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 void 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                 goto done;
 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                 goto done;
 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         } else {
 578                 usbnet_skb_return(dev, skb);
 579                 return;
 580         }
 581
 582 done:
 583         skb_queue_tail(&dev->done, skb);
 584 }
 585
 586 /*-------------------------------------------------------------------------*/
 587
 588 static void rx_complete (struct urb *urb)
 589 {
 590         struct sk_buff          *skb = (struct sk_buff *) urb->context;
 591         struct skb_data         *entry = (struct skb_data *) skb->cb;
 592         struct usbnet           *dev = entry->dev;
 593         int                     urb_status = urb->status;
 594         enum skb_state          state;
 595
 596         skb_put (skb, urb->actual_length);
 597         state = rx_done;
 598         entry->urb = NULL;
 599
 600         switch (urb_status) {
 601         /* success */
 602         case 0:
 603                 break;
 604
 605         /* stalls need manual reset. this is rare ... except that
 606          * when going through USB 2.0 TTs, unplug appears this way.
 607          * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 608          * storm, recovering as needed.
 609          */
 610         case -EPIPE:
 611                 dev->net->stats.rx_errors++;
 612                 usbnet_defer_kevent (dev, EVENT_RX_HALT);
 613                 fallthrough;
 614
 615         /* software-driven interface shutdown */
 616         case -ECONNRESET:               /* async unlink */
 617         case -ESHUTDOWN:                /* hardware gone */
 618                 netif_dbg(dev, ifdown, dev->net,
 619                           "rx shutdown, code %d\n", urb_status);
 620                 goto block;
 621
 622         /* we get controller i/o faults during hub_wq disconnect() delays.
 623          * throttle down resubmits, to avoid log floods; just temporarily,
 624          * so we still recover when the fault isn't a hub_wq delay.
 625          */
 626         case -EPROTO:
 627         case -ETIME:
 628         case -EILSEQ:
 629                 dev->net->stats.rx_errors++;
 630                 if (!timer_pending (&dev->delay)) {
 631                         mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 632                         netif_dbg(dev, link, dev->net,
 633                                   "rx throttle %d\n", urb_status);
 634                 }
 635 block:
 636                 state = rx_cleanup;
 637                 entry->urb = urb;
 638                 urb = NULL;
 639                 break;
 640
 641         /* data overrun ... flush fifo? */
 642         case -EOVERFLOW:
 643                 dev->net->stats.rx_over_errors++;
 644                 fallthrough;
 645
 646         default:
 647                 state = rx_cleanup;
 648                 dev->net->stats.rx_errors++;
 649                 netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 650                 break;
 651         }
 652
 653         /* stop rx if packet error rate is high */
 654         if (++dev->pkt_cnt > 30) {
 655                 dev->pkt_cnt = 0;
 656                 dev->pkt_err = 0;
 657         } else {
 658                 if (state == rx_cleanup)
 659                         dev->pkt_err++;
 660                 if (dev->pkt_err > 20)
 661                         set_bit(EVENT_RX_KILL, &dev->flags);
 662         }
 663
 664         state = defer_bh(dev, skb, &dev->rxq, state);
 665
 666         if (urb) {
 667                 if (netif_running (dev->net) &&
 668                     !test_bit (EVENT_RX_HALT, &dev->flags) &&
 669                     state != unlink_start) {
 670                         rx_submit (dev, urb, GFP_ATOMIC);
 671                         usb_mark_last_busy(dev->udev);
 672                         return;
 673                 }
 674                 usb_free_urb (urb);
 675         }
 676         netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 677 }
 678
 679 /*-------------------------------------------------------------------------*/
 680 void usbnet_pause_rx(struct usbnet *dev)
 681 {
 682         set_bit(EVENT_RX_PAUSED, &dev->flags);
 683
 684         netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 685 }
 686 EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 687
 688 void usbnet_resume_rx(struct usbnet *dev)
 689 {
 690         struct sk_buff *skb;
 691         int num = 0;
 692
 693         clear_bit(EVENT_RX_PAUSED, &dev->flags);
 694
 695         while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 696                 usbnet_skb_return(dev, skb);
 697                 num++;
 698         }
 699
 700         tasklet_schedule(&dev->bh);
 701
 702         netif_dbg(dev, rx_status, dev->net,
 703                   "paused rx queue disabled, %d skbs requeued\n", num);
 704 }
 705 EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 706
 707 void usbnet_purge_paused_rxq(struct usbnet *dev)
 708 {
 709         skb_queue_purge(&dev->rxq_pause);
 710 }
 711 EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 712
 713 /*-------------------------------------------------------------------------*/
 714
 715 // unlink pending rx/tx; completion handlers do all other cleanup
 716
 717 static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 718 {
 719         unsigned long           flags;
 720         struct sk_buff          *skb;
 721         int                     count = 0;
 722
 723         spin_lock_irqsave (&q->lock, flags);
 724         while (!skb_queue_empty(q)) {
 725                 struct skb_data         *entry;
 726                 struct urb              *urb;
 727                 int                     retval;
 728
 729                 skb_queue_walk(q, skb) {
 730                         entry = (struct skb_data *) skb->cb;
 731                         if (entry->state != unlink_start)
 732                                 goto found;
 733                 }
 734                 break;
 735 found:
 736                 entry->state = unlink_start;
 737                 urb = entry->urb;
 738
 739                 /*
 740                  * Get reference count of the URB to avoid it to be
 741                  * freed during usb_unlink_urb, which may trigger
 742                  * use-after-free problem inside usb_unlink_urb since
 743                  * usb_unlink_urb is always racing with .complete
 744                  * handler(include defer_bh).
