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 #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 // randomly generated ethernet address
  65 static u8       node_id [ETH_ALEN];
  66
  67 /* use ethtool to change the level for any given device */
  68 static int msg_level = -1;
  69 module_param (msg_level, int, 0);
  70 MODULE_PARM_DESC (msg_level, "Override default message level");
  71
  72 /*-------------------------------------------------------------------------*/
  73
  74 static const char * const usbnet_event_names[] = {
  75         [EVENT_TX_HALT]            = "EVENT_TX_HALT",
  76         [EVENT_RX_HALT]            = "EVENT_RX_HALT",
  77         [EVENT_RX_MEMORY]          = "EVENT_RX_MEMORY",
  78         [EVENT_STS_SPLIT]          = "EVENT_STS_SPLIT",
  79         [EVENT_LINK_RESET]         = "EVENT_LINK_RESET",
  80         [EVENT_RX_PAUSED]          = "EVENT_RX_PAUSED",
  81         [EVENT_DEV_ASLEEP]         = "EVENT_DEV_ASLEEP",
  82         [EVENT_DEV_OPEN]           = "EVENT_DEV_OPEN",
  83         [EVENT_DEVICE_REPORT_IDLE] = "EVENT_DEVICE_REPORT_IDLE",
  84         [EVENT_NO_RUNTIME_PM]      = "EVENT_NO_RUNTIME_PM",
  85         [EVENT_RX_KILL]            = "EVENT_RX_KILL",
  86         [EVENT_LINK_CHANGE]        = "EVENT_LINK_CHANGE",
  87         [EVENT_SET_RX_MODE]        = "EVENT_SET_RX_MODE",
  88         [EVENT_NO_IP_ALIGN]        = "EVENT_NO_IP_ALIGN",
  89 };
  90
  91 /* handles CDC Ethernet and many other network "bulk data" interfaces */
  92 int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  93 {
  94         int                             tmp;
  95         struct usb_host_interface       *alt = NULL;
  96         struct usb_host_endpoint        *in = NULL, *out = NULL;
  97         struct usb_host_endpoint        *status = NULL;
  98
  99         for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 100                 unsigned        ep;
 101
 102                 in = out = status = NULL;
 103                 alt = intf->altsetting + tmp;
 104
 105                 /* take the first altsetting with in-bulk + out-bulk;
 106                  * remember any status endpoint, just in case;
 107                  * ignore other endpoints and altsettings.
 108                  */
 109                 for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 110                         struct usb_host_endpoint        *e;
 111                         int                             intr = 0;
 112
 113                         e = alt->endpoint + ep;
 114
 115                         /* ignore endpoints which cannot transfer data */
 116                         if (!usb_endpoint_maxp(&e->desc))
 117                                 continue;
 118
 119                         switch (e->desc.bmAttributes) {
 120                         case USB_ENDPOINT_XFER_INT:
 121                                 if (!usb_endpoint_dir_in(&e->desc))
 122                                         continue;
 123                                 intr = 1;
 124                                 fallthrough;
 125                         case USB_ENDPOINT_XFER_BULK:
 126                                 break;
 127                         default:
 128                                 continue;
 129                         }
 130                         if (usb_endpoint_dir_in(&e->desc)) {
 131                                 if (!intr && !in)
 132                                         in = e;
 133                                 else if (intr && !status)
 134                                         status = e;
 135                         } else {
 136                                 if (!out)
 137                                         out = e;
 138                         }
 139                 }
 140                 if (in && out)
 141                         break;
 142         }
 143         if (!alt || !in || !out)
 144                 return -EINVAL;
 145
 146         if (alt->desc.bAlternateSetting != 0 ||
 147             !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 148                 tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 149                                 alt->desc.bAlternateSetting);
 150                 if (tmp < 0)
 151                         return tmp;
 152         }
 153
 154         dev->in = usb_rcvbulkpipe (dev->udev,
 155                         in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 156         dev->out = usb_sndbulkpipe (dev->udev,
 157                         out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 158         dev->status = status;
 159         return 0;
 160 }
 161 EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 162
 163 int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 164 {
 165         u8              addr[ETH_ALEN];
 166         int             tmp = -1, ret;
 167         unsigned char   buf [13];
 168
 169         ret = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 170         if (ret == 12)
 171                 tmp = hex2bin(addr, buf, 6);
 172         if (tmp < 0) {
 173                 dev_dbg(&dev->udev->dev,
 174                         "bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 175                 if (ret >= 0)
 176                         ret = -EINVAL;
 177                 return ret;
 178         }
 179         eth_hw_addr_set(dev->net, addr);
 180         return 0;
 181 }
 182 EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 183
 184 static void intr_complete (struct urb *urb)
 185 {
 186         struct usbnet   *dev = urb->context;
 187         int             status = urb->status;
 188
 189         switch (status) {
 190         /* success */
 191         case 0:
 192                 dev->driver_info->status(dev, urb);
 193                 break;
 194
 195         /* software-driven interface shutdown */
 196         case -ENOENT:           /* urb killed */
 197         case -ESHUTDOWN:        /* hardware gone */
 198                 netif_dbg(dev, ifdown, dev->net,
 199                           "intr shutdown, code %d\n", status);
 200                 return;
 201
 202         /* NOTE:  not throttling like RX/TX, since this endpoint
 203          * already polls infrequently
 204          */
 205         default:
 206                 netdev_dbg(dev->net, "intr status %d\n", status);
 207                 break;
 208         }
 209
 210         status = usb_submit_urb (urb, GFP_ATOMIC);
 211         if (status != 0)
 212                 netif_err(dev, timer, dev->net,
 213                           "intr resubmit --> %d\n", status);
 214 }
 215
 216 static int init_status (struct usbnet *dev, struct usb_interface *intf)
 217 {
 218         char            *buf = NULL;
 219         unsigned        pipe = 0;
 220         unsigned        maxp;
 221         unsigned        period;
 222
 223         if (!dev->driver_info->status)
 224                 return 0;
 225
 226         pipe = usb_rcvintpipe (dev->udev,
 227                         dev->status->desc.bEndpointAddress
 228                                 & USB_ENDPOINT_NUMBER_MASK);
 229         maxp = usb_maxpacket(dev->udev, pipe);
 230
 231         /* avoid 1 msec chatter:  min 8 msec poll rate */
 232         period = max ((int) dev->status->desc.bInterval,
 233                 (dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 234
 235         buf = kmalloc (maxp, GFP_KERNEL);
 236         if (buf) {
 237                 dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 238                 if (!dev->interrupt) {
 239                         kfree (buf);
 240                         return -ENOMEM;
 241                 } else {
 242                         usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 243                                 buf, maxp, intr_complete, dev, period);
 244                         dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 245                         dev_dbg(&intf->dev,
 246                                 "status ep%din, %d bytes period %d\n",
 247                                 usb_pipeendpoint(pipe), maxp, period);
 248                 }
 249         }
 250         return 0;
 251 }
 252
 253 /* Submit the interrupt URB if not previously submitted, increasing refcount */
 254 int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 255 {
 256         int ret = 0;
 257
 258         WARN_ON_ONCE(dev->interrupt == NULL);
 259         if (dev->interrupt) {
 260                 mutex_lock(&dev->interrupt_mutex);
 261
 262                 if (++dev->interrupt_count == 1)
 263                         ret = usb_submit_urb(dev->interrupt, mem_flags);
 264
 265                 dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 266                         dev->interrupt_count);
 267                 mutex_unlock(&dev->interrupt_mutex);
 268         }
 269         return ret;
 270 }
 271 EXPORT_SYMBOL_GPL(usbnet_status_start);
 272
 273 /* For resume; submit interrupt URB if previously submitted */
 274 static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 275 {
 276         int ret = 0;
 277
 278         mutex_lock(&dev->interrupt_mutex);
 279         if (dev->interrupt_count) {
 280                 ret = usb_submit_urb(dev->interrupt, mem_flags);
 281                 dev_dbg(&dev->udev->dev,
 282                         "submitted interrupt URB for resume\n");
 283         }
 284         mutex_unlock(&dev->interrupt_mutex);
 285         return ret;
 286 }
 287
 288 /* Kill the interrupt URB if all submitters want it killed */
 289 void usbnet_status_stop(struct usbnet *dev)
 290 {
 291         if (dev->interrupt) {
 292                 mutex_lock(&dev->interrupt_mutex);
 293                 WARN_ON(dev->interrupt_count == 0);
 294
 295                 if (dev->interrupt_count && --dev->interrupt_count == 0)
 296                         usb_kill_urb(dev->interrupt);
 297
 298                 dev_dbg(&dev->udev->dev,
 299                         "decremented interrupt URB count to %d\n",
 300                         dev->interrupt_count);
 301                 mutex_unlock(&dev->interrupt_mutex);
 302         }
 303 }
 304 EXPORT_SYMBOL_GPL(usbnet_status_stop);
 305
 306 /* For suspend; always kill interrupt URB */
 307 static void __usbnet_status_stop_force(struct usbnet *dev)
 308 {
 309         if (dev->interrupt) {
 310                 mutex_lock(&dev->interrupt_mutex);
 311                 usb_kill_urb(dev->interrupt);
 312                 dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 313                 mutex_unlock(&dev->interrupt_mutex);
 314         }
 315 }
 316
 317 /* Passes this packet up the stack, updating its accounting.
