suspend_count++) {
1893                 spin_lock_irq(&dev->txq.lock);
1894                 /* don't autosuspend while transmitting */
1895                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1896                         dev->suspend_count--;
1897                         spin_unlock_irq(&dev->txq.lock);
1898                         return -EBUSY;
1899                 } else {
1900                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1901                         spin_unlock_irq(&dev->txq.lock);
1902                 }
1903                 /*
1904                  * accelerate emptying of the rx and queues, to avoid
1905                  * having everything error out.
1906                  */
1907                 netif_device_detach (dev->net);
1908                 usbnet_terminate_urbs(dev);
1909                 __usbnet_status_stop_force(dev);
1910
1911                 /*
1912                  * reattach so runtime management can use and
1913                  * wake the device
1914                  */
1915                 netif_device_attach (dev->net);
1916         }
1917         return 0;
1918 }
1919 EXPORT_SYMBOL_GPL(usbnet_suspend);
1920
1921 int usbnet_resume (struct usb_interface *intf)
1922 {
1923         struct usbnet           *dev = usb_get_intfdata(intf);
1924         struct sk_buff          *skb;
1925         struct urb              *res;
1926         int                     retval;
1927
1928         if (!--dev->suspend_count) {
1929                 /* resume interrupt URB if it was previously submitted */
1930                 __usbnet_status_start_force(dev, GFP_NOIO);
1931
1932                 spin_lock_irq(&dev->txq.lock);
1933                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1934
1935                         skb = (struct sk_buff *)res->context;
1936                         retval = usb_submit_urb(res, GFP_ATOMIC);
1937                         if (retval < 0) {
1938                                 dev_kfree_skb_any(skb);
1939                                 kfree(res->sg);
1940                                 usb_free_urb(res);
1941                                 usb_autopm_put_interface_async(dev->intf);
1942                         } else {
1943                                 netif_trans_update(dev->net);
1944                                 __skb_queue_tail(&dev->txq, skb);
1945                         }
1946                 }
1947
1948                 smp_mb();
1949                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1950                 spin_unlock_irq(&dev->txq.lock);
1951
1952                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1953                         /* handle remote wakeup ASAP
1954                          * we cannot race against stop
1955                          */
1956                         if (netif_device_present(dev->net) &&
1957                                 !timer_pending(&dev->delay) &&
1958                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1959                                         rx_alloc_submit(dev, GFP_NOIO);
1960
1961                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1962                                 netif_tx_wake_all_queues(dev->net);
1963                         tasklet_schedule (&dev->bh);
1964                 }
1965         }
1966
1967         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1968                 usb_autopm_get_interface_no_resume(intf);
1969
1970         return 0;
1971 }
1972 EXPORT_SYMBOL_GPL(usbnet_resume);
1973
1974 /*
1975  * Either a subdriver implements manage_power, then it is assumed to always
1976  * be ready to be suspended or it reports the readiness to be suspended
1977  * explicitly
1978  */
1979 void usbnet_device_suggests_idle(struct usbnet *dev)
1980 {
1981         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1982                 dev->intf->needs_remote_wakeup = 1;
1983                 usb_autopm_put_interface_async(dev->intf);
1984         }
1985 }
1986 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1987
1988 /*
1989  * For devices that can do without special commands
1990  */
1991 int usbnet_manage_power(struct usbnet *dev, int on)
1992 {
1993         dev->intf->needs_remote_wakeup = on;
1994         return 0;
1995 }
1996 EXPORT_SYMBOL(usbnet_manage_power);
1997
1998 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1999 {
2000         /* update link after link is reseted */
2001         if (link && !need_reset)
2002                 netif_carrier_on(dev->net);
2003         else
2004                 netif_carrier_off(dev->net);
2005
2006         if (need_reset && link)
2007                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
2008         else
2009                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
2010 }
2011 EXPORT_SYMBOL(usbnet_link_change);
2012
2013 /*-------------------------------------------------------------------------*/
2014 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2015                              u16 value, u16 index, void *data, u16 size)
2016 {
2017         void *buf = NULL;
2018         int err = -ENOMEM;
2019
2020         netdev_dbg(dev->net, "usbnet_read_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 (size) {
2025                 buf = kmalloc(size, GFP_NOIO);
2026                 if (!buf)
2027                         goto out;
2028         }
2029
2030         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
2031                               cmd, reqtype, value, index, buf, size,
2032                               USB_CTRL_GET_TIMEOUT);
2033         if (err > 0 && err <= size) {
2034                 if (data)
2035                         memcpy(data, buf, err);
2036                 else
2037                         netdev_dbg(dev->net,
2038                                    "Huh? Data requested but thrown away.\n");
2039         }
2040         kfree(buf);
2041 out:
2042         return err;
2043 }
2044
2045 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2046                               u16 value, u16 index, const void *data,
2047                               u16 size)
2048 {
2049         void *buf = NULL;
2050         int err = -ENOMEM;
2051
2052         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2053                    " value=0x%04x index=0x%04x size=%d\n",
2054                    cmd, reqtype, value, index, size);
2055
2056         if (data) {
2057                 buf = kmemdup(data, size, GFP_NOIO);
2058                 if (!buf)
2059                         goto out;
2060         } else {
2061         if (size) {
2062             WARN_ON_ONCE(1);
2063             err = -EINVAL;
2064             goto out;
2065         }
2066     }
2067
2068         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2069                               cmd, reqtype, value, index, buf, size,
2070                               USB_CTRL_SET_TIMEOUT);
2071         kfree(buf);
2072
2073 out:
2074         return err;
2075 }
2076
2077 /*
2078  * The function can't be called inside suspend/resume callback,
2079  * otherwise deadlock will be caused.
