cdc-wdm: Fix more races on the read path
[pandora-kernel.git] / drivers / usb / class / cdc-wdm.c
1 /*
2  * cdc-wdm.c
3  *
4  * This driver supports USB CDC WCM Device Management.
5  *
6  * Copyright (c) 2007-2009 Oliver Neukum
7  *
8  * Some code taken from cdc-acm.c
9  *
10  * Released under the GPLv2.
11  *
12  * Many thanks to Carl Nordbeck
13  */
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/uaccess.h>
20 #include <linux/bitops.h>
21 #include <linux/poll.h>
22 #include <linux/usb.h>
23 #include <linux/usb/cdc.h>
24 #include <asm/byteorder.h>
25 #include <asm/unaligned.h>
26
27 /*
28  * Version Information
29  */
30 #define DRIVER_VERSION "v0.03"
31 #define DRIVER_AUTHOR "Oliver Neukum"
32 #define DRIVER_DESC "USB Abstract Control Model driver for USB WCM Device Management"
33
34 #define HUAWEI_VENDOR_ID        0x12D1
35
36 static const struct usb_device_id wdm_ids[] = {
37         {
38                 .match_flags = USB_DEVICE_ID_MATCH_INT_CLASS |
39                                  USB_DEVICE_ID_MATCH_INT_SUBCLASS,
40                 .bInterfaceClass = USB_CLASS_COMM,
41                 .bInterfaceSubClass = USB_CDC_SUBCLASS_DMM
42         },
43         {
44                 /* 
45                  * Huawei E392, E398 and possibly other Qualcomm based modems
46                  * embed the Qualcomm QMI protocol inside CDC on CDC ECM like
47                  * control interfaces.  Userspace access to this is required
48                  * to configure the accompanying data interface
49                  */
50                 .match_flags        = USB_DEVICE_ID_MATCH_VENDOR |
51                                         USB_DEVICE_ID_MATCH_INT_INFO,
52                 .idVendor           = HUAWEI_VENDOR_ID,
53                 .bInterfaceClass    = USB_CLASS_VENDOR_SPEC,
54                 .bInterfaceSubClass = 1,
55                 .bInterfaceProtocol = 9, /* NOTE: CDC ECM control interface! */
56         },
57         { }
58 };
59
60 MODULE_DEVICE_TABLE (usb, wdm_ids);
61
62 #define WDM_MINOR_BASE  176
63
64
65 #define WDM_IN_USE              1
66 #define WDM_DISCONNECTING       2
67 #define WDM_RESULT              3
68 #define WDM_READ                4
69 #define WDM_INT_STALL           5
70 #define WDM_POLL_RUNNING        6
71 #define WDM_RESPONDING          7
72 #define WDM_SUSPENDING          8
73 #define WDM_RESETTING           9
74
75 #define WDM_MAX                 16
76
77 /* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
78 #define WDM_DEFAULT_BUFSIZE     256
79
80 static DEFINE_MUTEX(wdm_mutex);
81
82 /* --- method tables --- */
83
84 struct wdm_device {
85         u8                      *inbuf; /* buffer for response */
86         u8                      *outbuf; /* buffer for command */
87         u8                      *sbuf; /* buffer for status */
88         u8                      *ubuf; /* buffer for copy to user space */
89
90         struct urb              *command;
91         struct urb              *response;
92         struct urb              *validity;
93         struct usb_interface    *intf;
94         struct usb_ctrlrequest  *orq;
95         struct usb_ctrlrequest  *irq;
96         spinlock_t              iuspin;
97
98         unsigned long           flags;
99         u16                     bufsize;
100         u16                     wMaxCommand;
101         u16                     wMaxPacketSize;
102         __le16                  inum;
103         int                     reslength;
104         int                     length;
105         int                     read;
106         int                     count;
107         dma_addr_t              shandle;
108         dma_addr_t              ihandle;
109         struct mutex            wlock;
110         struct mutex            rlock;
111         wait_queue_head_t       wait;
112         struct work_struct      rxwork;
113         int                     werr;
114         int                     rerr;
115 };
116
117 static struct usb_driver wdm_driver;
118
119 /* --- callbacks --- */
120 static void wdm_out_callback(struct urb *urb)
