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 static const char * const usbnet_event_names[] = {
  78         [EVENT_TX_HALT]            = "EVENT_TX_HALT",
  79         [EVENT_RX_HALT]            = "EVENT_RX_HALT",
  80         [EVENT_RX_MEMORY]          = "EVENT_RX_MEMORY",
  81         [EVENT_STS_SPLIT]          = "EVENT_STS_SPLIT",
  82         [EVENT_LINK_RESET]         = "EVENT_LINK_RESET",
  83         [EVENT_RX_PAUSED]          = "EVENT_RX_PAUSED",
  84         [EVENT_DEV_ASLEEP]         = "EVENT_DEV_ASLEEP",
  85         [EVENT_DEV_OPEN]           = "EVENT_DEV_OPEN",
  86         [EVENT_DEVICE_REPORT_IDLE] = "EVENT_DEVICE_REPORT_IDLE",
  87         [EVENT_NO_RUNTIME_PM]      = "EVENT_NO_RUNTIME_PM",
  88         [EVENT_RX_KILL]            = "EVENT_RX_KILL",
  89         [EVENT_LINK_CHANGE]        = "EVENT_LINK_CHANGE",
  90         [EVENT_SET_RX_MODE]        = "EVENT_SET_RX_MODE",
  91         [EVENT_NO_IP_ALIGN]        = "EVENT_NO_IP_ALIGN",
  92 };
  93
  94 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  95 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  96 {
  97         int                             tmp;
  98         struct usb_host_interface       *alt = NULL;
  99         struct usb_host_endpoint        *in = NULL, *out = NULL;
 100         struct usb_host_endpoint        *status = NULL;
 101
 102         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 103                 unsigned        ep;
 104
 105                 in = out = status = NULL;
 106                 alt = intf->altsetting + tmp;
 107
 108                 /* take the first altsetting with in-bulk + out-bulk;
 109                  * remember any status endpoint, just in case;
 110                  * ignore other endpoints and altsettings.
 111                  */
 112                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 113                         struct usb_host_endpoint        *e;
 114                         int                             intr = 0;
 115
 116                         e = alt->endpoint + ep;
 117
 118                         /* ignore endpoints which cannot transfer data */
 119                         if (!usb_endpoint_maxp(&e->desc))
 120                                 continue;
 121
 122                         switch (e->desc.bmAttributes) {
 123                         case USB_ENDPOINT_XFER_INT:
 124                                 if (!usb_endpoint_dir_in(&e->desc))
 125                                         continue;
 126                                 intr = 1;
 127                                 fallthrough;
 128                         case USB_ENDPOINT_XFER_BULK:
 129                                 break;
 130                         default:
 131                                 continue;
 132                         }
 133                         if (usb_endpoint_dir_in(&e->desc)) {
 134                                 if (!intr && !in)
 135                                         in = e;
 136                                 else if (intr && !status)
 137                                         status = e;
 138                         } else {
 139                                 if (!out)
 140                                         out = e;
 141                         }
 142                 }
 143                 if (in && out)
 144                         break;
 145         }
 146         if (!alt || !in || !out)
 147                 return -EINVAL;
 148
 149         if (alt->desc.bAlternateSetting != 0 ||
 150             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 151                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 152                                 alt->desc.bAlternateSetting);
 153                 if (tmp < 0)
 154                         return tmp;
 155         }
 156
 157         dev->in = usb_rcvbulkpipe (dev->udev,
 158                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 159         dev->out = usb_sndbulkpipe (dev->udev,
 160                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 161         dev->status = status;
 162         return 0;
 163 }
 164 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 165
 166 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 167 {
 168         int             tmp = -1, ret;
 169         unsigned char   buf [13];
 170
 171         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 172         if (ret == 12)
 173                 tmp = hex2bin(dev->net->dev_addr, buf, 6);
 174         if (tmp < 0) {
 175                 dev_dbg(&dev->udev->dev,
 176                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 177                 if (ret >= 0)
 178                         ret = -EINVAL;
 179                 return ret;
 180         }
 181         return 0;
 182 }
 183 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 184
 185 static void intr_complete (struct urb *urb)
 186 {
 187         struct usbnet   *dev = urb->context;
 188         int             status = urb->status;
 189
 190         switch (status) {
 191         /* success */
 192         case 0:
 193                 dev->driver_info->status(dev, urb);
 194                 break;
 195
 196         /* software-driven interface shutdown */
 197         case -ENOENT:           /* urb killed */
 198         case -ESHUTDOWN:        /* hardware gone */
 199                 netif_dbg(dev, ifdown, dev->net,
 200                           "intr shutdown, code %d\n", status);
 201                 return;
 202
 203         /* NOTE:  not throttling like RX/TX, since this endpoint
 204          * already polls infrequently
 205          */
 206         default:
 207                 netdev_dbg(dev->net, "intr status %d\n", status);
 208                 break;
 209         }
 210
 211         status = usb_submit_urb (urb, GFP_ATOMIC);
 212         if (status != 0)
 213                 netif_err(dev, timer, dev->net,
 214                           "intr resubmit --> %d\n", status);
 215 }
 216
 217 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 218 {
 219         char            *buf = NULL;
 220         unsigned        pipe = 0;
 221         unsigned        maxp;
 222         unsigned        period;
 223
 224         if (!dev->driver_info->status)
 225                 return 0;
 226
 227         pipe = usb_rcvintpipe (dev->udev,
 228                         dev->status->desc.bEndpointAddress
 229                                 & USB_ENDPOINT_NUMBER_MASK);
 230         maxp = usb_maxpacket (dev->udev, pipe, 0);
 231
 232         /* avoid 1 msec chatter:  min 8 msec poll rate */
 233         period = max ((int) dev->status->desc.bInterval,
 234                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 235
 236         buf = kmalloc (maxp, GFP_KERNEL);
 237         if (buf) {
 238                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 239                 if (!dev->interrupt) {
 240                         kfree (buf);
 241                         return -ENOMEM;
 242                 } else {
 243                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 244                                 buf, maxp, intr_complete, dev, period);
 245                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 246                         dev_dbg(&intf->dev,
 247                                 "status ep%din, %d bytes period %d\n",
 248                                 usb_pipeendpoint(pipe), maxp, period);
 249                 }
 250         }
 251         return 0;
 252 }
 253
 254 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 255 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 256 {
 257         int ret = 0;
 258
 259         WARN_ON_ONCE(dev->interrupt == NULL);
 260         if (dev->interrupt) {
 261                 mutex_lock(&dev->interrupt_mutex);
 262
 263                 if (++dev->interrupt_count == 1)
 264                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 265
 266                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 267                         dev->interrupt_count);
 268                 mutex_unlock(&dev->interrupt_mutex);
 269         }
 270         return ret;
 271 }
 272 EXPORT_SYMBOL_GPL(usbnet_status_start);
 273
 274 /* For resume; submit interrupt URB if previously submitted */
 275 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 276 {
 277         int ret = 0;
 278
 279         mutex_lock(&dev->interrupt_mutex);
 280         if (dev->interrupt_count) {
 281                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 282                 dev_dbg(&dev->udev->dev,
 283                         "submitted interrupt URB for resume\n");
 284         }
 285         mutex_unlock(&dev->interrupt_mutex);
 286         return ret;
 287 }
 288
 289 /* Kill the interrupt URB if all submitters want it killed */
 290 void usbnet_status_stop(struct usbnet *dev)
 291 {
 292         if (dev->interrupt) {
 293                 mutex_lock(&dev->interrupt_mutex);
 294                 WARN_ON(dev->interrupt_count == 0);
 295
 296                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 297                         usb_kill_urb(dev->interrupt);
 298
 299                 dev_dbg(&dev->udev->dev,
 300                         "decremented interrupt URB count to %d\n",
 301                         dev->interrupt_count);
 302                 mutex_unlock(&dev->interrupt_mutex);
 303         }
 304 }
 305 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 306
 307 /* For suspend; always kill interrupt URB */
 308 static void __usbnet_status_stop_force(struct usbnet *dev)
 309 {
 310         if (dev->interrupt) {
 311                 mutex_lock(&dev->interrupt_mutex);
 312                 usb_kill_urb(dev->interrupt);
 313                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 314                 mutex_unlock(&dev->interrupt_mutex);
 315         }
 316 }
 317
 318 /* Passes this packet up the stack, updating its accounting.
