cdc-wdm.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * cdc-wdm.c
   4 *
   5 * This driver supports USB CDC WCM Device Management.
   6 *
   7 * Copyright (c) 2007-2009 Oliver Neukum
   8 *
   9 * Some code taken from cdc-acm.c
  10 *
  11 * Released under the GPLv2.
  12 *
  13 * Many thanks to Carl Nordbeck
  14 */
  15#include <linux/kernel.h>
  16#include <linux/errno.h>
  17#include <linux/ioctl.h>
  18#include <linux/slab.h>
  19#include <linux/module.h>
  20#include <linux/mutex.h>
  21#include <linux/uaccess.h>
  22#include <linux/bitops.h>
  23#include <linux/poll.h>
  24#include <linux/skbuff.h>
  25#include <linux/usb.h>
  26#include <linux/usb/cdc.h>
  27#include <linux/wwan.h>
  28#include <asm/byteorder.h>
  29#include <linux/unaligned.h>
  30#include <linux/usb/cdc-wdm.h>
  31
  32#define DRIVER_AUTHOR "Oliver Neukum"
  33#define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
  34
  35static const struct usb_device_id wdm_ids[] = {
  36	{
  37		.match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
  38				 USB_DEVICE_ID_MATCH_INT_SUBCLASS,
  39		.bInterfaceClass = USB_CLASS_COMM,
  40		.bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
  41	},
  42	{ }
  43};
  44
  45MODULE_DEVICE_TABLE (usb, wdm_ids);
  46
  47#define WDM_MINOR_BASE	176
  48
  49
  50#define WDM_IN_USE		1
  51#define WDM_DISCONNECTING	2
  52#define WDM_RESULT		3
  53#define WDM_READ		4
  54#define WDM_INT_STALL		5
  55#define WDM_POLL_RUNNING	6
  56#define WDM_RESPONDING		7
  57#define WDM_SUSPENDING		8
  58#define WDM_RESETTING		9
  59#define WDM_OVERFLOW		10
  60#define WDM_WWAN_IN_USE		11
  61
  62#define WDM_MAX			16
  63
  64/* we cannot wait forever at flush() */
  65#define WDM_FLUSH_TIMEOUT	(30 * HZ)
  66
  67/* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
  68#define WDM_DEFAULT_BUFSIZE	256
  69
  70static DEFINE_MUTEX(wdm_mutex);
  71static DEFINE_SPINLOCK(wdm_device_list_lock);
  72static LIST_HEAD(wdm_device_list);
  73
  74/* --- method tables --- */
  75
  76struct wdm_device {
  77	u8			*inbuf; /* buffer for response */
  78	u8			*outbuf; /* buffer for command */
  79	u8			*sbuf; /* buffer for status */
  80	u8			*ubuf; /* buffer for copy to user space */
  81
  82	struct urb		*command;
  83	struct urb		*response;
  84	struct urb		*validity;
  85	struct usb_interface	*intf;
  86	struct usb_ctrlrequest	*orq;
  87	struct usb_ctrlrequest	*irq;
  88	spinlock_t		iuspin;
  89
  90	unsigned long		flags;
  91	u16			bufsize;
  92	u16			wMaxCommand;
  93	u16			wMaxPacketSize;
  94	__le16			inum;
  95	int			length;
  96	int			read;
  97	int			count;
  98	dma_addr_t		shandle;
  99	dma_addr_t		ihandle;
 100	struct mutex		wlock;
 101	struct mutex		rlock;
 102	wait_queue_head_t	wait;
 103	struct work_struct	rxwork;
 104	struct work_struct	service_outs_intr;
 105	int			werr;
 106	int			rerr;
 107	int                     resp_count;
 108
 109	struct list_head	device_list;
 110	int			(*manage_power)(struct usb_interface *, int);
 111
 112	enum wwan_port_type	wwanp_type;
 113	struct wwan_port	*wwanp;
 114};
 115
 116static struct usb_driver wdm_driver;
 117
 118/* return intfdata if we own the interface, else look up intf in the list */
 119static struct wdm_device *wdm_find_device(struct usb_interface *intf)
 120{
 121	struct wdm_device *desc;
 122
 123	spin_lock(&wdm_device_list_lock);
 124	list_for_each_entry(desc, &wdm_device_list, device_list)
 125		if (desc->intf == intf)
 126			goto found;
 127	desc = NULL;
 128found:
 129	spin_unlock(&wdm_device_list_lock);
 130
 131	return desc;
 132}
 133
 134static struct wdm_device *wdm_find_device_by_minor(int minor)
 135{
 136	struct wdm_device *desc;
 137
 138	spin_lock(&wdm_device_list_lock);
 139	list_for_each_entry(desc, &wdm_device_list, device_list)
 140		if (desc->intf->minor == minor)
 141			goto found;
 142	desc = NULL;
 143found:
 144	spin_unlock(&wdm_device_list_lock);
 145
 146	return desc;
 147}
 148
 149/* --- callbacks --- */
 150static void wdm_out_callback(struct urb *urb)
 151{
 152	struct wdm_device *desc;
 153	unsigned long flags;
 154
 155	desc = urb->context;
 156	spin_lock_irqsave(&desc->iuspin, flags);
 157	desc->werr = urb->status;
 158	spin_unlock_irqrestore(&desc->iuspin, flags);
 159	kfree(desc->outbuf);
 160	desc->outbuf = NULL;
 161	clear_bit(WDM_IN_USE, &desc->flags);
 162	wake_up_all(&desc->wait);
 163}
 164
 165static void wdm_wwan_rx(struct wdm_device *desc, int length);
 166
 167static void wdm_in_callback(struct urb *urb)
 168{
 169	unsigned long flags;
 170	struct wdm_device *desc = urb->context;
 171	int status = urb->status;
 172	int length = urb->actual_length;
 173
 174	spin_lock_irqsave(&desc->iuspin, flags);
 175	clear_bit(WDM_RESPONDING, &desc->flags);
 176
 177	if (status) {
 178		switch (status) {
 179		case -ENOENT:
 180			dev_dbg(&desc->intf->dev,
 181				"nonzero urb status received: -ENOENT\n");
 182			goto skip_error;
 183		case -ECONNRESET:
 184			dev_dbg(&desc->intf->dev,
 185				"nonzero urb status received: -ECONNRESET\n");
 186			goto skip_error;
 187		case -ESHUTDOWN:
 188			dev_dbg(&desc->intf->dev,
 189				"nonzero urb status received: -ESHUTDOWN\n");
 190			goto skip_error;
 191		case -EPIPE:
 192			dev_err(&desc->intf->dev,
 193				"nonzero urb status received: -EPIPE\n");
 194			break;
 195		default:
 196			dev_err(&desc->intf->dev,
 197				"Unexpected error %d\n", status);
 198			break;
 199		}
 200	}
 201
 202	if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) {
 203		wdm_wwan_rx(desc, length);
 204		goto out;
 205	}
 206
 207	/*
 208	 * only set a new error if there is no previous error.