121 {
122         struct wdm_device *desc;
123         desc = urb->context;
124         spin_lock(&desc->iuspin);
125         desc->werr = urb->status;
126         spin_unlock(&desc->iuspin);
127         clear_bit(WDM_IN_USE, &desc->flags);
128         kfree(desc->outbuf);
129         wake_up(&desc->wait);
130 }
131
132 static void wdm_in_callback(struct urb *urb)
133 {
134         struct wdm_device *desc = urb->context;
135         int status = urb->status;
136
137         spin_lock(&desc->iuspin);
138         clear_bit(WDM_RESPONDING, &desc->flags);
139
140         if (status) {
141                 switch (status) {
142                 case -ENOENT:
143                         dev_dbg(&desc->intf->dev,
144                                 "nonzero urb status received: -ENOENT");
145                         goto skip_error;
146                 case -ECONNRESET:
147                         dev_dbg(&desc->intf->dev,
148                                 "nonzero urb status received: -ECONNRESET");
149                         goto skip_error;
150                 case -ESHUTDOWN:
151                         dev_dbg(&desc->intf->dev,
152                                 "nonzero urb status received: -ESHUTDOWN");
153                         goto skip_error;
154                 case -EPIPE:
155                         dev_err(&desc->intf->dev,
156                                 "nonzero urb status received: -EPIPE\n");
157                         break;
158                 default:
159                         dev_err(&desc->intf->dev,
160                                 "Unexpected error %d\n", status);
161                         break;
162                 }
163         }
164
165         desc->rerr = status;
166         desc->reslength = urb->actual_length;
167         memmove(desc->ubuf + desc->length, desc->inbuf, desc->reslength);
168         desc->length += desc->reslength;
169 skip_error:
170         wake_up(&desc->wait);
171
172         set_bit(WDM_READ, &desc->flags);
173         spin_unlock(&desc->iuspin);
174 }
175
176 static void wdm_int_callback(struct urb *urb)
177 {
178         int rv = 0;
179         int status = urb->status;
180         struct wdm_device *desc;
181         struct usb_cdc_notification *dr;
182
183         desc = urb->context;
184         dr = (struct usb_cdc_notification *)desc->sbuf;
185
186         if (status) {
187                 switch (status) {
188                 case -ESHUTDOWN:
189                 case -ENOENT:
190                 case -ECONNRESET:
191                         return; /* unplug */
192                 case -EPIPE:
193                         set_bit(WDM_INT_STALL, &desc->flags);
194                         dev_err(&desc->intf->dev, "Stall on int endpoint\n");
195                         goto sw; /* halt is cleared in work */
196                 default:
197                         dev_err(&desc->intf->dev,
198                                 "nonzero urb status received: %d\n", status);
199                         break;
200                 }
201         }
202
203         if (urb->actual_length < sizeof(struct usb_cdc_notification)) {
204                 dev_err(&desc->intf->dev, "wdm_int_callback - %d bytes\n",
205                         urb->actual_length);
206                 goto exit;
207         }
208
209         switch (dr->bNotificationType) {
210         case USB_CDC_NOTIFY_RESPONSE_AVAILABLE:
211                 dev_dbg(&desc->intf->dev,
212                         "NOTIFY_RESPONSE_AVAILABLE received: index %d len %d",
213                         dr->wIndex, dr->wLength);
214                 break;
215
216         case USB_CDC_NOTIFY_NETWORK_CONNECTION:
217
218                 dev_dbg(&desc->intf->dev,
219                         "NOTIFY_NETWORK_CONNECTION %s network",
220                         dr->wValue ? "connected to" : "disconnected from");
221                 goto exit;
222         default:
223                 clear_bit(WDM_POLL_RUNNING, &desc->flags);
224                 dev_err(&desc->intf->dev,