 318  * Some link protocols batch packets, so their rx_fixup paths
 319  * can return clones as well as just modify the original skb.
 320  */
 321 void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 322 {
 323         struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
 324         unsigned long flags;
 325         int     status;
 326
 327         if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 328                 skb_queue_tail(&dev->rxq_pause, skb);
 329                 return;
 330         }
 331
 332         /* only update if unset to allow minidriver rx_fixup override */
 333         if (skb->protocol == 0)
 334                 skb->protocol = eth_type_trans (skb, dev->net);
 335
 336         flags = u64_stats_update_begin_irqsave(&stats64->syncp);
 337         u64_stats_inc(&stats64->rx_packets);
 338         u64_stats_add(&stats64->rx_bytes, skb->len);
 339         u64_stats_update_end_irqrestore(&stats64->syncp, flags);
 340
 341         netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 342                   skb->len + sizeof (struct ethhdr), skb->protocol);
 343         memset (skb->cb, 0, sizeof (struct skb_data));
 344
 345         if (skb_defer_rx_timestamp(skb))
 346                 return;
 347
 348         status = netif_rx (skb);
 349         if (status != NET_RX_SUCCESS)
 350                 netif_dbg(dev, rx_err, dev->net,
 351                           "netif_rx status %d\n", status);
 352 }
 353 EXPORT_SYMBOL_GPL(usbnet_skb_return);
 354
 355 /* must be called if hard_mtu or rx_urb_size changed */
 356 void usbnet_update_max_qlen(struct usbnet *dev)
 357 {
 358         enum usb_device_speed speed = dev->udev->speed;
 359
 360         if (!dev->rx_urb_size || !dev->hard_mtu)
 361                 goto insanity;
 362         switch (speed) {
 363         case USB_SPEED_HIGH:
 364                 dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 365                 dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 366                 break;
 367         case USB_SPEED_SUPER:
 368         case USB_SPEED_SUPER_PLUS:
 369                 /*
 370                  * Not take default 5ms qlen for super speed HC to
 371                  * save memory, and iperf tests show 2.5ms qlen can
 372                  * work well
 373                  */
 374                 dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 375                 dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 376                 break;
 377         default:
 378 insanity:
 379                 dev->rx_qlen = dev->tx_qlen = 4;
 380         }
 381 }
 382 EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 383
 384
 385 /*-------------------------------------------------------------------------
 386  *
 387  * Network Device Driver (peer link to "Host Device", from USB host)
 388  *
 389  *-------------------------------------------------------------------------*/
 390
 391 int usbnet_change_mtu (struct net_device *net, int new_mtu)
 392 {
 393         struct usbnet   *dev = netdev_priv(net);
 394         int             ll_mtu = new_mtu + net->hard_header_len;
 395         int             old_hard_mtu = dev->hard_mtu;
 396         int             old_rx_urb_size = dev->rx_urb_size;
 397
 398         // no second zero-length packet read wanted after mtu-sized packets
 399         if ((ll_mtu % dev->maxpacket) == 0)
 400                 return -EDOM;
 401         net->mtu = new_mtu;
 402
 403         dev->hard_mtu = net->mtu + net->hard_header_len;
 404         if (dev->rx_urb_size == old_hard_mtu) {
 405                 dev->rx_urb_size = dev->hard_mtu;
 406                 if (dev->rx_urb_size > old_rx_urb_size) {
 407                         usbnet_pause_rx(dev);
 408                         usbnet_unlink_rx_urbs(dev);
 409                         usbnet_resume_rx(dev);
 410                 }
 411         }
 412
 413         /* max qlen depend on hard_mtu and rx_urb_size */
 414         usbnet_update_max_qlen(dev);
 415
 416         return 0;
 417 }
 418 EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 419
 420 /* The caller must hold list->lock */
 421 static void __usbnet_queue_skb(struct sk_buff_head *list,
 422                         struct sk_buff *newsk, enum skb_state state)
 423 {
 424         struct skb_data *entry = (struct skb_data *) newsk->cb;
 425
 426         __skb_queue_tail(list, newsk);
 427         entry->state = state;
 428 }
 429
 430 /*-------------------------------------------------------------------------*/
 431
 432 /* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 433  * completion callbacks.  2.5 should have fixed those bugs...
 434  */
 435
 436 static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 437                 struct sk_buff_head *list, enum skb_state state)
 438 {
 439         unsigned long           flags;
 440         enum skb_state          old_state;
 441         struct skb_data *entry = (struct skb_data *) skb->cb;
 442
 443         spin_lock_irqsave(&list->lock, flags);
 444         old_state = entry->state;
 445         entry->state = state;
 446         __skb_unlink(skb, list);
 447
 448         /* defer_bh() is never called with list == &dev->done.
 449          * spin_lock_nested() tells lockdep that it is OK to take
 450          * dev->done.lock here with list->lock held.
 451          */
 452         spin_lock_nested(&dev->done.lock, SINGLE_DEPTH_NESTING);
 453
 454         __skb_queue_tail(&dev->done, skb);
 455         if (dev->done.qlen == 1)
 456                 tasklet_schedule(&dev->bh);
 457         spin_unlock(&dev->done.lock);
 458         spin_unlock_irqrestore(&list->lock, flags);
 459         return old_state;
 460 }
 461
 462 /* some work can't be done in tasklets, so we use keventd
 463  *
 464  * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 465  * but tasklet_schedule() doesn't.  hope the failure is rare.
 466  */
 467 void usbnet_defer_kevent (struct usbnet *dev, int work)
 468 {
 469         set_bit (work, &dev->flags);
 470         if (!schedule_work (&dev->kevent))
 471                 netdev_dbg(dev->net, "kevent %s may have been dropped\n", usbnet_event_names[work]);
 472         else
 473                 netdev_dbg(dev->net, "kevent %s scheduled\n", usbnet_event_names[work]);
 474 }
 475 EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 476
 477 /*-------------------------------------------------------------------------*/
 478
 479 static void rx_complete (struct urb *urb);
 480
 481 static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 482 {
 483         struct sk_buff          *skb;
 484         struct skb_data         *entry;
 485         int                     retval = 0;
 486         unsigned long           lockflags;
 487         size_t                  size = dev->rx_urb_size;
 488
 489         /* prevent rx skb allocation when error ratio is high */
 490         if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 491                 usb_free_urb(urb);
 492                 return -ENOLINK;
 493         }
 494
 495         if (test_bit(EVENT_NO_IP_ALIGN, &dev->flags))
 496                 skb = __netdev_alloc_skb(dev->net, size, flags);
 497         else
 498                 skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 499         if (!skb) {
 500                 netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 501                 usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 502                 usb_free_urb (urb);
 503                 return -ENOMEM;
 504         }
 505
 506         entry = (struct skb_data *) skb->cb;
 507         entry->urb = urb;
 508         entry->dev = dev;
 509         entry->length = 0;
 510
 511         usb_fill_bulk_urb (urb, dev->udev, dev->in,
 512                 skb->data, size, rx_complete, skb);
 513
 514         spin_lock_irqsave (&dev->rxq.lock, lockflags);
 515
 516         if (netif_running (dev->net) &&
 517             netif_device_present (dev->net) &&
 518             test_bit(EVENT_DEV_OPEN, &dev->flags) &&
 519             !test_bit (EVENT_RX_HALT, &dev->flags) &&
 520             !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 521                 switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 522                 case -EPIPE:
 523                         usbnet_defer_kevent (dev, EVENT_RX_HALT);
 524                         break;
 525                 case -ENOMEM:
 526                         usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 527                         break;
 528                 case -ENODEV:
 529                         netif_dbg(dev, ifdown, dev->net, "device gone\n");
 530                         netif_device_detach (dev->net);
 531                         break;
 532                 case -EHOSTUNREACH:
 533                         retval = -ENOLINK;
 534                         break;
 535                 default:
 536                         netif_dbg(dev, rx_err, dev->net,
 537                                   "rx submit, %d\n", retval);
 538                         tasklet_schedule (&dev->bh);
 539                         break;
 540                 case 0:
 541                         __usbnet_queue_skb(&dev->rxq, skb, rx_start);
 542                 }
 543         } else {
 544                 netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 545                 retval = -ENOLINK;
 546         }
 547         spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 548         if (retval) {
 549                 dev_kfree_skb_any (skb);
 550                 usb_free_urb (urb);
 551         }
 552         return retval;
 553 }
 554
 555
 556 /*-------------------------------------------------------------------------*/
 557
 558 static inline int rx_process(struct usbnet *dev, struct sk_buff *skb)
 559 {
 560         if (dev->driver_info->rx_fixup &&
 561             !dev->driver_info->rx_fixup (dev, skb)) {
 562                 /* With RX_ASSEMBLE, rx_fixup() must update counters */
 563                 if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 564                         dev->net->stats.rx_errors++;
 565                 return -EPROTO;
 566         }
 567         // else network stack removes extra byte if we forced a short packet
 568
 569         /* all data was already cloned from skb inside the driver */
 570         if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 571                 return -EALREADY;
 572
 573         if (skb->len < ETH_HLEN) {
 574                 dev->net->stats.rx_errors++;
 575                 dev->net->stats.rx_length_errors++;
 576                 netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 577                 return -EPROTO;
 578         }
 579
 580         usbnet_skb_return(dev, skb);
 581         return 0;
 582 }
 583
 584 /*-------------------------------------------------------------------------*/
 585
 586 static void rx_complete (struct urb *urb)
 587 {
 588         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 589         struct skb_data         *entry = (struct skb_data *) skb->cb;
 590         struct usbnet           *dev = entry->dev;
 591         int                     urb_status = urb->status;
 592         enum skb_state          state;
 593
 594         skb_put (skb, urb->actual_length);
 595         state = rx_done;
 596         entry->urb = NULL;
 597
 598         switch (urb_status) {
 599         /* success */
 600         case 0:
 601                 break;
 602
 603         /* stalls need manual reset. this is rare ... except that
 604          * when going through USB 2.0 TTs, unplug appears this way.
