1/*
   2 * USB Network driver infrastructure
   3 * Copyright (C) 2000-2005 by David Brownell
   4 * Copyright (C) 2003-2005 David Hollis <dhollis@davehollis.com>
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20/*
  21 * This is a generic "USB networking" framework that works with several
  22 * kinds of full and high speed networking devices:  host-to-host cables,
  23 * smart usb peripherals, and actual Ethernet adapters.
  24 *
  25 * These devices usually differ in terms of control protocols (if they
  26 * even have one!) and sometimes they define new framing to wrap or batch
  27 * Ethernet packets.  Otherwise, they talk to USB pretty much the same,
  28 * so interface (un)binding, endpoint I/O queues, fault handling, and other
  29 * issues can usefully be addressed by this framework.
  30 */
  31
  32// #define	DEBUG			// error path messages, extra info
  33// #define	VERBOSE			// more; success messages
  34
  35#include <linux/module.h>
  36#include <linux/init.h>
  37#include <linux/netdevice.h>
  38#include <linux/etherdevice.h>
  39#include <linux/ctype.h>
  40#include <linux/ethtool.h>
  41#include <linux/workqueue.h>
  42#include <linux/mii.h>
  43#include <linux/usb.h>
  44#include <linux/usb/usbnet.h>
  45#include <linux/slab.h>
  46#include <linux/kernel.h>
  47#include <linux/pm_runtime.h>
  48
  49#define DRIVER_VERSION		"22-Aug-2005"
  50
  51
  52/*-------------------------------------------------------------------------*/
  53
  54/*
  55 * Nineteen USB 1.1 max size bulk transactions per frame (ms), max.
  56 * Several dozen bytes of IPv4 data can fit in two such transactions.
  57 * One maximum size Ethernet packet takes twenty four of them.
  58 * For high speed, each frame comfortably fits almost 36 max size
  59 * Ethernet packets (so queues should be bigger).
  60 *
  61 * The goal is to let the USB host controller be busy for 5msec or
  62 * more before an irq is required, under load.  Jumbograms change
  63 * the equation.
  64 */
  65#define	MAX_QUEUE_MEMORY	(60 * 1518)
  66#define	RX_QLEN(dev)		((dev)->rx_qlen)
  67#define	TX_QLEN(dev)		((dev)->tx_qlen)
  68
  69// reawaken network queue this soon after stopping; else watchdog barks
  70#define TX_TIMEOUT_JIFFIES	(5*HZ)
  71
  72// throttle rx/tx briefly after some faults, so khubd might disconnect()
  73// us (it polls at HZ/4 usually) before we report too many false errors.
 
  74#define THROTTLE_JIFFIES	(HZ/8)
  75
  76// between wakeups
  77#define UNLINK_TIMEOUT_MS	3
  78
  79/*-------------------------------------------------------------------------*/
  80
  81// randomly generated ethernet address
  82static u8	node_id [ETH_ALEN];
  83
  84static const char driver_name [] = "usbnet";
  85
  86/* use ethtool to change the level for any given device */
  87static int msg_level = -1;
  88module_param (msg_level, int, 0);
  89MODULE_PARM_DESC (msg_level, "Override default message level");
  90
  91/*-------------------------------------------------------------------------*/
  92
  93/* handles CDC Ethernet and many other network "bulk data" interfaces */
  94int usbnet_get_endpoints(struct usbnet *dev, struct usb_interface *intf)
  95{
  96	int				tmp;
  97	struct usb_host_interface	*alt = NULL;
  98	struct usb_host_endpoint	*in = NULL, *out = NULL;
  99	struct usb_host_endpoint	*status = NULL;
 100
 101	for (tmp = 0; tmp < intf->num_altsetting; tmp++) {
 102		unsigned	ep;
 103
 104		in = out = status = NULL;
 105		alt = intf->altsetting + tmp;
 106
 107		/* take the first altsetting with in-bulk + out-bulk;
 108		 * remember any status endpoint, just in case;
 109		 * ignore other endpoints and altsettings.
 110		 */
 111		for (ep = 0; ep < alt->desc.bNumEndpoints; ep++) {
 112			struct usb_host_endpoint	*e;
 113			int				intr = 0;
 114
 115			e = alt->endpoint + ep;
 116			switch (e->desc.bmAttributes) {
 117			case USB_ENDPOINT_XFER_INT:
 118				if (!usb_endpoint_dir_in(&e->desc))
 119					continue;
 120				intr = 1;
 121				/* FALLTHROUGH */
 122			case USB_ENDPOINT_XFER_BULK:
 123				break;
 124			default:
 125				continue;
 126			}
 127			if (usb_endpoint_dir_in(&e->desc)) {
 128				if (!intr && !in)
 129					in = e;
 130				else if (intr && !status)
 131					status = e;
 132			} else {
 133				if (!out)
 134					out = e;
 135			}
 136		}
 137		if (in && out)
 138			break;
 139	}
 140	if (!alt || !in || !out)
 141		return -EINVAL;
 142
 143	if (alt->desc.bAlternateSetting != 0 ||
 144	    !(dev->driver_info->flags & FLAG_NO_SETINT)) {
 145		tmp = usb_set_interface (dev->udev, alt->desc.bInterfaceNumber,
 146				alt->desc.bAlternateSetting);
 147		if (tmp < 0)
 148			return tmp;
 149	}
 150
 151	dev->in = usb_rcvbulkpipe (dev->udev,
 152			in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 153	dev->out = usb_sndbulkpipe (dev->udev,
 154			out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
 155	dev->status = status;
 156	return 0;
 157}
 158EXPORT_SYMBOL_GPL(usbnet_get_endpoints);
 159
 160int usbnet_get_ethernet_addr(struct usbnet *dev, int iMACAddress)
 161{
 162	int 		tmp, i;
 163	unsigned char	buf [13];
 164
 165	tmp = usb_string(dev->udev, iMACAddress, buf, sizeof buf);
 166	if (tmp != 12) {
 
 
 167		dev_dbg(&dev->udev->dev,
 168			"bad MAC string %d fetch, %d\n", iMACAddress, tmp);
 169		if (tmp >= 0)
 170			tmp = -EINVAL;
 171		return tmp;
 172	}
 173	for (i = tmp = 0; i < 6; i++, tmp += 2)
 174		dev->net->dev_addr [i] =
 175			(hex_to_bin(buf[tmp]) << 4) + hex_to_bin(buf[tmp + 1]);
 176	return 0;
 177}
 178EXPORT_SYMBOL_GPL(usbnet_get_ethernet_addr);
 179
 180static void intr_complete (struct urb *urb)
 181{
 182	struct usbnet	*dev = urb->context;
 183	int		status = urb->status;
 184
 185	switch (status) {
 186	/* success */
 187	case 0:
 188		dev->driver_info->status(dev, urb);
 189		break;
 190
 191	/* software-driven interface shutdown */
 192	case -ENOENT:		/* urb killed */
 193	case -ESHUTDOWN:	/* hardware gone */
 194		netif_dbg(dev, ifdown, dev->net,
 195			  "intr shutdown, code %d\n", status);
 196		return;
 197
 198	/* NOTE:  not throttling like RX/TX, since this endpoint
 199	 * already polls infrequently
 200	 */
 201	default:
 202		netdev_dbg(dev->net, "intr status %d\n", status);
 203		break;
 204	}
 205
 206	status = usb_submit_urb (urb, GFP_ATOMIC);
 207	if (status != 0)
 208		netif_err(dev, timer, dev->net,
 209			  "intr resubmit --> %d\n", status);
 210}
 211
 212static int init_status (struct usbnet *dev, struct usb_interface *intf)
 213{
 214	char		*buf = NULL;
 215	unsigned	pipe = 0;
 216	unsigned	maxp;
 217	unsigned	period;
 218
 219	if (!dev->driver_info->status)
 220		return 0;
 221
 222	pipe = usb_rcvintpipe (dev->udev,
 223			dev->status->desc.bEndpointAddress
 224				& USB_ENDPOINT_NUMBER_MASK);
 225	maxp = usb_maxpacket (dev->udev, pipe, 0);
 226
 227	/* avoid 1 msec chatter:  min 8 msec poll rate */
 228	period = max ((int) dev->status->desc.bInterval,
 229		(dev->udev->speed == USB_SPEED_HIGH) ? 7 : 3);
 230
 231	buf = kmalloc (maxp, GFP_KERNEL);
 232	if (buf) {
 233		dev->interrupt = usb_alloc_urb (0, GFP_KERNEL);
 234		if (!dev->interrupt) {
 235			kfree (buf);
 236			return -ENOMEM;
 237		} else {
 238			usb_fill_int_urb(dev->interrupt, dev->udev, pipe,
 239				buf, maxp, intr_complete, dev, period);
 240			dev->interrupt->transfer_flags |= URB_FREE_BUFFER;
 241			dev_dbg(&intf->dev,
 242				"status ep%din, %d bytes period %d\n",
 243				usb_pipeendpoint(pipe), maxp, period);
 244		}
 245	}
 246	return 0;
 247}
 248
 249/* Submit the interrupt URB if not previously submitted, increasing refcount */
 250int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)
 251{
 252	int ret = 0;
 253
 254	WARN_ON_ONCE(dev->interrupt == NULL);
 255	if (dev->interrupt) {
 256		mutex_lock(&dev->interrupt_mutex);
 257
 258		if (++dev->interrupt_count == 1)
 259			ret = usb_submit_urb(dev->interrupt, mem_flags);
 260
 261		dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",
 262			dev->interrupt_count);
 263		mutex_unlock(&dev->interrupt_mutex);
 264	}
 265	return ret;
 266}
 267EXPORT_SYMBOL_GPL(usbnet_status_start);
 268
 269/* For resume; submit interrupt URB if previously submitted */
 270static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)
 271{
 272	int ret = 0;
 273
 274	mutex_lock(&dev->interrupt_mutex);
 275	if (dev->interrupt_count) {
 276		ret = usb_submit_urb(dev->interrupt, mem_flags);
 277		dev_dbg(&dev->udev->dev,
 278			"submitted interrupt URB for resume\n");
 279	}
 280	mutex_unlock(&dev->interrupt_mutex);
 281	return ret;
 282}
 283
 284/* Kill the interrupt URB if all submitters want it killed */
 285void usbnet_status_stop(struct usbnet *dev)
 286{
 287	if (dev->interrupt) {
 288		mutex_lock(&dev->interrupt_mutex);
 289		WARN_ON(dev->interrupt_count == 0);
 290
 291		if (dev->interrupt_count && --dev->interrupt_count == 0)
 292			usb_kill_urb(dev->interrupt);
 293
 294		dev_dbg(&dev->udev->dev,
 295			"decremented interrupt URB count to %d\n",
 296			dev->interrupt_count);
 297		mutex_unlock(&dev->interrupt_mutex);
 298	}
 299}
 300EXPORT_SYMBOL_GPL(usbnet_status_stop);
 301
 302/* For suspend; always kill interrupt URB */
 303static void __usbnet_status_stop_force(struct usbnet *dev)
 304{
 305	if (dev->interrupt) {
 306		mutex_lock(&dev->interrupt_mutex);
 307		usb_kill_urb(dev->interrupt);
 308		dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");
 309		mutex_unlock(&dev->interrupt_mutex);
 310	}
 311}
 312
 313/* Passes this packet up the stack, updating its accounting.
 314 * Some link protocols batch packets, so their rx_fixup paths
 315 * can return clones as well as just modify the original skb.
 316 */
 317void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb)
 318{
 