225                         "unknown notification %d received: index %d len %d\n",
226                         dr->bNotificationType, dr->wIndex, dr->wLength);
227                 goto exit;
228         }
229
230         spin_lock(&desc->iuspin);
231         clear_bit(WDM_READ, &desc->flags);
232         set_bit(WDM_RESPONDING, &desc->flags);
233         if (!test_bit(WDM_DISCONNECTING, &desc->flags)
234                 && !test_bit(WDM_SUSPENDING, &desc->flags)) {
235                 rv = usb_submit_urb(desc->response, GFP_ATOMIC);
236                 dev_dbg(&desc->intf->dev, "%s: usb_submit_urb %d",
237                         __func__, rv);
238         }
239         spin_unlock(&desc->iuspin);
240         if (rv < 0) {
241                 clear_bit(WDM_RESPONDING, &desc->flags);
242                 if (rv == -EPERM)
243                         return;
244                 if (rv == -ENOMEM) {
245 sw:
246                         rv = schedule_work(&desc->rxwork);
247                         if (rv)
248                                 dev_err(&desc->intf->dev,
249                                         "Cannot schedule work\n");
250                 }
251         }
252 exit:
253         rv = usb_submit_urb(urb, GFP_ATOMIC);
254         if (rv)
255                 dev_err(&desc->intf->dev,
256                         "%s - usb_submit_urb failed with result %d\n",
257                         __func__, rv);
258
259 }
260
261 static void kill_urbs(struct wdm_device *desc)
262 {
263         /* the order here is essential */
264         usb_kill_urb(desc->command);
265         usb_kill_urb(desc->validity);
266         usb_kill_urb(desc->response);
267 }
268
269 static void free_urbs(struct wdm_device *desc)
270 {
271         usb_free_urb(desc->validity);
272         usb_free_urb(desc->response);
273         usb_free_urb(desc->command);
274 }
275
276 static void cleanup(struct wdm_device *desc)
277 {
278         kfree(desc->sbuf);
279         kfree(desc->inbuf);
280         kfree(desc->orq);
281         kfree(desc->irq);
282         kfree(desc->ubuf);
283         free_urbs(desc);
284         kfree(desc);
285 }
286
287 static ssize_t wdm_write
288 (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
289 {
290         u8 *buf;
291         int rv = -EMSGSIZE, r, we;
292         struct wdm_device *desc = file->private_data;
293         struct usb_ctrlrequest *req;
294
295         if (count > desc->wMaxCommand)
296                 count = desc->wMaxCommand;
297
298         spin_lock_irq(&desc->iuspin);
299         we = desc->werr;
300         desc->werr = 0;
301         spin_unlock_irq(&desc->iuspin);
302         if (we < 0)
303                 return -EIO;
304
305         desc->outbuf = buf = kmalloc(count, GFP_KERNEL);
306         if (!buf) {
307                 rv = -ENOMEM;
308                 goto outnl;
309         }
310
311         r = copy_from_user(buf, buffer, count);
312         if (r > 0) {
313                 kfree(buf);
314                 rv = -EFAULT;
315                 goto outnl;
316         }
317
318         /* concurrent writes and disconnect */
319         r = mutex_lock_interruptible(&desc->wlock);
320         rv = -ERESTARTSYS;
321         if (r) {
322                 kfree(buf);
323                 goto outnl;
324         }
325
326         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
327                 kfree(buf);
328                 rv = -ENODEV;
329                 goto outnp;
330         }
331
332         r = usb_autopm_get_interface(desc->intf);
333         if (r < 0) {
334                 kfree(buf);
335                 goto outnp;
336         }
337
338         if (!(file->f_flags & O_NONBLOCK))
339                 r = wait_event_interruptible(desc->wait, !test_bit(WDM_IN_USE,
340                                                                 &desc->flags));
341         else
342                 if (test_bit(WDM_IN_USE, &desc->flags))
343                         r = -EAGAIN;
344
345         if (test_bit(WDM_RESETTING, &desc->flags))
346                 r = -EIO;
347
348         if (r < 0) {
349                 kfree(buf);