 209	 * Errors are only cleared during read/open
 210	 * Avoid propagating -EPIPE (stall) to userspace since it is
 211	 * better handled as an empty read
 212	 */
 213	if (desc->rerr == 0 && status != -EPIPE)
 214		desc->rerr = status;
 215
 216	if (length == 0) {
 217		dev_dbg(&desc->intf->dev, "received ZLP\n");
 218		goto skip_zlp;
 219	}
 220
 221	if (length + desc->length > desc->wMaxCommand) {
 222		/* The buffer would overflow */
 223		set_bit(WDM_OVERFLOW, &desc->flags);
 224	} else {
 225		/* we may already be in overflow */
 226		if (!test_bit(WDM_OVERFLOW, &desc->flags)) {
 227			memmove(desc->ubuf + desc->length, desc->inbuf, length);
 228			smp_wmb(); /* against wdm_read() */
 229			WRITE_ONCE(desc->length, desc->length + length);
 230		}
 231	}
 232skip_error:
 233
 234	if (desc->rerr) {
 235		/*
 236		 * If there was a ZLP or an error, userspace may decide to not
 237		 * read any data after poll'ing.
 238		 * We should respond to further attempts from the device to send
 239		 * data, so that we can get unstuck.
 240		 */
 241skip_zlp:
 242		schedule_work(&desc->service_outs_intr);
 243	} else {
 244		set_bit(WDM_READ, &desc->flags);
 245		wake_up(&desc->wait);
 246	}
 247out:
 248	spin_unlock_irqrestore(&desc->iuspin, flags);
 249}
 250
 251static void wdm_int_callback(struct urb *urb)
 252{
 253	unsigned long flags;
 254	int rv = 0;
 255	int responding;
 256	int status = urb->status;
 257	struct wdm_device *desc;
 258	struct usb_cdc_notification *dr;
 259
 260	desc = urb->context;
 261	dr = (struct usb_cdc_notification *)desc->sbuf;
 262
 263	if (status) {
 264		switch (status) {
 265		case -ESHUTDOWN:
 266		case -ENOENT:
 267		case -ECONNRESET:
 268			return; /* unplug */
 269		case -EPIPE:
 270			set_bit(WDM_INT_STALL, &desc->flags);
 271			dev_err(&desc->intf->dev, "Stall on int endpoint\n");
 272			goto sw; /* halt is cleared in work */
 273		default:
 274			dev_err_ratelimited(&desc->intf->dev,
 275				"nonzero urb status received: %d\n", status);
 276			break;
 277		}
 278	}
 279
 280	if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
 281		dev_err_ratelimited(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
 282			urb->actual_length);
 283		goto exit;
 284	}
 285
 286	switch (dr->bNotificationType) {
 287	case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
 288		dev_dbg(&desc->intf->dev,
 289			"NOTIFY_RESPONSE_AVAILABLE received: index %d len %d\n",
 290			le16_to_cpu(dr->wIndex), le16_to_cpu(dr->wLength));
 291		break;
 292
 293	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 294
 295		dev_dbg(&desc->intf->dev,
 296			"NOTIFY_NETWORK_CONNECTION %s network\n",
 297			dr->wValue ? "connected to" : "disconnected from");
 298		goto exit;
 299	case USB_CDC_NOTIFY_SPEED_CHANGE:
 300		dev_dbg(&desc->intf->dev, "SPEED_CHANGE received (len %u)\n",
 301			urb->actual_length);
 302		goto exit;
 303	default:
 304		clear_bit(WDM_POLL_RUNNING, &desc->flags);
 305		dev_err(&desc->intf->dev,
 306			"unknown notification %d received: index %d len %d\n",
 307			dr->bNotificationType,
 308			le16_to_cpu(dr->wIndex),
 309			le16_to_cpu(dr->wLength));
 310		goto exit;
 311	}
 312
 313	spin_lock_irqsave(&desc->iuspin, flags);
 314	responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
 315	if (!desc->resp_count++ && !responding
 316		&& !test_bit(WDM_DISCONNECTING, &desc->flags)
 317		&& !test_bit(WDM_SUSPENDING, &desc->flags)) {
 318		rv = usb_submit_urb(desc->response, GFP_ATOMIC);
 319		dev_dbg(&desc->intf->dev, "submit response URB %d\n", rv);
 320	}
 321	spin_unlock_irqrestore(&desc->iuspin, flags);
 322	if (rv < 0) {
 323		clear_bit(WDM_RESPONDING, &desc->flags);
 324		if (rv == -EPERM)
 325			return;
 326		if (rv == -ENOMEM) {
 327sw:
 328			rv = schedule_work(&desc->rxwork);
 329			if (rv)
 330				dev_err(&desc->intf->dev,
 331					"Cannot schedule work\n");
 332		}
 333	}
 334exit:
 335	rv = usb_submit_urb(urb, GFP_ATOMIC);