 
 319	int	status;
 320
 321	if (test_bit(EVENT_RX_PAUSED, &dev->flags)) {
 322		skb_queue_tail(&dev->rxq_pause, skb);
 323		return;
 324	}
 325
 326	skb->protocol = eth_type_trans (skb, dev->net);
 327	dev->net->stats.rx_packets++;
 328	dev->net->stats.rx_bytes += skb->len;
 
 
 
 
 
 329
 330	netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n",
 331		  skb->len + sizeof (struct ethhdr), skb->protocol);
 332	memset (skb->cb, 0, sizeof (struct skb_data));
 333
 334	if (skb_defer_rx_timestamp(skb))
 335		return;
 336
 337	status = netif_rx (skb);
 338	if (status != NET_RX_SUCCESS)
 339		netif_dbg(dev, rx_err, dev->net,
 340			  "netif_rx status %d\n", status);
 341}
 342EXPORT_SYMBOL_GPL(usbnet_skb_return);
 343
 344/* must be called if hard_mtu or rx_urb_size changed */
 345void usbnet_update_max_qlen(struct usbnet *dev)
 346{
 347	enum usb_device_speed speed = dev->udev->speed;
 348
 349	switch (speed) {
 350	case USB_SPEED_HIGH:
 351		dev->rx_qlen = MAX_QUEUE_MEMORY / dev->rx_urb_size;
 352		dev->tx_qlen = MAX_QUEUE_MEMORY / dev->hard_mtu;
 353		break;
 354	case USB_SPEED_SUPER:
 
 355		/*
 356		 * Not take default 5ms qlen for super speed HC to
 357		 * save memory, and iperf tests show 2.5ms qlen can
 358		 * work well
 359		 */
 360		dev->rx_qlen = 5 * MAX_QUEUE_MEMORY / dev->rx_urb_size;
 361		dev->tx_qlen = 5 * MAX_QUEUE_MEMORY / dev->hard_mtu;
 362		break;
 363	default:
 364		dev->rx_qlen = dev->tx_qlen = 4;
 365	}
 366}
 367EXPORT_SYMBOL_GPL(usbnet_update_max_qlen);
 368
 369
 370/*-------------------------------------------------------------------------
 371 *
 372 * Network Device Driver (peer link to "Host Device", from USB host)
 373 *
 374 *-------------------------------------------------------------------------*/
 375
 376int usbnet_change_mtu (struct net_device *net, int new_mtu)
 377{
 378	struct usbnet	*dev = netdev_priv(net);
 379	int		ll_mtu = new_mtu + net->hard_header_len;
 380	int		old_hard_mtu = dev->hard_mtu;
 381	int		old_rx_urb_size = dev->rx_urb_size;
 382
 383	if (new_mtu <= 0)
 384		return -EINVAL;
 385	// no second zero-length packet read wanted after mtu-sized packets
 386	if ((ll_mtu % dev->maxpacket) == 0)
 387		return -EDOM;
 388	net->mtu = new_mtu;
 389
 390	dev->hard_mtu = net->mtu + net->hard_header_len;
 391	if (dev->rx_urb_size == old_hard_mtu) {
 392		dev->rx_urb_size = dev->hard_mtu;
 393		if (dev->rx_urb_size > old_rx_urb_size)
 
 394			usbnet_unlink_rx_urbs(dev);
 
 
 395	}
 396
 397	/* max qlen depend on hard_mtu and rx_urb_size */
 398	usbnet_update_max_qlen(dev);
 399
 400	return 0;
 401}
 402EXPORT_SYMBOL_GPL(usbnet_change_mtu);
 403
 404/* The caller must hold list->lock */
 405static void __usbnet_queue_skb(struct sk_buff_head *list,
 406			struct sk_buff *newsk, enum skb_state state)
 407{
 408	struct skb_data *entry = (struct skb_data *) newsk->cb;
 409
 410	__skb_queue_tail(list, newsk);
 411	entry->state = state;
 412}
 413
 414/*-------------------------------------------------------------------------*/
 415
 416/* some LK 2.4 HCDs oopsed if we freed or resubmitted urbs from
 417 * completion callbacks.  2.5 should have fixed those bugs...
 418 */
 419
 420static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb,
 421		struct sk_buff_head *list, enum skb_state state)
 422{
 423	unsigned long		flags;
 424	enum skb_state 		old_state;
 425	struct skb_data *entry = (struct skb_data *) skb->cb;
 426
 427	spin_lock_irqsave(&list->lock, flags);
 428	old_state = entry->state;
 429	entry->state = state;
 430	__skb_unlink(skb, list);
 431	spin_unlock(&list->lock);
 432	spin_lock(&dev->done.lock);
 
 
 
 
 
 433	__skb_queue_tail(&dev->done, skb);
 434	if (dev->done.qlen == 1)
 435		tasklet_schedule(&dev->bh);
 436	spin_unlock_irqrestore(&dev->done.lock, flags);
 
 437	return old_state;
 438}
 439
 440/* some work can't be done in tasklets, so we use keventd
 441 *
 442 * NOTE:  annoying asymmetry:  if it's active, schedule_work() fails,
 443 * but tasklet_schedule() doesn't.  hope the failure is rare.
 444 */
 445void usbnet_defer_kevent (struct usbnet *dev, int work)
 446{
 447	set_bit (work, &dev->flags);
 448	if (!schedule_work (&dev->kevent)) {
 449		if (net_ratelimit())
 450			netdev_err(dev->net, "kevent %d may have been dropped\n", work);
 451	} else {
 452		netdev_dbg(dev->net, "kevent %d scheduled\n", work);
 453	}
 454}
 455EXPORT_SYMBOL_GPL(usbnet_defer_kevent);
 456
 457/*-------------------------------------------------------------------------*/
 458
 459static void rx_complete (struct urb *urb);
 460
 461static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 462{
 463	struct sk_buff		*skb;
 464	struct skb_data		*entry;
 465	int			retval = 0;
 466	unsigned long		lockflags;
 467	size_t			size = dev->rx_urb_size;
 468
 469	/* prevent rx skb allocation when error ratio is high */
 470	if (test_bit(EVENT_RX_KILL, &dev->flags)) {
 471		usb_free_urb(urb);
 472		return -ENOLINK;
 473	}
 474
 475	skb = __netdev_alloc_skb_ip_align(dev->net, size, flags);
 
 
 