 319  * Some link protocols batch packets, so their rx_fixup paths
 320  * can return clones as well as just modify the original skb.
 321  */
 322 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 323 {
 324         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
 325         unsigned long flags;
 326         int     status;
 327
 328         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 329                 skb_queue_tail(&dev->rxq_pause, skb);
 330                 return;
 331         }
 332
 333         /* only update if unset to allow minidriver rx_fixup override */
 334         if (skb->protocol == 0)
 335                 skb->protocol = eth_type_trans (skb, dev->net);
 336
 337         flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 338         stats64->rx_packets++;
 339         stats64->rx_bytes += skb->len;
 340         u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 341
 342         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 343                   skb->len + sizeof (struct ethhdr), skb->protocol);
 344         memset (skb->cb, 0, sizeof (struct skb_data));
 345
 346         if (skb_defer_rx_timestamp(skb))
 347                 return;
 348
 349         status = netif_rx (skb);
 350         if (status != NET_RX_SUCCESS)
 351                 netif_dbg(dev, rx_err, dev->net,
 352                           "netif_rx status %d\n", status);
 353 }
 354 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 355
 356 /* must be called if hard_mtu or rx_urb_size changed */
 357 void usbnet_update_max_qlen(struct usbnet *dev)
 358 {
 359         enum usb_device_speed speed = dev->udev->speed;
 360
 361         if (!dev->rx_urb_size || !dev->hard_mtu)
 362                 goto insanity;
 363         switch (speed) {
 364         case USB_SPEED_HIGH:
 365                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 366                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 367                 break;
 368         case USB_SPEED_SUPER:
 369         case USB_SPEED_SUPER_PLUS:
 370                 /*
 371                  * Not take default 5ms qlen for super speed HC to
 372                  * save memory, and iperf tests show 2.5ms qlen can
 373                  * work well
 374                  */
 375                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 376                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 377                 break;
 378         default:
 379 insanity:
 380                 dev->rx_qlen = dev->tx_qlen = 4;
 381         }
 382 }
 383 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 384
 385 \f
 386 /*-------------------------------------------------------------------------
 387  *
 388  * Network Device Driver (peer link to "Host Device", from USB host)
 389  *
 390  *-------------------------------------------------------------------------*/
 391
 392 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 393 {
 394         struct usbnet   *dev = netdev_priv(net);
 395         int             ll_mtu = new_mtu + net->hard_header_len;
 396         int             old_hard_mtu = dev->hard_mtu;
 397         int             old_rx_urb_size = dev->rx_urb_size;
 398
 399         // no second zero-length packet read wanted after mtu-sized packets
 400         if ((ll_mtu % dev->maxpacket) == 0)
 401                 return -EDOM;
 402         net->mtu = new_mtu;
 403
 404         dev->hard_mtu = net->mtu + net->hard_header_len;
 405         if (dev->rx_urb_size == old_hard_mtu) {
 406                 dev->rx_urb_size = dev->hard_mtu;
 407                 if (dev->rx_urb_size > old_rx_urb_size) {
 408                         usbnet_pause_rx(dev);
 409                         usbnet_unlink_rx_urbs(dev);
 410                         usbnet_resume_rx(dev);
 411                 }
 412         }
 413
 414         /* max qlen depend on hard_mtu and rx_urb_size */
 415         usbnet_update_max_qlen(dev);
 416
 417         return 0;
 418 }
 419 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 420
 421 /* The caller must hold list->lock */
 422 static void __usbnet_queue_skb(struct sk_buff_head *list,
 423                         struct sk_buff *newsk, enum skb_state state)
 424 {
 425         struct skb_data *entry = (struct skb_data *) newsk->cb;
 426
 427         __skb_queue_tail(list, newsk);
 428         entry->state = state;
 429 }
 430
 431 /*-------------------------------------------------------------------------*/
 432
 433 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 434  * completion callbacks.  2.5 should have fixed those bugs...
 435  */
 436
 437 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 438                 struct sk_buff_head *list, enum skb_state state)
 439 {
 440         unsigned long           flags;
 441         enum skb_state          old_state;
 442         struct skb_data *entry = (struct skb_data *) skb->cb;
 443
 444         spin_lock_irqsave(&list->lock, flags);
 445         old_state = entry->state;
 446         entry->state = state;
 447         __skb_unlink(skb, list);
 448
 449         /* defer_bh() is never called with list == &dev->done.
 450          * spin_lock_nested() tells lockdep that it is OK to take
 451          * dev->done.lock here with list->lock held.
 452          */
 453         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 454
 455         __skb_queue_tail(&dev->done, skb);
 456         if (dev->done.qlen == 1)
 457                 tasklet_schedule(&dev->bh);
 458         spin_unlock(&dev->done.lock);
 459         spin_unlock_irqrestore(&list->lock, flags);
 460         return old_state;
 461 }
 462
 463 /* some work can't be done in tasklets, so we use keventd
 464  *
 465  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 466  * but tasklet_schedule() doesn't.  hope the failure is rare.