 605          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 606          * storm, recovering as needed.
 607          */
 608         case -EPIPE:
 609                 dev->net->stats.rx_errors++;
 610                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 611                 fallthrough;
 612
 613         /* software-driven interface shutdown */
 614         case -ECONNRESET:               /* async unlink */
 615         case -ESHUTDOWN:                /* hardware gone */
 616                 netif_dbg(dev, ifdown, dev->net,
 617                           "rx shutdown, code %d\n", urb_status);
 618                 goto block;
 619
 620         /* we get controller i/o faults during hub_wq disconnect() delays.
 621          * throttle down resubmits, to avoid log floods; just temporarily,
 622          * so we still recover when the fault isn't a hub_wq delay.
 623          */
 624         case -EPROTO:
 625         case -ETIME:
 626         case -EILSEQ:
 627                 dev->net->stats.rx_errors++;
 628                 if (!timer_pending (&dev->delay)) {
 629                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 630                         netif_dbg(dev, link, dev->net,
 631                                   "rx throttle %d\n", urb_status);
 632                 }
 633 block:
 634                 state = rx_cleanup;
 635                 entry->urb = urb;
 636                 urb = NULL;
 637                 break;
 638
 639         /* data overrun ... flush fifo? */
 640         case -EOVERFLOW:
 641                 dev->net->stats.rx_over_errors++;
 642                 fallthrough;
 643
 644         default:
 645                 state = rx_cleanup;
 646                 dev->net->stats.rx_errors++;
 647                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 648                 break;
 649         }
 650
 651         /* stop rx if packet error rate is high */
 652         if (++dev->pkt_cnt > 30) {
 653                 dev->pkt_cnt = 0;
 654                 dev->pkt_err = 0;
 655         } else {
 656                 if (state == rx_cleanup)
 657                         dev->pkt_err++;
 658                 if (dev->pkt_err > 20)
 659                         set_bit(EVENT_RX_KILL, &dev->flags);
 660         }
 661
 662         state = defer_bh(dev, skb, &dev->rxq, state);
 663
 664         if (urb) {
 665                 if (netif_running (dev->net) &&
 666                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 667                     state != unlink_start) {
 668                         rx_submit (dev, urb, GFP_ATOMIC);
 669                         usb_mark_last_busy(dev->udev);
 670                         return;
 671                 }
 672                 usb_free_urb (urb);
 673         }
 674         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 675 }
 676
 677 /*-------------------------------------------------------------------------*/
 678 void usbnet_pause_rx(struct usbnet *dev)
 679 {
 680         set_bit(EVENT_RX_PAUSED, &dev->flags);
 681
 682         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 683 }
 684 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 685
 686 void usbnet_resume_rx(struct usbnet *dev)
 687 {
 688         struct sk_buff *skb;
 689         int num = 0;
 690
 691         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 692
 693         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 694                 usbnet_skb_return(dev, skb);
 695                 num++;
 696         }
 697
 698         tasklet_schedule(&dev->bh);
 699
 700         netif_dbg(dev, rx_status, dev->net,
 701                   "paused rx queue disabled, %d skbs requeued\n", num);
 702 }
 703 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 704
 705 void usbnet_purge_paused_rxq(struct usbnet *dev)
 706 {
 707         skb_queue_purge(&dev->rxq_pause);
 708 }
 709 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 710
 711 /*-------------------------------------------------------------------------*/
 712
 713 // unlink pending rx/tx; completion handlers do all other cleanup
 714
 715 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 716 {
 717         unsigned long           flags;
 718         struct sk_buff          *skb;
 719         int                     count = 0;
 720
 721         spin_lock_irqsave (&q->lock, flags);
 722         while (!skb_queue_empty(q)) {
 723                 struct skb_data         *entry;
 724                 struct urb              *urb;
 725                 int                     retval;
 726
 727                 skb_queue_walk(q, skb) {
 728                         entry = (struct skb_data *) skb->cb;
 729                         if (entry->state != unlink_start)
 730                                 goto found;
 731                 }
 732                 break;
 733 found:
 734                 entry->state = unlink_start;
 735                 urb = entry->urb;
 736
 737                 /*
 738                  * Get reference count of the URB to avoid it to be
 739                  * freed during usb_unlink_urb, which may trigger
 740                  * use-after-free problem inside usb_unlink_urb since
 741                  * usb_unlink_urb is always racing with .complete
 742                  * handler(include defer_bh).
 743                  */
 744                 usb_get_urb(urb);
 745                 spin_unlock_irqrestore(&q->lock, flags);
 746                 // during some PM-driven resume scenarios,
 747                 // these (async) unlinks complete immediately
 748                 retval = usb_unlink_urb (urb);
 749                 if (retval != -EINPROGRESS && retval != 0)
 750                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 751                 else
 752                         count++;
 753                 usb_put_urb(urb);
 754                 spin_lock_irqsave(&q->lock, flags);
 755         }
 756         spin_unlock_irqrestore (&q->lock, flags);
 757         return count;
 758 }
 759
 760 // Flush all pending rx urbs
 761 // minidrivers may need to do this when the MTU changes
 762
 763 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 764 {
 765         if (netif_running(dev->net)) {
 766                 (void) unlink_urbs (dev, &dev->rxq);
 767                 tasklet_schedule(&dev->bh);
 768         }
 769 }
 770 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 771
 772 /*-------------------------------------------------------------------------*/
 773
 774 static void wait_skb_queue_empty(struct sk_buff_head *q)
 775 {
 776         unsigned long flags;
 777
 778         spin_lock_irqsave(&q->lock, flags);
 779         while (!skb_queue_empty(q)) {
 780                 spin_unlock_irqrestore(&q->lock, flags);
 781                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 782                 set_current_state(TASK_UNINTERRUPTIBLE);
 783                 spin_lock_irqsave(&q->lock, flags);
 784         }
 785         spin_unlock_irqrestore(&q->lock, flags);
 786 }
 787
 788 // precondition: never called in_interrupt
 789 static void usbnet_terminate_urbs(struct usbnet *dev)
 790 {
 791         DECLARE_WAITQUEUE(wait, current);
 792         int temp;
 793
 794         /* ensure there are no more active urbs */
 795         add_wait_queue(&dev->wait, &wait);
 796         set_current_state(TASK_UNINTERRUPTIBLE);
 797         temp = unlink_urbs(dev, &dev->txq) +
 798                 unlink_urbs(dev, &dev->rxq);
 799
 800         /* maybe wait for deletions to finish. */
 801         wait_skb_queue_empty(&dev->rxq);
 802         wait_skb_queue_empty(&dev->txq);
 803         wait_skb_queue_empty(&dev->done);
 804         netif_dbg(dev, ifdown, dev->net,
 805                   "waited for %d urb completions\n", temp);
 806         set_current_state(TASK_RUNNING);
 807         remove_wait_queue(&dev->wait, &wait);
 808 }
 809
 810 int usbnet_stop (struct net_device *net)
 811 {
 812         struct usbnet           *dev = netdev_priv(net);
 813         const struct driver_info *info = dev->driver_info;
 814         int                     retval, pm, mpn;
 815
 816         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 817         netif_stop_queue (net);
 818
 819         netif_info(dev, ifdown, dev->net,
 820                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 821                    net->stats.rx_packets, net->stats.tx_packets,
 822                    net->stats.rx_errors, net->stats.tx_errors);
 823
 824         /* to not race resume */
 825         pm = usb_autopm_get_interface(dev->intf);
 826         /* allow minidriver to stop correctly (wireless devices to turn off
 827          * radio etc) */
 828         if (info->stop) {
 829                 retval = info->stop(dev);
 830                 if (retval < 0)
 831                         netif_info(dev, ifdown, dev->net,
 832                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 833                                    retval,
 834                                    dev->udev->bus->bus_name, dev->udev->devpath,
 835                                    info->description);
 836         }
 837
 838         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 839                 usbnet_terminate_urbs(dev);
 840
 841         usbnet_status_stop(dev);
 842
 843         usbnet_purge_paused_rxq(dev);
 844
 845         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 846
 847         /* deferred work (timer, softirq, task) must also stop */
 848         dev->flags = 0;
 849         del_timer_sync (&dev->delay);
 850         tasklet_kill (&dev->bh);
 851         cancel_work_sync(&dev->kevent);
 852         if (!pm)
 853                 usb_autopm_put_interface(dev->intf);
 854
 855         if (info->manage_power && mpn)
 856                 info->manage_power(dev, 0);
 857         else
 858                 usb_autopm_put_interface(dev->intf);
 859
 860         return 0;
 861 }
 862 EXPORT_SYMBOL_GPL(usbnet_stop);
 863