 476	if (!skb) {
 477		netif_dbg(dev, rx_err, dev->net, "no rx skb\n");
 478		usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 479		usb_free_urb (urb);
 480		return -ENOMEM;
 481	}
 482
 483	entry = (struct skb_data *) skb->cb;
 484	entry->urb = urb;
 485	entry->dev = dev;
 486	entry->length = 0;
 487
 488	usb_fill_bulk_urb (urb, dev->udev, dev->in,
 489		skb->data, size, rx_complete, skb);
 490
 491	spin_lock_irqsave (&dev->rxq.lock, lockflags);
 492
 493	if (netif_running (dev->net) &&
 494	    netif_device_present (dev->net) &&
 495	    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 496	    !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
 497		switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
 498		case -EPIPE:
 499			usbnet_defer_kevent (dev, EVENT_RX_HALT);
 500			break;
 501		case -ENOMEM:
 502			usbnet_defer_kevent (dev, EVENT_RX_MEMORY);
 503			break;
 504		case -ENODEV:
 505			netif_dbg(dev, ifdown, dev->net, "device gone\n");
 506			netif_device_detach (dev->net);
 507			break;
 508		case -EHOSTUNREACH:
 509			retval = -ENOLINK;
 510			break;
 511		default:
 512			netif_dbg(dev, rx_err, dev->net,
 513				  "rx submit, %d\n", retval);
 514			tasklet_schedule (&dev->bh);
 515			break;
 516		case 0:
 517			__usbnet_queue_skb(&dev->rxq, skb, rx_start);
 518		}
 519	} else {
 520		netif_dbg(dev, ifdown, dev->net, "rx: stopped\n");
 521		retval = -ENOLINK;
 522	}
 523	spin_unlock_irqrestore (&dev->rxq.lock, lockflags);
 524	if (retval) {
 525		dev_kfree_skb_any (skb);
 526		usb_free_urb (urb);
 527	}
 528	return retval;
 529}
 530
 531
 532/*-------------------------------------------------------------------------*/
 533
 534static inline void rx_process (struct usbnet *dev, struct sk_buff *skb)
 535{
 536	if (dev->driver_info->rx_fixup &&
 537	    !dev->driver_info->rx_fixup (dev, skb)) {
 538		/* With RX_ASSEMBLE, rx_fixup() must update counters */
 539		if (!(dev->driver_info->flags & FLAG_RX_ASSEMBLE))
 540			dev->net->stats.rx_errors++;
 541		goto done;
 542	}
 543	// else network stack removes extra byte if we forced a short packet
 544
 545	/* all data was already cloned from skb inside the driver */
 546	if (dev->driver_info->flags & FLAG_MULTI_PACKET)
 547		goto done;
 548
 549	if (skb->len < ETH_HLEN) {
 550		dev->net->stats.rx_errors++;
 551		dev->net->stats.rx_length_errors++;
 552		netif_dbg(dev, rx_err, dev->net, "rx length %d\n", skb->len);
 553	} else {
 554		usbnet_skb_return(dev, skb);
 555		return;
 556	}
 557
 558done:
 559	skb_queue_tail(&dev->done, skb);
 560}
 561
 562/*-------------------------------------------------------------------------*/
 563
 564static void rx_complete (struct urb *urb)
 565{
 566	struct sk_buff		*skb = (struct sk_buff *) urb->context;
 567	struct skb_data		*entry = (struct skb_data *) skb->cb;
 568	struct usbnet		*dev = entry->dev;
 569	int			urb_status = urb->status;
 570	enum skb_state		state;
 571
 572	skb_put (skb, urb->actual_length);
 573	state = rx_done;
 574	entry->urb = NULL;
 575
 576	switch (urb_status) {
 577	/* success */
 578	case 0:
 579		break;
 580
 581	/* stalls need manual reset. this is rare ... except that
 582	 * when going through USB 2.0 TTs, unplug appears this way.
 583	 * we avoid the highspeed version of the ETIMEDOUT/EILSEQ
 584	 * storm, recovering as needed.
 585	 */
 586	case -EPIPE:
 587		dev->net->stats.rx_errors++;
 588		usbnet_defer_kevent (dev, EVENT_RX_HALT);
 589		// FALLTHROUGH
 590
 591	/* software-driven interface shutdown */
 592	case -ECONNRESET:		/* async unlink */
 593	case -ESHUTDOWN:		/* hardware gone */
 594		netif_dbg(dev, ifdown, dev->net,
 595			  "rx shutdown, code %d\n", urb_status);
 596		goto block;
 597
 598	/* we get controller i/o faults during khubd disconnect() delays.
 599	 * throttle down resubmits, to avoid log floods; just temporarily,
 600	 * so we still recover when the fault isn't a khubd delay.
 601	 */
 602	case -EPROTO:
 603	case -ETIME:
 604	case -EILSEQ:
 605		dev->net->stats.rx_errors++;
 606		if (!timer_pending (&dev->delay)) {
 607			mod_timer (&dev->delay, jiffies + THROTTLE_JIFFIES);
 608			netif_dbg(dev, link, dev->net,
 609				  "rx throttle %d\n", urb_status);
 610		}
 611block:
 612		state = rx_cleanup;
 613		entry->urb = urb;
 614		urb = NULL;
 615		break;
 616
 617	/* data overrun ... flush fifo? */
 618	case -EOVERFLOW:
 619		dev->net->stats.rx_over_errors++;
 620		// FALLTHROUGH
 621
 622	default:
 623		state = rx_cleanup;
 624		dev->net->stats.rx_errors++;
 625		netif_dbg(dev, rx_err, dev->net, "rx status %d\n", urb_status);
 626		break;
 627	}
 628
 629	/* stop rx if packet error rate is high */
 630	if (++dev->pkt_cnt > 30) {
 631		dev->pkt_cnt = 0;
 632		dev->pkt_err = 0;
 633	} else {
 634		if (state == rx_cleanup)
 635			dev->pkt_err++;
 636		if (dev->pkt_err > 20)
 637			set_bit(EVENT_RX_KILL, &dev->flags);
 638	}
 639
 640	state = defer_bh(dev, skb, &dev->rxq, state);
 641
 642	if (urb) {
 643		if (netif_running (dev->net) &&
 644		    !test_bit (EVENT_RX_HALT, &dev->flags) &&
 645		    state != unlink_start) {
 646			rx_submit (dev, urb, GFP_ATOMIC);
 647			usb_mark_last_busy(dev->udev);
 648			return;
 649		}
 650		usb_free_urb (urb);
 651	}
 652	netif_dbg(dev, rx_err, dev->net, "no read resubmitted\n");
 653}
 654
 655/*-------------------------------------------------------------------------*/
 656void usbnet_pause_rx(struct usbnet *dev)
 657{
 658	set_bit(EVENT_RX_PAUSED, &dev->flags);
 659
 660	netif_dbg(dev, rx_status, dev->net, "paused rx queue enabled\n");
 661}
 662EXPORT_SYMBOL_GPL(usbnet_pause_rx);
 663
 664void usbnet_resume_rx(struct usbnet *dev)
 665{
 666	struct sk_buff *skb;
 667	int num = 0;
 668
 669	clear_bit(EVENT_RX_PAUSED, &dev->flags);
 670
 671	while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) {
 672		usbnet_skb_return(dev, skb);
 673		num++;
 674	}
 675
 676	tasklet_schedule(&dev->bh);
 677
 678	netif_dbg(dev, rx_status, dev->net,
 679		  "paused rx queue disabled, %d skbs requeued\n", num);
 680}
 681EXPORT_SYMBOL_GPL(usbnet_resume_rx);
 682
 683void usbnet_purge_paused_rxq(struct usbnet *dev)
 684{
 685	skb_queue_purge(&dev->rxq_pause);
 686}
 687EXPORT_SYMBOL_GPL(usbnet_purge_paused_rxq);
 688
 689/*-------------------------------------------------------------------------*/
 690
 691// unlink pending rx/tx; completion handlers do all other cleanup
 692
 693static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
 694{
 695	unsigned long		flags;
 696	struct sk_buff		*skb;
 697	int			count = 0;
 698
 699	spin_lock_irqsave (&q->lock, flags);
 700	while (!skb_queue_empty(q)) {
 701		struct skb_data		*entry;
 702		struct urb		*urb;
 703		int			retval;
 704
 705		skb_queue_walk(q, skb) {
 706			entry = (struct skb_data *) skb->cb;
 707			if (entry->state != unlink_start)
 708				goto found;
 709		}
 710		break;
 711found:
 712		entry->state = unlink_start;
 713		urb = entry->urb;
 714
 715		/*
 716		 * Get reference count of the URB to avoid it to be
 717		 * freed during usb_unlink_urb, which may trigger
 718		 * use-after-free problem inside usb_unlink_urb since
 719		 * usb_unlink_urb is always racing with .complete
 720		 * handler(include defer_bh).
 721		 */
 722		usb_get_urb(urb);
 723		spin_unlock_irqrestore(&q->lock, flags);
 724		// during some PM-driven resume scenarios,
 725		// these (async) unlinks complete immediately
 726		retval = usb_unlink_urb (urb);
 727		if (retval != -EINPROGRESS && retval != 0)
 728			netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
 729		else
 730			count++;
 731		usb_put_urb(urb);
 732		spin_lock_irqsave(&q->lock, flags);
 733	}
 734	spin_unlock_irqrestore (&q->lock, flags);
 735	return count;
 736}
 737
 738// Flush all pending rx urbs
 739// minidrivers may need to do this when the MTU changes
 740
 741void usbnet_unlink_rx_urbs(struct usbnet *dev)
 742{
 743	if (netif_running(dev->net)) {
 744		(void) unlink_urbs (dev, &dev->rxq);
 745		tasklet_schedule(&dev->bh);
 746	}
 747}
 748EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 749
 750/*-------------------------------------------------------------------------*/
 751
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 752// precondition: never called in_interrupt
 753static void usbnet_terminate_urbs(struct usbnet *dev)
 754{
 755	DECLARE_WAITQUEUE(wait, current);
 756	int temp;
 757
 758	/* ensure there are no more active urbs */
 759	add_wait_queue(&dev->wait, &wait);
 760	set_current_state(TASK_UNINTERRUPTIBLE);
 761	temp = unlink_urbs(dev, &dev->txq) +
 762		unlink_urbs(dev, &dev->rxq);
 763
 764	/* maybe wait for deletions to finish. */
 765	while (!skb_queue_empty(&dev->rxq)
 766		&& !skb_queue_empty(&dev->txq)
 767		&& !skb_queue_empty(&dev->done)) {
 768			schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
 769			set_current_state(TASK_UNINTERRUPTIBLE);
 770			netif_dbg(dev, ifdown, dev->net,
 771				  "waited for %d urb completions\n", temp);
 772	}
 773	set_current_state(TASK_RUNNING);
 774	remove_wait_queue(&dev->wait, &wait);
 775}
 776
 777int usbnet_stop (struct net_device *net)
 778{
 779	struct usbnet		*dev = netdev_priv(net);
 780	struct driver_info	*info = dev->driver_info;
 781	int			retval, pm;
 782
 783	clear_bit(EVENT_DEV_OPEN, &dev->flags);
 784	netif_stop_queue (net);
 785
 786	netif_info(dev, ifdown, dev->net,
 787		   "stop stats: rx/tx %lu/%lu, errs %lu/%lu\n",
 788		   net->stats.rx_packets, net->stats.tx_packets,
 789		   net->stats.rx_errors, net->stats.tx_errors);
 790
 791	/* to not race resume */
 792	pm = usb_autopm_get_interface(dev->intf);
 793	/* allow minidriver to stop correctly (wireless devices to turn off
 794	 * radio etc) */
 795	if (info->stop) {
 796		retval = info->stop(dev);
 797		if (retval < 0)
 798			netif_info(dev, ifdown, dev->net,
 799				   "stop fail (%d) usbnet usb-%s-%s, %s\n",
 800				   retval,
 801				   dev->udev->bus->bus_name, dev->udev->devpath,
 802				   info->description);
 803	}
 804
 805	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
 806		usbnet_terminate_urbs(dev);
 807
 808	usbnet_status_stop(dev);
 809
 810	usbnet_purge_paused_rxq(dev);
 811
 