 745                  */
 746                 usb_get_urb(urb);
 747                 spin_unlock_irqrestore(&q->lock, flags);
 748                 // during some PM-driven resume scenarios,
 749                 // these (async) unlinks complete immediately
 750                 retval = usb_unlink_urb (urb);
 751                 if (retval != -EINPROGRESS && retval != 0)
 752                         netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 753                 else
 754                         count++;
 755                 usb_put_urb(urb);
 756                 spin_lock_irqsave(&q->lock, flags);
 757         }
 758         spin_unlock_irqrestore (&q->lock, flags);
 759         return count;
 760 }
 761
 762 // Flush all pending rx urbs
 763 // minidrivers may need to do this when the MTU changes
 764
 765 void usbnet_unlink_rx_urbs(struct usbnet *dev)
 766 {
 767         if (netif_running(dev->net)) {
 768                 (void) unlink_urbs (dev, &dev->rxq);
 769                 tasklet_schedule(&dev->bh);
 770         }
 771 }
 772 EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 773
 774 /*-------------------------------------------------------------------------*/
 775
 776 static void wait_skb_queue_empty(struct sk_buff_head *q)
 777 {
 778         unsigned long flags;
 779
 780         spin_lock_irqsave(&q->lock, flags);
 781         while (!skb_queue_empty(q)) {
 782                 spin_unlock_irqrestore(&q->lock, flags);
 783                 schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 784                 set_current_state(TASK_UNINTERRUPTIBLE);
 785                 spin_lock_irqsave(&q->lock, flags);
 786         }
 787         spin_unlock_irqrestore(&q->lock, flags);
 788 }
 789
 790 // precondition: never called in_interrupt
 791 static void usbnet_terminate_urbs(struct usbnet *dev)
 792 {
 793         DECLARE_WAITQUEUE(wait, current);
 794         int temp;
 795
 796         /* ensure there are no more active urbs */
 797         add_wait_queue(&dev->wait, &wait);
 798         set_current_state(TASK_UNINTERRUPTIBLE);
 799         temp = unlink_urbs(dev, &dev->txq) +
 800                 unlink_urbs(dev, &dev->rxq);
 801
 802         /* maybe wait for deletions to finish. */
 803         wait_skb_queue_empty(&dev->rxq);
 804         wait_skb_queue_empty(&dev->txq);
 805         wait_skb_queue_empty(&dev->done);
 806         netif_dbg(dev, ifdown, dev->net,
 807                   "waited for %d urb completions\n", temp);
 808         set_current_state(TASK_RUNNING);
 809         remove_wait_queue(&dev->wait, &wait);
 810 }
 811
 812 int usbnet_stop (struct net_device *net)
 813 {
 814         struct usbnet           *dev = netdev_priv(net);
 815         const struct driver_info *info = dev->driver_info;
 816         int                     retval, pm, mpn;
 817
 818         clear_bit(EVENT_DEV_OPEN, &dev->flags);
 819         netif_stop_queue (net);
 820
 821         netif_info(dev, ifdown, dev->net,
 822                    "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 823                    net->stats.rx_packets, net->stats.tx_packets,
 824                    net->stats.rx_errors, net->stats.tx_errors);
 825
 826         /* to not race resume */
 827         pm = usb_autopm_get_interface(dev->intf);
 828         /* allow minidriver to stop correctly (wireless devices to turn off
 829          * radio etc) */
 830         if (info->stop) {
 831                 retval = info->stop(dev);
 832                 if (retval < 0)
 833                         netif_info(dev, ifdown, dev->net,
 834                                    "stop fail (%d) usbnet usb-%s-%s, %s\n",
 835                                    retval,
 836                                    dev->udev->bus->bus_name, dev->udev->devpath,
 837                                    info->description);
 838         }
 839
 840         if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 841                 usbnet_terminate_urbs(dev);
 842
 843         usbnet_status_stop(dev);
 844
 845         usbnet_purge_paused_rxq(dev);
 846
 847         mpn = !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 848
 849         /* deferred work (timer, softirq, task) must also stop */
 850         dev->flags = 0;
 851         del_timer_sync (&dev->delay);
 852         tasklet_kill (&dev->bh);
 853         cancel_work_sync(&dev->kevent);
 854         if (!pm)
 855                 usb_autopm_put_interface(dev->intf);
 856
 857         if (info->manage_power && mpn)
 858                 info->manage_power(dev, 0);
 859         else
 860                 usb_autopm_put_interface(dev->intf);
 861
 862         return 0;
 863 }
 864 EXPORT_SYMBOL_GPL(usbnet_stop);
 865
 866 /*-------------------------------------------------------------------------*/
 867
 868 // posts reads, and enables write queuing
 869
 870 // precondition: never called in_interrupt
 871
 872 int usbnet_open (struct net_device *net)
 873 {
 874         struct usbnet           *dev = netdev_priv(net);
 875         int                     retval;
 876         const struct driver_info *info = dev->driver_info;
 877
 878         if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 879                 netif_info(dev, ifup, dev->net,
 880                            "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 881                            retval,
 882                            dev->udev->bus->bus_name,
 883                            dev->udev->devpath,
 884                            info->description);
 885                 goto done_nopm;
 886         }
 887
 888         // put into "known safe" state
 889         if (info->reset && (retval = info->reset (dev)) < 0) {
 890                 netif_info(dev, ifup, dev->net,
 891                            "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 892                            retval,
 893                            dev->udev->bus->bus_name,
 894                            dev->udev->devpath,
 895                            info->description);
 896                 goto done;
 897         }
 898
 899         /* hard_mtu or rx_urb_size may change in reset() */
 900         usbnet_update_max_qlen(dev);
 901
 902         // insist peer be connected
 903         if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 904                 netif_err(dev, ifup, dev->net, "can't open; %d\n", retval);
 905                 goto done;
 906         }
 907
 908         /* start any status interrupt transfer */
 909         if (dev->interrupt) {
 910                 retval = usbnet_status_start(dev, GFP_KERNEL);
 911                 if (retval < 0) {
 912                         netif_err(dev, ifup, dev->net,
 913                                   "intr submit %d\n", retval);
 914                         goto done;
 915                 }
 916         }
 917
 918         set_bit(EVENT_DEV_OPEN, &dev->flags);
 919         netif_start_queue (net);
 920         netif_info(dev, ifup, dev->net,
 921                    "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 922                    (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 923                    dev->net->mtu,
 924                    (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 925                    (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 926                    (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 927                    (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 928                    (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 929                    "simple");
 930
 931         /* reset rx error state */
 932         dev->pkt_cnt = 0;
 933         dev->pkt_err = 0;
 934         clear_bit(EVENT_RX_KILL, &dev->flags);
 935
 936         // delay posting reads until we're fully open
 937         tasklet_schedule (&dev->bh);
 938         if (info->manage_power) {
 939                 retval = info->manage_power(dev, 1);
 940                 if (retval < 0) {
 941                         retval = 0;
 942                         set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 943                 } else {
 944                         usb_autopm_put_interface(dev->intf);
 945                 }
 946         }
 947         return retval;
 948 done:
 949         usb_autopm_put_interface(dev->intf);
 950 done_nopm:
 951         return retval;
 952 }
 953 EXPORT_SYMBOL_GPL(usbnet_open);
 954
 955 /*-------------------------------------------------------------------------*/
 956
 957 /* ethtool methods; minidrivers may need to add some more, but
 958  * they'll probably want to use this base set.
