Merge 3.2-rc1 into usb-linus

This is needed to catch the resume bug that was bothering lots of us from testing some XHCI bug fixes in the suspend/resume path. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Merge 3.2-rc1 into usb-linus
This is needed to catch the resume bug that was bothering lots of us from testing some XHCI bug fixes in the suspend/resume path. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Greg Kroah-Hartman
2 parents 0034102808 a2457ee691
Showing 7 changed files Side-by-side Diff
Documentation/usb/URB.txt
Documentation/usb/usbmon.txt
drivers/usb/Kconfig
drivers/usb/core/message.c
drivers/usb/core/urb.c
drivers/usb/gadget/inode.c
drivers/usb/storage/usb.c
@@ -168,6 +168,28 @@
 they will get a -EPERM error.  Thus you can be sure that when
 usb_kill_urb() returns, the URB is totally idle.
  
+There is a lifetime issue to consider.  An URB may complete at any
+time, and the completion handler may free the URB.  If this happens
+while usb_unlink_urb or usb_kill_urb is running, it will cause a
+memory-access violation.  The driver is responsible for avoiding this,
+which often means some sort of lock will be needed to prevent the URB
+from being deallocated while it is still in use.
+
+On the other hand, since usb_unlink_urb may end up calling the
+completion handler, the handler must not take any lock that is held
+when usb_unlink_urb is invoked.  The general solution to this problem
+is to increment the URB's reference count while holding the lock, then
+drop the lock and call usb_unlink_urb or usb_kill_urb, and then
+decrement the URB's reference count.  You increment the reference
+count by calling
+
+	struct urb *usb_get_urb(struct urb *urb)
+
+(ignore the return value; it is the same as the argument) and
+decrement the reference count by calling usb_free_urb.  Of course,
+none of this is necessary if there's no danger of the URB being freed
+by the completion handler.
+
  
 1.7. What about the completion handler?
  
@@ -183,10 +183,10 @@
 d5ea89a0 3575914555 S Ci:1:001:0 s a3 00 0000 0003 0004 4 <
 d5ea89a0 3575914560 C Ci:1:001:0 0 4 = 01050000
  
-An output bulk transfer to send a SCSI command 0x5E in a 31-byte Bulk wrapper
-to a storage device at address 5:
+An output bulk transfer to send a SCSI command 0x28 (READ_10) in a 31-byte
+Bulk wrapper to a storage device at address 5:
  
-dd65f0e8 4128379752 S Bo:1:005:2 -115 31 = 55534243 5e000000 00000000 00000600 00000000 00000000 00000000 000000
+dd65f0e8 4128379752 S Bo:1:005:2 -115 31 = 55534243 ad000000 00800000 80010a28 20000000 20000040 00000000 000000
 dd65f0e8 4128379808 C Bo:1:005:2 0 31 >
  
 * Raw binary format and API
@@ -2,14 +2,6 @@
 # USB device configuration
 #
  
-menuconfig USB_SUPPORT
-	bool "USB support"
-	depends on HAS_IOMEM
-	default y
-	---help---
-	  This option adds core support for Universal Serial Bus (USB).
-	  You will also need drivers from the following menu to make use of it.
-
 # many non-PCI SOC chips embed OHCI
 config USB_ARCH_HAS_OHCI
 	boolean
@@ -62,6 +54,14 @@
 config USB_ARCH_HAS_XHCI
 	boolean
 	default PCI
+
+menuconfig USB_SUPPORT
+	bool "USB support"
+	depends on HAS_IOMEM
+	default y
+	---help---
+	  This option adds core support for Universal Serial Bus (USB).
+	  You will also need drivers from the following menu to make use of it.
  
 if USB_SUPPORT
  
@@ -308,7 +308,8 @@
 				retval = usb_unlink_urb(io->urbs [i]);
 				if (retval != -EINPROGRESS &&
 				    retval != -ENODEV &&
-				    retval != -EBUSY)
+				    retval != -EBUSY &&
+				    retval != -EIDRM)
 					dev_err(&io->dev->dev,
 						"%s, unlink --> %d\n",
 						__func__, retval);
@@ -317,7 +318,6 @@
 		}
 		spin_lock(&io->lock);
 	}
-	urb->dev = NULL;
  
 	/* on the last completion, signal usb_sg_wait() */
 	io->bytes += urb->actual_length;
@@ -524,7 +524,6 @@
 		case -ENXIO:	/* hc didn't queue this one */
 		case -EAGAIN:
 		case -ENOMEM:
-			io->urbs[i]->dev = NULL;
 			retval = 0;
 			yield();
 			break;
@@ -542,7 +541,6 @@
  