 336	if (rv)
 337		dev_err(&desc->intf->dev,
 338			"%s - usb_submit_urb failed with result %d\n",
 339			__func__, rv);
 340
 341}
 342
 343static void poison_urbs(struct wdm_device *desc)
 344{
 345	/* the order here is essential */
 346	usb_poison_urb(desc->command);
 347	usb_poison_urb(desc->validity);
 348	usb_poison_urb(desc->response);
 349}
 350
 351static void unpoison_urbs(struct wdm_device *desc)
 352{
 353	/*
 354	 *  the order here is not essential
 355	 *  it is symmetrical just to be nice
 356	 */
 357	usb_unpoison_urb(desc->response);
 358	usb_unpoison_urb(desc->validity);
 359	usb_unpoison_urb(desc->command);
 360}
 361
 362static void free_urbs(struct wdm_device *desc)
 363{
 364	usb_free_urb(desc->validity);
 365	usb_free_urb(desc->response);
 366	usb_free_urb(desc->command);
 367}
 368
 369static void cleanup(struct wdm_device *desc)
 370{
 371	kfree(desc->sbuf);
 372	kfree(desc->inbuf);
 373	kfree(desc->orq);
 374	kfree(desc->irq);
 375	kfree(desc->ubuf);
 376	free_urbs(desc);
 377	kfree(desc);
 378}
 379
 380static ssize_t wdm_write
 381(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
 382{
 383	u8 *buf;
 384	int rv = -EMSGSIZE, r, we;
 385	struct wdm_device *desc = file->private_data;
 386	struct usb_ctrlrequest *req;
 387
 388	if (count > desc->wMaxCommand)
 389		count = desc->wMaxCommand;
 390
 391	spin_lock_irq(&desc->iuspin);
 392	we = desc->werr;
 393	desc->werr = 0;
 394	spin_unlock_irq(&desc->iuspin);
 395	if (we < 0)
 396		return usb_translate_errors(we);
 397
 398	buf = memdup_user(buffer, count);
 399	if (IS_ERR(buf))
 400		return PTR_ERR(buf);
 401
 402	/* concurrent writes and disconnect */
 403	r = mutex_lock_interruptible(&desc->wlock);
 404	rv = -ERESTARTSYS;
 405	if (r)
 406		goto out_free_mem;
 407
 408	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 409		rv = -ENODEV;
 410		goto out_free_mem_lock;
 411	}
 412
 413	r = usb_autopm_get_interface(desc->intf);
 414	if (r < 0) {
 415		rv = usb_translate_errors(r);
 416		goto out_free_mem_lock;
 417	}
 418
 419	if (!(file->f_flags & O_NONBLOCK))
 420		r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
 421								&desc->flags));
 422	else
 423		if (test_bit(WDM_IN_USE, &desc->flags))
 424			r = -EAGAIN;
 425
 426	if (test_bit(WDM_RESETTING, &desc->flags))
 427		r = -EIO;
 428
 429	if (test_bit(WDM_DISCONNECTING, &desc->flags))
 430		r = -ENODEV;
 431
 432	if (r < 0) {
 433		rv = r;
 434		goto out_free_mem_pm;
 435	}
 436
 437	req = desc->orq;
 438	usb_fill_control_urb(
 439		desc->command,
 440		interface_to_usbdev(desc->intf),
 441		/* using common endpoint 0 */
 442		usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
 443		(unsigned char *)req,
 444		buf,
 445		count,
 446		wdm_out_callback,
 447		desc
 448	);
 449
 450	req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
 451			     USB_RECIP_INTERFACE);
 452	req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 453	req->wValue = 0;
 454	req->wIndex = desc->inum; /* already converted */
 455	req->wLength = cpu_to_le16(count);
 456	set_bit(WDM_IN_USE, &desc->flags);
 457	desc->outbuf = buf;
 458
 459	rv = usb_submit_urb(desc->command, GFP_KERNEL);
 460	if (rv < 0) {
 461		desc->outbuf = NULL;
 462		clear_bit(WDM_IN_USE, &desc->flags);
 463		wake_up_all(&desc->wait); /* for wdm_wait_for_response() */
 464		dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
 465		rv = usb_translate_errors(rv);
 466		goto out_free_mem_pm;
 467	} else {
 468		dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d\n",
 469			le16_to_cpu(req->wIndex));
 470	}
 471
 472	usb_autopm_put_interface(desc->intf);
 473	mutex_unlock(&desc->wlock);
 474	return count;
 475
 476out_free_mem_pm:
 477	usb_autopm_put_interface(desc->intf);
 478out_free_mem_lock:
 479	mutex_unlock(&desc->wlock);
 480out_free_mem:
 481	kfree(buf);
 482	return rv;
 483}
 484
 485/*
 486 * Submit the read urb if resp_count is non-zero.