 959  */
 960
 961 /* These methods are written on the assumption that the device
 962  * uses MII
 963  */
 964 int usbnet_get_link_ksettings_mii(struct net_device *net,
 965                               struct ethtool_link_ksettings *cmd)
 966 {
 967         struct usbnet *dev = netdev_priv(net);
 968
 969         if (!dev->mii.mdio_read)
 970                 return -EOPNOTSUPP;
 971
 972         mii_ethtool_get_link_ksettings(&dev->mii, cmd);
 973
 974         return 0;
 975 }
 976 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_mii);
 977
 978 int usbnet_get_link_ksettings_internal(struct net_device *net,
 979                                         struct ethtool_link_ksettings *cmd)
 980 {
 981         struct usbnet *dev = netdev_priv(net);
 982
 983         /* the assumption that speed is equal on tx and rx
 984          * is deeply engrained into the networking layer.
 985          * For wireless stuff it is not true.
 986          * We assume that rx_speed matters more.
 987          */
 988         if (dev->rx_speed != SPEED_UNSET)
 989                 cmd->base.speed = dev->rx_speed / 1000000;
 990         else if (dev->tx_speed != SPEED_UNSET)
 991                 cmd->base.speed = dev->tx_speed / 1000000;
 992         else
 993                 cmd->base.speed = SPEED_UNKNOWN;
 994
 995         return 0;
 996 }
 997 EXPORT_SYMBOL_GPL(usbnet_get_link_ksettings_internal);
 998
 999 int usbnet_set_link_ksettings_mii(struct net_device *net,
1000                               const struct ethtool_link_ksettings *cmd)
1001 {
1002         struct usbnet *dev = netdev_priv(net);
1003         int retval;
1004
1005         if (!dev->mii.mdio_write)
1006                 return -EOPNOTSUPP;
1007
1008         retval = mii_ethtool_set_link_ksettings(&dev->mii, cmd);
1009
1010         /* link speed/duplex might have changed */
1011         if (dev->driver_info->link_reset)
1012                 dev->driver_info->link_reset(dev);
1013
1014         /* hard_mtu or rx_urb_size may change in link_reset() */
1015         usbnet_update_max_qlen(dev);
1016
1017         return retval;
1018 }
1019 EXPORT_SYMBOL_GPL(usbnet_set_link_ksettings_mii);
1020
1021 u32 usbnet_get_link (struct net_device *net)
1022 {
1023         struct usbnet *dev = netdev_priv(net);
1024
1025         /* If a check_connect is defined, return its result */
1026         if (dev->driver_info->check_connect)
1027                 return dev->driver_info->check_connect (dev) == 0;
1028
1029         /* if the device has mii operations, use those */
1030         if (dev->mii.mdio_read)
1031                 return mii_link_ok(&dev->mii);
1032
1033         /* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
1034         return ethtool_op_get_link(net);
1035 }
1036 EXPORT_SYMBOL_GPL(usbnet_get_link);
1037
1038 int usbnet_nway_reset(struct net_device *net)
1039 {
1040         struct usbnet *dev = netdev_priv(net);
1041
1042         if (!dev->mii.mdio_write)
1043                 return -EOPNOTSUPP;
1044
1045         return mii_nway_restart(&dev->mii);
1046 }
1047 EXPORT_SYMBOL_GPL(usbnet_nway_reset);
1048
1049 void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
1050 {
1051         struct usbnet *dev = netdev_priv(net);
1052
1053         strscpy(info->driver, dev->driver_name, sizeof(info->driver));
1054         strscpy(info->fw_version, dev->driver_info->description,
1055                 sizeof(info->fw_version));
1056         usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
1057 }
1058 EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
1059
1060 u32 usbnet_get_msglevel (struct net_device *net)
1061 {
1062         struct usbnet *dev = netdev_priv(net);
1063
1064         return dev->msg_enable;
1065 }
1066 EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1067
1068 void usbnet_set_msglevel (struct net_device *net, u32 level)
1069 {
1070         struct usbnet *dev = netdev_priv(net);
1071
1072         dev->msg_enable = level;
1073 }
1074 EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1075
1076 /* drivers may override default ethtool_ops in their bind() routine */
1077 static const struct ethtool_ops usbnet_ethtool_ops = {
1078         .get_link               = usbnet_get_link,
1079         .nway_reset             = usbnet_nway_reset,
1080         .get_drvinfo            = usbnet_get_drvinfo,
1081         .get_msglevel           = usbnet_get_msglevel,
1082         .set_msglevel           = usbnet_set_msglevel,
1083         .get_ts_info            = ethtool_op_get_ts_info,
1084         .get_link_ksettings     = usbnet_get_link_ksettings_mii,
1085         .set_link_ksettings     = usbnet_set_link_ksettings_mii,
1086 };
1087
1088 /*-------------------------------------------------------------------------*/
1089
1090 static void __handle_link_change(struct usbnet *dev)
1091 {
1092         if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1093                 return;
1094
1095         if (!netif_carrier_ok(dev->net)) {
1096                 /* kill URBs for reading packets to save bus bandwidth */
1097                 unlink_urbs(dev, &dev->rxq);
1098
1099                 /*
1100                  * tx_timeout will unlink URBs for sending packets and
1101                  * tx queue is stopped by netcore after link becomes off
1102                  */
1103         } else {
1104                 /* submitting URBs for reading packets */
1105                 tasklet_schedule(&dev->bh);
1106         }
1107
1108         /* hard_mtu or rx_urb_size may change during link change */
1109         usbnet_update_max_qlen(dev);
1110
1111         clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1112 }
1113
1114 void usbnet_set_rx_mode(struct net_device *net)
1115 {
1116         struct usbnet           *dev = netdev_priv(net);
1117
1118         usbnet_defer_kevent(dev, EVENT_SET_RX_MODE);
1119 }
1120 EXPORT_SYMBOL_GPL(usbnet_set_rx_mode);
1121
1122 static void __handle_set_rx_mode(struct usbnet *dev)
1123 {
1124         if (dev->driver_info->set_rx_mode)
1125                 (dev->driver_info->set_rx_mode)(dev);
1126
1127         clear_bit(EVENT_SET_RX_MODE, &dev->flags);
1128 }
1129
1130 /* work that cannot be done in interrupt context uses keventd.