 467  */
 468 void usbnet_defer_kevent (struct usbnet *dev, int work)
 469 {
 470         set_bit (work, &dev->flags);
 471         if (!schedule_work (&dev->kevent))
 472                 netdev_dbg(dev->net, "kevent %s may have been dropped\n", usbnet_event_names[work]);
 473         else
 474                 netdev_dbg(dev->net, "kevent %s scheduled\n", usbnet_event_names[work]);
 475 }
 476 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 477
 478 /*-------------------------------------------------------------------------*/
 479
 480 static void rx_complete (struct urb *urb);
 481
 482 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 483 {
 484         struct sk_buff          *skb;
 485         struct skb_data         *entry;
 486         int                     retval = 0;
 487         unsigned long           lockflags;
 488         size_t                  size = dev->rx_urb_size;
 489
 490         /* prevent rx skb allocation when error ratio is high */
 491         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 492                 usb_free_urb(urb);
 493                 return -ENOLINK;
 494         }
 495
 496         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 497                 skb = __netdev_alloc_skb(dev->net, size, flags);
 498         else
 499                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 500         if (!skb) {
 501                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 502                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 503                 usb_free_urb (urb);
 504                 return -ENOMEM;
 505         }
 506
 507         entry = (struct skb_data *) skb->cb;
 508         entry->urb = urb;
 509         entry->dev = dev;
 510         entry->length = 0;
 511
 512         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 513                 skb->data, size, rx_complete, skb);
 514
 515         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 516
 517         if (netif_running (dev->net) &&
 518             netif_device_present (dev->net) &&
 519             test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 520             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 521             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 522                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 523                 case -EPIPE:
 524                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 525                         break;
 526                 case -ENOMEM:
 527                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 528                         break;
 529                 case -ENODEV:
 530                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 531                         netif_device_detach (dev->net);
 532                         break;
 533                 case -EHOSTUNREACH:
 534                         retval = -ENOLINK;
 535                         break;
 536                 default:
 537                         netif_dbg(dev, rx_err, dev->net,
 538                                   "rx submit, %d\n", retval);
 539                         tasklet_schedule (&dev->bh);
 540                         break;
 541                 case 0:
 542                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 543                 }
 544         } else {
 545                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 546                 retval = -ENOLINK;
 547         }
 548         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 549         if (retval) {
 550                 dev_kfree_skb_any (skb);
 551                 usb_free_urb (urb);
 552         }
 553         return retval;
 554 }
 555
 556
 557 /*-------------------------------------------------------------------------*/
 558
 559 static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 560 {
 561         if (dev->driver_info->rx_fixup &&
 562             !dev->driver_info->rx_fixup (dev, skb)) {
 563                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 564                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 565                         dev->net->stats.rx_errors++;
 566                 goto done;
 567         }
 568         // else network stack removes extra byte if we forced a short packet
 569
 570         /* all data was already cloned from skb inside the driver */
 571         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 572                 goto done;
 573
 574         if (skb->len < ETH_HLEN) {
 575                 dev->net->stats.rx_errors++;
 576                 dev->net->stats.rx_length_errors++;
 577                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 578         } else {
 579                 usbnet_skb_return(dev, skb);
 580                 return;
 581         }
 582
 583 done:
 584         skb_queue_tail(&dev->done, skb);
 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 (task, timer, softirq) must also stop.
 851          * can't flush_scheduled_work() until we drop rtnl (later),
 852          * else workers could deadlock; so make workers a NOP.
 853          */
 854         dev->flags = 0;
 855         del_timer_sync (&dev->delay);
 856         tasklet_kill (&dev->bh);
 857         if (!pm)
 858                 usb_autopm_put_interface(dev->intf);
 859
 860         if (info->manage_power && mpn)
 861                 info->manage_power(dev, 0);
 862         else
 863                 usb_autopm_put_interface(dev->intf);
 864
 865         return 0;
 866 }
 867 EXPORT_SYMBOL_GPL(usbnet_stop);
 868
 869 /*-------------------------------------------------------------------------*/
 870
 871 // posts reads, and enables write queuing
 872
 873 // precondition: never called in_interrupt
 874
 875 int usbnet_open (struct net_device *net)
 876 {
 877         struct usbnet           *dev = netdev_priv(net);
 878         int                     retval;
 879         const struct driver_info *info = dev->driver_info;
 880
 881         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 882                 netif_info(dev, ifup, dev->net,
 883                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 884                            retval,
 885                            dev->udev->bus->bus_name,
 886                            dev->udev->devpath,
 887                            info->description);
 888                 goto done_nopm;
 889         }
 890
 891         // put into "known safe" state
 892         if (info->reset && (retval = info->reset (dev)) < 0) {
 893                 netif_info(dev, ifup, dev->net,
 894                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 895                            retval,
 896                            dev->udev->bus->bus_name,
 897                            dev->udev->devpath,
 898                            info->description);
 899                 goto done;
 900         }
 901
 902         /* hard_mtu or rx_urb_size may change in reset() */
 903         usbnet_update_max_qlen(dev);
 904
 905         // insist peer be connected
 906         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 907                 netif_err(dev, ifup, dev->net, "can't open; %d\n", retval);
 908                 goto done;
 909         }
 910
 911         /* start any status interrupt transfer */
 912         if (dev->interrupt) {
 913                 retval = usbnet_status_start(dev, GFP_KERNEL);
 914                 if (retval < 0) {
 915                         netif_err(dev, ifup, dev->net,
 916                                   "intr submit %d\n", retval);
 917                         goto done;
 918                 }
 919         }
 920
 921         set_bit(EVENT_DEV_OPEN, &dev->flags);
 922         netif_start_queue (net);
 923         netif_info(dev, ifup, dev->net,
 924                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 925                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 926                    dev->net->mtu,
 927                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 928                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 929                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 930                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 931                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 932                    "simple");
 933
 934         /* reset rx error state */
 935         dev->pkt_cnt = 0;
 936         dev->pkt_err = 0;
 937         clear_bit(EVENT_RX_KILL, &dev->flags);
 938
 939         // delay posting reads until we're fully open
 940         tasklet_schedule (&dev->bh);
 941         if (info->manage_power) {
 942                 retval = info->manage_power(dev, 1);
 943                 if (retval < 0) {
 944                         retval = 0;
 945                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 946                 } else {
 947                         usb_autopm_put_interface(dev->intf);
 948                 }
 949         }
 950         return retval;
 951 done:
 952         usb_autopm_put_interface(dev->intf);
 953 done_nopm:
 954         return retval;
 955 }
 956 EXPORT_SYMBOL_GPL(usbnet_open);
 957
 958 /*-------------------------------------------------------------------------*/
 959
 960 /* ethtool methods; minidrivers may need to add some more, but
 961  * they'll probably want to use this base set.
 962  */
 963
 964 /* These methods are written on the assumption that the device
 965  * uses MII
 966  */
 967 int usbnet_get_link_ksettings_mii(struct net_device *net,
 968                               struct ethtool_link_ksettings *cmd)
 969 {
 970         struct usbnet *dev = netdev_priv(net);
 971
 972         if (!dev->mii.mdio_read)
 973                 return -EOPNOTSUPP;
 974
 975         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 976
 977         return 0;
 978 }
 979 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_mii);
 980
 981 int usbnet_get_link_ksettings_internal(struct net_device *net,
 982                                         struct ethtool_link_ksettings *cmd)
 983 {
 984         struct usbnet *dev = netdev_priv(net);
 985
 986         /* the assumption that speed is equal on tx and rx
 987          * is deeply engrained into the networking layer.
 988          * For wireless stuff it is not true.
 989          * We assume that rx_speed matters more.