 487 *
 488 * Called with desc->iuspin locked
 489 */
 490static int service_outstanding_interrupt(struct wdm_device *desc)
 491{
 492	int rv = 0;
 493
 494	/* submit read urb only if the device is waiting for it */
 495	if (!desc->resp_count || !--desc->resp_count)
 496		goto out;
 497
 498	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 499		rv = -ENODEV;
 500		goto out;
 501	}
 502	if (test_bit(WDM_RESETTING, &desc->flags)) {
 503		rv = -EIO;
 504		goto out;
 505	}
 506
 507	set_bit(WDM_RESPONDING, &desc->flags);
 508	spin_unlock_irq(&desc->iuspin);
 509	rv = usb_submit_urb(desc->response, GFP_KERNEL);
 510	spin_lock_irq(&desc->iuspin);
 511	if (rv) {
 512		if (!test_bit(WDM_DISCONNECTING, &desc->flags))
 513			dev_err(&desc->intf->dev,
 514				"usb_submit_urb failed with result %d\n", rv);
 515
 516		/* make sure the next notification trigger a submit */
 517		clear_bit(WDM_RESPONDING, &desc->flags);
 518		desc->resp_count = 0;
 519	}
 520out:
 521	return rv;
 522}
 523
 524static ssize_t wdm_read
 525(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
 526{
 527	int rv, cntr;
 528	int i = 0;
 529	struct wdm_device *desc = file->private_data;
 530
 531
 532	rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
 533	if (rv < 0)
 534		return -ERESTARTSYS;
 535
 536	cntr = READ_ONCE(desc->length);
 537	smp_rmb(); /* against wdm_in_callback() */
 538	if (cntr == 0) {
 539		desc->read = 0;
 540retry:
 541		if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 542			rv = -ENODEV;
 543			goto err;
 544		}
 545		if (test_bit(WDM_OVERFLOW, &desc->flags)) {
 546			clear_bit(WDM_OVERFLOW, &desc->flags);
 547			rv = -ENOBUFS;
 548			goto err;
 549		}
 550		i++;
 551		if (file->f_flags & O_NONBLOCK) {
 552			if (!test_bit(WDM_READ, &desc->flags)) {
 553				rv = -EAGAIN;
 554				goto err;
 555			}
 556			rv = 0;
 557		} else {
 558			rv = wait_event_interruptible(desc->wait,
 559				test_bit(WDM_READ, &desc->flags));
 560		}
 561
 562		/* may have happened while we slept */
 563		if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 564			rv = -ENODEV;
 565			goto err;
 566		}
 567		if (test_bit(WDM_RESETTING, &desc->flags)) {
 568			rv = -EIO;
 569			goto err;
 570		}
 571		usb_mark_last_busy(interface_to_usbdev(desc->intf));
 572		if (rv < 0) {
 573			rv = -ERESTARTSYS;
 574			goto err;
 575		}
 576
 577		spin_lock_irq(&desc->iuspin);
 578
 579		if (desc->rerr) { /* read completed, error happened */
 580			rv = usb_translate_errors(desc->rerr);
 581			desc->rerr = 0;
 582			spin_unlock_irq(&desc->iuspin);
 583			goto err;
 584		}
 585		/*
 586		 * recheck whether we've lost the race
 587		 * against the completion handler
 588		 */
 589		if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
 590			spin_unlock_irq(&desc->iuspin);
 591			goto retry;
 592		}
 593
 594		cntr = desc->length;
 595		spin_unlock_irq(&desc->iuspin);
 596	}
 597
 598	if (cntr > count)
 599		cntr = count;
 600	rv = copy_to_user(buffer, desc->ubuf, cntr);
 601	if (rv > 0) {
 602		rv = -EFAULT;
 603		goto err;
 604	}
 605
 606	spin_lock_irq(&desc->iuspin);
 607
 608	for (i = 0; i < desc->length - cntr; i++)
 609		desc->ubuf[i] = desc->ubuf[i + cntr];
 610
 611	desc->length -= cntr;
 612	/* in case we had outstanding data */
 613	if (!desc->length) {
 614		clear_bit(WDM_READ, &desc->flags);
 615		service_outstanding_interrupt(desc);
 616	}
 617	spin_unlock_irq(&desc->iuspin);
 618	rv = cntr;
 619
 620err:
 621	mutex_unlock(&desc->rlock);
 622	return rv;
 623}
 624
 625static int wdm_wait_for_response(struct file *file, long timeout)
 626{
 627	struct wdm_device *desc = file->private_data;
 628	long rv; /* Use long here because (int) MAX_SCHEDULE_TIMEOUT < 0. */
 629
 630	/*
 631	 * Needs both flags. We cannot do with one because resetting it would
 632	 * cause a race with write() yet we need to signal a disconnect.
 633	 */
 634	rv = wait_event_interruptible_timeout(desc->wait,
 635			      !test_bit(WDM_IN_USE, &desc->flags) ||
 636			      test_bit(WDM_DISCONNECTING, &desc->flags),
 637			      timeout);
 638
 639	/*
 640	 * To report the correct error. This is best effort.
 641	 * We are inevitably racing with the hardware.
 642	 */
 643	if (test_bit(WDM_DISCONNECTING, &desc->flags))
 644		return -ENODEV;
 645	if (!rv)
 646		return -EIO;
 647	if (rv < 0)
 648		return -EINTR;
 649
 650	spin_lock_irq(&desc->iuspin);
 651	rv = desc->werr;
 652	desc->werr = 0;
 653	spin_unlock_irq(&desc->iuspin);
 654
 655	return usb_translate_errors(rv);
 656
 657}
 658
 659/*
 660 * You need to send a signal when you react to malicious or defective hardware.
 661 * Also, don't abort when fsync() returned -EINVAL, for older kernels which do
 662 * not implement wdm_flush() will return -EINVAL.
 663 */
 664static int wdm_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 665{
 666	return wdm_wait_for_response(file, MAX_SCHEDULE_TIMEOUT);
 667}
 668
 669/*
 670 * Same with wdm_fsync(), except it uses finite timeout in order to react to
 671 * malicious or defective hardware which ceased communication after close() was
 672 * implicitly called due to process termination.