1131  *
1132  * NOTE:  with 2.5 we could do more of this using completion callbacks,
1133  * especially now that control transfers can be queued.
1134  */
1135 static void
1136 usbnet_deferred_kevent (struct work_struct *work)
1137 {
1138         struct usbnet           *dev =
1139                 container_of(work, struct usbnet, kevent);
1140         int                     status;
1141
1142         /* usb_clear_halt() needs a thread context */
1143         if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1144                 unlink_urbs (dev, &dev->txq);
1145                 status = usb_autopm_get_interface(dev->intf);
1146                 if (status < 0)
1147                         goto fail_pipe;
1148                 status = usb_clear_halt (dev->udev, dev->out);
1149                 usb_autopm_put_interface(dev->intf);
1150                 if (status < 0 &&
1151                     status != -EPIPE &&
1152                     status != -ESHUTDOWN) {
1153                         if (netif_msg_tx_err (dev))
1154 fail_pipe:
1155                                 netdev_err(dev->net, "can't clear tx halt, status %d\n",
1156                                            status);
1157                 } else {
1158                         clear_bit (EVENT_TX_HALT, &dev->flags);
1159                         if (status != -ESHUTDOWN)
1160                                 netif_wake_queue (dev->net);
1161                 }
1162         }
1163         if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1164                 unlink_urbs (dev, &dev->rxq);
1165                 status = usb_autopm_get_interface(dev->intf);
1166                 if (status < 0)
1167                         goto fail_halt;
1168                 status = usb_clear_halt (dev->udev, dev->in);
1169                 usb_autopm_put_interface(dev->intf);
1170                 if (status < 0 &&
1171                     status != -EPIPE &&
1172                     status != -ESHUTDOWN) {
1173                         if (netif_msg_rx_err (dev))
1174 fail_halt:
1175                                 netdev_err(dev->net, "can't clear rx halt, status %d\n",
1176                                            status);
1177                 } else {
1178                         clear_bit (EVENT_RX_HALT, &dev->flags);
1179                         tasklet_schedule (&dev->bh);
1180                 }
1181         }
1182
1183         /* tasklet could resubmit itself forever if memory is tight */
1184         if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1185                 struct urb      *urb = NULL;
1186                 int resched = 1;
1187
1188                 if (netif_running (dev->net))
1189                         urb = usb_alloc_urb (0, GFP_KERNEL);
1190                 else
1191                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1192                 if (urb != NULL) {
1193                         clear_bit (EVENT_RX_MEMORY, &dev->flags);
1194                         status = usb_autopm_get_interface(dev->intf);
1195                         if (status < 0) {
1196                                 usb_free_urb(urb);
1197                                 goto fail_lowmem;
1198                         }
1199                         if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1200                                 resched = 0;
1201                         usb_autopm_put_interface(dev->intf);
1202 fail_lowmem:
1203                         if (resched)
1204                                 tasklet_schedule (&dev->bh);
1205                 }
1206         }
1207
1208         if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1209                 const struct driver_info *info = dev->driver_info;
1210                 int                     retval = 0;
1211
1212                 clear_bit (EVENT_LINK_RESET, &dev->flags);
1213                 status = usb_autopm_get_interface(dev->intf);
1214                 if (status < 0)
1215                         goto skip_reset;
1216                 if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1217                         usb_autopm_put_interface(dev->intf);
1218 skip_reset:
1219                         netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1220                                     retval,
1221                                     dev->udev->bus->bus_name,
1222                                     dev->udev->devpath,
1223                                     info->description);
1224                 } else {
1225                         usb_autopm_put_interface(dev->intf);
1226                 }
1227
1228                 /* handle link change from link resetting */
1229                 __handle_link_change(dev);
1230         }
1231
1232         if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1233                 __handle_link_change(dev);
1234
1235         if (test_bit (EVENT_SET_RX_MODE, &dev->flags))
1236                 __handle_set_rx_mode(dev);
1237
1238
1239         if (dev->flags)
1240                 netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1241 }
1242
1243 /*-------------------------------------------------------------------------*/
1244
1245 static void tx_complete (struct urb *urb)
1246 {
1247         struct sk_buff          *skb = (struct sk_buff *) urb->context;
1248         struct skb_data         *entry = (struct skb_data *) skb->cb;
1249         struct usbnet           *dev = entry->dev;
1250
1251         if (urb->status == 0) {
1252                 struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats);
1253                 unsigned long flags;
1254
1255                 flags = u64_stats_update_begin_irqsave(&stats64->syncp);
1256                 u64_stats_add(&stats64->tx_packets, entry->packets);
1257                 u64_stats_add(&stats64->tx_bytes, entry->length);
1258                 u64_stats_update_end_irqrestore(&stats64->syncp, flags);
1259         } else {
1260                 dev->net->stats.tx_errors++;
1261
1262                 switch (urb->status) {
1263                 case -EPIPE:
1264                         usbnet_defer_kevent (dev, EVENT_TX_HALT);
1265                         break;
1266
1267                 /* software-driven interface shutdown */
1268                 case -ECONNRESET:               // async unlink
1269                 case -ESHUTDOWN:                // hardware gone
1270                         break;
1271
1272                 /* like rx, tx gets controller i/o faults during hub_wq
1273                  * delays and so it uses the same throttling mechanism.
1274                  */
1275                 case -EPROTO:
1276                 case -ETIME:
1277                 case -EILSEQ:
1278                         usb_mark_last_busy(dev->udev);
1279                         if (!timer_pending (&dev->delay)) {
1280                                 mod_timer (&dev->delay,
1281                                         jiffies + THROTTLE_JIFFIES);
1282                                 netif_dbg(dev, link, dev->net,
1283                                           "tx throttle %d\n", urb->status);
1284                         }
1285                         netif_stop_queue (dev->net);
1286                         break;
1287                 default:
1288                         netif_dbg(dev, tx_err, dev->net,
1289                                   "tx err %d\n", entry->urb->status);
1290                         break;
1291                 }
1292         }
1293
1294         usb_autopm_put_interface_async(dev->intf);
1295         (void) defer_bh(dev, skb, &dev->txq, tx_done);
1296 }
1297
1298 /*-------------------------------------------------------------------------*/
1299
1300 void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue)
1301 {
1302         struct usbnet           *dev = netdev_priv(net);
1303
1304         unlink_urbs (dev, &dev->txq);
1305         tasklet_schedule (&dev->bh);
1306         /* this needs to be handled individually because the generic layer
1307          * doesn't know what is sufficient and could not restore private
1308          * information if a remedy of an unconditional reset were used.