 864 /*-------------------------------------------------------------------------*/
 865
 866 // posts reads, and enables write queuing
 867
 868 // precondition: never called in_interrupt
 869
 870 int usbnet_open (struct net_device *net)
 871 {
 872         struct usbnet           *dev = netdev_priv(net);
 873         int                     retval;
 874         const struct driver_info *info = dev->driver_info;
 875
 876         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 877                 netif_info(dev, ifup, dev->net,
 878                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 879                            retval,
 880                            dev->udev->bus->bus_name,
 881                            dev->udev->devpath,
 882                            info->description);
 883                 goto done_nopm;
 884         }
 885
 886         // put into "known safe" state
 887         if (info->reset && (retval = info->reset (dev)) < 0) {
 888                 netif_info(dev, ifup, dev->net,
 889                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 890                            retval,
 891                            dev->udev->bus->bus_name,
 892                            dev->udev->devpath,
 893                            info->description);
 894                 goto done;
 895         }
 896
 897         /* hard_mtu or rx_urb_size may change in reset() */
 898         usbnet_update_max_qlen(dev);
 899
 900         // insist peer be connected
 901         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 902                 netif_err(dev, ifup, dev->net, "can't open; %d\n", retval);
 903                 goto done;
 904         }
 905
 906         /* start any status interrupt transfer */
 907         if (dev->interrupt) {
 908                 retval = usbnet_status_start(dev, GFP_KERNEL);
 909                 if (retval < 0) {
 910                         netif_err(dev, ifup, dev->net,
 911                                   "intr submit %d\n", retval);
 912                         goto done;
 913                 }
 914         }
 915
 916         set_bit(EVENT_DEV_OPEN, &dev->flags);
 917         netif_start_queue (net);
 918         netif_info(dev, ifup, dev->net,
 919                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 920                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 921                    dev->net->mtu,
 922                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 923                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 924                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 925                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 926                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 927                    "simple");
 928
 929         /* reset rx error state */
 930         dev->pkt_cnt = 0;
 931         dev->pkt_err = 0;
 932         clear_bit(EVENT_RX_KILL, &dev->flags);
 933
 934         // delay posting reads until we're fully open
 935         tasklet_schedule (&dev->bh);
 936         if (info->manage_power) {
 937                 retval = info->manage_power(dev, 1);
 938                 if (retval < 0) {
 939                         retval = 0;
 940                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 941                 } else {
 942                         usb_autopm_put_interface(dev->intf);
 943                 }
 944         }
 945         return retval;
 946 done:
 947         usb_autopm_put_interface(dev->intf);
 948 done_nopm:
 949         return retval;
 950 }
 951 EXPORT_SYMBOL_GPL(usbnet_open);
 952
 953 /*-------------------------------------------------------------------------*/
 954
 955 /* ethtool methods; minidrivers may need to add some more, but
 956  * they'll probably want to use this base set.
 957  */
 958
 959 /* These methods are written on the assumption that the device
 960  * uses MII
 961  */
 962 int usbnet_get_link_ksettings_mii(struct net_device *net,
 963                               struct ethtool_link_ksettings *cmd)
 964 {
 965         struct usbnet *dev = netdev_priv(net);
 966
 967         if (!dev->mii.mdio_read)
 968                 return -EOPNOTSUPP;
 969
 970         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 971
 972         return 0;
 973 }
 974 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_mii);
 975
 976 int usbnet_get_link_ksettings_internal(struct net_device *net,
 977                                         struct ethtool_link_ksettings *cmd)
 978 {
 979         struct usbnet *dev = netdev_priv(net);
 980
 981         /* the assumption that speed is equal on tx and rx
 982          * is deeply engrained into the networking layer.
 983          * For wireless stuff it is not true.
 984          * We assume that rx_speed matters more.
 985          */
 986         if (dev->rx_speed != SPEED_UNSET)
 987                 cmd->base.speed = dev->rx_speed / 1000000;
 988         else if (dev->tx_speed != SPEED_UNSET)
 989                 cmd->base.speed = dev->tx_speed / 1000000;
 990         else
 991                 cmd->base.speed = SPEED_UNKNOWN;
 992
 993         return 0;
 994 }
 995 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_internal);
 996
 997 int usbnet_set_link_ksettings_mii(struct net_device *net,
 998                               const struct ethtool_link_ksettings *cmd)
 999 {
1000         struct usbnet *dev = netdev_priv(net);
1001         int retval;
1002
1003         if (!dev->mii.mdio_write)
1004                 return -EOPNOTSUPP;
1005
1006         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
1007
1008         /* link speed/duplex might have changed */
1009         if (dev->driver_info->link_reset)
1010                 dev->driver_info->link_reset(dev);
1011
1012         /* hard_mtu or rx_urb_size may change in link_reset() */
1013         usbnet_update_max_qlen(dev);
1014
1015         return retval;
1016 }
1017 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings_mii);
1018
1019 u32 usbnet_get_link (struct net_device *net)
1020 {
1021         struct usbnet *dev = netdev_priv(net);
1022
1023         /* If a check_connect is defined, return its result */
1024         if (dev->driver_info->check_connect)
1025                 return dev->driver_info->check_connect (dev) == 0;
1026
1027         /* if the device has mii operations, use those */
1028         if (dev->mii.mdio_read)
1029                 return mii_link_ok(&dev->mii);
1030
1031         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1032         return ethtool_op_get_link(net);
1033 }
1034 EXPORT_SYMBOL_GPL(usbnet_get_link);
1035
1036 int usbnet_nway_reset(struct net_device *net)
1037 {
1038         struct usbnet *dev = netdev_priv(net);
1039
1040         if (!dev->mii.mdio_write)
1041                 return -EOPNOTSUPP;
1042
1043         return mii_nway_restart(&dev->mii);
1044 }
1045 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1046
1047 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1048 {
1049         struct usbnet *dev = netdev_priv(net);
1050
1051         strscpy(info->driver, dev->driver_name, sizeof(info->driver));
1052         strscpy(info->fw_version, dev->driver_info->description,
1053                 sizeof(info->fw_version));
1054         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1055 }
1056 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1057
1058 u32 usbnet_get_msglevel (struct net_device *net)
1059 {
1060         struct usbnet *dev = netdev_priv(net);
1061
1062         return dev->msg_enable;
1063 }
1064 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1065
1066 void usbnet_set_msglevel (struct net_device *net, u32 level)
1067 {
1068         struct usbnet *dev = netdev_priv(net);
1069
1070         dev->msg_enable = level;
1071 }
1072 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1073
1074 /* drivers may override default ethtool_ops in their bind() routine */
1075 static const struct ethtool_ops usbnet_ethtool_ops = {
1076         .get_link               = usbnet_get_link,
1077         .nway_reset             = usbnet_nway_reset,
1078         .get_drvinfo            = usbnet_get_drvinfo,
1079         .get_msglevel           = usbnet_get_msglevel,
1080         .set_msglevel           = usbnet_set_msglevel,
1081         .get_ts_info            = ethtool_op_get_ts_info,
1082         .get_link_ksettings     = usbnet_get_link_ksettings_mii,
1083         .set_link_ksettings     = usbnet_set_link_ksettings_mii,
1084 };
1085
1086 /*-------------------------------------------------------------------------*/
1087
1088 static void __handle_link_change(struct usbnet *dev)
1089 {
1090         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1091                 return;
1092
1093         if (!netif_carrier_ok(dev->net)) {
1094                 /* kill URBs for reading packets to save bus bandwidth */
1095                 unlink_urbs(dev, &dev->rxq);
1096
1097                 /*
1098                  * tx_timeout will unlink URBs for sending packets and
1099                  * tx queue is stopped by netcore after link becomes off
1100                  */
1101         } else {
1102                 /* submitting URBs for reading packets */
1103                 tasklet_schedule(&dev->bh);
1104         }
1105
1106         /* hard_mtu or rx_urb_size may change during link change */
1107         usbnet_update_max_qlen(dev);
1108
1109         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1110 }
1111
1112 void usbnet_set_rx_mode(struct net_device *net)
1113 {
1114         struct usbnet           *dev = netdev_priv(net);
1115
1116         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1117 }
1118 EXPORT_SYMBOL_GPL(usbnet_set_rx_mode);
1119
1120 static void __handle_set_rx_mode(struct usbnet *dev)
1121 {
1122         if (dev->driver_info->set_rx_mode)
1123                 (dev->driver_info->set_rx_mode)(dev);
1124
1125         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1126 }
1127
1128 /* work that cannot be done in interrupt context uses keventd.