 990          */
 991         if (dev->rx_speed != SPEED_UNSET)
 992                 cmd->base.speed = dev->rx_speed / 1000000;
 993         else if (dev->tx_speed != SPEED_UNSET)
 994                 cmd->base.speed = dev->tx_speed / 1000000;
 995         else
 996                 cmd->base.speed = SPEED_UNKNOWN;
 997
 998         return 0;
 999 }
1000 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_internal);
1001
1002 int usbnet_set_link_ksettings_mii(struct net_device *net,
1003                               const struct ethtool_link_ksettings *cmd)
1004 {
1005         struct usbnet *dev = netdev_priv(net);
1006         int retval;
1007
1008         if (!dev->mii.mdio_write)
1009                 return -EOPNOTSUPP;
1010
1011         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
1012
1013         /* link speed/duplex might have changed */
1014         if (dev->driver_info->link_reset)
1015                 dev->driver_info->link_reset(dev);
1016
1017         /* hard_mtu or rx_urb_size may change in link_reset() */
1018         usbnet_update_max_qlen(dev);
1019
1020         return retval;
1021 }
1022 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings_mii);
1023
1024 u32 usbnet_get_link (struct net_device *net)
1025 {
1026         struct usbnet *dev = netdev_priv(net);
1027
1028         /* If a check_connect is defined, return its result */
1029         if (dev->driver_info->check_connect)
1030                 return dev->driver_info->check_connect (dev) == 0;
1031
1032         /* if the device has mii operations, use those */
1033         if (dev->mii.mdio_read)
1034                 return mii_link_ok(&dev->mii);
1035
1036         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1037         return ethtool_op_get_link(net);
1038 }
1039 EXPORT_SYMBOL_GPL(usbnet_get_link);
1040
1041 int usbnet_nway_reset(struct net_device *net)
1042 {
1043         struct usbnet *dev = netdev_priv(net);
1044
1045         if (!dev->mii.mdio_write)
1046                 return -EOPNOTSUPP;
1047
1048         return mii_nway_restart(&dev->mii);
1049 }
1050 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1051
1052 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1053 {
1054         struct usbnet *dev = netdev_priv(net);
1055
1056         strlcpy (info->driver, dev->driver_name, sizeof info->driver);
1057         strlcpy (info->fw_version, dev->driver_info->description,
1058                 sizeof info->fw_version);
1059         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1060 }
1061 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1062
1063 u32 usbnet_get_msglevel (struct net_device *net)
1064 {
1065         struct usbnet *dev = netdev_priv(net);
1066
1067         return dev->msg_enable;
1068 }
1069 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1070
1071 void usbnet_set_msglevel (struct net_device *net, u32 level)
1072 {
1073         struct usbnet *dev = netdev_priv(net);
1074
1075         dev->msg_enable = level;
1076 }
1077 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1078
1079 /* drivers may override default ethtool_ops in their bind() routine */
1080 static const struct ethtool_ops usbnet_ethtool_ops = {
1081         .get_link               = usbnet_get_link,
1082         .nway_reset             = usbnet_nway_reset,
1083         .get_drvinfo            = usbnet_get_drvinfo,
1084         .get_msglevel           = usbnet_get_msglevel,
1085         .set_msglevel           = usbnet_set_msglevel,
1086         .get_ts_info            = ethtool_op_get_ts_info,
1087         .get_link_ksettings     = usbnet_get_link_ksettings_mii,
1088         .set_link_ksettings     = usbnet_set_link_ksettings_mii,
1089 };
1090
1091 /*-------------------------------------------------------------------------*/
1092
1093 static void __handle_link_change(struct usbnet *dev)
1094 {
1095         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1096                 return;
1097
1098         if (!netif_carrier_ok(dev->net)) {
1099                 /* kill URBs for reading packets to save bus bandwidth */
1100                 unlink_urbs(dev, &dev->rxq);
1101
1102                 /*
1103                  * tx_timeout will unlink URBs for sending packets and
1104                  * tx queue is stopped by netcore after link becomes off
1105                  */
1106         } else {
1107                 /* submitting URBs for reading packets */
1108                 tasklet_schedule(&dev->bh);
1109         }
1110
1111         /* hard_mtu or rx_urb_size may change during link change */
1112         usbnet_update_max_qlen(dev);
1113
1114         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1115 }
1116
1117 void usbnet_set_rx_mode(struct net_device *net)
1118 {
1119         struct usbnet           *dev = netdev_priv(net);
1120
1121         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1122 }
1123 EXPORT_SYMBOL_GPL(usbnet_set_rx_mode);
1124
1125 static void __handle_set_rx_mode(struct usbnet *dev)
1126 {
1127         if (dev->driver_info->set_rx_mode)
1128                 (dev->driver_info->set_rx_mode)(dev);
1129
1130         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1131 }
1132
1133 /* work that cannot be done in interrupt context uses keventd.
1134  *
1135  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1136  * especially now that control transfers can be queued.
1137  */
1138 static void
1139 usbnet_deferred_kevent (struct work_struct *work)
1140 {
1141         struct usbnet           *dev =
1142                 container_of(work, struct usbnet, kevent);
1143         int                     status;
1144
1145         /* usb_clear_halt() needs a thread context */
1146         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1147                 unlink_urbs (dev, &dev->txq);
1148                 status = usb_autopm_get_interface(dev->intf);
1149                 if (status < 0)
1150                         goto fail_pipe;
1151                 status = usb_clear_halt (dev->udev, dev->out);
1152                 usb_autopm_put_interface(dev->intf);
1153                 if (status < 0 &&
1154                     status != -EPIPE &&
1155                     status != -ESHUTDOWN) {
1156                         if (netif_msg_tx_err (dev))
1157 fail_pipe:
1158                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1159                                            status);
1160                 } else {
1161                         clear_bit (EVENT_TX_HALT, &dev->flags);
1162                         if (status != -ESHUTDOWN)
1163                                 netif_wake_queue (dev->net);
1164                 }
1165         }
1166         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1167                 unlink_urbs (dev, &dev->rxq);
1168                 status = usb_autopm_get_interface(dev->intf);
1169                 if (status < 0)
1170                         goto fail_halt;
1171                 status = usb_clear_halt (dev->udev, dev->in);
1172                 usb_autopm_put_interface(dev->intf);
1173                 if (status < 0 &&
1174                     status != -EPIPE &&
1175                     status != -ESHUTDOWN) {
1176                         if (netif_msg_rx_err (dev))
1177 fail_halt:
1178                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1179                                            status);
1180                 } else {
1181                         clear_bit (EVENT_RX_HALT, &dev->flags);
1182                         tasklet_schedule (&dev->bh);
1183                 }
1184         }
1185
1186         /* tasklet could resubmit itself forever if memory is tight */
1187         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1188                 struct urb      *urb = NULL;
1189                 int resched = 1;
1190
1191                 if (netif_running (dev->net))
1192                         urb = usb_alloc_urb (0, GFP_KERNEL);
1193                 else
1194                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1195                 if (urb != NULL) {
1196                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1197                         status = usb_autopm_get_interface(dev->intf);
1198                         if (status < 0) {
1199                                 usb_free_urb(urb);
1200                                 goto fail_lowmem;
1201                         }
1202                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1203                                 resched = 0;
1204                         usb_autopm_put_interface(dev->intf);
1205 fail_lowmem:
1206                         if (resched)
1207                                 tasklet_schedule (&dev->bh);
1208                 }
1209         }
1210
1211         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1212                 const struct driver_info *info = dev->driver_info;
1213                 int                     retval = 0;
1214
1215                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1216                 status = usb_autopm_get_interface(dev->intf);
1217                 if (status < 0)
1218                         goto skip_reset;
1219                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1220                         usb_autopm_put_interface(dev->intf);
1221 skip_reset:
1222                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1223                                     retval,
1224                                     dev->udev->bus->bus_name,
1225                                     dev->udev->devpath,
1226                                     info->description);
1227                 } else {
1228                         usb_autopm_put_interface(dev->intf);
1229                 }
1230
1231                 /* handle link change from link resetting */
1232                 __handle_link_change(dev);
1233         }
1234
1235         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1236                 __handle_link_change(dev);
1237
1238         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1239                 __handle_set_rx_mode(dev);
1240
1241
1242         if (dev->flags)
1243                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1244 }
1245
1246 /*-------------------------------------------------------------------------*/
1247
1248 static void tx_complete (struct urb *urb)
1249 {
1250         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1251         struct skb_data         *entry = (struct skb_data *) skb->cb;
1252         struct usbnet           *dev = entry->dev;
1253
1254         if (urb->status == 0) {
1255                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
1256                 unsigned long flags;
1257
1258                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1259                 stats64->tx_packets += entry->packets;
1260                 stats64->tx_bytes += entry->length;
1261                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1262         } else {
1263                 dev->net->stats.tx_errors++;
1264
1265                 switch (urb->status) {
1266                 case -EPIPE:
1267                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1268                         break;
1269
1270                 /* software-driven interface shutdown */
1271                 case -ECONNRESET:               // async unlink
1272                 case -ESHUTDOWN:                // hardware gone
1273                         break;
1274
1275                 /* like rx, tx gets controller i/o faults during hub_wq
1276                  * delays and so it uses the same throttling mechanism.