1309          */
1310         if (dev->driver_info->recover)
1311                 (dev->driver_info->recover)(dev);
1312 }
1313 EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1314
1315 /*-------------------------------------------------------------------------*/
1316
1317 static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1318 {
1319         unsigned num_sgs, total_len = 0;
1320         int i, s = 0;
1321
1322         num_sgs = skb_shinfo(skb)->nr_frags + 1;
1323         if (num_sgs == 1)
1324                 return 0;
1325
1326         /* reserve one for zero packet */
1327         urb->sg = kmalloc_array(num_sgs + 1, sizeof(struct scatterlist),
1328                                 GFP_ATOMIC);
1329         if (!urb->sg)
1330                 return -ENOMEM;
1331
1332         urb->num_sgs = num_sgs;
1333         sg_init_table(urb->sg, urb->num_sgs + 1);
1334
1335         sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1336         total_len += skb_headlen(skb);
1337
1338         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1339                 skb_frag_t *f = &skb_shinfo(skb)->frags[i];
1340
1341                 total_len += skb_frag_size(f);
1342                 sg_set_page(&urb->sg[i + s], skb_frag_page(f), skb_frag_size(f),
1343                             skb_frag_off(f));
1344         }
1345         urb->transfer_buffer_length = total_len;
1346
1347         return 1;
1348 }
1349
1350 netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1351                                      struct net_device *net)
1352 {
1353         struct usbnet           *dev = netdev_priv(net);
1354         unsigned int                    length;
1355         struct urb              *urb = NULL;
1356         struct skb_data         *entry;
1357         const struct driver_info *info = dev->driver_info;
1358         unsigned long           flags;
1359         int retval;
1360
1361         if (skb)
1362                 skb_tx_timestamp(skb);
1363
1364         // some devices want funky USB-level framing, for
1365         // win32 driver (usually) and/or hardware quirks
1366         if (info->tx_fixup) {
1367                 skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1368                 if (!skb) {
1369                         /* packet collected; minidriver waiting for more */
1370                         if (info->flags & FLAG_MULTI_PACKET)
1371                                 goto not_drop;
1372                         netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1373                         goto drop;
1374                 }
1375         }
1376
1377         if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1378                 netif_dbg(dev, tx_err, dev->net, "no urb\n");
1379                 goto drop;
1380         }
1381
1382         entry = (struct skb_data *) skb->cb;
1383         entry->urb = urb;
1384         entry->dev = dev;
1385
1386         usb_fill_bulk_urb (urb, dev->udev, dev->out,
1387                         skb->data, skb->len, tx_complete, skb);
1388         if (dev->can_dma_sg) {
1389                 if (build_dma_sg(skb, urb) < 0)
1390                         goto drop;
1391         }
1392         length = urb->transfer_buffer_length;
1393
1394         /* don't assume the hardware handles USB_ZERO_PACKET
1395          * NOTE:  strictly conforming cdc-ether devices should expect
1396          * the ZLP here, but ignore the one-byte packet.
1397          * NOTE2: CDC NCM specification is different from CDC ECM when
1398          * handling ZLP/short packets, so cdc_ncm driver will make short
1399          * packet itself if needed.
1400          */
1401         if (length % dev->maxpacket == 0) {
1402                 if (!(info->flags & FLAG_SEND_ZLP)) {
1403                         if (!(info->flags & FLAG_MULTI_PACKET)) {
1404                                 length++;
1405                                 if (skb_tailroom(skb) && !urb->num_sgs) {
1406                                         skb->data[skb->len] = 0;
1407                                         __skb_put(skb, 1);
1408                                 } else if (urb->num_sgs)
1409                                         sg_set_buf(&urb->sg[urb->num_sgs++],
1410                                                         dev->padding_pkt, 1);
1411                         }
1412                 } else
1413                         urb->transfer_flags |= URB_ZERO_PACKET;
1414         }
1415         urb->transfer_buffer_length = length;
1416
1417         if (info->flags & FLAG_MULTI_PACKET) {
1418                 /* Driver has set number of packets and a length delta.
1419                  * Calculate the complete length and ensure that it's
1420                  * positive.