1129  *
1130  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1131  * especially now that control transfers can be queued.
1132  */
1133 static void
1134 usbnet_deferred_kevent (struct work_struct *work)
1135 {
1136         struct usbnet           *dev =
1137                 container_of(work, struct usbnet, kevent);
1138         int                     status;
1139
1140         /* usb_clear_halt() needs a thread context */
1141         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1142                 unlink_urbs (dev, &dev->txq);
1143                 status = usb_autopm_get_interface(dev->intf);
1144                 if (status < 0)
1145                         goto fail_pipe;
1146                 status = usb_clear_halt (dev->udev, dev->out);
1147                 usb_autopm_put_interface(dev->intf);
1148                 if (status < 0 &&
1149                     status != -EPIPE &&
1150                     status != -ESHUTDOWN) {
1151                         if (netif_msg_tx_err (dev))
1152 fail_pipe:
1153                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1154                                            status);
1155                 } else {
1156                         clear_bit (EVENT_TX_HALT, &dev->flags);
1157                         if (status != -ESHUTDOWN)
1158                                 netif_wake_queue (dev->net);
1159                 }
1160         }
1161         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1162                 unlink_urbs (dev, &dev->rxq);
1163                 status = usb_autopm_get_interface(dev->intf);
1164                 if (status < 0)
1165                         goto fail_halt;
1166                 status = usb_clear_halt (dev->udev, dev->in);
1167                 usb_autopm_put_interface(dev->intf);
1168                 if (status < 0 &&
1169                     status != -EPIPE &&
1170                     status != -ESHUTDOWN) {
1171                         if (netif_msg_rx_err (dev))
1172 fail_halt:
1173                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1174                                            status);
1175                 } else {
1176                         clear_bit (EVENT_RX_HALT, &dev->flags);
1177                         tasklet_schedule (&dev->bh);
1178                 }
1179         }
1180
1181         /* tasklet could resubmit itself forever if memory is tight */
1182         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1183                 struct urb      *urb = NULL;
1184                 int resched = 1;
1185
1186                 if (netif_running (dev->net))
1187                         urb = usb_alloc_urb (0, GFP_KERNEL);
1188                 else
1189                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1190                 if (urb != NULL) {
1191                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1192                         status = usb_autopm_get_interface(dev->intf);
1193                         if (status < 0) {
1194                                 usb_free_urb(urb);
1195                                 goto fail_lowmem;
1196                         }
1197                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1198                                 resched = 0;
1199                         usb_autopm_put_interface(dev->intf);
1200 fail_lowmem:
1201                         if (resched)
1202                                 tasklet_schedule (&dev->bh);
1203                 }
1204         }
1205
1206         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1207                 const struct driver_info *info = dev->driver_info;
1208                 int                     retval = 0;
1209
1210                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1211                 status = usb_autopm_get_interface(dev->intf);
1212                 if (status < 0)
1213                         goto skip_reset;
1214                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1215                         usb_autopm_put_interface(dev->intf);
1216 skip_reset:
1217                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1218                                     retval,
1219                                     dev->udev->bus->bus_name,
1220                                     dev->udev->devpath,
1221                                     info->description);
1222                 } else {
1223                         usb_autopm_put_interface(dev->intf);
1224                 }
1225
1226                 /* handle link change from link resetting */
1227                 __handle_link_change(dev);
1228         }
1229
1230         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1231                 __handle_link_change(dev);
1232
1233         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1234                 __handle_set_rx_mode(dev);
1235
1236
1237         if (dev->flags)
1238                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1239 }
1240
1241 /*-------------------------------------------------------------------------*/
1242
1243 static void tx_complete (struct urb *urb)
1244 {
1245         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1246         struct skb_data         *entry = (struct skb_data *) skb->cb;
1247         struct usbnet           *dev = entry->dev;
1248
1249         if (urb->status == 0) {
1250                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
1251                 unsigned long flags;
1252
1253                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1254                 u64_stats_add(&stats64->tx_packets, entry->packets);
1255                 u64_stats_add(&stats64->tx_bytes, entry->length);
1256                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1257         } else {
1258                 dev->net->stats.tx_errors++;
1259
1260                 switch (urb->status) {
1261                 case -EPIPE:
1262                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1263                         break;
1264
1265                 /* software-driven interface shutdown */
1266                 case -ECONNRESET:               // async unlink
1267                 case -ESHUTDOWN:                // hardware gone
1268                         break;
1269
1270                 /* like rx, tx gets controller i/o faults during hub_wq
1271                  * delays and so it uses the same throttling mechanism.
1272                  */
1273                 case -EPROTO:
1274                 case -ETIME:
1275                 case -EILSEQ:
1276                         usb_mark_last_busy(dev->udev);
1277                         if (!timer_pending (&dev->delay)) {
1278                                 mod_timer (&dev->delay,
1279                                         jiffies + THROTTLE_JIFFIES);
1280                                 netif_dbg(dev, link, dev->net,
1281                                           "tx throttle %d\n", urb->status);
1282                         }
1283                         netif_stop_queue (dev->net);
1284                         break;
1285                 default:
1286                         netif_dbg(dev, tx_err, dev->net,
1287                                   "tx err %d\n", entry->urb->status);
1288                         break;
1289                 }
1290         }
1291
1292         usb_autopm_put_interface_async(dev->intf);
1293         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1294 }
1295
1296 /*-------------------------------------------------------------------------*/
1297
1298 void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue)
1299 {
1300         struct usbnet           *dev = netdev_priv(net);
1301
1302         unlink_urbs (dev, &dev->txq);
1303         tasklet_schedule (&dev->bh);
1304         /* this needs to be handled individually because the generic layer
1305          * doesn't know what is sufficient and could not restore private
1306          * information if a remedy of an unconditional reset were used.
1307          */
1308         if (dev->driver_info->recover)
1309                 (dev->driver_info->recover)(dev);
1310 }
1311 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1312
1313 /*-------------------------------------------------------------------------*/
1314
1315 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1316 {
1317         unsigned num_sgs, total_len = 0;
1318         int i, s = 0;
1319
1320         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1321         if (num_sgs == 1)
1322                 return 0;
1323
1324         /* reserve one for zero packet */
1325         urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1326                                 GFP_ATOMIC);
1327         if (!urb->sg)
1328                 return -ENOMEM;
1329
1330         urb->num_sgs = num_sgs;
1331         sg_init_table(urb->sg, urb->num_sgs + 1);
1332
1333         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1334         total_len += skb_headlen(skb);
1335
1336         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1337                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1338
1339                 total_len += skb_frag_size(f);
1340                 sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1341                             skb_frag_off(f));
1342         }
1343         urb->transfer_buffer_length = total_len;
1344
1345         return 1;
1346 }
1347
1348 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1349                                      struct net_device *net)
1350 {
1351         struct usbnet           *dev = netdev_priv(net);
1352         unsigned int                    length;
1353         struct urb              *urb = NULL;
1354         struct skb_data         *entry;
1355         const struct driver_info *info = dev->driver_info;
1356         unsigned long           flags;
1357         int retval;
1358
1359         if (skb)
1360                 skb_tx_timestamp(skb);
1361
1362         // some devices want funky USB-level framing, for
1363         // win32 driver (usually) and/or hardware quirks
1364         if (info->tx_fixup) {
1365                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1366                 if (!skb) {
1367                         /* packet collected; minidriver waiting for more */
1368                         if (info->flags & FLAG_MULTI_PACKET)
1369                                 goto not_drop;
1370                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1371                         goto drop;
1372                 }
1373         }
1374
1375         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1376                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1377                 goto drop;
1378         }
1379
1380         entry = (struct skb_data *) skb->cb;
1381         entry->urb = urb;
1382         entry->dev = dev;
1383
1384         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1385                         skb->data, skb->len, tx_complete, skb);
1386         if (dev->can_dma_sg) {
1387                 if (build_dma_sg(skb, urb) < 0)
1388                         goto drop;
1389         }
1390         length = urb->transfer_buffer_length;
1391
1392         /* don't assume the hardware handles USB_ZERO_PACKET
1393          * NOTE:  strictly conforming cdc-ether devices should expect
1394          * the ZLP here, but ignore the one-byte packet.
1395          * NOTE2: CDC NCM specification is different from CDC ECM when
1396          * handling ZLP/short packets, so cdc_ncm driver will make short
1397          * packet itself if needed.