 
 812	/* deferred work (task, timer, softirq) must also stop.
 813	 * can't flush_scheduled_work() until we drop rtnl (later),
 814	 * else workers could deadlock; so make workers a NOP.
 815	 */
 816	dev->flags = 0;
 817	del_timer_sync (&dev->delay);
 818	tasklet_kill (&dev->bh);
 819	if (!pm)
 820		usb_autopm_put_interface(dev->intf);
 821
 822	if (info->manage_power &&
 823	    !test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
 824		info->manage_power(dev, 0);
 825	else
 826		usb_autopm_put_interface(dev->intf);
 827
 828	return 0;
 829}
 830EXPORT_SYMBOL_GPL(usbnet_stop);
 831
 832/*-------------------------------------------------------------------------*/
 833
 834// posts reads, and enables write queuing
 835
 836// precondition: never called in_interrupt
 837
 838int usbnet_open (struct net_device *net)
 839{
 840	struct usbnet		*dev = netdev_priv(net);
 841	int			retval;
 842	struct driver_info	*info = dev->driver_info;
 843
 844	if ((retval = usb_autopm_get_interface(dev->intf)) < 0) {
 845		netif_info(dev, ifup, dev->net,
 846			   "resumption fail (%d) usbnet usb-%s-%s, %s\n",
 847			   retval,
 848			   dev->udev->bus->bus_name,
 849			   dev->udev->devpath,
 850			   info->description);
 851		goto done_nopm;
 852	}
 853
 854	// put into "known safe" state
 855	if (info->reset && (retval = info->reset (dev)) < 0) {
 856		netif_info(dev, ifup, dev->net,
 857			   "open reset fail (%d) usbnet usb-%s-%s, %s\n",
 858			   retval,
 859			   dev->udev->bus->bus_name,
 860			   dev->udev->devpath,
 861			   info->description);
 862		goto done;
 863	}
 864
 865	/* hard_mtu or rx_urb_size may change in reset() */
 866	usbnet_update_max_qlen(dev);
 867
 868	// insist peer be connected
 869	if (info->check_connect && (retval = info->check_connect (dev)) < 0) {
 870		netif_dbg(dev, ifup, dev->net, "can't open; %d\n", retval);
 871		goto done;
 872	}
 873
 874	/* start any status interrupt transfer */
 875	if (dev->interrupt) {
 876		retval = usbnet_status_start(dev, GFP_KERNEL);
 877		if (retval < 0) {
 878			netif_err(dev, ifup, dev->net,
 879				  "intr submit %d\n", retval);
 880			goto done;
 881		}
 882	}
 883
 884	set_bit(EVENT_DEV_OPEN, &dev->flags);
 885	netif_start_queue (net);
 886	netif_info(dev, ifup, dev->net,
 887		   "open: enable queueing (rx %d, tx %d) mtu %d %s framing\n",
 888		   (int)RX_QLEN(dev), (int)TX_QLEN(dev),
 889		   dev->net->mtu,
 890		   (dev->driver_info->flags & FLAG_FRAMING_NC) ? "NetChip" :
 891		   (dev->driver_info->flags & FLAG_FRAMING_GL) ? "GeneSys" :
 892		   (dev->driver_info->flags & FLAG_FRAMING_Z) ? "Zaurus" :
 893		   (dev->driver_info->flags & FLAG_FRAMING_RN) ? "RNDIS" :
 894		   (dev->driver_info->flags & FLAG_FRAMING_AX) ? "ASIX" :
 895		   "simple");
 896
 897	/* reset rx error state */
 898	dev->pkt_cnt = 0;
 899	dev->pkt_err = 0;
 900	clear_bit(EVENT_RX_KILL, &dev->flags);
 901
 902	// delay posting reads until we're fully open
 903	tasklet_schedule (&dev->bh);
 904	if (info->manage_power) {
 905		retval = info->manage_power(dev, 1);
 906		if (retval < 0) {
 907			retval = 0;
 908			set_bit(EVENT_NO_RUNTIME_PM, &dev->flags);
 909		} else {
 910			usb_autopm_put_interface(dev->intf);
 911		}
 912	}
 913	return retval;
 914done:
 915	usb_autopm_put_interface(dev->intf);
 916done_nopm:
 917	return retval;
 918}
 919EXPORT_SYMBOL_GPL(usbnet_open);
 920
 921/*-------------------------------------------------------------------------*/
 922
 923/* ethtool methods; minidrivers may need to add some more, but
 924 * they'll probably want to use this base set.
 925 */
 926
 927int usbnet_get_settings (struct net_device *net, struct ethtool_cmd *cmd)
 
 928{
 929	struct usbnet *dev = netdev_priv(net);
 930
 931	if (!dev->mii.mdio_read)
 932		return -EOPNOTSUPP;
 933
 934	return mii_ethtool_gset(&dev->mii, cmd);
 
 
 935}
 936EXPORT_SYMBOL_GPL(usbnet_get_settings);
 937
 938int usbnet_set_settings (struct net_device *net, struct ethtool_cmd *cmd)
 
 939{
 940	struct usbnet *dev = netdev_priv(net);
 941	int retval;
 942
 943	if (!dev->mii.mdio_write)
 944		return -EOPNOTSUPP;
 945
 946	retval = mii_ethtool_sset(&dev->mii, cmd);
 947
 948	/* link speed/duplex might have changed */
 949	if (dev->driver_info->link_reset)
 950		dev->driver_info->link_reset(dev);
 951
 952	/* hard_mtu or rx_urb_size may change in link_reset() */
 953	usbnet_update_max_qlen(dev);
 954
 955	return retval;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 956
 
 
 
 
 
 
 
 
 
 
 
 
 
 957}
 958EXPORT_SYMBOL_GPL(usbnet_set_settings);
 959
 960u32 usbnet_get_link (struct net_device *net)
 961{
 962	struct usbnet *dev = netdev_priv(net);
 963
 964	/* If a check_connect is defined, return its result */
 965	if (dev->driver_info->check_connect)
 966		return dev->driver_info->check_connect (dev) == 0;
 967
 968	/* if the device has mii operations, use those */
 969	if (dev->mii.mdio_read)
 970		return mii_link_ok(&dev->mii);
 971
 972	/* Otherwise, dtrt for drivers calling netif_carrier_{on,off} */
 973	return ethtool_op_get_link(net);
 974}
 975EXPORT_SYMBOL_GPL(usbnet_get_link);
 976
 977int usbnet_nway_reset(struct net_device *net)
 978{
 979	struct usbnet *dev = netdev_priv(net);
 980
 981	if (!dev->mii.mdio_write)
 982		return -EOPNOTSUPP;
 983
 984	return mii_nway_restart(&dev->mii);
 985}
 986EXPORT_SYMBOL_GPL(usbnet_nway_reset);
 987
 988void usbnet_get_drvinfo (struct net_device *net, struct ethtool_drvinfo *info)
 989{
 990	struct usbnet *dev = netdev_priv(net);
 991
 992	strlcpy (info->driver, dev->driver_name, sizeof info->driver);
 993	strlcpy (info->version, DRIVER_VERSION, sizeof info->version);
 994	strlcpy (info->fw_version, dev->driver_info->description,
 995		sizeof info->fw_version);
 996	usb_make_path (dev->udev, info->bus_info, sizeof info->bus_info);
 997}
 998EXPORT_SYMBOL_GPL(usbnet_get_drvinfo);
 999
1000u32 usbnet_get_msglevel (struct net_device *net)
1001{
1002	struct usbnet *dev = netdev_priv(net);
1003
1004	return dev->msg_enable;
1005}
1006EXPORT_SYMBOL_GPL(usbnet_get_msglevel);
1007
1008void usbnet_set_msglevel (struct net_device *net, u32 level)
1009{
1010	struct usbnet *dev = netdev_priv(net);
1011
1012	dev->msg_enable = level;
1013}
1014EXPORT_SYMBOL_GPL(usbnet_set_msglevel);
1015
1016/* drivers may override default ethtool_ops in their bind() routine */
1017static const struct ethtool_ops usbnet_ethtool_ops = {
1018	.get_settings		= usbnet_get_settings,
1019	.set_settings		= usbnet_set_settings,
1020	.get_link		= usbnet_get_link,
1021	.nway_reset		= usbnet_nway_reset,
1022	.get_drvinfo		= usbnet_get_drvinfo,
1023	.get_msglevel		= usbnet_get_msglevel,
1024	.set_msglevel		= usbnet_set_msglevel,
1025	.get_ts_info		= ethtool_op_get_ts_info,
 