 			/* fail any uncompleted urbs */
 		default:
-			io->urbs[i]->dev = NULL;
 			io->urbs[i]->status = retval;
 			dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
 				__func__, retval);
@@ -593,7 +591,10 @@
 			if (!io->urbs [i]->dev)
 				continue;
 			retval = usb_unlink_urb(io->urbs [i]);
-			if (retval != -EINPROGRESS && retval != -EBUSY)
+			if (retval != -EINPROGRESS
+					&& retval != -ENODEV
+					&& retval != -EBUSY
+					&& retval != -EIDRM)
 				dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
 					__func__, retval);
 		}
@@ -539,6 +539,10 @@
  * never submitted, or it was unlinked before, or the hardware is already
  * finished with it), even if the completion handler has not yet run.
  *
+ * The URB must not be deallocated while this routine is running.  In
+ * particular, when a driver calls this routine, it must insure that the
+ * completion handler cannot deallocate the URB.
+ *
  * Unlinking and Endpoint Queues:
  *
  * [The behaviors and guarantees described below do not apply to virtual
@@ -603,6 +607,10 @@
  * with error -EPERM.  Thus even if the URB's completion handler always
  * tries to resubmit, it will not succeed and the URB will become idle.
  *
+ * The URB must not be deallocated while this routine is running.  In
+ * particular, when a driver calls this routine, it must insure that the
+ * completion handler cannot deallocate the URB.
+ *
  * This routine may not be used in an interrupt context (such as a bottom
  * half or a completion handler), or when holding a spinlock, or in other
  * situations where the caller can't schedule().
@@ -639,6 +647,10 @@
  * After and while the routine runs, attempts to resubmit the URB will fail
  * with error -EPERM.  Thus even if the URB's completion handler always
  * tries to resubmit, it will not succeed and the URB will become idle.
+ *
+ * The URB must not be deallocated while this routine is running.  In
+ * particular, when a driver calls this routine, it must insure that the
+ * completion handler cannot deallocate the URB.
  *
  * This routine may not be used in an interrupt context (such as a bottom
  * half or a completion handler), or when holding a spinlock, or in other
@@ -1574,7 +1574,6 @@
 	DBG (dev, "%s %d\n", __func__, dev->state);
  
 	/* dev->state must prevent interference */
-restart:
 	spin_lock_irq (&dev->lock);
 	while (!list_empty(&dev->epfiles)) {
 		struct ep_data	*ep;
@@ -132,7 +132,36 @@
 #undef COMPLIANT_DEV
 #undef USUAL_DEV
  
+#ifdef CONFIG_LOCKDEP
  
+static struct lock_class_key us_interface_key[USB_MAXINTERFACES];
+
+static void us_set_lock_class(struct mutex *mutex,
+		struct usb_interface *intf)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct usb_host_config *config = udev->actconfig;
+	int i;
+
+	for (i = 0; i < config->desc.bNumInterfaces; i++) {
+		if (config->interface[i] == intf)
+			break;
+	}
+
+	BUG_ON(i == config->desc.bNumInterfaces);
+
+	lockdep_set_class(mutex, &us_interface_key[i]);
+}
+
+#else
+
+static void us_set_lock_class(struct mutex *mutex,
+		struct usb_interface *intf)
+{
+}
+
+#endif
+
 #ifdef CONFIG_PM	/* Minimal support for suspend and resume */
  