1398          */
1399         if (length % dev->maxpacket == 0) {
1400                 if (!(info->flags & FLAG_SEND_ZLP)) {
1401                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1402                                 length++;
1403                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1404                                         skb->data[skb->len] = 0;
1405                                         __skb_put(skb, 1);
1406                                 } else if (urb->num_sgs)
1407                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1408                                                         dev->padding_pkt, 1);
1409                         }
1410                 } else
1411                         urb->transfer_flags |= URB_ZERO_PACKET;
1412         }
1413         urb->transfer_buffer_length = length;
1414
1415         if (info->flags & FLAG_MULTI_PACKET) {
1416                 /* Driver has set number of packets and a length delta.
1417                  * Calculate the complete length and ensure that it's
1418                  * positive.
1419                  */
1420                 entry->length += length;
1421                 if (WARN_ON_ONCE(entry->length <= 0))
1422                         entry->length = length;
1423         } else {
1424                 usbnet_set_skb_tx_stats(skb, 1, length);
1425         }
1426
1427         spin_lock_irqsave(&dev->txq.lock, flags);
1428         retval = usb_autopm_get_interface_async(dev->intf);
1429         if (retval < 0) {
1430                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1431                 goto drop;
1432         }
1433         if (netif_queue_stopped(net)) {
1434                 usb_autopm_put_interface_async(dev->intf);
1435                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1436                 goto drop;
1437         }
1438
1439 #ifdef CONFIG_PM
1440         /* if this triggers the device is still a sleep */
1441         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1442                 /* transmission will be done in resume */
1443                 usb_anchor_urb(urb, &dev->deferred);
1444                 /* no use to process more packets */
1445                 netif_stop_queue(net);
1446                 usb_put_urb(urb);
1447                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1448                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1449                 goto deferred;
1450         }
1451 #endif
1452
1453         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1454         case -EPIPE:
1455                 netif_stop_queue (net);
1456                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1457                 usb_autopm_put_interface_async(dev->intf);
1458                 break;
1459         default:
1460                 usb_autopm_put_interface_async(dev->intf);
1461                 netif_dbg(dev, tx_err, dev->net,
1462                           "tx: submit urb err %d\n", retval);
1463                 break;
1464         case 0:
1465                 netif_trans_update(net);
1466                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1467                 if (dev->txq.qlen >= TX_QLEN (dev))
1468                         netif_stop_queue (net);
1469         }
1470         spin_unlock_irqrestore (&dev->txq.lock, flags);
1471
1472         if (retval) {
1473                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1474 drop:
1475                 dev->net->stats.tx_dropped++;
1476 not_drop:
1477                 if (skb)
1478                         dev_kfree_skb_any (skb);
1479                 if (urb) {
1480                         kfree(urb->sg);
1481                         usb_free_urb(urb);
1482                 }
1483         } else
1484                 netif_dbg(dev, tx_queued, dev->net,
1485                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1486 #ifdef CONFIG_PM
1487 deferred:
1488 #endif
1489         return NETDEV_TX_OK;
1490 }
1491 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1492
1493 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1494 {
1495         struct urb      *urb;
1496         int             i;
1497         int             ret = 0;
1498
1499         /* don't refill the queue all at once */
1500         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1501                 urb = usb_alloc_urb(0, flags);
1502                 if (urb != NULL) {
1503                         ret = rx_submit(dev, urb, flags);
1504                         if (ret)
1505                                 goto err;
1506                 } else {
1507                         ret = -ENOMEM;
1508                         goto err;
1509                 }
1510         }
1511 err:
1512         return ret;
1513 }
1514
1515 static inline void usb_free_skb(struct sk_buff *skb)
1516 {
1517         struct skb_data *entry = (struct skb_data *)skb->cb;
1518
1519         usb_free_urb(entry->urb);
1520         dev_kfree_skb(skb);
1521 }
1522
1523 /*-------------------------------------------------------------------------*/
1524
1525 // tasklet (work deferred from completions, in_irq) or timer
1526
1527 static void usbnet_bh (struct timer_list *t)
1528 {
1529         struct usbnet           *dev = from_timer(dev, t, delay);
1530         struct sk_buff          *skb;
1531         struct skb_data         *entry;
1532
1533         while ((skb = skb_dequeue (&dev->done))) {
1534                 entry = (struct skb_data *) skb->cb;
1535                 switch (entry->state) {
1536                 case rx_done:
1537                         if (rx_process(dev, skb))
1538                                 usb_free_skb(skb);
1539                         continue;
1540                 case tx_done:
1541                         kfree(entry->urb->sg);
1542                         fallthrough;
1543                 case rx_cleanup:
1544                         usb_free_skb(skb);
1545                         continue;
1546                 default:
1547                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1548                 }
1549         }
1550
1551         /* restart RX again after disabling due to high error rate */
1552         clear_bit(EVENT_RX_KILL, &dev->flags);
1553
1554         /* waiting for all pending urbs to complete?
1555          * only then can we forgo submitting anew
1556          */
1557         if (waitqueue_active(&dev->wait)) {
1558                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1559                         wake_up_all(&dev->wait);
1560
1561         // or are we maybe short a few urbs?
1562         } else if (netif_running (dev->net) &&
1563                    netif_device_present (dev->net) &&
1564                    netif_carrier_ok(dev->net) &&
1565                    !timer_pending(&dev->delay) &&
1566                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1567                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1568                 int     temp = dev->rxq.qlen;
1569
1570                 if (temp < RX_QLEN(dev)) {
1571                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1572                                 return;
1573                         if (temp != dev->rxq.qlen)
1574                                 netif_dbg(dev, link, dev->net,
1575                                           "rxqlen %d --> %d\n",
1576                                           temp, dev->rxq.qlen);
1577                         if (dev->rxq.qlen < RX_QLEN(dev))
1578                                 tasklet_schedule (&dev->bh);
1579                 }
1580                 if (dev->txq.qlen < TX_QLEN (dev))
1581                         netif_wake_queue (dev->net);
1582         }
1583 }
1584
1585 static void usbnet_bh_tasklet(struct tasklet_struct *t)
1586 {
1587         struct usbnet *dev = from_tasklet(dev, t, bh);
1588
1589         usbnet_bh(&dev->delay);
1590 }
1591
1592
1593 /*-------------------------------------------------------------------------
1594  *
1595  * USB Device Driver support
1596  *
1597  *-------------------------------------------------------------------------*/
1598
1599 // precondition: never called in_interrupt
1600
1601 void usbnet_disconnect (struct usb_interface *intf)
1602 {
1603         struct usbnet           *dev;
1604         struct usb_device       *xdev;
1605         struct net_device       *net;
1606         struct urb              *urb;
1607
1608         dev = usb_get_intfdata(intf);
1609         usb_set_intfdata(intf, NULL);
1610         if (!dev)
1611                 return;
1612
1613         xdev = interface_to_usbdev (intf);
1614
1615         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1616                    intf->dev.driver->name,
1617                    xdev->bus->bus_name, xdev->devpath,
1618                    dev->driver_info->description);
1619
1620         net = dev->net;
1621         unregister_netdev (net);
1622
1623         while ((urb = usb_get_from_anchor(&dev->deferred))) {
1624                 dev_kfree_skb(urb->context);
1625                 kfree(urb->sg);
1626                 usb_free_urb(urb);
1627         }
1628
1629         if (dev->driver_info->unbind)
1630                 dev->driver_info->unbind(dev, intf);
1631
1632         usb_kill_urb(dev->interrupt);
1633         usb_free_urb(dev->interrupt);
1634         kfree(dev->padding_pkt);
1635
1636         free_percpu(net->tstats);
1637         free_netdev(net);
1638 }
1639 EXPORT_SYMBOL_GPL(usbnet_disconnect);
1640
1641 static const struct net_device_ops usbnet_netdev_ops = {
1642         .ndo_open               = usbnet_open,
1643         .ndo_stop               = usbnet_stop,
1644         .ndo_start_xmit         = usbnet_start_xmit,
1645         .ndo_tx_timeout         = usbnet_tx_timeout,
1646         .ndo_set_rx_mode        = usbnet_set_rx_mode,
1647         .ndo_change_mtu         = usbnet_change_mtu,
1648         .ndo_get_stats64        = dev_get_tstats64,
1649         .ndo_set_mac_address    = eth_mac_addr,
1650         .ndo_validate_addr      = eth_validate_addr,
1651 };
1652
1653 /*-------------------------------------------------------------------------*/
1654
1655 // precondition: never called in_interrupt
1656
1657 static struct device_type wlan_type = {
1658         .name   = "wlan",
1659 };
1660
1661 static struct device_type wwan_type = {
1662         .name   = "wwan",
1663 };
1664
1665 int
1666 usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1667 {
1668         struct usbnet                   *dev;
1669         struct net_device               *net;
1670         struct usb_host_interface       *interface;
1671         const struct driver_info        *info;
1672         struct usb_device               *xdev;
1673         int                             status;
1674         const char                      *name;
1675         struct usb_driver       *driver = to_usb_driver(udev->dev.driver);
1676
1677         /* usbnet already took usb runtime pm, so have to enable the feature
1678          * for usb interface, otherwise usb_autopm_get_interface may return
1679          * failure if RUNTIME_PM is enabled.