350                 goto out;
351         }
352
353         req = desc->orq;
354         usb_fill_control_urb(
355                 desc->command,
356                 interface_to_usbdev(desc->intf),
357                 /* using common endpoint 0 */
358                 usb_sndctrlpipe(interface_to_usbdev(desc->intf), 0),
359                 (unsigned char *)req,
360                 buf,
361                 count,
362                 wdm_out_callback,
363                 desc
364         );
365
366         req->bRequestType = (USB_DIR_OUT | USB_TYPE_CLASS |
367                              USB_RECIP_INTERFACE);
368         req->bRequest = USB_CDC_SEND_ENCAPSULATED_COMMAND;
369         req->wValue = 0;
370         req->wIndex = desc->inum;
371         req->wLength = cpu_to_le16(count);
372         set_bit(WDM_IN_USE, &desc->flags);
373
374         rv = usb_submit_urb(desc->command, GFP_KERNEL);
375         if (rv < 0) {
376                 kfree(buf);
377                 clear_bit(WDM_IN_USE, &desc->flags);
378                 dev_err(&desc->intf->dev, "Tx URB error: %d\n", rv);
379         } else {
380                 dev_dbg(&desc->intf->dev, "Tx URB has been submitted index=%d",
381                         req->wIndex);
382         }
383 out:
384         usb_autopm_put_interface(desc->intf);
385 outnp:
386         mutex_unlock(&desc->wlock);
387 outnl:
388         return rv < 0 ? rv : count;
389 }
390
391 static ssize_t wdm_read
392 (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
393 {
394         int rv, cntr;
395         int i = 0;
396         struct wdm_device *desc = file->private_data;
397
398
399         rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
400         if (rv < 0)
401                 return -ERESTARTSYS;
402
403         cntr = ACCESS_ONCE(desc->length);
404         if (cntr == 0) {
405                 desc->read = 0;
406 retry:
407                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
408                         rv = -ENODEV;
409                         goto err;
410                 }
411                 i++;
412                 if (file->f_flags & O_NONBLOCK) {
413                         if (!test_bit(WDM_READ, &desc->flags)) {
414                                 rv = cntr ? cntr : -EAGAIN;
415                                 goto err;
416                         }
417                         rv = 0;
418                 } else {
419                         rv = wait_event_interruptible(desc->wait,
420                                 test_bit(WDM_READ, &desc->flags));
421                 }
422
423                 /* may have happened while we slept */
424                 if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
425                         rv = -ENODEV;
426                         goto err;
427                 }
428                 if (test_bit(WDM_RESETTING, &desc->flags)) {
429                         rv = -EIO;
430                         goto err;
431                 }
432                 usb_mark_last_busy(interface_to_usbdev(desc->intf));
433                 if (rv < 0) {
434                         rv = -ERESTARTSYS;
435                         goto err;
436                 }
437
438                 spin_lock_irq(&desc->iuspin);
439
440                 if (desc->rerr) { /* read completed, error happened */
441                         desc->rerr = 0;
442                         spin_unlock_irq(&desc->iuspin);
443                         rv = -EIO;
444                         goto err;
445                 }
446                 /*
447                  * recheck whether we've lost the race
448                  * against the completion handler
449                  */
450                 if (!test_bit(WDM_READ, &desc->flags)) { /* lost race */
451                         spin_unlock_irq(&desc->iuspin);
452                         goto retry;
453                 }
454                 if (!desc->reslength) { /* zero length read */
455                         spin_unlock_irq(&desc->iuspin);
456                         goto retry;
457                 }