1277                  */
1278                 case -EPROTO:
1279                 case -ETIME:
1280                 case -EILSEQ:
1281                         usb_mark_last_busy(dev->udev);
1282                         if (!timer_pending (&dev->delay)) {
1283                                 mod_timer (&dev->delay,
1284                                         jiffies + THROTTLE_JIFFIES);
1285                                 netif_dbg(dev, link, dev->net,
1286                                           "tx throttle %d\n", urb->status);
1287                         }
1288                         netif_stop_queue (dev->net);
1289                         break;
1290                 default:
1291                         netif_dbg(dev, tx_err, dev->net,
1292                                   "tx err %d\n", entry->urb->status);
1293                         break;
1294                 }
1295         }
1296
1297         usb_autopm_put_interface_async(dev->intf);
1298         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1299 }
1300
1301 /*-------------------------------------------------------------------------*/
1302
1303 void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue)
1304 {
1305         struct usbnet           *dev = netdev_priv(net);
1306
1307         unlink_urbs (dev, &dev->txq);
1308         tasklet_schedule (&dev->bh);
1309         /* this needs to be handled individually because the generic layer
1310          * doesn't know what is sufficient and could not restore private
1311          * information if a remedy of an unconditional reset were used.
1312          */
1313         if (dev->driver_info->recover)
1314                 (dev->driver_info->recover)(dev);
1315 }
1316 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1317
1318 /*-------------------------------------------------------------------------*/
1319
1320 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1321 {
1322         unsigned num_sgs, total_len = 0;
1323         int i, s = 0;
1324
1325         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1326         if (num_sgs == 1)
1327                 return 0;
1328
1329         /* reserve one for zero packet */
1330         urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1331                                 GFP_ATOMIC);
1332         if (!urb->sg)
1333                 return -ENOMEM;
1334
1335         urb->num_sgs = num_sgs;
1336         sg_init_table(urb->sg, urb->num_sgs + 1);
1337
1338         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1339         total_len += skb_headlen(skb);
1340
1341         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1342                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1343
1344                 total_len += skb_frag_size(f);
1345                 sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1346                             skb_frag_off(f));
1347         }
1348         urb->transfer_buffer_length = total_len;
1349
1350         return 1;
1351 }
1352
1353 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1354                                      struct net_device *net)
1355 {
1356         struct usbnet           *dev = netdev_priv(net);
1357         unsigned int                    length;
1358         struct urb              *urb = NULL;
1359         struct skb_data         *entry;
1360         const struct driver_info *info = dev->driver_info;
1361         unsigned long           flags;
1362         int retval;
1363
1364         if (skb)
1365                 skb_tx_timestamp(skb);
1366
1367         // some devices want funky USB-level framing, for
1368         // win32 driver (usually) and/or hardware quirks
1369         if (info->tx_fixup) {
1370                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1371                 if (!skb) {
1372                         /* packet collected; minidriver waiting for more */
1373                         if (info->flags & FLAG_MULTI_PACKET)
1374                                 goto not_drop;
1375                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1376                         goto drop;
1377                 }
1378         }
1379
1380         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1381                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1382                 goto drop;
1383         }
1384
1385         entry = (struct skb_data *) skb->cb;
1386         entry->urb = urb;
1387         entry->dev = dev;
1388
1389         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1390                         skb->data, skb->len, tx_complete, skb);
1391         if (dev->can_dma_sg) {
1392                 if (build_dma_sg(skb, urb) < 0)
1393                         goto drop;
1394         }
1395         length = urb->transfer_buffer_length;
1396
1397         /* don't assume the hardware handles USB_ZERO_PACKET
1398          * NOTE:  strictly conforming cdc-ether devices should expect
1399          * the ZLP here, but ignore the one-byte packet.
1400          * NOTE2: CDC NCM specification is different from CDC ECM when
1401          * handling ZLP/short packets, so cdc_ncm driver will make short
1402          * packet itself if needed.
1403          */
1404         if (length % dev->maxpacket == 0) {
1405                 if (!(info->flags & FLAG_SEND_ZLP)) {
1406                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1407                                 length++;
1408                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1409                                         skb->data[skb->len] = 0;
1410                                         __skb_put(skb, 1);
1411                                 } else if (urb->num_sgs)
1412                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1413                                                         dev->padding_pkt, 1);
1414                         }
1415                 } else
1416                         urb->transfer_flags |= URB_ZERO_PACKET;
1417         }
1418         urb->transfer_buffer_length = length;
1419
1420         if (info->flags & FLAG_MULTI_PACKET) {
1421                 /* Driver has set number of packets and a length delta.
1422                  * Calculate the complete length and ensure that it's
1423                  * positive.
1424                  */
1425                 entry->length += length;
1426                 if (WARN_ON_ONCE(entry->length <= 0))
1427                         entry->length = length;
1428         } else {
1429                 usbnet_set_skb_tx_stats(skb, 1, length);
1430         }
1431
1432         spin_lock_irqsave(&dev->txq.lock, flags);
1433         retval = usb_autopm_get_interface_async(dev->intf);
1434         if (retval < 0) {
1435                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1436                 goto drop;
1437         }
1438         if (netif_queue_stopped(net)) {
1439                 usb_autopm_put_interface_async(dev->intf);
1440                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1441                 goto drop;
1442         }
1443
1444 #ifdef CONFIG_PM
1445         /* if this triggers the device is still a sleep */
1446         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1447                 /* transmission will be done in resume */
1448                 usb_anchor_urb(urb, &dev->deferred);
1449                 /* no use to process more packets */
1450                 netif_stop_queue(net);
1451                 usb_put_urb(urb);
1452                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1453                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1454                 goto deferred;
1455         }
1456 #endif
1457
1458         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1459         case -EPIPE:
1460                 netif_stop_queue (net);
1461                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1462                 usb_autopm_put_interface_async(dev->intf);
1463                 break;
1464         default:
1465                 usb_autopm_put_interface_async(dev->intf);
1466                 netif_dbg(dev, tx_err, dev->net,
1467                           "tx: submit urb err %d\n", retval);
1468                 break;
1469         case 0:
1470                 netif_trans_update(net);
1471                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1472                 if (dev->txq.qlen >= TX_QLEN (dev))
1473                         netif_stop_queue (net);
1474         }
1475         spin_unlock_irqrestore (&dev->txq.lock, flags);
1476
1477         if (retval) {
1478                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1479 drop:
1480                 dev->net->stats.tx_dropped++;
1481 not_drop:
1482                 if (skb)
1483                         dev_kfree_skb_any (skb);
1484                 if (urb) {
1485                         kfree(urb->sg);
1486                         usb_free_urb(urb);
1487                 }
1488         } else
1489                 netif_dbg(dev, tx_queued, dev->net,
1490                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1491 #ifdef CONFIG_PM
1492 deferred:
1493 #endif
1494         return NETDEV_TX_OK;
1495 }
1496 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1497
1498 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1499 {
1500         struct urb      *urb;
1501         int             i;
1502         int             ret = 0;
1503
1504         /* don't refill the queue all at once */
1505         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1506                 urb = usb_alloc_urb(0, flags);
1507                 if (urb != NULL) {
1508                         ret = rx_submit(dev, urb, flags);
1509                         if (ret)
1510                                 goto err;
1511                 } else {
1512                         ret = -ENOMEM;
1513                         goto err;
1514                 }
1515         }
1516 err:
1517         return ret;
1518 }
1519
1520 /*-------------------------------------------------------------------------*/
1521
1522 // tasklet (work deferred from completions, in_irq) or timer
1523
1524 static void usbnet_bh (struct timer_list *t)
1525 {
1526         struct usbnet           *dev = from_timer(dev, t, delay);
1527         struct sk_buff          *skb;
1528         struct skb_data         *entry;
1529
1530         while ((skb = skb_dequeue (&dev->done))) {
1531                 entry = (struct skb_data *) skb->cb;
1532                 switch (entry->state) {
1533                 case rx_done:
1534                         entry->state = rx_cleanup;
1535                         rx_process (dev, skb);
1536                         continue;
1537                 case tx_done:
1538                         kfree(entry->urb->sg);
1539                         fallthrough;
1540                 case rx_cleanup:
1541                         usb_free_urb (entry->urb);
1542                         dev_kfree_skb (skb);
1543                         continue;
1544                 default:
1545                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1546                 }
1547         }
1548
1549         /* restart RX again after disabling due to high error rate */
1550         clear_bit(EVENT_RX_KILL, &dev->flags);
1551
1552         /* waiting for all pending urbs to complete?