 673 */
 674static int wdm_flush(struct file *file, fl_owner_t id)
 675{
 676	return wdm_wait_for_response(file, WDM_FLUSH_TIMEOUT);
 677}
 678
 679static __poll_t wdm_poll(struct file *file, struct poll_table_struct *wait)
 680{
 681	struct wdm_device *desc = file->private_data;
 682	unsigned long flags;
 683	__poll_t mask = 0;
 684
 685	spin_lock_irqsave(&desc->iuspin, flags);
 686	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 687		mask = EPOLLHUP | EPOLLERR;
 688		spin_unlock_irqrestore(&desc->iuspin, flags);
 689		goto desc_out;
 690	}
 691	if (test_bit(WDM_READ, &desc->flags))
 692		mask = EPOLLIN | EPOLLRDNORM;
 693	if (desc->rerr || desc->werr)
 694		mask |= EPOLLERR;
 695	if (!test_bit(WDM_IN_USE, &desc->flags))
 696		mask |= EPOLLOUT | EPOLLWRNORM;
 697	spin_unlock_irqrestore(&desc->iuspin, flags);
 698
 699	poll_wait(file, &desc->wait, wait);
 700
 701desc_out:
 702	return mask;
 703}
 704
 705static int wdm_open(struct inode *inode, struct file *file)
 706{
 707	int minor = iminor(inode);
 708	int rv = -ENODEV;
 709	struct usb_interface *intf;
 710	struct wdm_device *desc;
 711
 712	mutex_lock(&wdm_mutex);
 713	desc = wdm_find_device_by_minor(minor);
 714	if (!desc)
 715		goto out;
 716
 717	intf = desc->intf;
 718	if (test_bit(WDM_DISCONNECTING, &desc->flags))
 719		goto out;
 720	file->private_data = desc;
 721
 722	if (test_bit(WDM_WWAN_IN_USE, &desc->flags)) {
 723		rv = -EBUSY;
 724		goto out;
 725	}
 726	smp_rmb(); /* ordered against wdm_wwan_port_stop() */
 727	rv = usb_autopm_get_interface(desc->intf);
 728	if (rv < 0) {
 729		dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
 730		goto out;
 731	}
 732
 733	/* using write lock to protect desc->count */
 734	mutex_lock(&desc->wlock);
 735	if (!desc->count++) {
 736		desc->werr = 0;
 737		desc->rerr = 0;
 738		rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 739		if (rv < 0) {
 740			desc->count--;
 741			dev_err(&desc->intf->dev,
 742				"Error submitting int urb - %d\n", rv);
 743			rv = usb_translate_errors(rv);
 744		}
 745	} else {
 746		rv = 0;
 747	}
 748	mutex_unlock(&desc->wlock);
 749	if (desc->count == 1)
 750		desc->manage_power(intf, 1);
 751	usb_autopm_put_interface(desc->intf);
 752out:
 753	mutex_unlock(&wdm_mutex);
 754	return rv;
 755}
 756
 757static int wdm_release(struct inode *inode, struct file *file)
 758{
 759	struct wdm_device *desc = file->private_data;
 760
 761	mutex_lock(&wdm_mutex);
 762
 763	/* using write lock to protect desc->count */
 764	mutex_lock(&desc->wlock);
 765	desc->count--;
 766	mutex_unlock(&desc->wlock);
 767
 768	if (!desc->count) {
 769		if (!test_bit(WDM_DISCONNECTING, &desc->flags)) {
 770			dev_dbg(&desc->intf->dev, "wdm_release: cleanup\n");
 771			poison_urbs(desc);
 772			spin_lock_irq(&desc->iuspin);
 773			desc->resp_count = 0;
 774			clear_bit(WDM_RESPONDING, &desc->flags);
 775			spin_unlock_irq(&desc->iuspin);
 776			desc->manage_power(desc->intf, 0);
 777			unpoison_urbs(desc);
 778		} else {
 779			/* must avoid dev_printk here as desc->intf is invalid */
 780			pr_debug(KBUILD_MODNAME " %s: device gone - cleaning up\n", __func__);
 781			cleanup(desc);
 782		}
 783	}
 784	mutex_unlock(&wdm_mutex);
 785	return 0;
 786}
 787
 788static long wdm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 789{
 790	struct wdm_device *desc = file->private_data;
 791	int rv = 0;
 792
 793	switch (cmd) {
 794	case IOCTL_WDM_MAX_COMMAND:
 795		if (copy_to_user((void __user *)arg, &desc->wMaxCommand, sizeof(desc->wMaxCommand)))
 796			rv = -EFAULT;
 797		break;
 798	default:
 799		rv = -ENOTTY;
 800	}
 801	return rv;
 802}
 803
 804static const struct file_operations wdm_fops = {
 805	.owner =	THIS_MODULE,
 806	.read =		wdm_read,
 807	.write =	wdm_write,
 808	.fsync =	wdm_fsync,
 809	.open =		wdm_open,
 810	.flush =	wdm_flush,
 811	.release =	wdm_release,
 812	.poll =		wdm_poll,
 813	.unlocked_ioctl = wdm_ioctl,
 814	.compat_ioctl = compat_ptr_ioctl,
 815	.llseek =	noop_llseek,
 816};
 817
 818static struct usb_class_driver wdm_class = {
 819	.name =		"cdc-wdm%d",
 820	.fops =		&wdm_fops,
 821	.minor_base =	WDM_MINOR_BASE,
 822};
 823
 824/* --- WWAN framework integration --- */
 825#ifdef CONFIG_WWAN
 826static int wdm_wwan_port_start(struct wwan_port *port)
 827{
 828	struct wdm_device *desc = wwan_port_get_drvdata(port);
 829	int rv;
 830
 831	/* The interface is both exposed via the WWAN framework and as a
 832	 * legacy usbmisc chardev. If chardev is already open, just fail
 833	 * to prevent concurrent usage. Otherwise, switch to WWAN mode.