2080  */
2081 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2082                     u16 value, u16 index, void *data, u16 size)
2083 {
2084         int ret;
2085
2086         if (usb_autopm_get_interface(dev->intf) < 0)
2087                 return -ENODEV;
2088         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2089                                 data, size);
2090         usb_autopm_put_interface(dev->intf);
2091         return ret;
2092 }
2093 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2094
2095 /*
2096  * The function can't be called inside suspend/resume callback,
2097  * otherwise deadlock will be caused.
2098  */
2099 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2100                      u16 value, u16 index, const void *data, u16 size)
2101 {
2102         int ret;
2103
2104         if (usb_autopm_get_interface(dev->intf) < 0)
2105                 return -ENODEV;
2106         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2107                                  data, size);
2108         usb_autopm_put_interface(dev->intf);
2109         return ret;
2110 }
2111 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2112
2113 /*
2114  * The function can be called inside suspend/resume callback safely
2115  * and should only be called by suspend/resume callback generally.
2116  */
2117 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2118                           u16 value, u16 index, void *data, u16 size)
2119 {
2120         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2121                                  data, size);
2122 }
2123 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2124
2125 /*
2126  * The function can be called inside suspend/resume callback safely
2127  * and should only be called by suspend/resume callback generally.
2128  */
2129 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2130                           u16 value, u16 index, const void *data,
2131                           u16 size)
2132 {
2133         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2134                                   data, size);
2135 }
2136 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2137
2138 static void usbnet_async_cmd_cb(struct urb *urb)
2139 {
2140         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2141         int status = urb->status;
2142
2143         if (status < 0)
2144                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2145                         __func__, status);
2146
2147         kfree(req);
2148         usb_free_urb(urb);
2149 }
2150
2151 /*
2152  * The caller must make sure that device can't be put into suspend
2153  * state until the control URB completes.
2154  */
2155 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2156                            u16 value, u16 index, const void *data, u16 size)
2157 {
2158         struct usb_ctrlrequest *req;
2159         struct urb *urb;
2160         int err = -ENOMEM;
2161         void *buf = NULL;
2162
2163         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2164                    " value=0x%04x index=0x%04x size=%d\n",
2165                    cmd, reqtype, value, index, size);
2166
2167         urb = usb_alloc_urb(0, GFP_ATOMIC);
2168         if (!urb)
2169                 goto fail;
2170
2171         if (data) {
2172                 buf = kmemdup(data, size, GFP_ATOMIC);
2173                 if (!buf) {
2174                         netdev_err(dev->net, "Error allocating buffer"
2175                                    " in %s!\n", __func__);
2176                         goto fail_free_urb;
2177                 }
2178         }
2179
2180         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2181         if (!req)
2182                 goto fail_free_buf;
2183
2184         req->bRequestType = reqtype;
2185         req->bRequest = cmd;
2186         req->wValue = cpu_to_le16(value);
2187         req->wIndex = cpu_to_le16(index);
2188         req->wLength = cpu_to_le16(size);
2189
2190         usb_fill_control_urb(urb, dev->udev,
2191                              usb_sndctrlpipe(dev->udev, 0),
2192                              (void *)req, buf, size,
2193                              usbnet_async_cmd_cb, req);
2194         urb->transfer_flags |= URB_FREE_BUFFER;
2195
2196         err = usb_submit_urb(urb, GFP_ATOMIC);
2197         if (err < 0) {
2198                 netdev_err(dev->net, "Error submitting the control"
2199                            " message: status=%d\n", err);
2200                 goto fail_free_all;
2201         }
2202         return 0;
2203
2204 fail_free_all:
2205         kfree(req);
2206 fail_free_buf:
2207         kfree(buf);
2208         /*
2209          * avoid a double free
2210          * needed because the flag can be set only
2211          * after filling the URB
2212          */
2213         urb->transfer_flags = 0;
2214 fail_free_urb:
2215         usb_free_urb(urb);
2216 fail:
2217         return err;
2218
2219 }
2220 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2221 /*-------------------------------------------------------------------------*/
2222
2223 static int __init usbnet_init(void)
2224 {
2225         /* Compiler should optimize this out. */
2226         BUILD_BUG_ON(
2227                 sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data));
2228
2229         return 0;
2230 }
2231 module_init(usbnet_init);
2232
2233 static void __exit usbnet_exit(void)
2234 {
2235 }
2236 module_exit(usbnet_exit);
2237
2238 MODULE_AUTHOR("David Brownell");
2239 MODULE_DESCRIPTION("USB network driver framework");
2240 MODULE_LICENSE("GPL");