1421                  */
1422                 entry->length += length;
1423                 if (WARN_ON_ONCE(entry->length <= 0))
1424                         entry->length = length;
1425         } else {
1426                 usbnet_set_skb_tx_stats(skb, 1, length);
1427         }
1428
1429         spin_lock_irqsave(&dev->txq.lock, flags);
1430         retval = usb_autopm_get_interface_async(dev->intf);
1431         if (retval < 0) {
1432                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1433                 goto drop;
1434         }
1435         if (netif_queue_stopped(net)) {
1436                 usb_autopm_put_interface_async(dev->intf);
1437                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1438                 goto drop;
1439         }
1440
1441 #ifdef CONFIG_PM
1442         /* if this triggers the device is still a sleep */
1443         if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1444                 /* transmission will be done in resume */
1445                 usb_anchor_urb(urb, &dev->deferred);
1446                 /* no use to process more packets */
1447                 netif_stop_queue(net);
1448                 usb_put_urb(urb);
1449                 spin_unlock_irqrestore(&dev->txq.lock, flags);
1450                 netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1451                 goto deferred;
1452         }
1453 #endif
1454
1455         switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1456         case -EPIPE:
1457                 netif_stop_queue (net);
1458                 usbnet_defer_kevent (dev, EVENT_TX_HALT);
1459                 usb_autopm_put_interface_async(dev->intf);
1460                 break;
1461         default:
1462                 usb_autopm_put_interface_async(dev->intf);
1463                 netif_dbg(dev, tx_err, dev->net,
1464                           "tx: submit urb err %d\n", retval);
1465                 break;
1466         case 0:
1467                 netif_trans_update(net);
1468                 __usbnet_queue_skb(&dev->txq, skb, tx_start);
1469                 if (dev->txq.qlen >= TX_QLEN (dev))
1470                         netif_stop_queue (net);
1471         }
1472         spin_unlock_irqrestore (&dev->txq.lock, flags);
1473
1474         if (retval) {
1475                 netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1476 drop:
1477                 dev->net->stats.tx_dropped++;
1478 not_drop:
1479                 if (skb)
1480                         dev_kfree_skb_any (skb);
1481                 if (urb) {
1482                         kfree(urb->sg);
1483                         usb_free_urb(urb);
1484                 }
1485         } else
1486                 netif_dbg(dev, tx_queued, dev->net,
1487                           "> tx, len %u, type 0x%x\n", length, skb->protocol);
1488 #ifdef CONFIG_PM
1489 deferred:
1490 #endif
1491         return NETDEV_TX_OK;
1492 }
1493 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1494
1495 static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1496 {
1497         struct urb      *urb;
1498         int             i;
1499         int             ret = 0;
1500
1501         /* don't refill the queue all at once */
1502         for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1503                 urb = usb_alloc_urb(0, flags);
1504                 if (urb != NULL) {
1505                         ret = rx_submit(dev, urb, flags);
1506                         if (ret)
1507                                 goto err;
1508                 } else {
1509                         ret = -ENOMEM;
1510                         goto err;
1511                 }
1512         }
1513 err:
1514         return ret;
1515 }
1516
1517 /*-------------------------------------------------------------------------*/
1518
1519 // tasklet (work deferred from completions, in_irq) or timer
1520
1521 static void usbnet_bh (struct timer_list *t)
1522 {
1523         struct usbnet           *dev = from_timer(dev, t, delay);
1524         struct sk_buff          *skb;
1525         struct skb_data         *entry;
1526
1527         while ((skb = skb_dequeue (&dev->done))) {
1528                 entry = (struct skb_data *) skb->cb;
1529                 switch (entry->state) {
1530                 case rx_done:
1531                         entry->state = rx_cleanup;
1532                         rx_process (dev, skb);
1533                         continue;
1534                 case tx_done:
1535                         kfree(entry->urb->sg);
1536                         fallthrough;
1537                 case rx_cleanup:
1538                         usb_free_urb (entry->urb);
1539                         dev_kfree_skb (skb);
1540                         continue;
1541                 default:
1542                         netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1543                 }
1544         }
1545
1546         /* restart RX again after disabling due to high error rate */
1547         clear_bit(EVENT_RX_KILL, &dev->flags);
1548
1549         /* waiting for all pending urbs to complete?
1550          * only then can we forgo submitting anew
1551          */
1552         if (waitqueue_active(&dev->wait)) {
1553                 if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1554                         wake_up_all(&dev->wait);
1555
1556         // or are we maybe short a few urbs?
1557         } else if (netif_running (dev->net) &&
1558                    netif_device_present (dev->net) &&
1559                    netif_carrier_ok(dev->net) &&
1560                    !timer_pending(&dev->delay) &&
1561                    !test_bit(EVENT_RX_PAUSED, &dev->flags) &&
1562                    !test_bit(EVENT_RX_HALT, &dev->flags)) {
1563                 int     temp = dev->rxq.qlen;
1564
1565                 if (temp < RX_QLEN(dev)) {
1566                         if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1567                                 return;
1568                         if (temp != dev->rxq.qlen)
1569                                 netif_dbg(dev, link, dev->net,
1570                                           "rxqlen %d --> %d\n",
1571                                           temp, dev->rxq.qlen);
1572                         if (dev->rxq.qlen < RX_QLEN(dev))
1573                                 tasklet_schedule (&dev->bh);
1574                 }
1575                 if (dev->txq.qlen < TX_QLEN (dev))
1576                         netif_wake_queue (dev->net);
1577         }
1578 }
1579
1580 static void usbnet_bh_tasklet(struct tasklet_struct *t)
1581 {
1582         struct usbnet *dev = from_tasklet(dev, t, bh);
1583
1584         usbnet_bh(&dev->delay);
1585 }
1586
1587
1588 /*-------------------------------------------------------------------------
1589  *
1590  * USB Device Driver support
1591  *
1592  *-------------------------------------------------------------------------*/
1593
1594 // precondition: never called in_interrupt
1595
1596 void usbnet_disconnect (struct usb_interface *intf)
1597 {
1598         struct usbnet           *dev;
1599         struct usb_device       *xdev;
1600         struct net_device       *net;
1601         struct urb              *urb;
1602
1603         dev = usb_get_intfdata(intf);
1604         usb_set_intfdata(intf, NULL);
1605         if (!dev)
1606                 return;
1607
1608         xdev = interface_to_usbdev (intf);
1609
1610         netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1611                    intf->dev.driver->name,
1612                    xdev->bus->bus_name, xdev->devpath,
1613                    dev->driver_info->description);
1614
1615         net = dev->net;
1616         unregister_netdev (net);
1617
1618         while ((urb = usb_get_from_anchor(&dev->deferred))) {
1619                 dev_kfree_skb(urb->context);
1620                 kfree(urb->sg);
1621                 usb_free_urb(urb);
1622         }
1623
1624         if (dev->driver_info->unbind)
1625                 dev->driver_info->unbind(dev, intf);
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         eth_hw_addr_set(net, 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);
1791         if (dev->maxpacket == 0) {
1792                 /* that is a broken device */
1793                 status = -ENODEV;
1794                 goto out4;
1795         }
1796
1797         /* let userspace know we have a random address */
1798         if (ether_addr_equal(net->dev_addr, node_id))
1799                 net->addr_assign_type = NET_ADDR_RANDOM;
1800
1801         if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1802                 SET_NETDEV_DEVTYPE(net, &wlan_type);
1803         if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1804                 SET_NETDEV_DEVTYPE(net, &wwan_type);
1805
1806         /* initialize max rx_qlen and tx_qlen */
1807         usbnet_update_max_qlen(dev);
1808
1809         if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1810                 !(info->flags & FLAG_MULTI_PACKET)) {
1811                 dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1812                 if (!dev->padding_pkt) {
1813                         status = -ENOMEM;
1814                         goto out4;
1815                 }
1816         }
1817
1818         status = register_netdev (net);
1819         if (status)
1820                 goto out5;
1821         netif_info(dev, probe, dev->net,
1822                    "register '%s' at usb-%s-%s, %s, %pM\n",
1823                    udev->dev.driver->name,
1824                    xdev->bus->bus_name, xdev->devpath,
1825                    dev->driver_info->description,
1826                    net->dev_addr);
1827
1828         // ok, it's ready to go.