 834	 */
 835	mutex_lock(&wdm_mutex);
 836	if (desc->count) {
 837		mutex_unlock(&wdm_mutex);
 838		return -EBUSY;
 839	}
 840	set_bit(WDM_WWAN_IN_USE, &desc->flags);
 841	mutex_unlock(&wdm_mutex);
 842
 843	desc->manage_power(desc->intf, 1);
 844
 845	/* tx is allowed */
 846	wwan_port_txon(port);
 847
 848	/* Start getting events */
 849	rv = usb_submit_urb(desc->validity, GFP_KERNEL);
 850	if (rv < 0) {
 851		wwan_port_txoff(port);
 852		desc->manage_power(desc->intf, 0);
 853		/* this must be last lest we race with chardev open */
 854		clear_bit(WDM_WWAN_IN_USE, &desc->flags);
 855	}
 856
 857	return rv;
 858}
 859
 860static void wdm_wwan_port_stop(struct wwan_port *port)
 861{
 862	struct wdm_device *desc = wwan_port_get_drvdata(port);
 863
 864	/* Stop all transfers and disable WWAN mode */
 865	poison_urbs(desc);
 866	desc->manage_power(desc->intf, 0);
 867	clear_bit(WDM_READ, &desc->flags);
 868	unpoison_urbs(desc);
 869	smp_wmb(); /* ordered against wdm_open() */
 870	/* this must be last lest we open a poisoned device */
 871	clear_bit(WDM_WWAN_IN_USE, &desc->flags);
 872}
 873
 874static void wdm_wwan_port_tx_complete(struct urb *urb)
 875{
 876	struct sk_buff *skb = urb->context;
 877	struct wdm_device *desc = skb_shinfo(skb)->destructor_arg;
 878
 879	usb_autopm_put_interface_async(desc->intf);
 880	wwan_port_txon(desc->wwanp);
 881	kfree_skb(skb);
 882}
 883
 884static int wdm_wwan_port_tx(struct wwan_port *port, struct sk_buff *skb)
 885{
 886	struct wdm_device *desc = wwan_port_get_drvdata(port);
 887	struct usb_interface *intf = desc->intf;
 888	struct usb_ctrlrequest *req = desc->orq;
 889	int rv;
 890
 891	rv = usb_autopm_get_interface(intf);
 892	if (rv)
 893		return rv;
 894
 895	usb_fill_control_urb(
 896		desc->command,
 897		interface_to_usbdev(intf),
 898		usb_sndctrlpipe(interface_to_usbdev(intf), 0),
 899		(unsigned char *)req,
 900		skb->data,
 901		skb->len,
 902		wdm_wwan_port_tx_complete,
 903		skb
 904	);
 905
 906	req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
 907	req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
 908	req->wValue = 0;
 909	req->wIndex = desc->inum; /* already converted */
 910	req->wLength = cpu_to_le16(skb->len);
 911
 912	skb_shinfo(skb)->destructor_arg = desc;
 913
 914	rv = usb_submit_urb(desc->command, GFP_KERNEL);
 915	if (rv)
 916		usb_autopm_put_interface(intf);
 917	else /* One transfer at a time, stop TX until URB completion */
 918		wwan_port_txoff(port);
 919
 920	return rv;
 921}
 922
 923static const struct wwan_port_ops wdm_wwan_port_ops = {
 924	.start = wdm_wwan_port_start,
 925	.stop = wdm_wwan_port_stop,
 926	.tx = wdm_wwan_port_tx,
 927};
 928
 929static void wdm_wwan_init(struct wdm_device *desc)
 930{
 931	struct usb_interface *intf = desc->intf;
 932	struct wwan_port *port;
 933
 934	/* Only register to WWAN core if protocol/type is known */
 935	if (desc->wwanp_type == WWAN_PORT_UNKNOWN) {
 936		dev_info(&intf->dev, "Unknown control protocol\n");
 937		return;
 938	}
 939
 940	port = wwan_create_port(&intf->dev, desc->wwanp_type, &wdm_wwan_port_ops,
 941				NULL, desc);
 942	if (IS_ERR(port)) {
 943		dev_err(&intf->dev, "%s: Unable to create WWAN port\n",
 944			dev_name(intf->usb_dev));
 945		return;
 946	}
 947
 948	desc->wwanp = port;
 949}
 950
 951static void wdm_wwan_deinit(struct wdm_device *desc)
 952{
 953	if (!desc->wwanp)
 954		return;
 955
 956	wwan_remove_port(desc->wwanp);
 957	desc->wwanp = NULL;
 958}
 959
 960static void wdm_wwan_rx(struct wdm_device *desc, int length)
 961{
 962	struct wwan_port *port = desc->wwanp;
 963	struct sk_buff *skb;
 964
 965	/* Forward data to WWAN port */
 966	skb = alloc_skb(length, GFP_ATOMIC);
 967	if (!skb)
 968		return;
 969
 970	skb_put_data(skb, desc->inbuf, length);
 971	wwan_port_rx(port, skb);
 972
 973	/* inbuf has been copied, it is safe to check for outstanding data */
 974	schedule_work(&desc->service_outs_intr);
 975}
 976#else /* CONFIG_WWAN */
 977static void wdm_wwan_init(struct wdm_device *desc) {}
 978static void wdm_wwan_deinit(struct wdm_device *desc) {}
 979static void wdm_wwan_rx(struct wdm_device *desc, int length) {}
 980#endif /* CONFIG_WWAN */
 981
 982/* --- error handling --- */
 983static void wdm_rxwork(struct work_struct *work)
 984{
 985	struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
 986	unsigned long flags;
 987	int rv = 0;
 988	int responding;
 989
 990	spin_lock_irqsave(&desc->iuspin, flags);
 991	if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
 992		spin_unlock_irqrestore(&desc->iuspin, flags);
 993	} else {
 994		responding = test_and_set_bit(WDM_RESPONDING, &desc->flags);
 995		spin_unlock_irqrestore(&desc->iuspin, flags);
 996		if (!responding)
 997			rv = usb_submit_urb(desc->response, GFP_KERNEL);
 998		if (rv < 0 && rv != -EPERM) {
 999			spin_lock_irqsave(&desc->iuspin, flags);
1000			clear_bit(WDM_RESPONDING, &desc->flags);
1001			if (!test_bit(WDM_DISCONNECTING, &desc->flags))
1002				schedule_work(&desc->rxwork);
1003			spin_unlock_irqrestore(&desc->iuspin, flags);
1004		}
1005	}
1006}
1007
1008static void service_interrupt_work(struct work_struct *work)
1009{
1010	struct wdm_device *desc;
1011
1012	desc = container_of(work, struct wdm_device, service_outs_intr);
1013
1014	spin_lock_irq(&desc->iuspin);
1015	service_outstanding_interrupt(desc);
1016	if (!desc->resp_count && (desc->length || desc->rerr)) {
1017		set_bit(WDM_READ, &desc->flags);
1018		wake_up(&desc->wait);
1019	}