1680          */
1681         if (!driver->supports_autosuspend) {
1682                 driver->supports_autosuspend = 1;
1683                 pm_runtime_enable(&udev->dev);
1684         }
1685
1686         name = udev->dev.driver->name;
1687         info = (const struct driver_info *) prod->driver_info;
1688         if (!info) {
1689                 dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1690                 return -ENODEV;
1691         }
1692         xdev = interface_to_usbdev (udev);
1693         interface = udev->cur_altsetting;
1694
1695         status = -ENOMEM;
1696
1697         // set up our own records
1698         net = alloc_etherdev(sizeof(*dev));
1699         if (!net)
1700                 goto out;
1701
1702         /* netdev_printk() needs this so do it as early as possible */
1703         SET_NETDEV_DEV(net, &udev->dev);
1704
1705         dev = netdev_priv(net);
1706         dev->udev = xdev;
1707         dev->intf = udev;
1708         dev->driver_info = info;
1709         dev->driver_name = name;
1710         dev->rx_speed = SPEED_UNSET;
1711         dev->tx_speed = SPEED_UNSET;
1712
1713         net->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1714         if (!net->tstats)
1715                 goto out0;
1716
1717         dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1718                                 | NETIF_MSG_PROBE | NETIF_MSG_LINK);
1719         init_waitqueue_head(&dev->wait);
1720         skb_queue_head_init (&dev->rxq);
1721         skb_queue_head_init (&dev->txq);
1722         skb_queue_head_init (&dev->done);
1723         skb_queue_head_init(&dev->rxq_pause);
1724         tasklet_setup(&dev->bh, usbnet_bh_tasklet);
1725         INIT_WORK (&dev->kevent, usbnet_deferred_kevent);
1726         init_usb_anchor(&dev->deferred);
1727         timer_setup(&dev->delay, usbnet_bh, 0);
1728         mutex_init (&dev->phy_mutex);
1729         mutex_init(&dev->interrupt_mutex);
1730         dev->interrupt_count = 0;
1731
1732         dev->net = net;
1733         strscpy(net->name, "usb%d", sizeof(net->name));
1734         eth_hw_addr_set(net, node_id);
1735
1736         /* rx and tx sides can use different message sizes;
1737          * bind() should set rx_urb_size in that case.
1738          */
1739         dev->hard_mtu = net->mtu + net->hard_header_len;
1740         net->min_mtu = 0;
1741         net->max_mtu = ETH_MAX_MTU;
1742
1743         net->netdev_ops = &usbnet_netdev_ops;
1744         net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1745         net->ethtool_ops = &usbnet_ethtool_ops;
1746
1747         // allow device-specific bind/init procedures
1748         // NOTE net->name still not usable ...
1749         if (info->bind) {
1750                 status = info->bind (dev, udev);
1751                 if (status < 0)
1752                         goto out1;
1753
1754                 // heuristic:  "usb%d" for links we know are two-host,
1755                 // else "eth%d" when there's reasonable doubt.  userspace
1756                 // can rename the link if it knows better.
1757                 if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1758                     ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1759                      (net->dev_addr [0] & 0x02) == 0))
1760                         strscpy(net->name, "eth%d", sizeof(net->name));
1761                 /* WLAN devices should always be named "wlan%d" */
1762                 if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1763                         strscpy(net->name, "wlan%d", sizeof(net->name));
1764                 /* WWAN devices should always be named "wwan%d" */
1765                 if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1766                         strscpy(net->name, "wwan%d", sizeof(net->name));
1767
1768                 /* devices that cannot do ARP */
1769                 if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1770                         net->flags |= IFF_NOARP;
1771
1772                 /* maybe the remote can't receive an Ethernet MTU */
1773                 if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1774                         net->mtu = dev->hard_mtu - net->hard_header_len;
1775         } else if (!info->in || !info->out)
1776                 status = usbnet_get_endpoints (dev, udev);
1777         else {
1778                 u8 ep_addrs[3] = {
1779                         info->in + USB_DIR_IN, info->out + USB_DIR_OUT, 0
1780                 };
1781
1782                 dev->in = usb_rcvbulkpipe (xdev, info->in);
1783                 dev->out = usb_sndbulkpipe (xdev, info->out);
1784                 if (!(info->flags & FLAG_NO_SETINT))
1785                         status = usb_set_interface (xdev,
1786                                 interface->desc.bInterfaceNumber,
1787                                 interface->desc.bAlternateSetting);
1788                 else
1789                         status = 0;
1790
1791                 if (status == 0 && !usb_check_bulk_endpoints(udev, ep_addrs))
1792                         status = -EINVAL;
1793         }
1794         if (status >= 0 && dev->status)
1795                 status = init_status (dev, udev);
1796         if (status < 0)
1797                 goto out3;
1798
1799         if (!dev->rx_urb_size)
1800                 dev->rx_urb_size = dev->hard_mtu;
1801         dev->maxpacket = usb_maxpacket(dev->udev, dev->out);
1802         if (dev->maxpacket == 0) {
1803                 /* that is a broken device */
1804                 status = -ENODEV;
1805                 goto out4;
1806         }
1807
1808         /* let userspace know we have a random address */
1809         if (ether_addr_equal(net->dev_addr, node_id))
1810                 net->addr_assign_type = NET_ADDR_RANDOM;
1811
1812         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1813                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1814         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1815                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1816
1817         /* initialize max rx_qlen and tx_qlen */
1818         usbnet_update_max_qlen(dev);
1819
1820         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1821                 !(info->flags & FLAG_MULTI_PACKET)) {
1822                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1823                 if (!dev->padding_pkt) {
1824                         status = -ENOMEM;
1825                         goto out4;
1826                 }
1827         }
1828
1829         status = register_netdev (net);
1830         if (status)
1831                 goto out5;
1832         netif_info(dev, probe, dev->net,
1833                    "register '%s' at usb-%s-%s, %s, %pM\n",
1834                    udev->dev.driver->name,
1835                    xdev->bus->bus_name, xdev->devpath,
1836                    dev->driver_info->description,
1837                    net->dev_addr);
1838
1839         // ok, it's ready to go.
1840         usb_set_intfdata (udev, dev);
1841
1842         netif_device_attach (net);
1843
1844         if (dev->driver_info->flags & FLAG_LINK_INTR)
1845                 usbnet_link_change(dev, 0, 0);
1846
1847         return 0;
1848
1849 out5:
1850         kfree(dev->padding_pkt);
1851 out4:
1852         usb_free_urb(dev->interrupt);
1853 out3:
1854         if (info->unbind)
1855                 info->unbind (dev, udev);
1856 out1:
1857         /* subdrivers must undo all they did in bind() if they
1858          * fail it, but we may fail later and a deferred kevent
1859          * may trigger an error resubmitting itself and, worse,
1860          * schedule a timer. So we kill it all just in case.
1861          */
1862         cancel_work_sync(&dev->kevent);
1863         del_timer_sync(&dev->delay);
1864         free_percpu(net->tstats);
1865 out0:
1866         free_netdev(net);
1867 out:
1868         return status;
1869 }
1870 EXPORT_SYMBOL_GPL(usbnet_probe);
1871
1872 /*-------------------------------------------------------------------------*/
1873
1874 /*
1875  * suspend the whole driver as soon as the first interface is suspended
1876  * resume only when the last interface is resumed
1877  */
1878
1879 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1880 {
1881         struct usbnet           *dev = usb_get_intfdata(intf);
1882
1883         if (!dev->suspend_count++) {
1884                 spin_lock_irq(&dev->txq.lock);
1885                 /* don't autosuspend while transmitting */
1886                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1887                         dev->suspend_count--;
1888                         spin_unlock_irq(&dev->txq.lock);
1889                         return -EBUSY;
1890                 } else {
1891                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1892                         spin_unlock_irq(&dev->txq.lock);
1893                 }
1894                 /*
1895                  * accelerate emptying of the rx and queues, to avoid
1896                  * having everything error out.