 
1026};
1027
1028/*-------------------------------------------------------------------------*/
1029
1030static void __handle_link_change(struct usbnet *dev)
1031{
1032	if (!test_bit(EVENT_DEV_OPEN, &dev->flags))
1033		return;
1034
1035	if (!netif_carrier_ok(dev->net)) {
1036		/* kill URBs for reading packets to save bus bandwidth */
1037		unlink_urbs(dev, &dev->rxq);
1038
1039		/*
1040		 * tx_timeout will unlink URBs for sending packets and
1041		 * tx queue is stopped by netcore after link becomes off
1042		 */
1043	} else {
1044		/* submitting URBs for reading packets */
1045		tasklet_schedule(&dev->bh);
1046	}
1047
1048	/* hard_mtu or rx_urb_size may change during link change */
1049	usbnet_update_max_qlen(dev);
1050
1051	clear_bit(EVENT_LINK_CHANGE, &dev->flags);
1052}
1053
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1054/* work that cannot be done in interrupt context uses keventd.
1055 *
1056 * NOTE:  with 2.5 we could do more of this using completion callbacks,
1057 * especially now that control transfers can be queued.
1058 */
1059static void
1060kevent (struct work_struct *work)
1061{
1062	struct usbnet		*dev =
1063		container_of(work, struct usbnet, kevent);
1064	int			status;
1065
1066	/* usb_clear_halt() needs a thread context */
1067	if (test_bit (EVENT_TX_HALT, &dev->flags)) {
1068		unlink_urbs (dev, &dev->txq);
1069		status = usb_autopm_get_interface(dev->intf);
1070		if (status < 0)
1071			goto fail_pipe;
1072		status = usb_clear_halt (dev->udev, dev->out);
1073		usb_autopm_put_interface(dev->intf);
1074		if (status < 0 &&
1075		    status != -EPIPE &&
1076		    status != -ESHUTDOWN) {
1077			if (netif_msg_tx_err (dev))
1078fail_pipe:
1079				netdev_err(dev->net, "can't clear tx halt, status %d\n",
1080					   status);
1081		} else {
1082			clear_bit (EVENT_TX_HALT, &dev->flags);
1083			if (status != -ESHUTDOWN)
1084				netif_wake_queue (dev->net);
1085		}
1086	}
1087	if (test_bit (EVENT_RX_HALT, &dev->flags)) {
1088		unlink_urbs (dev, &dev->rxq);
1089		status = usb_autopm_get_interface(dev->intf);
1090		if (status < 0)
1091			goto fail_halt;
1092		status = usb_clear_halt (dev->udev, dev->in);
1093		usb_autopm_put_interface(dev->intf);
1094		if (status < 0 &&
1095		    status != -EPIPE &&
1096		    status != -ESHUTDOWN) {
1097			if (netif_msg_rx_err (dev))
1098fail_halt:
1099				netdev_err(dev->net, "can't clear rx halt, status %d\n",
1100					   status);
1101		} else {
1102			clear_bit (EVENT_RX_HALT, &dev->flags);
1103			tasklet_schedule (&dev->bh);
1104		}
1105	}
1106
1107	/* tasklet could resubmit itself forever if memory is tight */
1108	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {
1109		struct urb	*urb = NULL;
1110		int resched = 1;
1111
1112		if (netif_running (dev->net))
1113			urb = usb_alloc_urb (0, GFP_KERNEL);
1114		else
1115			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1116		if (urb != NULL) {
1117			clear_bit (EVENT_RX_MEMORY, &dev->flags);
1118			status = usb_autopm_get_interface(dev->intf);
1119			if (status < 0) {
1120				usb_free_urb(urb);
1121				goto fail_lowmem;
1122			}
1123			if (rx_submit (dev, urb, GFP_KERNEL) == -ENOLINK)
1124				resched = 0;
1125			usb_autopm_put_interface(dev->intf);
1126fail_lowmem:
1127			if (resched)
1128				tasklet_schedule (&dev->bh);
1129		}
1130	}
1131
1132	if (test_bit (EVENT_LINK_RESET, &dev->flags)) {
1133		struct driver_info	*info = dev->driver_info;
1134		int			retval = 0;
1135
1136		clear_bit (EVENT_LINK_RESET, &dev->flags);
1137		status = usb_autopm_get_interface(dev->intf);
1138		if (status < 0)
1139			goto skip_reset;
1140		if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
1141			usb_autopm_put_interface(dev->intf);
1142skip_reset:
1143			netdev_info(dev->net, "link reset failed (%d) usbnet usb-%s-%s, %s\n",
1144				    retval,
1145				    dev->udev->bus->bus_name,
1146				    dev->udev->devpath,
1147				    info->description);
1148		} else {
1149			usb_autopm_put_interface(dev->intf);
1150		}
1151
1152		/* handle link change from link resetting */
1153		__handle_link_change(dev);
1154	}
1155
1156	if (test_bit (EVENT_LINK_CHANGE, &dev->flags))
1157		__handle_link_change(dev);
1158
 
 
 
 
1159	if (dev->flags)
1160		netdev_dbg(dev->net, "kevent done, flags = 0x%lx\n", dev->flags);
1161}
1162
1163/*-------------------------------------------------------------------------*/
1164
1165static void tx_complete (struct urb *urb)
1166{
1167	struct sk_buff		*skb = (struct sk_buff *) urb->context;
1168	struct skb_data		*entry = (struct skb_data *) skb->cb;
1169	struct usbnet		*dev = entry->dev;
1170
1171	if (urb->status == 0) {
1172		if (!(dev->driver_info->flags & FLAG_MULTI_PACKET))
1173			dev->net->stats.tx_packets++;
1174		dev->net->stats.tx_bytes += entry->length;
 
 
 
 
1175	} else {
1176		dev->net->stats.tx_errors++;
1177
1178		switch (urb->status) {
1179		case -EPIPE:
1180			usbnet_defer_kevent (dev, EVENT_TX_HALT);
1181			break;
1182
1183		/* software-driven interface shutdown */
1184		case -ECONNRESET:		// async unlink
1185		case -ESHUTDOWN:		// hardware gone
1186			break;
1187
1188		// like rx, tx gets controller i/o faults during khubd delays
1189		// and so it uses the same throttling mechanism.
 
1190		case -EPROTO:
1191		case -ETIME:
1192		case -EILSEQ:
1193			usb_mark_last_busy(dev->udev);
1194			if (!timer_pending (&dev->delay)) {
1195				mod_timer (&dev->delay,
1196					jiffies + THROTTLE_JIFFIES);
1197				netif_dbg(dev, link, dev->net,
1198					  "tx throttle %d\n", urb->status);
1199			}
1200			netif_stop_queue (dev->net);
1201			break;
1202		default:
1203			netif_dbg(dev, tx_err, dev->net,
1204				  "tx err %d\n", entry->urb->status);
1205			break;
1206		}
1207	}
1208
1209	usb_autopm_put_interface_async(dev->intf);
1210	(void) defer_bh(dev, skb, &dev->txq, tx_done);
1211}
1212
1213/*-------------------------------------------------------------------------*/
1214
1215void usbnet_tx_timeout (struct net_device *net)
1216{
1217	struct usbnet		*dev = netdev_priv(net);
1218
1219	unlink_urbs (dev, &dev->txq);
1220	tasklet_schedule (&dev->bh);
1221
1222	// FIXME: device recovery -- reset?
 
 
 
 
1223}
1224EXPORT_SYMBOL_GPL(usbnet_tx_timeout);
1225
1226/*-------------------------------------------------------------------------*/
1227
1228static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
1229{
1230	unsigned num_sgs, total_len = 0;
1231	int i, s = 0;
1232
1233	num_sgs = skb_shinfo(skb)->nr_frags + 1;
1234	if (num_sgs == 1)
1235		return 0;
1236
1237	/* reserve one for zero packet */
1238	urb->sg = kmalloc((num_sgs + 1) * sizeof(struct scatterlist),
1239			  GFP_ATOMIC);
1240	if (!urb->sg)
1241		return -ENOMEM;
1242
1243	urb->num_sgs = num_sgs;
1244	sg_init_table(urb->sg, urb->num_sgs + 1);
1245
1246	sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
1247	total_len += skb_headlen(skb);
1248
1249	for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
1250		struct skb_frag_struct *f = &skb_shinfo(skb)->frags[i];
1251
1252		total_len += skb_frag_size(f);
1253		sg_set_page(&urb->sg[i + s], f->page.p, f->size,
1254				f->page_offset);
1255	}
1256	urb->transfer_buffer_length = total_len;
1257
1258	return 1;
1259}
1260
1261netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
1262				     struct net_device *net)
1263{
1264	struct usbnet		*dev = netdev_priv(net);
1265	int			length;
1266	struct urb		*urb = NULL;
1267	struct skb_data		*entry;
1268	struct driver_info	*info = dev->driver_info;
1269	unsigned long		flags;
1270	int retval;
1271
1272	if (skb)
1273		skb_tx_timestamp(skb);
1274
1275	// some devices want funky USB-level framing, for
1276	// win32 driver (usually) and/or hardware quirks
1277	if (info->tx_fixup) {
1278		skb = info->tx_fixup (dev, skb, GFP_ATOMIC);
1279		if (!skb) {
1280			/* packet collected; minidriver waiting for more */
1281			if (info->flags & FLAG_MULTI_PACKET)
1282				goto not_drop;
1283			netif_dbg(dev, tx_err, dev->net, "can't tx_fixup skb\n");
1284			goto drop;
1285		}
1286	}
1287
1288	if (!(urb = usb_alloc_urb (0, GFP_ATOMIC))) {
1289		netif_dbg(dev, tx_err, dev->net, "no urb\n");
1290		goto drop;
1291	}
1292
1293	entry = (struct skb_data *) skb->cb;
1294	entry->urb = urb;
1295	entry->dev = dev;
1296
1297	usb_fill_bulk_urb (urb, dev->udev, dev->out,
1298			skb->data, skb->len, tx_complete, skb);
1299	if (dev->can_dma_sg) {
1300		if (build_dma_sg(skb, urb) < 0)
1301			goto drop;
1302	}
1303	length = urb->transfer_buffer_length;
1304
1305	/* don't assume the hardware handles USB_ZERO_PACKET
1306	 * NOTE:  strictly conforming cdc-ether devices should expect
1307	 * the ZLP here, but ignore the one-byte packet.
1308	 * NOTE2: CDC NCM specification is different from CDC ECM when
1309	 * handling ZLP/short packets, so cdc_ncm driver will make short
1310	 * packet itself if needed.
1311	 */
1312	if (length % dev->maxpacket == 0) {
1313		if (!(info->flags & FLAG_SEND_ZLP)) {
1314			if (!(info->flags & FLAG_MULTI_PACKET)) {
1315				length++;
1316				if (skb_tailroom(skb) && !urb->num_sgs) {
1317					skb->data[skb->len] = 0;
1318					__skb_put(skb, 1);
1319				} else if (urb->num_sgs)
1320					sg_set_buf(&urb->sg[urb->num_sgs++],
1321							dev->padding_pkt, 1);
1322			}
1323		} else
1324			urb->transfer_flags |= URB_ZERO_PACKET;
1325	}
1326	entry->length = urb->transfer_buffer_length = length;
 