1020	spin_unlock_irq(&desc->iuspin);
1021}
1022
1023/* --- hotplug --- */
1024
1025static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descriptor *ep,
1026		      u16 bufsize, enum wwan_port_type type,
1027		      int (*manage_power)(struct usb_interface *, int))
1028{
1029	int rv = -ENOMEM;
1030	struct wdm_device *desc;
1031
1032	desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
1033	if (!desc)
1034		goto out;
1035	INIT_LIST_HEAD(&desc->device_list);
1036	mutex_init(&desc->rlock);
1037	mutex_init(&desc->wlock);
1038	spin_lock_init(&desc->iuspin);
1039	init_waitqueue_head(&desc->wait);
1040	desc->wMaxCommand = bufsize;
1041	/* this will be expanded and needed in hardware endianness */
1042	desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
1043	desc->intf = intf;
1044	desc->wwanp_type = type;
1045	INIT_WORK(&desc->rxwork, wdm_rxwork);
1046	INIT_WORK(&desc->service_outs_intr, service_interrupt_work);
1047
1048	if (!usb_endpoint_is_int_in(ep)) {
1049		rv = -EINVAL;
1050		goto err;
1051	}
1052
1053	desc->wMaxPacketSize = usb_endpoint_maxp(ep);
1054
1055	desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
1056	if (!desc->orq)
1057		goto err;
1058	desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
1059	if (!desc->irq)
1060		goto err;
1061
1062	desc->validity = usb_alloc_urb(0, GFP_KERNEL);
1063	if (!desc->validity)
1064		goto err;
1065
1066	desc->response = usb_alloc_urb(0, GFP_KERNEL);
1067	if (!desc->response)
1068		goto err;
1069
1070	desc->command = usb_alloc_urb(0, GFP_KERNEL);
1071	if (!desc->command)
1072		goto err;
1073
1074	desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
1075	if (!desc->ubuf)
1076		goto err;
1077
1078	desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
1079	if (!desc->sbuf)
1080		goto err;
1081
1082	desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
1083	if (!desc->inbuf)
1084		goto err;
1085
1086	usb_fill_int_urb(
1087		desc->validity,
1088		interface_to_usbdev(intf),
1089		usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
1090		desc->sbuf,
1091		desc->wMaxPacketSize,
1092		wdm_int_callback,
1093		desc,
1094		ep->bInterval
1095	);
1096
1097	desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
1098	desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
1099	desc->irq->wValue = 0;
1100	desc->irq->wIndex = desc->inum; /* already converted */
1101	desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
1102
1103	usb_fill_control_urb(
1104		desc->response,
1105		interface_to_usbdev(intf),
1106		/* using common endpoint 0 */
1107		usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
1108		(unsigned char *)desc->irq,
1109		desc->inbuf,
1110		desc->wMaxCommand,
1111		wdm_in_callback,
1112		desc
1113	);
1114
1115	desc->manage_power = manage_power;
1116
1117	spin_lock(&wdm_device_list_lock);
1118	list_add(&desc->device_list, &wdm_device_list);
1119	spin_unlock(&wdm_device_list_lock);
1120
1121	rv = usb_register_dev(intf, &wdm_class);
1122	if (rv < 0)
1123		goto err;
1124	else
1125		dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
1126
1127	wdm_wwan_init(desc);
1128
1129out:
1130	return rv;
1131err:
1132	spin_lock(&wdm_device_list_lock);
1133	list_del(&desc->device_list);
1134	spin_unlock(&wdm_device_list_lock);
1135	cleanup(desc);
1136	return rv;
1137}
1138
1139static int wdm_manage_power(struct usb_interface *intf, int on)
1140{
1141	/* need autopm_get/put here to ensure the usbcore sees the new value */
1142	int rv = usb_autopm_get_interface(intf);
1143
1144	intf->needs_remote_wakeup = on;
1145	if (!rv)
1146		usb_autopm_put_interface(intf);
1147	return 0;
1148}
1149
1150static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
1151{
1152	int rv = -EINVAL;
1153	struct usb_host_interface *iface;
1154	struct usb_endpoint_descriptor *ep;
1155	struct usb_cdc_parsed_header hdr;
1156	u8 *buffer = intf->altsetting->extra;
1157	int buflen = intf->altsetting->extralen;
1158	u16 maxcom = WDM_DEFAULT_BUFSIZE;
1159
1160	if (!buffer)
1161		goto err;
1162
1163	cdc_parse_cdc_header(&hdr, intf, buffer, buflen);
1164
1165	if (hdr.usb_cdc_dmm_desc)
1166		maxcom = le16_to_cpu(hdr.usb_cdc_dmm_desc->wMaxCommand);
1167
1168	iface = intf->cur_altsetting;
1169	if (iface->desc.bNumEndpoints != 1)
1170		goto err;
1171	ep = &iface->endpoint[0].desc;
1172
1173	rv = wdm_create(intf, ep, maxcom, WWAN_PORT_UNKNOWN, &wdm_manage_power);
1174
1175err:
1176	return rv;
1177}
1178
1179/**
1180 * usb_cdc_wdm_register - register a WDM subdriver
1181 * @intf: usb interface the subdriver will associate with
1182 * @ep: interrupt endpoint to monitor for notifications
1183 * @bufsize: maximum message size to support for read/write
1184 * @type: Type/protocol of the transported data (MBIM, QMI...)
1185 * @manage_power: call-back invoked during open and release to
1186 *                manage the device's power
1187 * Create WDM usb class character device and associate it with intf
1188 * without binding, allowing another driver to manage the interface.
1189 *
1190 * The subdriver will manage the given interrupt endpoint exclusively
1191 * and will issue control requests referring to the given intf. It
1192 * will otherwise avoid interferring, and in particular not do
1193 * usb_set_intfdata/usb_get_intfdata on intf.
1194 *
1195 * The return value is a pointer to the subdriver's struct usb_driver.
1196 * The registering driver is responsible for calling this subdriver's
1197 * disconnect, suspend, resume, pre_reset and post_reset methods from
1198 * its own.