1897                  */
1898                 netif_device_detach (dev->net);
1899                 usbnet_terminate_urbs(dev);
1900                 __usbnet_status_stop_force(dev);
1901
1902                 /*
1903                  * reattach so runtime management can use and
1904                  * wake the device
1905                  */
1906                 netif_device_attach (dev->net);
1907         }
1908         return 0;
1909 }
1910 EXPORT_SYMBOL_GPL(usbnet_suspend);
1911
1912 int usbnet_resume (struct usb_interface *intf)
1913 {
1914         struct usbnet           *dev = usb_get_intfdata(intf);
1915         struct sk_buff          *skb;
1916         struct urb              *res;
1917         int                     retval;
1918
1919         if (!--dev->suspend_count) {
1920                 /* resume interrupt URB if it was previously submitted */
1921                 __usbnet_status_start_force(dev, GFP_NOIO);
1922
1923                 spin_lock_irq(&dev->txq.lock);
1924                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1925
1926                         skb = (struct sk_buff *)res->context;
1927                         retval = usb_submit_urb(res, GFP_ATOMIC);
1928                         if (retval < 0) {
1929                                 dev_kfree_skb_any(skb);
1930                                 kfree(res->sg);
1931                                 usb_free_urb(res);
1932                                 usb_autopm_put_interface_async(dev->intf);
1933                         } else {
1934                                 netif_trans_update(dev->net);
1935                                 __skb_queue_tail(&dev->txq, skb);
1936                         }
1937                 }
1938
1939                 smp_mb();
1940                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1941                 spin_unlock_irq(&dev->txq.lock);
1942
1943                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1944                         /* handle remote wakeup ASAP
1945                          * we cannot race against stop
1946                          */
1947                         if (netif_device_present(dev->net) &&
1948                                 !timer_pending(&dev->delay) &&
1949                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1950                                         rx_alloc_submit(dev, GFP_NOIO);
1951
1952                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1953                                 netif_tx_wake_all_queues(dev->net);
1954                         tasklet_schedule (&dev->bh);
1955                 }
1956         }
1957
1958         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1959                 usb_autopm_get_interface_no_resume(intf);
1960
1961         return 0;
1962 }
1963 EXPORT_SYMBOL_GPL(usbnet_resume);
1964
1965 /*
1966  * Either a subdriver implements manage_power, then it is assumed to always
1967  * be ready to be suspended or it reports the readiness to be suspended
1968  * explicitly
1969  */
1970 void usbnet_device_suggests_idle(struct usbnet *dev)
1971 {
1972         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1973                 dev->intf->needs_remote_wakeup = 1;
1974                 usb_autopm_put_interface_async(dev->intf);
1975         }
1976 }
1977 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1978
1979 /*
1980  * For devices that can do without special commands
1981  */
1982 int usbnet_manage_power(struct usbnet *dev, int on)
1983 {
1984         dev->intf->needs_remote_wakeup = on;
1985         return 0;
1986 }
1987 EXPORT_SYMBOL(usbnet_manage_power);
1988
1989 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1990 {
1991         /* update link after link is reseted */
1992         if (link && !need_reset)
1993                 netif_carrier_on(dev->net);
1994         else
1995                 netif_carrier_off(dev->net);
1996
1997         if (need_reset && link)
1998                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1999         else
2000                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
2001 }
2002 EXPORT_SYMBOL(usbnet_link_change);
2003
2004 /*-------------------------------------------------------------------------*/
2005 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2006                              u16 value, u16 index, void *data, u16 size)
2007 {
2008         void *buf = NULL;
2009         int err = -ENOMEM;
2010
2011         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
2012                    " value=0x%04x index=0x%04x size=%d\n",
2013                    cmd, reqtype, value, index, size);
2014
2015         if (size) {
2016                 buf = kmalloc(size, GFP_NOIO);
2017                 if (!buf)
2018                         goto out;
2019         }
2020
2021         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
2022                               cmd, reqtype, value, index, buf, size,
2023                               USB_CTRL_GET_TIMEOUT);
2024         if (err > 0 && err <= size) {
2025                 if (data)
2026                         memcpy(data, buf, err);
2027                 else
2028                         netdev_dbg(dev->net,
2029                                    "Huh? Data requested but thrown away.\n");
2030         }
2031         kfree(buf);
2032 out:
2033         return err;
2034 }
2035
2036 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2037                               u16 value, u16 index, const void *data,
2038                               u16 size)
2039 {
2040         void *buf = NULL;
2041         int err = -ENOMEM;
2042
2043         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2044                    " value=0x%04x index=0x%04x size=%d\n",
2045                    cmd, reqtype, value, index, size);
2046
2047         if (data) {
2048                 buf = kmemdup(data, size, GFP_NOIO);
2049                 if (!buf)
2050                         goto out;
2051         } else {
2052         if (size) {
2053             WARN_ON_ONCE(1);
2054             err = -EINVAL;
2055             goto out;
2056         }
2057     }
2058
2059         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2060                               cmd, reqtype, value, index, buf, size,
2061                               USB_CTRL_SET_TIMEOUT);
2062         kfree(buf);
2063
2064 out:
2065         return err;
2066 }
2067
2068 /*
2069  * The function can't be called inside suspend/resume callback,
2070  * otherwise deadlock will be caused.
2071  */
2072 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2073                     u16 value, u16 index, void *data, u16 size)
2074 {
2075         int ret;
2076
2077         if (usb_autopm_get_interface(dev->intf) < 0)
2078                 return -ENODEV;
2079         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2080                                 data, size);
2081         usb_autopm_put_interface(dev->intf);
2082         return ret;
2083 }
2084 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2085
2086 /*
2087  * The function can't be called inside suspend/resume callback,
2088  * otherwise deadlock will be caused.
2089  */
2090 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2091                      u16 value, u16 index, const void *data, u16 size)
2092 {
2093         int ret;
2094
2095         if (usb_autopm_get_interface(dev->intf) < 0)
2096                 return -ENODEV;
2097         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2098                                  data, size);
2099         usb_autopm_put_interface(dev->intf);
2100         return ret;
2101 }
2102 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2103
2104 /*
2105  * The function can be called inside suspend/resume callback safely
2106  * and should only be called by suspend/resume callback generally.
2107  */
2108 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2109                           u16 value, u16 index, void *data, u16 size)
2110 {
2111         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2112                                  data, size);
2113 }
2114 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2115
2116 /*
2117  * The function can be called inside suspend/resume callback safely
2118  * and should only be called by suspend/resume callback generally.
2119  */
2120 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2121                           u16 value, u16 index, const void *data,
2122                           u16 size)
2123 {
2124         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2125                                   data, size);
2126 }
2127 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2128
2129 static void usbnet_async_cmd_cb(struct urb *urb)
2130 {
2131         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2132         int status = urb->status;
2133
2134         if (status < 0)
2135                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2136                         __func__, status);
2137
2138         kfree(req);
2139         usb_free_urb(urb);
2140 }
2141
2142 /*
2143  * The caller must make sure that device can't be put into suspend
2144  * state until the control URB completes.
2145  */
2146 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2147                            u16 value, u16 index, const void *data, u16 size)
2148 {
2149         struct usb_ctrlrequest *req;
2150         struct urb *urb;
2151         int err = -ENOMEM;
2152         void *buf = NULL;
2153
2154         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2155                    " value=0x%04x index=0x%04x size=%d\n",
2156                    cmd, reqtype, value, index, size);
2157
2158         urb = usb_alloc_urb(0, GFP_ATOMIC);
2159         if (!urb)
2160                 goto fail;
2161
2162         if (data) {
2163                 buf = kmemdup(data, size, GFP_ATOMIC);
2164                 if (!buf) {
2165                         netdev_err(dev->net, "Error allocating buffer"
2166                                    " in %s!\n", __func__);
2167                         goto fail_free_urb;
2168                 }
2169         }
2170
2171         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2172         if (!req)
2173                 goto fail_free_buf;
2174
2175         req->bRequestType = reqtype;
2176         req->bRequest = cmd;
2177         req->wValue = cpu_to_le16(value);
2178         req->wIndex = cpu_to_le16(index);
2179         req->wLength = cpu_to_le16(size);
2180
2181         usb_fill_control_urb(urb, dev->udev,
2182                              usb_sndctrlpipe(dev->udev, 0),
2183                              (void *)req, buf, size,
2184                              usbnet_async_cmd_cb, req);
2185         urb->transfer_flags |= URB_FREE_BUFFER;
2186
2187         err = usb_submit_urb(urb, GFP_ATOMIC);
2188         if (err < 0) {
2189                 netdev_err(dev->net, "Error submitting the control"
2190                            " message: status=%d\n", err);
2191                 goto fail_free_all;
2192         }
2193         return 0;
2194
2195 fail_free_all:
2196         kfree(req);
2197 fail_free_buf:
2198         kfree(buf);
2199         /*
2200          * avoid a double free
2201          * needed because the flag can be set only
2202          * after filling the URB
2203          */
2204         urb->transfer_flags = 0;
2205 fail_free_urb:
2206         usb_free_urb(urb);
2207 fail:
2208         return err;
2209
2210 }
2211 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2212 /*-------------------------------------------------------------------------*/
2213
2214 static int __init usbnet_init(void)
2215 {
2216         /* Compiler should optimize this out. */
2217         BUILD_BUG_ON(
2218                 sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data));
2219
2220         eth_random_addr(node_id);
2221         return 0;
2222 }
2223 module_init(usbnet_init);
2224
2225 static void __exit usbnet_exit(void)
2226 {
2227 }
2228 module_exit(usbnet_exit);
2229
2230 MODULE_AUTHOR("David Brownell");
2231 MODULE_DESCRIPTION("USB network driver framework");
2232 MODULE_LICENSE("GPL");