458                 clear_bit(WDM_READ, &desc->flags);
459                 cntr = desc->length;
460                 spin_unlock_irq(&desc->iuspin);
461         }
462
463         if (cntr > count)
464                 cntr = count;
465         rv = copy_to_user(buffer, desc->ubuf, cntr);
466         if (rv > 0) {
467                 rv = -EFAULT;
468                 goto err;
469         }
470
471         spin_lock_irq(&desc->iuspin);
472
473         for (i = 0; i < desc->length - cntr; i++)
474                 desc->ubuf[i] = desc->ubuf[i + cntr];
475
476         desc->length -= cntr;
477         /* in case we had outstanding data */
478         if (!desc->length)
479                 clear_bit(WDM_READ, &desc->flags);
480
481         spin_unlock_irq(&desc->iuspin);
482
483         rv = cntr;
484
485 err:
486         mutex_unlock(&desc->rlock);
487         return rv;
488 }
489
490 static int wdm_flush(struct file *file, fl_owner_t id)
491 {
492         struct wdm_device *desc = file->private_data;
493
494         wait_event(desc->wait, !test_bit(WDM_IN_USE, &desc->flags));
495         if (desc->werr < 0)
496                 dev_err(&desc->intf->dev, "Error in flush path: %d\n",
497                         desc->werr);
498
499         return desc->werr;
500 }
501
502 static unsigned int wdm_poll(struct file *file, struct poll_table_struct *wait)
503 {
504         struct wdm_device *desc = file->private_data;
505         unsigned long flags;
506         unsigned int mask = 0;
507
508         spin_lock_irqsave(&desc->iuspin, flags);
509         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
510                 mask = POLLERR;
511                 spin_unlock_irqrestore(&desc->iuspin, flags);
512                 goto desc_out;
513         }
514         if (test_bit(WDM_READ, &desc->flags))
515                 mask = POLLIN | POLLRDNORM;
516         if (desc->rerr || desc->werr)
517                 mask |= POLLERR;
518         if (!test_bit(WDM_IN_USE, &desc->flags))
519                 mask |= POLLOUT | POLLWRNORM;
520         spin_unlock_irqrestore(&desc->iuspin, flags);
521
522         poll_wait(file, &desc->wait, wait);
523
524 desc_out:
525         return mask;
526 }
527
528 static int wdm_open(struct inode *inode, struct file *file)
529 {
530         int minor = iminor(inode);
531         int rv = -ENODEV;
532         struct usb_interface *intf;
533         struct wdm_device *desc;
534
535         mutex_lock(&wdm_mutex);
536         intf = usb_find_interface(&wdm_driver, minor);
537         if (!intf)
538                 goto out;
539
540         desc = usb_get_intfdata(intf);
541         if (test_bit(WDM_DISCONNECTING, &desc->flags))
542                 goto out;
543         file->private_data = desc;
544
545         rv = usb_autopm_get_interface(desc->intf);
546         if (rv < 0) {
547                 dev_err(&desc->intf->dev, "Error autopm - %d\n", rv);
548                 goto out;
549         }
550         intf->needs_remote_wakeup = 1;
551
552         /* using write lock to protect desc->count */
553         mutex_lock(&desc->wlock);
554         if (!desc->count++) {
555                 desc->werr = 0;
556                 desc->rerr = 0;
557                 rv = usb_submit_urb(desc->validity, GFP_KERNEL);
558                 if (rv < 0) {
559                         desc->count--;
560                         dev_err(&desc->intf->dev,
561                                 "Error submitting int urb - %d\n", rv);
562                 }
563         } else {
564                 rv = 0;
565         }
566         mutex_unlock(&desc->wlock);
567         usb_autopm_put_interface(desc->intf);
568 out:
569         mutex_unlock(&wdm_mutex);
570         return rv;
571 }
572
573 static int wdm_release(struct inode *inode, struct file *file)
574 {
575         struct wdm_device *desc = file->private_data;
576
577         mutex_lock(&wdm_mutex);
578
579         /* using write lock to protect desc->count */
580         mutex_lock(&desc->wlock);
581         desc->count--;
582         mutex_unlock(&desc->wlock);
583