1829         usb_set_intfdata (udev, dev);
1830
1831         netif_device_attach (net);
1832
1833         if (dev->driver_info->flags & FLAG_LINK_INTR)
1834                 usbnet_link_change(dev, 0, 0);
1835
1836         return 0;
1837
1838 out5:
1839         kfree(dev->padding_pkt);
1840 out4:
1841         usb_free_urb(dev->interrupt);
1842 out3:
1843         if (info->unbind)
1844                 info->unbind (dev, udev);
1845 out1:
1846         /* subdrivers must undo all they did in bind() if they
1847          * fail it, but we may fail later and a deferred kevent
1848          * may trigger an error resubmitting itself and, worse,
1849          * schedule a timer. So we kill it all just in case.
1850          */
1851         cancel_work_sync(&dev->kevent);
1852         del_timer_sync(&dev->delay);
1853         free_percpu(net->tstats);
1854 out0:
1855         free_netdev(net);
1856 out:
1857         return status;
1858 }
1859 EXPORT_SYMBOL_GPL(usbnet_probe);
1860
1861 /*-------------------------------------------------------------------------*/
1862
1863 /*
1864  * suspend the whole driver as soon as the first interface is suspended
1865  * resume only when the last interface is resumed
1866  */
1867
1868 int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1869 {
1870         struct usbnet           *dev = usb_get_intfdata(intf);
1871
1872         if (!dev->suspend_count++) {
1873                 spin_lock_irq(&dev->txq.lock);
1874                 /* don't autosuspend while transmitting */
1875                 if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1876                         dev->suspend_count--;
1877                         spin_unlock_irq(&dev->txq.lock);
1878                         return -EBUSY;
1879                 } else {
1880                         set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1881                         spin_unlock_irq(&dev->txq.lock);
1882                 }
1883                 /*
1884                  * accelerate emptying of the rx and queues, to avoid
1885                  * having everything error out.
1886                  */
1887                 netif_device_detach (dev->net);
1888                 usbnet_terminate_urbs(dev);
1889                 __usbnet_status_stop_force(dev);
1890
1891                 /*
1892                  * reattach so runtime management can use and
1893                  * wake the device
1894                  */
1895                 netif_device_attach (dev->net);
1896         }
1897         return 0;
1898 }
1899 EXPORT_SYMBOL_GPL(usbnet_suspend);
1900
1901 int usbnet_resume (struct usb_interface *intf)
1902 {
1903         struct usbnet           *dev = usb_get_intfdata(intf);
1904         struct sk_buff          *skb;
1905         struct urb              *res;
1906         int                     retval;
1907
1908         if (!--dev->suspend_count) {
1909                 /* resume interrupt URB if it was previously submitted */
1910                 __usbnet_status_start_force(dev, GFP_NOIO);
1911
1912                 spin_lock_irq(&dev->txq.lock);
1913                 while ((res = usb_get_from_anchor(&dev->deferred))) {
1914
1915                         skb = (struct sk_buff *)res->context;
1916                         retval = usb_submit_urb(res, GFP_ATOMIC);
1917                         if (retval < 0) {
1918                                 dev_kfree_skb_any(skb);
1919                                 kfree(res->sg);
1920                                 usb_free_urb(res);
1921                                 usb_autopm_put_interface_async(dev->intf);
1922                         } else {
1923                                 netif_trans_update(dev->net);
1924                                 __skb_queue_tail(&dev->txq, skb);
1925                         }
1926                 }
1927
1928                 smp_mb();
1929                 clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1930                 spin_unlock_irq(&dev->txq.lock);
1931
1932                 if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1933                         /* handle remote wakeup ASAP
1934                          * we cannot race against stop
1935                          */
1936                         if (netif_device_present(dev->net) &&
1937                                 !timer_pending(&dev->delay) &&
1938                                 !test_bit(EVENT_RX_HALT, &dev->flags))
1939                                         rx_alloc_submit(dev, GFP_NOIO);
1940
1941                         if (!(dev->txq.qlen >= TX_QLEN(dev)))
1942                                 netif_tx_wake_all_queues(dev->net);
1943                         tasklet_schedule (&dev->bh);
1944                 }
1945         }
1946
1947         if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1948                 usb_autopm_get_interface_no_resume(intf);
1949
1950         return 0;
1951 }
1952 EXPORT_SYMBOL_GPL(usbnet_resume);
1953
1954 /*
1955  * Either a subdriver implements manage_power, then it is assumed to always
1956  * be ready to be suspended or it reports the readiness to be suspended
1957  * explicitly
1958  */
1959 void usbnet_device_suggests_idle(struct usbnet *dev)
1960 {
1961         if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1962                 dev->intf->needs_remote_wakeup = 1;
1963                 usb_autopm_put_interface_async(dev->intf);
1964         }
1965 }
1966 EXPORT_SYMBOL(usbnet_device_suggests_idle);
1967
1968 /*
1969  * For devices that can do without special commands
1970  */
1971 int usbnet_manage_power(struct usbnet *dev, int on)
1972 {
1973         dev->intf->needs_remote_wakeup = on;
1974         return 0;
1975 }
1976 EXPORT_SYMBOL(usbnet_manage_power);
1977
1978 void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1979 {
1980         /* update link after link is reseted */
1981         if (link && !need_reset)
1982                 netif_carrier_on(dev->net);
1983         else
1984                 netif_carrier_off(dev->net);
1985
1986         if (need_reset && link)
1987                 usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1988         else
1989                 usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1990 }
1991 EXPORT_SYMBOL(usbnet_link_change);
1992
1993 /*-------------------------------------------------------------------------*/
1994 static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1995                              u16 value, u16 index, void *data, u16 size)
1996 {
1997         void *buf = NULL;
1998         int err = -ENOMEM;
1999
2000         netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
2001                    " value=0x%04x index=0x%04x size=%d\n",
2002                    cmd, reqtype, value, index, size);
2003
2004         if (size) {
2005                 buf = kmalloc(size, GFP_NOIO);
2006                 if (!buf)
2007                         goto out;
2008         }
2009
2010         err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
2011                               cmd, reqtype, value, index, buf, size,
2012                               USB_CTRL_GET_TIMEOUT);
2013         if (err > 0 && err <= size) {
2014                 if (data)
2015                         memcpy(data, buf, err);
2016                 else
2017                         netdev_dbg(dev->net,
2018                                    "Huh? Data requested but thrown away.\n");
2019         }
2020         kfree(buf);
2021 out:
2022         return err;
2023 }
2024
2025 static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2026                               u16 value, u16 index, const void *data,
2027                               u16 size)
2028 {
2029         void *buf = NULL;
2030         int err = -ENOMEM;
2031
2032         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2033                    " value=0x%04x index=0x%04x size=%d\n",
2034                    cmd, reqtype, value, index, size);
2035
2036         if (data) {
2037                 buf = kmemdup(data, size, GFP_NOIO);
2038                 if (!buf)
2039                         goto out;
2040         } else {
2041         if (size) {
2042             WARN_ON_ONCE(1);
2043             err = -EINVAL;
2044             goto out;
2045         }
2046     }
2047
2048         err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
2049                               cmd, reqtype, value, index, buf, size,
2050                               USB_CTRL_SET_TIMEOUT);
2051         kfree(buf);
2052
2053 out:
2054         return err;
2055 }
2056
2057 /*
2058  * The function can't be called inside suspend/resume callback,
2059  * otherwise deadlock will be caused.