 
 
 
 
 
 
 
 
 
 
 
1327
1328	spin_lock_irqsave(&dev->txq.lock, flags);
1329	retval = usb_autopm_get_interface_async(dev->intf);
1330	if (retval < 0) {
1331		spin_unlock_irqrestore(&dev->txq.lock, flags);
1332		goto drop;
1333	}
1334
1335#ifdef CONFIG_PM
1336	/* if this triggers the device is still a sleep */
1337	if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
1338		/* transmission will be done in resume */
1339		usb_anchor_urb(urb, &dev->deferred);
1340		/* no use to process more packets */
1341		netif_stop_queue(net);
1342		usb_put_urb(urb);
1343		spin_unlock_irqrestore(&dev->txq.lock, flags);
1344		netdev_dbg(dev->net, "Delaying transmission for resumption\n");
1345		goto deferred;
1346	}
1347#endif
1348
1349	switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
1350	case -EPIPE:
1351		netif_stop_queue (net);
1352		usbnet_defer_kevent (dev, EVENT_TX_HALT);
1353		usb_autopm_put_interface_async(dev->intf);
1354		break;
1355	default:
1356		usb_autopm_put_interface_async(dev->intf);
1357		netif_dbg(dev, tx_err, dev->net,
1358			  "tx: submit urb err %d\n", retval);
1359		break;
1360	case 0:
1361		net->trans_start = jiffies;
1362		__usbnet_queue_skb(&dev->txq, skb, tx_start);
1363		if (dev->txq.qlen >= TX_QLEN (dev))
1364			netif_stop_queue (net);
1365	}
1366	spin_unlock_irqrestore (&dev->txq.lock, flags);
1367
1368	if (retval) {
1369		netif_dbg(dev, tx_err, dev->net, "drop, code %d\n", retval);
1370drop:
1371		dev->net->stats.tx_dropped++;
1372not_drop:
1373		if (skb)
1374			dev_kfree_skb_any (skb);
1375		if (urb) {
1376			kfree(urb->sg);
1377			usb_free_urb(urb);
1378		}
1379	} else
1380		netif_dbg(dev, tx_queued, dev->net,
1381			  "> tx, len %d, type 0x%x\n", length, skb->protocol);
1382#ifdef CONFIG_PM
1383deferred:
1384#endif
1385	return NETDEV_TX_OK;
1386}
1387EXPORT_SYMBOL_GPL(usbnet_start_xmit);
1388
1389static int rx_alloc_submit(struct usbnet *dev, gfp_t flags)
1390{
1391	struct urb	*urb;
1392	int		i;
1393	int		ret = 0;
1394
1395	/* don't refill the queue all at once */
1396	for (i = 0; i < 10 && dev->rxq.qlen < RX_QLEN(dev); i++) {
1397		urb = usb_alloc_urb(0, flags);
1398		if (urb != NULL) {
1399			ret = rx_submit(dev, urb, flags);
1400			if (ret)
1401				goto err;
1402		} else {
1403			ret = -ENOMEM;
1404			goto err;
1405		}
1406	}
1407err:
1408	return ret;
1409}
1410
1411/*-------------------------------------------------------------------------*/
1412
1413// tasklet (work deferred from completions, in_irq) or timer
1414
1415static void usbnet_bh (unsigned long param)
1416{
1417	struct usbnet		*dev = (struct usbnet *) param;
1418	struct sk_buff		*skb;
1419	struct skb_data		*entry;
1420
1421	while ((skb = skb_dequeue (&dev->done))) {
1422		entry = (struct skb_data *) skb->cb;
1423		switch (entry->state) {
1424		case rx_done:
1425			entry->state = rx_cleanup;
1426			rx_process (dev, skb);
1427			continue;
1428		case tx_done:
1429			kfree(entry->urb->sg);
1430		case rx_cleanup:
1431			usb_free_urb (entry->urb);
1432			dev_kfree_skb (skb);
1433			continue;
1434		default:
1435			netdev_dbg(dev->net, "bogus skb state %d\n", entry->state);
1436		}
1437	}
1438
1439	/* restart RX again after disabling due to high error rate */
1440	clear_bit(EVENT_RX_KILL, &dev->flags);
1441
1442	/* waiting for all pending urbs to complete?
1443	 * only then can we forgo submitting anew
1444	 */
1445	if (waitqueue_active(&dev->wait)) {
1446		if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
1447			wake_up_all(&dev->wait);
1448
1449	// or are we maybe short a few urbs?
1450	} else if (netif_running (dev->net) &&
1451		   netif_device_present (dev->net) &&
1452		   netif_carrier_ok(dev->net) &&
1453		   !timer_pending (&dev->delay) &&
1454		   !test_bit (EVENT_RX_HALT, &dev->flags)) {
 
1455		int	temp = dev->rxq.qlen;
1456
1457		if (temp < RX_QLEN(dev)) {
1458			if (rx_alloc_submit(dev, GFP_ATOMIC) == -ENOLINK)
1459				return;
1460			if (temp != dev->rxq.qlen)
1461				netif_dbg(dev, link, dev->net,
1462					  "rxqlen %d --> %d\n",
1463					  temp, dev->rxq.qlen);
1464			if (dev->rxq.qlen < RX_QLEN(dev))
1465				tasklet_schedule (&dev->bh);
1466		}
1467		if (dev->txq.qlen < TX_QLEN (dev))
1468			netif_wake_queue (dev->net);
1469	}
1470}
1471
1472
1473/*-------------------------------------------------------------------------
1474 *
1475 * USB Device Driver support
1476 *
1477 *-------------------------------------------------------------------------*/
1478
1479// precondition: never called in_interrupt
1480
1481void usbnet_disconnect (struct usb_interface *intf)
1482{
1483	struct usbnet		*dev;
1484	struct usb_device	*xdev;
1485	struct net_device	*net;
1486
1487	dev = usb_get_intfdata(intf);
1488	usb_set_intfdata(intf, NULL);
1489	if (!dev)
1490		return;
1491
1492	xdev = interface_to_usbdev (intf);
1493
1494	netif_info(dev, probe, dev->net, "unregister '%s' usb-%s-%s, %s\n",
1495		   intf->dev.driver->name,
1496		   xdev->bus->bus_name, xdev->devpath,
1497		   dev->driver_info->description);
1498
1499	net = dev->net;
1500	unregister_netdev (net);
1501
1502	cancel_work_sync(&dev->kevent);
1503
1504	usb_scuttle_anchored_urbs(&dev->deferred);
1505
1506	if (dev->driver_info->unbind)
1507		dev->driver_info->unbind (dev, intf);
1508
1509	usb_kill_urb(dev->interrupt);
1510	usb_free_urb(dev->interrupt);
1511	kfree(dev->padding_pkt);
1512
 
1513	free_netdev(net);
1514}
1515EXPORT_SYMBOL_GPL(usbnet_disconnect);
1516
1517static const struct net_device_ops usbnet_netdev_ops = {
1518	.ndo_open		= usbnet_open,
1519	.ndo_stop		= usbnet_stop,
1520	.ndo_start_xmit		= usbnet_start_xmit,
1521	.ndo_tx_timeout		= usbnet_tx_timeout,
 