584         if (!desc->count) {
585                 dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
586                 kill_urbs(desc);
587                 if (!test_bit(WDM_DISCONNECTING, &desc->flags))
588                         desc->intf->needs_remote_wakeup = 0;
589         }
590         mutex_unlock(&wdm_mutex);
591         return 0;
592 }
593
594 static const struct file_operations wdm_fops = {
595         .owner =        THIS_MODULE,
596         .read =         wdm_read,
597         .write =        wdm_write,
598         .open =         wdm_open,
599         .flush =        wdm_flush,
600         .release =      wdm_release,
601         .poll =         wdm_poll,
602         .llseek =       noop_llseek,
603 };
604
605 static struct usb_class_driver wdm_class = {
606         .name =         "cdc-wdm%d",
607         .fops =         &wdm_fops,
608         .minor_base =   WDM_MINOR_BASE,
609 };
610
611 /* --- error handling --- */
612 static void wdm_rxwork(struct work_struct *work)
613 {
614         struct wdm_device *desc = container_of(work, struct wdm_device, rxwork);
615         unsigned long flags;
616         int rv;
617
618         spin_lock_irqsave(&desc->iuspin, flags);
619         if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
620                 spin_unlock_irqrestore(&desc->iuspin, flags);
621         } else {
622                 spin_unlock_irqrestore(&desc->iuspin, flags);
623                 rv = usb_submit_urb(desc->response, GFP_KERNEL);
624                 if (rv < 0 && rv != -EPERM) {
625                         spin_lock_irqsave(&desc->iuspin, flags);
626                         if (!test_bit(WDM_DISCONNECTING, &desc->flags))
627                                 schedule_work(&desc->rxwork);
628                         spin_unlock_irqrestore(&desc->iuspin, flags);
629                 }
630         }
631 }
632
633 /* --- hotplug --- */
634
635 static int wdm_probe(struct usb_interface *intf, const struct usb_device_id *id)
636 {
637         int rv = -EINVAL;
638         struct wdm_device *desc;
639         struct usb_host_interface *iface;
640         struct usb_endpoint_descriptor *ep;
641         struct usb_cdc_dmm_desc *dmhd;
642         u8 *buffer = intf->altsetting->extra;
643         int buflen = intf->altsetting->extralen;
644         u16 maxcom = WDM_DEFAULT_BUFSIZE;
645
646         if (!buffer)
647                 goto out;
648
649         while (buflen > 2) {
650                 if (buffer [1] != USB_DT_CS_INTERFACE) {
651                         dev_err(&intf->dev, "skipping garbage\n");
652                         goto next_desc;
653                 }
654
655                 switch (buffer [2]) {
656                 case USB_CDC_HEADER_TYPE:
657                         break;
658                 case USB_CDC_DMM_TYPE:
659                         dmhd = (struct usb_cdc_dmm_desc *)buffer;
660                         maxcom = le16_to_cpu(dmhd->wMaxCommand);
661                         dev_dbg(&intf->dev,
662                                 "Finding maximum buffer length: %d", maxcom);
663                         break;
664                 default:
665                         dev_err(&intf->dev,
666                                 "Ignoring extra header, type %d, length %d\n",
667                                 buffer[2], buffer[0]);
668                         break;
669                 }
670 next_desc:
671                 buflen -= buffer[0];
672                 buffer += buffer[0];
673         }
674
675         rv = -ENOMEM;
676         desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
677         if (!desc)
678                 goto out;
679         mutex_init(&desc->rlock);
680         mutex_init(&desc->wlock);
681         spin_lock_init(&desc->iuspin);
682         init_waitqueue_head(&desc->wait);
683         desc->wMaxCommand = maxcom;
684         /* this will be expanded and needed in hardware endianness */
685         desc->inum = cpu_to_le16((u16)intf->cur_altsetting->desc.bInterfaceNumber);
686         desc->intf = intf;
687         INIT_WORK(&desc->rxwork, wdm_rxwork);