1553          * only then can we forgo submitting anew
1554          */
1555         if (waitqueue_active(&dev->wait)) {
1556                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1557                         wake_up_all(&dev->wait);
1558
1559         // or are we maybe short a few urbs?
1560         } else if (netif_running (dev->net) &&
1561                    netif_device_present (dev->net) &&
1562                    netif_carrier_ok(dev->net) &&
1563                    !timer_pending(&dev->delay) &&
1564                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1565                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1566                 int     temp = dev->rxq.qlen;
1567
1568                 if (temp < RX_QLEN(dev)) {
1569                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1570                                 return;
1571                         if (temp != dev->rxq.qlen)
1572                                 netif_dbg(dev, link, dev->net,
1573                                           "rxqlen %d --> %d\n",
1574                                           temp, dev->rxq.qlen);
1575                         if (dev->rxq.qlen < RX_QLEN(dev))
1576                                 tasklet_schedule (&dev->bh);
1577                 }
1578                 if (dev->txq.qlen < TX_QLEN (dev))
1579                         netif_wake_queue (dev->net);
1580         }
1581 }
1582
1583 static void usbnet_bh_tasklet(struct tasklet_struct *t)
1584 {
1585         struct usbnet *dev = from_tasklet(dev, t, bh);
1586
1587         usbnet_bh(&dev->delay);
1588 }
1589
1590
1591 /*-------------------------------------------------------------------------
1592  *
1593  * USB Device Driver support
1594  *
1595  *-------------------------------------------------------------------------*/
1596
1597 // precondition: never called in_interrupt
1598
1599 void usbnet_disconnect (struct usb_interface *intf)
1600 {
1601         struct usbnet           *dev;
1602         struct usb_device       *xdev;
1603         struct net_device       *net;
1604
1605         dev = usb_get_intfdata(intf);
1606         usb_set_intfdata(intf, NULL);
1607         if (!dev)
1608                 return;
1609
1610         xdev = interface_to_usbdev (intf);
1611
1612         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1613                    intf->dev.driver->name,
1614                    xdev->bus->bus_name, xdev->devpath,
1615                    dev->driver_info->description);
1616
1617         if (dev->driver_info->unbind)
1618                 dev->driver_info->unbind(dev, intf);
1619
1620         net = dev->net;
1621         unregister_netdev (net);
1622
1623         cancel_work_sync(&dev->kevent);
1624
1625         usb_scuttle_anchored_urbs(&dev->deferred);
1626
1627         usb_kill_urb(dev->interrupt);
1628         usb_free_urb(dev->interrupt);
1629         kfree(dev->padding_pkt);
1630
1631         free_percpu(net->tstats);
1632         free_netdev(net);
1633 }
1634 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1635
1636 static const struct net_device_ops usbnet_netdev_ops = {
1637         .ndo_open               = usbnet_open,
1638         .ndo_stop               = usbnet_stop,
1639         .ndo_start_xmit         = usbnet_start_xmit,
1640         .ndo_tx_timeout         = usbnet_tx_timeout,
1641         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1642         .ndo_change_mtu         = usbnet_change_mtu,
1643         .ndo_get_stats64        = dev_get_tstats64,
1644         .ndo_set_mac_address    = eth_mac_addr,
1645         .ndo_validate_addr      = eth_validate_addr,
1646 };
1647
1648 /*-------------------------------------------------------------------------*/
1649
1650 // precondition: never called in_interrupt
1651
1652 static struct device_type wlan_type = {
1653         .name   = "wlan",
1654 };
1655
1656 static struct device_type wwan_type = {
1657         .name   = "wwan",
1658 };
1659
1660 int
1661 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1662 {
1663         struct usbnet                   *dev;
1664         struct net_device               *net;
1665         struct usb_host_interface       *interface;
1666         const struct driver_info        *info;
1667         struct usb_device               *xdev;
1668         int                             status;
1669         const char                      *name;
1670         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1671
1672         /* usbnet already took usb runtime pm, so have to enable the feature
1673          * for usb interface, otherwise usb_autopm_get_interface may return
1674          * failure if RUNTIME_PM is enabled.
1675          */
1676         if (!driver->supports_autosuspend) {
1677                 driver->supports_autosuspend = 1;
1678                 pm_runtime_enable(&udev->dev);
1679         }
1680
1681         name = udev->dev.driver->name;
1682         info = (const struct driver_info *) prod->driver_info;
1683         if (!info) {
1684                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1685                 return -ENODEV;
1686         }
1687         xdev = interface_to_usbdev (udev);
1688         interface = udev->cur_altsetting;
1689
1690         status = -ENOMEM;
1691
1692         // set up our own records
1693         net = alloc_etherdev(sizeof(*dev));
1694         if (!net)
1695                 goto out;
1696
1697         /* netdev_printk() needs this so do it as early as possible */
1698         SET_NETDEV_DEV(net, &udev->dev);
1699
1700         dev = netdev_priv(net);
1701         dev->udev = xdev;
1702         dev->intf = udev;
1703         dev->driver_info = info;
1704         dev->driver_name = name;
1705         dev->rx_speed = SPEED_UNSET;
1706         dev->tx_speed = SPEED_UNSET;
1707
1708         net->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1709         if (!net->tstats)
1710                 goto out0;
1711
1712         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1713                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1714         init_waitqueue_head(&dev->wait);
1715         skb_queue_head_init (&dev->rxq);
1716         skb_queue_head_init (&dev->txq);
1717         skb_queue_head_init (&dev->done);
1718         skb_queue_head_init(&dev->rxq_pause);
1719         tasklet_setup(&dev->bh, usbnet_bh_tasklet);
1720         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1721         init_usb_anchor(&dev->deferred);
1722         timer_setup(&dev->delay, usbnet_bh, 0);
1723         mutex_init (&dev->phy_mutex);
1724         mutex_init(&dev->interrupt_mutex);
1725         dev->interrupt_count = 0;
1726
1727         dev->net = net;
1728         strscpy(net->name, "usb%d", sizeof(net->name));
1729         memcpy (net->dev_addr, node_id, sizeof node_id);
1730
1731         /* rx and tx sides can use different message sizes;
1732          * bind() should set rx_urb_size in that case.