1522	.ndo_change_mtu		= usbnet_change_mtu,
 
1523	.ndo_set_mac_address 	= eth_mac_addr,
1524	.ndo_validate_addr	= eth_validate_addr,
1525};
1526
1527/*-------------------------------------------------------------------------*/
1528
1529// precondition: never called in_interrupt
1530
1531static struct device_type wlan_type = {
1532	.name	= "wlan",
1533};
1534
1535static struct device_type wwan_type = {
1536	.name	= "wwan",
1537};
1538
1539int
1540usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
1541{
1542	struct usbnet			*dev;
1543	struct net_device		*net;
1544	struct usb_host_interface	*interface;
1545	struct driver_info		*info;
1546	struct usb_device		*xdev;
1547	int				status;
1548	const char			*name;
1549	struct usb_driver 	*driver = to_usb_driver(udev->dev.driver);
1550
1551	/* usbnet already took usb runtime pm, so have to enable the feature
1552	 * for usb interface, otherwise usb_autopm_get_interface may return
1553	 * failure if RUNTIME_PM is enabled.
1554	 */
1555	if (!driver->supports_autosuspend) {
1556		driver->supports_autosuspend = 1;
1557		pm_runtime_enable(&udev->dev);
1558	}
1559
1560	name = udev->dev.driver->name;
1561	info = (struct driver_info *) prod->driver_info;
1562	if (!info) {
1563		dev_dbg (&udev->dev, "blacklisted by %s\n", name);
1564		return -ENODEV;
1565	}
1566	xdev = interface_to_usbdev (udev);
1567	interface = udev->cur_altsetting;
1568
1569	status = -ENOMEM;
1570
1571	// set up our own records
1572	net = alloc_etherdev(sizeof(*dev));
1573	if (!net)
1574		goto out;
1575
1576	/* netdev_printk() needs this so do it as early as possible */
1577	SET_NETDEV_DEV(net, &udev->dev);
1578
1579	dev = netdev_priv(net);
1580	dev->udev = xdev;
1581	dev->intf = udev;
1582	dev->driver_info = info;
1583	dev->driver_name = name;
 
 
 
 
 
1584	dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
1585				| NETIF_MSG_PROBE | NETIF_MSG_LINK);
1586	init_waitqueue_head(&dev->wait);
1587	skb_queue_head_init (&dev->rxq);
1588	skb_queue_head_init (&dev->txq);
1589	skb_queue_head_init (&dev->done);
1590	skb_queue_head_init(&dev->rxq_pause);
1591	dev->bh.func = usbnet_bh;
1592	dev->bh.data = (unsigned long) dev;
1593	INIT_WORK (&dev->kevent, kevent);
1594	init_usb_anchor(&dev->deferred);
1595	dev->delay.function = usbnet_bh;
1596	dev->delay.data = (unsigned long) dev;
1597	init_timer (&dev->delay);
1598	mutex_init (&dev->phy_mutex);
1599	mutex_init(&dev->interrupt_mutex);
1600	dev->interrupt_count = 0;
1601
1602	dev->net = net;
1603	strcpy (net->name, "usb%d");
1604	memcpy (net->dev_addr, node_id, sizeof node_id);
1605
1606	/* rx and tx sides can use different message sizes;
1607	 * bind() should set rx_urb_size in that case.
1608	 */
1609	dev->hard_mtu = net->mtu + net->hard_header_len;
1610#if 0
1611// dma_supported() is deeply broken on almost all architectures
1612	// possible with some EHCI controllers
1613	if (dma_supported (&udev->dev, DMA_BIT_MASK(64)))
1614		net->features |= NETIF_F_HIGHDMA;
1615#endif
1616
1617	net->netdev_ops = &usbnet_netdev_ops;
1618	net->watchdog_timeo = TX_TIMEOUT_JIFFIES;
1619	net->ethtool_ops = &usbnet_ethtool_ops;
1620
1621	// allow device-specific bind/init procedures
1622	// NOTE net->name still not usable ...
1623	if (info->bind) {
1624		status = info->bind (dev, udev);
1625		if (status < 0)
1626			goto out1;
1627
1628		// heuristic:  "usb%d" for links we know are two-host,
1629		// else "eth%d" when there's reasonable doubt.  userspace
1630		// can rename the link if it knows better.
1631		if ((dev->driver_info->flags & FLAG_ETHER) != 0 &&
1632		    ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 ||
1633		     (net->dev_addr [0] & 0x02) == 0))
1634			strcpy (net->name, "eth%d");
1635		/* WLAN devices should always be named "wlan%d" */
1636		if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1637			strcpy(net->name, "wlan%d");
1638		/* WWAN devices should always be named "wwan%d" */
1639		if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1640			strcpy(net->name, "wwan%d");
1641
1642		/* devices that cannot do ARP */
1643		if ((dev->driver_info->flags & FLAG_NOARP) != 0)
1644			net->flags |= IFF_NOARP;
1645
1646		/* maybe the remote can't receive an Ethernet MTU */
1647		if (net->mtu > (dev->hard_mtu - net->hard_header_len))
1648			net->mtu = dev->hard_mtu - net->hard_header_len;
1649	} else if (!info->in || !info->out)
1650		status = usbnet_get_endpoints (dev, udev);
1651	else {
1652		dev->in = usb_rcvbulkpipe (xdev, info->in);
1653		dev->out = usb_sndbulkpipe (xdev, info->out);
1654		if (!(info->flags & FLAG_NO_SETINT))
1655			status = usb_set_interface (xdev,
1656				interface->desc.bInterfaceNumber,
1657				interface->desc.bAlternateSetting);
1658		else
1659			status = 0;
1660
1661	}
1662	if (status >= 0 && dev->status)
1663		status = init_status (dev, udev);
1664	if (status < 0)
1665		goto out3;
1666
1667	if (!dev->rx_urb_size)
1668		dev->rx_urb_size = dev->hard_mtu;
1669	dev->maxpacket = usb_maxpacket (dev->udev, dev->out, 1);
1670
1671	/* let userspace know we have a random address */
1672	if (ether_addr_equal(net->dev_addr, node_id))
1673		net->addr_assign_type = NET_ADDR_RANDOM;
1674
1675	if ((dev->driver_info->flags & FLAG_WLAN) != 0)
1676		SET_NETDEV_DEVTYPE(net, &wlan_type);
1677	if ((dev->driver_info->flags & FLAG_WWAN) != 0)
1678		SET_NETDEV_DEVTYPE(net, &wwan_type);
1679
1680	/* initialize max rx_qlen and tx_qlen */
1681	usbnet_update_max_qlen(dev);
1682
1683	if (dev->can_dma_sg && !(info->flags & FLAG_SEND_ZLP) &&
1684		!(info->flags & FLAG_MULTI_PACKET)) {
1685		dev->padding_pkt = kzalloc(1, GFP_KERNEL);
1686		if (!dev->padding_pkt) {
1687			status = -ENOMEM;
1688			goto out4;
1689		}
1690	}
1691
1692	status = register_netdev (net);
1693	if (status)
1694		goto out5;
1695	netif_info(dev, probe, dev->net,
1696		   "register '%s' at usb-%s-%s, %s, %pM\n",
1697		   udev->dev.driver->name,
1698		   xdev->bus->bus_name, xdev->devpath,
1699		   dev->driver_info->description,
1700		   net->dev_addr);
1701
1702	// ok, it's ready to go.
1703	usb_set_intfdata (udev, dev);
1704
1705	netif_device_attach (net);
1706
1707	if (dev->driver_info->flags & FLAG_LINK_INTR)
1708		usbnet_link_change(dev, 0, 0);
1709
1710	return 0;
1711
1712out5:
1713	kfree(dev->padding_pkt);
1714out4:
1715	usb_free_urb(dev->interrupt);
1716out3:
1717	if (info->unbind)
1718		info->unbind (dev, udev);
1719out1:
 
 
 
 
 
 
 
 
 