688
689         rv = -EINVAL;
690         iface = intf->cur_altsetting;
691         if (iface->desc.bNumEndpoints != 1)
692                 goto err;
693         ep = &iface->endpoint[0].desc;
694         if (!ep || !usb_endpoint_is_int_in(ep))
695                 goto err;
696
697         desc->wMaxPacketSize = usb_endpoint_maxp(ep);
698
699         desc->orq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
700         if (!desc->orq)
701                 goto err;
702         desc->irq = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
703         if (!desc->irq)
704                 goto err;
705
706         desc->validity = usb_alloc_urb(0, GFP_KERNEL);
707         if (!desc->validity)
708                 goto err;
709
710         desc->response = usb_alloc_urb(0, GFP_KERNEL);
711         if (!desc->response)
712                 goto err;
713
714         desc->command = usb_alloc_urb(0, GFP_KERNEL);
715         if (!desc->command)
716                 goto err;
717
718         desc->ubuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
719         if (!desc->ubuf)
720                 goto err;
721
722         desc->sbuf = kmalloc(desc->wMaxPacketSize, GFP_KERNEL);
723         if (!desc->sbuf)
724                 goto err;
725
726         desc->inbuf = kmalloc(desc->wMaxCommand, GFP_KERNEL);
727         if (!desc->inbuf)
728                 goto err;
729
730         usb_fill_int_urb(
731                 desc->validity,
732                 interface_to_usbdev(intf),
733                 usb_rcvintpipe(interface_to_usbdev(intf), ep->bEndpointAddress),
734                 desc->sbuf,
735                 desc->wMaxPacketSize,
736                 wdm_int_callback,
737                 desc,
738                 ep->bInterval
739         );
740
741         desc->irq->bRequestType = (USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE);
742         desc->irq->bRequest = USB_CDC_GET_ENCAPSULATED_RESPONSE;
743         desc->irq->wValue = 0;
744         desc->irq->wIndex = desc->inum;
745         desc->irq->wLength = cpu_to_le16(desc->wMaxCommand);
746
747         usb_fill_control_urb(
748                 desc->response,
749                 interface_to_usbdev(intf),
750                 /* using common endpoint 0 */
751                 usb_rcvctrlpipe(interface_to_usbdev(desc->intf), 0),
752                 (unsigned char *)desc->irq,
753                 desc->inbuf,
754                 desc->wMaxCommand,
755                 wdm_in_callback,
756                 desc
757         );
758
759         usb_set_intfdata(intf, desc);
760         rv = usb_register_dev(intf, &wdm_class);
761         if (rv < 0)
762                 goto err2;
763         else
764                 dev_info(&intf->dev, "%s: USB WDM device\n", dev_name(intf->usb_dev));
765 out:
766         return rv;
767 err2:
768         usb_set_intfdata(intf, NULL);
769 err:
770         free_urbs(desc);
771         kfree(desc->inbuf);
772         kfree(desc->sbuf);
773         kfree(desc->ubuf);
774         kfree(desc->orq);
775         kfree(desc->irq);
776         kfree(desc);
777         return rv;
778 }
779
780 static void wdm_disconnect(struct usb_interface *intf)
781 {
782         struct wdm_device *desc;
783         unsigned long flags;
784
785         usb_deregister_dev(intf, &wdm_class);
786         mutex_lock(&wdm_mutex);
787         desc = usb_get_intfdata(intf);
788
789         /* the spinlock makes sure no new urbs are generated in the callbacks */
790         spin_lock_irqsave(&desc->iuspin, flags);
791         set_bit(WDM_DISCONNECTING, &desc->flags);
792         set_bit(WDM_READ, &desc->flags);
793         /* to terminate pending flushes */
794         clear_bit(WDM_IN_USE, &desc->flags);
795         spin_unlock_irqrestore(&desc->iuspin, flags);
796         wake_up_all(&desc->wait);
797         mutex_lock(&desc->rlock);
798         mutex_lock(&desc->wlock);
799         kill_urbs(desc);
800         cancel_work_sync(&desc->rxwork);
801         mutex_unlock(&desc->wlock);
802         mutex_unlock(&desc->rlock);
803         if (!desc->count)