1733          */
1734         dev->hard_mtu = net->mtu + net->hard_header_len;
1735         net->min_mtu = 0;
1736         net->max_mtu = ETH_MAX_MTU;
1737
1738         net->netdev_ops = &usbnet_netdev_ops;
1739         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1740         net->ethtool_ops = &usbnet_ethtool_ops;
1741
1742         // allow device-specific bind/init procedures
1743         // NOTE net->name still not usable ...
1744         if (info->bind) {
1745                 status = info->bind (dev, udev);
1746                 if (status < 0)
1747                         goto out1;
1748
1749                 // heuristic:  "usb%d" for links we know are two-host,
1750                 // else "eth%d" when there's reasonable doubt.  userspace
1751                 // can rename the link if it knows better.
1752                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1753                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1754                      (net->dev_addr [0] & 0x02) == 0))
1755                         strscpy(net->name, "eth%d", sizeof(net->name));
1756                 /* WLAN devices should always be named "wlan%d" */
1757                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1758                         strscpy(net->name, "wlan%d", sizeof(net->name));
1759                 /* WWAN devices should always be named "wwan%d" */
1760                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1761                         strscpy(net->name, "wwan%d", sizeof(net->name));
1762
1763                 /* devices that cannot do ARP */
1764                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1765                         net->flags |= IFF_NOARP;
1766
1767                 /* maybe the remote can't receive an Ethernet MTU */
1768                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1769                         net->mtu = dev->hard_mtu - net->hard_header_len;
1770         } else if (!info->in || !info->out)
1771                 status = usbnet_get_endpoints (dev, udev);
1772         else {
1773                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1774                 dev->out = usb_sndbulkpipe (xdev, info->out);
1775                 if (!(info->flags & FLAG_NO_SETINT))
1776                         status = usb_set_interface (xdev,
1777                                 interface->desc.bInterfaceNumber,
1778                                 interface->desc.bAlternateSetting);
1779                 else
1780                         status = 0;
1781
1782         }
1783         if (status >= 0 && dev->status)
1784                 status = init_status (dev, udev);
1785         if (status < 0)
1786                 goto out3;
1787
1788         if (!dev->rx_urb_size)
1789                 dev->rx_urb_size = dev->hard_mtu;
1790         dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1791
1792         /* let userspace know we have a random address */
1793         if (ether_addr_equal(net->dev_addr, node_id))
1794                 net->addr_assign_type = NET_ADDR_RANDOM;
1795
1796         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1797                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1798         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1799                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1800
1801         /* initialize max rx_qlen and tx_qlen */
1802         usbnet_update_max_qlen(dev);
1803
1804         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1805                 !(info->flags & FLAG_MULTI_PACKET)) {
1806                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1807                 if (!dev->padding_pkt) {
1808                         status = -ENOMEM;
1809                         goto out4;
1810                 }
1811         }
1812
1813         status = register_netdev (net);
1814         if (status)
1815                 goto out5;
1816         netif_info(dev, probe, dev->net,
1817                    "register '%s' at usb-%s-%s, %s, %pM\n",
1818                    udev->dev.driver->name,
1819                    xdev->bus->bus_name, xdev->devpath,
1820                    dev->driver_info->description,
1821                    net->dev_addr);
1822
1823         // ok, it's ready to go.
1824         usb_set_intfdata (udev, dev);
1825
1826         netif_device_attach (net);
1827
1828         if (dev->driver_info->flags & FLAG_LINK_INTR)
1829                 usbnet_link_change(dev, 0, 0);
1830
1831         return 0;
1832
1833 out5:
1834         kfree(dev->padding_pkt);
1835 out4:
1836         usb_free_urb(dev->interrupt);
1837 out3:
1838         if (info->unbind)
1839                 info->unbind (dev, udev);
1840 out1:
1841         /* subdrivers must undo all they did in bind() if they
1842          * fail it, but we may fail later and a deferred kevent
1843          * may trigger an error resubmitting itself and, worse,
1844          * schedule a timer. So we kill it all just in case.
1845          */
1846         cancel_work_sync(&dev->kevent);
1847         del_timer_sync(&dev->delay);
1848         free_percpu(net->tstats);
1849 out0:
1850         free_netdev(net);
1851 out:
1852         return status;
1853 }
1854 EXPORT_SYMBOL_GPL(usbnet_probe);
1855
1856 /*-------------------------------------------------------------------------*/
1857
1858 /*
1859  * suspend the whole driver as soon as the first interface is suspended
1860  * resume only when the last interface is resumed
1861  */
1862
1863 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1864 {
1865         struct usbnet           *dev = usb_get_intfdata(intf);
1866
1867         if (!dev->suspend_count++) {
1868                 spin_lock_irq(&dev->txq.lock);
1869                 /* don't autosuspend while transmitting */
1870                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1871                         dev->suspend_count--;
1872                         spin_unlock_irq(&dev->txq.lock);
1873                         return -EBUSY;
1874                 } else {
1875                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1876                         spin_unlock_irq(&dev->txq.lock);
1877                 }
1878                 /*
1879                  * accelerate emptying of the rx and queues, to avoid
1880                  * having everything error out.