1720	free_netdev(net);
1721out:
1722	return status;
1723}
1724EXPORT_SYMBOL_GPL(usbnet_probe);
1725
1726/*-------------------------------------------------------------------------*/
1727
1728/*
1729 * suspend the whole driver as soon as the first interface is suspended
1730 * resume only when the last interface is resumed
1731 */
1732
1733int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
1734{
1735	struct usbnet		*dev = usb_get_intfdata(intf);
1736
1737	if (!dev->suspend_count++) {
1738		spin_lock_irq(&dev->txq.lock);
1739		/* don't autosuspend while transmitting */
1740		if (dev->txq.qlen && PMSG_IS_AUTO(message)) {
1741			dev->suspend_count--;
1742			spin_unlock_irq(&dev->txq.lock);
1743			return -EBUSY;
1744		} else {
1745			set_bit(EVENT_DEV_ASLEEP, &dev->flags);
1746			spin_unlock_irq(&dev->txq.lock);
1747		}
1748		/*
1749		 * accelerate emptying of the rx and queues, to avoid
1750		 * having everything error out.
1751		 */
1752		netif_device_detach (dev->net);
1753		usbnet_terminate_urbs(dev);
1754		__usbnet_status_stop_force(dev);
1755
1756		/*
1757		 * reattach so runtime management can use and
1758		 * wake the device
1759		 */
1760		netif_device_attach (dev->net);
1761	}
1762	return 0;
1763}
1764EXPORT_SYMBOL_GPL(usbnet_suspend);
1765
1766int usbnet_resume (struct usb_interface *intf)
1767{
1768	struct usbnet		*dev = usb_get_intfdata(intf);
1769	struct sk_buff          *skb;
1770	struct urb              *res;
1771	int                     retval;
1772
1773	if (!--dev->suspend_count) {
1774		/* resume interrupt URB if it was previously submitted */
1775		__usbnet_status_start_force(dev, GFP_NOIO);
1776
1777		spin_lock_irq(&dev->txq.lock);
1778		while ((res = usb_get_from_anchor(&dev->deferred))) {
1779
1780			skb = (struct sk_buff *)res->context;
1781			retval = usb_submit_urb(res, GFP_ATOMIC);
1782			if (retval < 0) {
1783				dev_kfree_skb_any(skb);
1784				kfree(res->sg);
1785				usb_free_urb(res);
1786				usb_autopm_put_interface_async(dev->intf);
1787			} else {
1788				dev->net->trans_start = jiffies;
1789				__skb_queue_tail(&dev->txq, skb);
1790			}
1791		}
1792
1793		smp_mb();
1794		clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
1795		spin_unlock_irq(&dev->txq.lock);
1796
1797		if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
1798			/* handle remote wakeup ASAP
1799			 * we cannot race against stop
1800			 */
1801			if (netif_device_present(dev->net) &&
1802				!timer_pending(&dev->delay) &&
1803				!test_bit(EVENT_RX_HALT, &dev->flags))
1804					rx_alloc_submit(dev, GFP_NOIO);
1805
1806			if (!(dev->txq.qlen >= TX_QLEN(dev)))
1807				netif_tx_wake_all_queues(dev->net);
1808			tasklet_schedule (&dev->bh);
1809		}
1810	}
1811
1812	if (test_and_clear_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags))
1813		usb_autopm_get_interface_no_resume(intf);
1814
1815	return 0;
1816}
1817EXPORT_SYMBOL_GPL(usbnet_resume);
1818
1819/*
1820 * Either a subdriver implements manage_power, then it is assumed to always
1821 * be ready to be suspended or it reports the readiness to be suspended
1822 * explicitly
1823 */
1824void usbnet_device_suggests_idle(struct usbnet *dev)
1825{
1826	if (!test_and_set_bit(EVENT_DEVICE_REPORT_IDLE, &dev->flags)) {
1827		dev->intf->needs_remote_wakeup = 1;
1828		usb_autopm_put_interface_async(dev->intf);
1829	}
1830}
1831EXPORT_SYMBOL(usbnet_device_suggests_idle);
1832
1833/*
1834 * For devices that can do without special commands
1835 */
1836int usbnet_manage_power(struct usbnet *dev, int on)
1837{
1838	dev->intf->needs_remote_wakeup = on;
1839	return 0;
1840}
1841EXPORT_SYMBOL(usbnet_manage_power);
1842
1843void usbnet_link_change(struct usbnet *dev, bool link, bool need_reset)
1844{
1845	/* update link after link is reseted */
1846	if (link && !need_reset)
1847		netif_carrier_on(dev->net);
1848	else
1849		netif_carrier_off(dev->net);
1850
1851	if (need_reset && link)
1852		usbnet_defer_kevent(dev, EVENT_LINK_RESET);
1853	else
1854		usbnet_defer_kevent(dev, EVENT_LINK_CHANGE);
1855}
1856EXPORT_SYMBOL(usbnet_link_change);
1857
1858/*-------------------------------------------------------------------------*/
1859static int __usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1860			     u16 value, u16 index, void *data, u16 size)
1861{
1862	void *buf = NULL;
1863	int err = -ENOMEM;
1864
1865	netdev_dbg(dev->net, "usbnet_read_cmd cmd=0x%02x reqtype=%02x"
1866		   " value=0x%04x index=0x%04x size=%d\n",
1867		   cmd, reqtype, value, index, size);
1868
1869	if (data) {
1870		buf = kmalloc(size, GFP_KERNEL);
1871		if (!buf)
1872			goto out;
1873	}
1874
1875	err = usb_control_msg(dev->udev, usb_rcvctrlpipe(dev->udev, 0),
1876			      cmd, reqtype, value, index, buf, size,
1877			      USB_CTRL_GET_TIMEOUT);
1878	if (err > 0 && err <= size)
1879		memcpy(data, buf, err);
 
 
 
 
 
1880	kfree(buf);
1881out:
1882	return err;
1883}
1884
1885static int __usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1886			      u16 value, u16 index, const void *data,
1887			      u16 size)
1888{
1889	void *buf = NULL;
1890	int err = -ENOMEM;
1891
1892	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1893		   " value=0x%04x index=0x%04x size=%d\n",
1894		   cmd, reqtype, value, index, size);
1895
1896	if (data) {
1897		buf = kmemdup(data, size, GFP_KERNEL);
1898		if (!buf)
1899			goto out;
1900	}
 
 
 
 
 
 
1901
1902	err = usb_control_msg(dev->udev, usb_sndctrlpipe(dev->udev, 0),
1903			      cmd, reqtype, value, index, buf, size,
1904			      USB_CTRL_SET_TIMEOUT);
1905	kfree(buf);
1906
1907out:
1908	return err;
1909}
1910
1911/*
1912 * The function can't be called inside suspend/resume callback,
1913 * otherwise deadlock will be caused.
1914 */
1915int usbnet_read_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1916		    u16 value, u16 index, void *data, u16 size)
1917{
1918	int ret;
1919
1920	if (usb_autopm_get_interface(dev->intf) < 0)
1921		return -ENODEV;
1922	ret = __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1923				data, size);
1924	usb_autopm_put_interface(dev->intf);
1925	return ret;
1926}
1927EXPORT_SYMBOL_GPL(usbnet_read_cmd);
1928
1929/*
1930 * The function can't be called inside suspend/resume callback,
1931 * otherwise deadlock will be caused.
1932 */
1933int usbnet_write_cmd(struct usbnet *dev, u8 cmd, u8 reqtype,
1934		     u16 value, u16 index, const void *data, u16 size)
1935{
1936	int ret;
1937
1938	if (usb_autopm_get_interface(dev->intf) < 0)
1939		return -ENODEV;
1940	ret = __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1941				 data, size);
1942	usb_autopm_put_interface(dev->intf);
1943	return ret;
1944}
1945EXPORT_SYMBOL_GPL(usbnet_write_cmd);
1946
1947/*
1948 * The function can be called inside suspend/resume callback safely
1949 * and should only be called by suspend/resume callback generally.
1950 */
1951int usbnet_read_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1952			  u16 value, u16 index, void *data, u16 size)
1953{
1954	return __usbnet_read_cmd(dev, cmd, reqtype, value, index,
1955				 data, size);
1956}
1957EXPORT_SYMBOL_GPL(usbnet_read_cmd_nopm);
1958
1959/*
1960 * The function can be called inside suspend/resume callback safely
1961 * and should only be called by suspend/resume callback generally.
1962 */
1963int usbnet_write_cmd_nopm(struct usbnet *dev, u8 cmd, u8 reqtype,
1964			  u16 value, u16 index, const void *data,
1965			  u16 size)
1966{
1967	return __usbnet_write_cmd(dev, cmd, reqtype, value, index,
1968				  data, size);
1969}
1970EXPORT_SYMBOL_GPL(usbnet_write_cmd_nopm);
1971
1972static void usbnet_async_cmd_cb(struct urb *urb)
1973{
1974	struct usb_ctrlrequest *req = (struct usb_ctrlrequest *)urb->context;
1975	int status = urb->status;
1976
1977	if (status < 0)
1978		dev_dbg(&urb->dev->dev, "%s failed with %d",
1979			__func__, status);
1980
1981	kfree(req);
1982	usb_free_urb(urb);
1983}
1984
1985/*
1986 * The caller must make sure that device can't be put into suspend
1987 * state until the control URB completes.
1988 */
1989int usbnet_write_cmd_async(struct usbnet *dev, u8 cmd, u8 reqtype,
1990			   u16 value, u16 index, const void *data, u16 size)
1991{
1992	struct usb_ctrlrequest *req = NULL;
1993	struct urb *urb;
1994	int err = -ENOMEM;
1995	void *buf = NULL;
1996
1997	netdev_dbg(dev->net, "usbnet_write_cmd cmd=0x%02x reqtype=%02x"
1998		   " value=0x%04x index=0x%04x size=%d\n",
1999		   cmd, reqtype, value, index, size);
2000
2001	urb = usb_alloc_urb(0, GFP_ATOMIC);
2002	if (!urb) {
2003		netdev_err(dev->net, "Error allocating URB in"
2004			   " %s!\n", __func__);
2005		goto fail;
2006	}
2007
2008	if (data) {
2009		buf = kmemdup(data, size, GFP_ATOMIC);
2010		if (!buf) {
2011			netdev_err(dev->net, "Error allocating buffer"
2012				   " in %s!\n", __func__);
2013			goto fail_free;
2014		}
2015	}
2016
2017	req = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC);
2018	if (!req)
2019		goto fail_free_buf;
2020
2021	req->bRequestType = reqtype;
2022	req->bRequest = cmd;
2023	req->wValue = cpu_to_le16(value);
2024	req->wIndex = cpu_to_le16(index);
2025	req->wLength = cpu_to_le16(size);
2026
2027	usb_fill_control_urb(urb, dev->udev,
2028			     usb_sndctrlpipe(dev->udev, 0),
2029			     (void *)req, buf, size,
2030			     usbnet_async_cmd_cb, req);
2031	urb->transfer_flags |= URB_FREE_BUFFER;
2032
2033	err = usb_submit_urb(urb, GFP_ATOMIC);
2034	if (err < 0) {
2035		netdev_err(dev->net, "Error submitting the control"
2036			   " message: status=%d\n", err);
2037		goto fail_free;
2038	}
2039	return 0;
2040
2041fail_free_buf:
2042	kfree(buf);
2043fail_free:
2044	kfree(req);
2045	usb_free_urb(urb);
2046fail:
2047	return err;
2048
2049}
2050EXPORT_SYMBOL_GPL(usbnet_write_cmd_async);
2051/*-------------------------------------------------------------------------*/
2052
2053static int __init usbnet_init(void)
2054{
2055	/* Compiler should optimize this out. */
2056	BUILD_BUG_ON(
2057		FIELD_SIZEOF(struct sk_buff, cb) < sizeof(struct skb_data));
2058
2059	eth_random_addr(node_id);
2060	return 0;
2061}
2062module_init(usbnet_init);
2063
2064static void __exit usbnet_exit(void)
2065{
2066}
2067module_exit(usbnet_exit);
2068
2069MODULE_AUTHOR("David Brownell");
2070MODULE_DESCRIPTION("USB network driver framework");
2071MODULE_LICENSE("GPL");