1199 */
1200struct usb_driver *usb_cdc_wdm_register(struct usb_interface *intf,
1201					struct usb_endpoint_descriptor *ep,
1202					int bufsize, enum wwan_port_type type,
1203					int (*manage_power)(struct usb_interface *, int))
1204{
1205	int rv;
1206
1207	rv = wdm_create(intf, ep, bufsize, type, manage_power);
1208	if (rv < 0)
1209		goto err;
1210
1211	return &wdm_driver;
1212err:
1213	return ERR_PTR(rv);
1214}
1215EXPORT_SYMBOL(usb_cdc_wdm_register);
1216
1217static void wdm_disconnect(struct usb_interface *intf)
1218{
1219	struct wdm_device *desc;
1220	unsigned long flags;
1221
1222	usb_deregister_dev(intf, &wdm_class);
1223	desc = wdm_find_device(intf);
1224	mutex_lock(&wdm_mutex);
1225
1226	wdm_wwan_deinit(desc);
1227
1228	/* the spinlock makes sure no new urbs are generated in the callbacks */
1229	spin_lock_irqsave(&desc->iuspin, flags);
1230	set_bit(WDM_DISCONNECTING, &desc->flags);
1231	set_bit(WDM_READ, &desc->flags);
1232	spin_unlock_irqrestore(&desc->iuspin, flags);
1233	wake_up_all(&desc->wait);
1234	mutex_lock(&desc->rlock);
1235	mutex_lock(&desc->wlock);
1236	poison_urbs(desc);
1237	cancel_work_sync(&desc->rxwork);
1238	cancel_work_sync(&desc->service_outs_intr);
1239	mutex_unlock(&desc->wlock);
1240	mutex_unlock(&desc->rlock);
1241
1242	/* the desc->intf pointer used as list key is now invalid */
1243	spin_lock(&wdm_device_list_lock);
1244	list_del(&desc->device_list);
1245	spin_unlock(&wdm_device_list_lock);
1246
1247	if (!desc->count)
1248		cleanup(desc);
1249	else
1250		dev_dbg(&intf->dev, "%d open files - postponing cleanup\n", desc->count);
1251	mutex_unlock(&wdm_mutex);
1252}
1253
1254#ifdef CONFIG_PM
1255static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
1256{
1257	struct wdm_device *desc = wdm_find_device(intf);
1258	int rv = 0;
1259
1260	dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
1261
1262	/* if this is an autosuspend the caller does the locking */
1263	if (!PMSG_IS_AUTO(message)) {
1264		mutex_lock(&desc->rlock);
1265		mutex_lock(&desc->wlock);
1266	}
1267	spin_lock_irq(&desc->iuspin);
1268
1269	if (PMSG_IS_AUTO(message) &&
1270			(test_bit(WDM_IN_USE, &desc->flags)
1271			|| test_bit(WDM_RESPONDING, &desc->flags))) {
1272		spin_unlock_irq(&desc->iuspin);
1273		rv = -EBUSY;
1274	} else {
1275
1276		set_bit(WDM_SUSPENDING, &desc->flags);
1277		spin_unlock_irq(&desc->iuspin);
1278		/* callback submits work - order is essential */
1279		poison_urbs(desc);
1280		cancel_work_sync(&desc->rxwork);
1281		cancel_work_sync(&desc->service_outs_intr);
1282		unpoison_urbs(desc);
1283	}
1284	if (!PMSG_IS_AUTO(message)) {
1285		mutex_unlock(&desc->wlock);
1286		mutex_unlock(&desc->rlock);
1287	}
1288
1289	return rv;
1290}
1291#endif
1292
1293static int recover_from_urb_loss(struct wdm_device *desc)
1294{
1295	int rv = 0;
1296
1297	if (desc->count) {
1298		rv = usb_submit_urb(desc->validity, GFP_NOIO);
1299		if (rv < 0)
1300			dev_err(&desc->intf->dev,
1301				"Error resume submitting int urb - %d\n", rv);
1302	}
1303	return rv;
1304}
1305
1306#ifdef CONFIG_PM
1307static int wdm_resume(struct usb_interface *intf)
1308{
1309	struct wdm_device *desc = wdm_find_device(intf);
1310	int rv;
1311
1312	dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
1313
1314	clear_bit(WDM_SUSPENDING, &desc->flags);
1315	rv = recover_from_urb_loss(desc);
1316
1317	return rv;
1318}
1319#endif
1320
1321static int wdm_pre_reset(struct usb_interface *intf)
1322{
1323	struct wdm_device *desc = wdm_find_device(intf);
1324
1325	/*
1326	 * we notify everybody using poll of
1327	 * an exceptional situation
1328	 * must be done before recovery lest a spontaneous
1329	 * message from the device is lost
1330	 */
1331	spin_lock_irq(&desc->iuspin);
1332	set_bit(WDM_RESETTING, &desc->flags);	/* inform read/write */
1333	set_bit(WDM_READ, &desc->flags);	/* unblock read */
1334	clear_bit(WDM_IN_USE, &desc->flags);	/* unblock write */
1335	desc->rerr = -EINTR;
1336	spin_unlock_irq(&desc->iuspin);
1337	wake_up_all(&desc->wait);
1338	mutex_lock(&desc->rlock);
1339	mutex_lock(&desc->wlock);
1340	poison_urbs(desc);
1341	cancel_work_sync(&desc->rxwork);
1342	cancel_work_sync(&desc->service_outs_intr);
1343	return 0;
1344}
1345
1346static int wdm_post_reset(struct usb_interface *intf)
1347{
1348	struct wdm_device *desc = wdm_find_device(intf);
1349	int rv;
1350
1351	unpoison_urbs(desc);
1352	clear_bit(WDM_OVERFLOW, &desc->flags);
1353	clear_bit(WDM_RESETTING, &desc->flags);
1354	rv = recover_from_urb_loss(desc);
1355	mutex_unlock(&desc->wlock);
1356	mutex_unlock(&desc->rlock);
1357	return rv;
1358}
1359
1360static struct usb_driver wdm_driver = {
1361	.name =		"cdc_wdm",
1362	.probe =	wdm_probe,
1363	.disconnect =	wdm_disconnect,
1364#ifdef CONFIG_PM
1365	.suspend =	wdm_suspend,
1366	.resume =	wdm_resume,
1367	.reset_resume =	wdm_resume,
1368#endif
1369	.pre_reset =	wdm_pre_reset,
1370	.post_reset =	wdm_post_reset,
1371	.id_table =	wdm_ids,
1372	.supports_autosuspend = 1,
1373	.disable_hub_initiated_lpm = 1,
1374};
1375
1376module_usb_driver(wdm_driver);
1377
1378MODULE_AUTHOR(DRIVER_AUTHOR);
1379MODULE_DESCRIPTION(DRIVER_DESC);
1380MODULE_LICENSE("GPL");