2060  */
2061 int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2062                     u16 value, u16 index, void *data, u16 size)
2063 {
2064         int ret;
2065
2066         if (usb_autopm_get_interface(dev->intf) < 0)
2067                 return -ENODEV;
2068         ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2069                                 data, size);
2070         usb_autopm_put_interface(dev->intf);
2071         return ret;
2072 }
2073 EXPORT_SYMBOL_GPL(usbnet_read_cmd);
2074
2075 /*
2076  * The function can't be called inside suspend/resume callback,
2077  * otherwise deadlock will be caused.
2078  */
2079 int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
2080                      u16 value, u16 index, const void *data, u16 size)
2081 {
2082         int ret;
2083
2084         if (usb_autopm_get_interface(dev->intf) < 0)
2085                 return -ENODEV;
2086         ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2087                                  data, size);
2088         usb_autopm_put_interface(dev->intf);
2089         return ret;
2090 }
2091 EXPORT_SYMBOL_GPL(usbnet_write_cmd);
2092
2093 /*
2094  * The function can be called inside suspend/resume callback safely
2095  * and should only be called by suspend/resume callback generally.
2096  */
2097 int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2098                           u16 value, u16 index, void *data, u16 size)
2099 {
2100         return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
2101                                  data, size);
2102 }
2103 EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
2104
2105 /*
2106  * The function can be called inside suspend/resume callback safely
2107  * and should only be called by suspend/resume callback generally.
2108  */
2109 int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
2110                           u16 value, u16 index, const void *data,
2111                           u16 size)
2112 {
2113         return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
2114                                   data, size);
2115 }
2116 EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
2117
2118 static void usbnet_async_cmd_cb(struct urb *urb)
2119 {
2120         struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
2121         int status = urb->status;
2122
2123         if (status < 0)
2124                 dev_dbg(&urb->dev->dev, "%s failed with %d",
2125                         __func__, status);
2126
2127         kfree(req);
2128         usb_free_urb(urb);
2129 }
2130
2131 /*
2132  * The caller must make sure that device can't be put into suspend
2133  * state until the control URB completes.
2134  */
2135 int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
2136                            u16 value, u16 index, const void *data, u16 size)
2137 {
2138         struct usb_ctrlrequest *req;
2139         struct urb *urb;
2140         int err = -ENOMEM;
2141         void *buf = NULL;
2142
2143         netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
2144                    " value=0x%04x index=0x%04x size=%d\n",
2145                    cmd, reqtype, value, index, size);
2146
2147         urb = usb_alloc_urb(0, GFP_ATOMIC);
2148         if (!urb)
2149                 goto fail;
2150
2151         if (data) {
2152                 buf = kmemdup(data, size, GFP_ATOMIC);
2153                 if (!buf) {
2154                         netdev_err(dev->net, "Error allocating buffer"
2155                                    " in %s!\n", __func__);
2156                         goto fail_free_urb;
2157                 }
2158         }
2159
2160         req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2161         if (!req)
2162                 goto fail_free_buf;
2163
2164         req->bRequestType = reqtype;
2165         req->bRequest = cmd;
2166         req->wValue = cpu_to_le16(value);
2167         req->wIndex = cpu_to_le16(index);
2168         req->wLength = cpu_to_le16(size);
2169
2170         usb_fill_control_urb(urb, dev->udev,
2171                              usb_sndctrlpipe(dev->udev, 0),
2172                              (void *)req, buf, size,
2173                              usbnet_async_cmd_cb, req);
2174         urb->transfer_flags |= URB_FREE_BUFFER;
2175
2176         err = usb_submit_urb(urb, GFP_ATOMIC);
2177         if (err < 0) {
2178                 netdev_err(dev->net, "Error submitting the control"
2179                            " message: status=%d\n", err);
2180                 goto fail_free_all;
2181         }
2182         return 0;
2183
2184 fail_free_all:
2185         kfree(req);
2186 fail_free_buf:
2187         kfree(buf);
2188         /*
2189          * avoid a double free
2190          * needed because the flag can be set only
2191          * after filling the URB
2192          */
2193         urb->transfer_flags = 0;
2194 fail_free_urb:
2195         usb_free_urb(urb);
2196 fail:
2197         return err;
2198
2199 }
2200 EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2201 /*-------------------------------------------------------------------------*/
2202
2203 static int __init usbnet_init(void)
2204 {
2205         /* Compiler should optimize this out. */
2206         BUILD_BUG_ON(
2207                 sizeof_field(struct sk_buff, cb) < sizeof(struct skb_data));
2208
2209         eth_random_addr(node_id);
2210         return 0;
2211 }
2212 module_init(usbnet_init);
2213
2214 static void __exit usbnet_exit(void)
2215 {
2216 }
2217 module_exit(usbnet_exit);
2218
2219 MODULE_AUTHOR("David Brownell");
2220 MODULE_DESCRIPTION("USB network driver framework");
2221 MODULE_LICENSE("GPL");