1881                  */
1882                 netif_device_detach (dev->net);
1883                 usbnet_terminate_urbs(dev);
1884                 __usbnet_status_stop_force(dev);
1885
1886                 /*
1887                  * reattach so runtime management can use and
1888                  * wake the device
1889                  */
1890                 netif_device_attach (dev->net);
1891         }
1892         return 0;
1893 }
1894 EXPORT_SYMBOL_GPL(usbnet_suspend);
1895
1896 int usbnet_resume (struct usb_interface *intf)
1897 {
1898         struct usbnet           *dev = usb_get_intfdata(intf);
1899         struct sk_buff          *skb;
1900         struct urb              *res;
1901         int                     retval;
1902
1903         if (!--dev->suspend_count) {
1904                 /* resume interrupt URB if it was previously submitted */
1905                 __usbnet_status_start_force(dev, GFP_NOIO);
1906
1907                 spin_lock_irq(&dev->txq.lock);
1908                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1909
1910                         skb = (struct sk_buff *)res->context;
1911                         retval = usb_submit_urb(res, GFP_ATOMIC);
1912                         if (retval < 0) {
1913                                 dev_kfree_skb_any(skb);
1914                                 kfree(res->sg);
1915                                 usb_free_urb(res);
1916                                 usb_autopm_put_interface_async(dev->intf);
1917                         } else {
1918                                 netif_trans_update(dev->net);
1919                                 __skb_queue_tail(&dev->txq, skb);
1920                         }
1921                 }
1922
1923                 smp_mb();
1924                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1925                 spin_unlock_irq(&dev->txq.lock);
1926
1927                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1928                         /* handle remote wakeup ASAP
1929                          * we cannot race against stop
1930                          */
1931                         if (netif_device_present(dev->net) &&
1932                                 !timer_pending(&dev->delay) &&
1933                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1934                                         rx_alloc_submit(dev, GFP_NOIO);
1935
1936                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1937                                 netif_tx_wake_all_queues(dev->net);
1938                         tasklet_schedule (&dev->bh);
1939                 }
1940         }
1941
1942         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1943                 usb_autopm_get_interface_no_resume(intf);
1944
1945         return 0;
1946 }
1947 EXPORT_SYMBOL_GPL(usbnet_resume);
1948
1949 /*
1950  * Either a subdriver implements manage_power, then it is assumed to always
1951  * be ready to be suspended or it reports the readiness to be suspended
1952  * explicitly
1953  */
1954 void usbnet_device_suggests_idle(struct usbnet *dev)
1955 {
1956         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1957                 dev->intf->needs_remote_wakeup = 1;
1958                 usb_autopm_put_interface_async(dev->intf);
1959         }
1960 }
1961 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1962
1963 /*
1964  * For devices that can do without special commands
1965  */
1966 int usbnet_manage_power(struct usbnet *dev, int on)
1967 {
1968         dev->intf->needs_remote_wakeup = on;
1969         return 0;
1970 }
1971 EXPORT_SYMBOL(usbnet_manage_power);
1972
1973 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1974 {
1975         /* update link after link is reseted */
1976         if (link && !need_reset)
1977                 netif_carrier_on(dev->net);
1978         else
1979                 netif_carrier_off(dev->net);
1980
1981         if (need_reset && link)
1982                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1983         else
1984                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1985 }
1986 EXPORT_SYMBOL(usbnet_link_change);
1987
1988 /*-------------------------------------------------------------------------*/
1989 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1990                              u16 value, u16 index, void *data, u16 size)
1991 {
1992         void *buf = NULL;
1993         int err = -ENOMEM;
1994
1995         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1996                    " value=0x%04x index=0x%04x size=%d\n",
1997                    cmd, reqtype, value, index, size);
1998
1999         if (size) {
2000                 buf = kmalloc(size, GFP_KERNEL);
2001                 if (!buf)
2002                         goto out;
2003         }
2004
2005         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
2006                               cmd, reqtype, value, index, buf, size,
2007                               USB_CTRL_GET_TIMEOUT);
2008         if (err > 0 && err <= size) {
2009                 if (data)
2010                         memcpy(data, buf, err);
2011                 else
2012                         netdev_dbg(dev->net,
2013                                    "Huh? Data requested but thrown away.\n");
2014         }
2015         kfree(buf);
2016 out:
2017         return err;
2018 }
2019
2020 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2021                               u16 value, u16 index, const void *data,
2022                               u16 size)
2023 {
2024         void *buf = NULL;
2025         int err = -ENOMEM;
2026
2027         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2028                    " value=0x%04x index=0x%04x size=%d\n",
2029                    cmd, reqtype, value, index, size);
2030
2031         if (data) {
2032                 buf = kmemdup(data, size, GFP_KERNEL);
2033                 if (!buf)
2034                         goto out;
2035         } else {
2036         if (size) {
2037             WARN_ON_ONCE(1);
2038             err = -EINVAL;
2039             goto out;
2040         }
2041     }
2042
2043         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2044                               cmd, reqtype, value, index, buf, size,
2045                               USB_CTRL_SET_TIMEOUT);
2046         kfree(buf);
2047
2048 out:
2049         return err;
2050 }
2051
2052 /*
2053  * The function can't be called inside suspend/resume callback,
2054  * otherwise deadlock will be caused.
2055  */
2056 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2057                     u16 value, u16 index, void *data, u16 size)
2058 {
2059         int ret;
2060
2061         if (usb_autopm_get_interface(dev->intf) < 0)
2062                 return -ENODEV;
2063         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2064                                 data, size);
2065         usb_autopm_put_interface(dev->intf);
2066         return ret;
2067 }
2068 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2069
2070 /*
2071  * The function can't be called inside suspend/resume callback,
2072  * otherwise deadlock will be caused.
2073  */
2074 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2075                      u16 value, u16 index, const void *data, u16 size)
2076 {
2077         int ret;
2078
2079         if (usb_autopm_get_interface(dev->intf) < 0)
2080                 return -ENODEV;
2081         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2082                                  data, size);
2083         usb_autopm_put_interface(dev->intf);
2084         return ret;
2085 }
2086 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2087
2088 /*
2089  * The function can be called inside suspend/resume callback safely
2090  * and should only be called by suspend/resume callback generally.
2091  */
2092 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2093                           u16 value, u16 index, void *data, u16 size)
2094 {
2095         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2096                                  data, size);
2097 }
2098 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2099
2100 /*
2101  * The function can be called inside suspend/resume callback safely
2102  * and should only be called by suspend/resume callback generally.
2103  */
2104 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2105                           u16 value, u16 index, const void *data,
2106                           u16 size)
2107 {
2108         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2109                                   data, size);
2110 }
2111 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2112
2113 static void usbnet_async_cmd_cb(struct urb *urb)
2114 {
2115         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2116         int status = urb->status;
2117
2118         if (status < 0)
2119                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2120                         __func__, status);
2121
2122         kfree(req);
2123         usb_free_urb(urb);
2124 }
2125
2126 /*
2127  * The caller must make sure that device can't be put into suspend
2128  * state until the control URB completes.
2129  */
2130 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2131                            u16 value, u16 index, const void *data, u16 size)
2132 {
2133         struct usb_ctrlrequest *req = NULL;
2134         struct urb *urb;
2135         int err = -ENOMEM;
2136         void *buf = NULL;
2137
2138         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2139                    " value=0x%04x index=0x%04x size=%d\n",
2140                    cmd, reqtype, value, index, size);
2141
2142         urb = usb_alloc_urb(0, GFP_ATOMIC);
2143         if (!urb)
2144                 goto fail;
2145
2146         if (data) {
2147                 buf = kmemdup(data, size, GFP_ATOMIC);
2148                 if (!buf) {
2149                         netdev_err(dev->net, "Error allocating buffer"
2150                                    " in %s!\n", __func__);
2151                         goto fail_free;
2152                 }
2153         }
2154
2155         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2156         if (!req)
2157                 goto fail_free_buf;
2158
2159         req->bRequestType = reqtype;
2160         req->bRequest = cmd;
2161         req->wValue = cpu_to_le16(value);
2162         req->wIndex = cpu_to_le16(index);
2163         req->wLength = cpu_to_le16(size);
2164
2165         usb_fill_control_urb(urb, dev->udev,
2166                              usb_sndctrlpipe(dev->udev, 0),
2167                              (void *)req, buf, size,
2168                              usbnet_async_cmd_cb, req);
2169         urb->transfer_flags |= URB_FREE_BUFFER;
2170
2171         err = usb_submit_urb(urb, GFP_ATOMIC);
2172         if (err < 0) {
2173                 netdev_err(dev->net, "Error submitting the control"
2174                            " message: status=%d\n", err);
2175                 goto fail_free;
2176         }
2177         return 0;
2178
2179 fail_free_buf:
2180         kfree(buf);
2181 fail_free:
2182         kfree(req);
2183         usb_free_urb(urb);
2184 fail:
2185         return err;
2186
2187 }
2188 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2189 /*-------------------------------------------------------------------------*/
2190
2191 static int __init usbnet_init(void)
2192 {
2193         /* Compiler should optimize this out. */
2194         BUILD_BUG_ON(
2195                 sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data));
2196
2197         eth_random_addr(node_id);
2198         return 0;
2199 }
2200 module_init(usbnet_init);
2201
2202 static void __exit usbnet_exit(void)
2203 {
2204 }
2205 module_exit(usbnet_exit);
2206
2207 MODULE_AUTHOR("David Brownell");
2208 MODULE_DESCRIPTION("USB network driver framework");
2209 MODULE_LICENSE("GPL");