804                 cleanup(desc);
805         mutex_unlock(&wdm_mutex);
806 }
807
808 #ifdef CONFIG_PM
809 static int wdm_suspend(struct usb_interface *intf, pm_message_t message)
810 {
811         struct wdm_device *desc = usb_get_intfdata(intf);
812         int rv = 0;
813
814         dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
815
816         /* if this is an autosuspend the caller does the locking */
817         if (!PMSG_IS_AUTO(message)) {
818                 mutex_lock(&desc->rlock);
819                 mutex_lock(&desc->wlock);
820         }
821         spin_lock_irq(&desc->iuspin);
822
823         if (PMSG_IS_AUTO(message) &&
824                         (test_bit(WDM_IN_USE, &desc->flags)
825                         || test_bit(WDM_RESPONDING, &desc->flags))) {
826                 spin_unlock_irq(&desc->iuspin);
827                 rv = -EBUSY;
828         } else {
829
830                 set_bit(WDM_SUSPENDING, &desc->flags);
831                 spin_unlock_irq(&desc->iuspin);
832                 /* callback submits work - order is essential */
833                 kill_urbs(desc);
834                 cancel_work_sync(&desc->rxwork);
835         }
836         if (!PMSG_IS_AUTO(message)) {
837                 mutex_unlock(&desc->wlock);
838                 mutex_unlock(&desc->rlock);
839         }
840
841         return rv;
842 }
843 #endif
844
845 static int recover_from_urb_loss(struct wdm_device *desc)
846 {
847         int rv = 0;
848
849         if (desc->count) {
850                 rv = usb_submit_urb(desc->validity, GFP_NOIO);
851                 if (rv < 0)
852                         dev_err(&desc->intf->dev,
853                                 "Error resume submitting int urb - %d\n", rv);
854         }
855         return rv;
856 }
857
858 #ifdef CONFIG_PM
859 static int wdm_resume(struct usb_interface *intf)
860 {
861         struct wdm_device *desc = usb_get_intfdata(intf);
862         int rv;
863
864         dev_dbg(&desc->intf->dev, "wdm%d_resume\n", intf->minor);
865
866         clear_bit(WDM_SUSPENDING, &desc->flags);
867         rv = recover_from_urb_loss(desc);
868
869         return rv;
870 }
871 #endif
872
873 static int wdm_pre_reset(struct usb_interface *intf)
874 {
875         struct wdm_device *desc = usb_get_intfdata(intf);
876
877         /*
878          * we notify everybody using poll of
879          * an exceptional situation
880          * must be done before recovery lest a spontaneous
881          * message from the device is lost
882          */
883         spin_lock_irq(&desc->iuspin);
884         set_bit(WDM_RESETTING, &desc->flags);   /* inform read/write */
885         set_bit(WDM_READ, &desc->flags);        /* unblock read */
886         clear_bit(WDM_IN_USE, &desc->flags);    /* unblock write */
887         desc->rerr = -EINTR;
888         spin_unlock_irq(&desc->iuspin);
889         wake_up_all(&desc->wait);
890         mutex_lock(&desc->rlock);
891         mutex_lock(&desc->wlock);
892         kill_urbs(desc);
893         cancel_work_sync(&desc->rxwork);
894         return 0;
895 }
896
897 static int wdm_post_reset(struct usb_interface *intf)
898 {
899         struct wdm_device *desc = usb_get_intfdata(intf);
900         int rv;
901
902         clear_bit(WDM_RESETTING, &desc->flags);
903         rv = recover_from_urb_loss(desc);
904         mutex_unlock(&desc->wlock);
905         mutex_unlock(&desc->rlock);
906         return 0;
907 }
908
909 static struct usb_driver wdm_driver = {
910         .name =         "cdc_wdm",
911         .probe =        wdm_probe,
912         .disconnect =   wdm_disconnect,
913 #ifdef CONFIG_PM
914         .suspend =      wdm_suspend,
915         .resume =       wdm_resume,
916         .reset_resume = wdm_resume,
917 #endif
918         .pre_reset =    wdm_pre_reset,
919         .post_reset =   wdm_post_reset,
920         .id_table =     wdm_ids,
921         .supports_autosuspend = 1,
922 };
923
924 module_usb_driver(wdm_driver);
925
926 MODULE_AUTHOR(DRIVER_AUTHOR);
927 MODULE_DESCRIPTION(DRIVER_DESC);
928 MODULE_LICENSE("GPL");