 int usb_stor_suspend(struct usb_interface *iface, pm_message_t message)
@@ -895,6 +924,7 @@
 	*pus = us = host_to_us(host);
 	memset(us, 0, sizeof(struct us_data));
 	mutex_init(&(us->dev_mutex));
+	us_set_lock_class(&us->dev_mutex, intf);
 	init_completion(&us->cmnd_ready);
 	init_completion(&(us->notify));
 	init_waitqueue_head(&us->delay_wait);
...	...	@@ -168,6 +168,28 @@
168	168	they will get a -EPERM error. Thus you can be sure that when
169	169	usb_kill_urb() returns, the URB is totally idle.
170	170
	171	+There is a lifetime issue to consider. An URB may complete at any
	172	+time, and the completion handler may free the URB. If this happens
	173	+while usb_unlink_urb or usb_kill_urb is running, it will cause a
	174	+memory-access violation. The driver is responsible for avoiding this,
	175	+which often means some sort of lock will be needed to prevent the URB
	176	+from being deallocated while it is still in use.
	177	+
	178	+On the other hand, since usb_unlink_urb may end up calling the
	179	+completion handler, the handler must not take any lock that is held
	180	+when usb_unlink_urb is invoked. The general solution to this problem
	181	+is to increment the URB's reference count while holding the lock, then
	182	+drop the lock and call usb_unlink_urb or usb_kill_urb, and then
	183	+decrement the URB's reference count. You increment the reference
	184	+count by calling
	185	+
	186	+ struct urb usb_get_urb(struct urb urb)
	187	+
	188	+(ignore the return value; it is the same as the argument) and
	189	+decrement the reference count by calling usb_free_urb. Of course,
	190	+none of this is necessary if there's no danger of the URB being freed
	191	+by the completion handler.
	192	+
171	193
172	194	1.7. What about the completion handler?
173	195
...	...	@@ -183,10 +183,10 @@
183	183	d5ea89a0 3575914555 S Ci:1:001:0 s a3 00 0000 0003 0004 4 <
184	184	d5ea89a0 3575914560 C Ci:1:001:0 0 4 = 01050000
185	185
186		-An output bulk transfer to send a SCSI command 0x5E in a 31-byte Bulk wrapper
187		-to a storage device at address 5:
	186	+An output bulk transfer to send a SCSI command 0x28 (READ_10) in a 31-byte
	187	+Bulk wrapper to a storage device at address 5:
188	188
189		-dd65f0e8 4128379752 S Bo:1:005:2 -115 31 = 55534243 5e000000 00000000 00000600 00000000 00000000 00000000 000000
	189	+dd65f0e8 4128379752 S Bo:1:005:2 -115 31 = 55534243 ad000000 00800000 80010a28 20000000 20000040 00000000 000000
190	190	dd65f0e8 4128379808 C Bo:1:005:2 0 31 >
191	191
192	192	* Raw binary format and API
...	...	@@ -2,14 +2,6 @@
2	2	# USB device configuration
3	3	#
4	4
5		-menuconfig USB_SUPPORT
6		- bool "USB support"
7		- depends on HAS_IOMEM
8		- default y
9		- ---help---
10		- This option adds core support for Universal Serial Bus (USB).
11		- You will also need drivers from the following menu to make use of it.
12		-
13	5	# many non-PCI SOC chips embed OHCI
14	6	config USB_ARCH_HAS_OHCI
15	7	boolean
...	...	@@ -62,6 +54,14 @@
62	54	config USB_ARCH_HAS_XHCI
63	55	boolean
64	56	default PCI
	57	+
	58	+menuconfig USB_SUPPORT
	59	+ bool "USB support"
	60	+ depends on HAS_IOMEM
	61	+ default y
	62	+ ---help---
	63	+ This option adds core support for Universal Serial Bus (USB).
	64	+ You will also need drivers from the following menu to make use of it.
65	65
66	66	if USB_SUPPORT
67	67
...	...	@@ -308,7 +308,8 @@
308	308	retval = usb_unlink_urb(io->urbs [i]);
309	309	if (retval != -EINPROGRESS &&
310	310	retval != -ENODEV &&
311		- retval != -EBUSY)
	311	+ retval != -EBUSY &&
	312	+ retval != -EIDRM)
312	313	dev_err(&io->dev->dev,
313	314	"%s, unlink --> %d\n",
314	315	__func__, retval);
...	...	@@ -317,7 +318,6 @@
317	318	}
318	319	spin_lock(&io->lock);
319	320	}
320		- urb->dev = NULL;
321	321
322	322	/* on the last completion, signal usb_sg_wait() */
323	323	io->bytes += urb->actual_length;
...	...	@@ -524,7 +524,6 @@
524	524	case -ENXIO: /* hc didn't queue this one */
525	525	case -EAGAIN:
526	526	case -ENOMEM:
527		- io->urbs[i]->dev = NULL;
528	527	retval = 0;
529	528	yield();
530	529	break;
...	...	@@ -542,7 +541,6 @@
542	541
543	542	/* fail any uncompleted urbs */
544	543	default:
545		- io->urbs[i]->dev = NULL;
546	544	io->urbs[i]->status = retval;
547	545	dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
548	546	__func__, retval);
...	...	@@ -593,7 +591,10 @@
593	591	if (!io->urbs [i]->dev)
594	592	continue;
595	593	retval = usb_unlink_urb(io->urbs [i]);
596		- if (retval != -EINPROGRESS && retval != -EBUSY)
	594	+ if (retval != -EINPROGRESS
	595	+ && retval != -ENODEV
	596	+ && retval != -EBUSY
	597	+ && retval != -EIDRM)
597	598	dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
598	599	__func__, retval);
599	600	}
...	...	@@ -539,6 +539,10 @@
539	539	* never submitted, or it was unlinked before, or the hardware is already
540	540	* finished with it), even if the completion handler has not yet run.
541	541	*
	542	+ * The URB must not be deallocated while this routine is running. In
	543	+ * particular, when a driver calls this routine, it must insure that the
	544	+ * completion handler cannot deallocate the URB.
	545	+ *
542	546	* Unlinking and Endpoint Queues:
543	547	*
544	548	* [The behaviors and guarantees described below do not apply to virtual
...	...	@@ -603,6 +607,10 @@
603	607	* with error -EPERM. Thus even if the URB's completion handler always
604	608	* tries to resubmit, it will not succeed and the URB will become idle.
605	609	*
	610	+ * The URB must not be deallocated while this routine is running. In
	611	+ * particular, when a driver calls this routine, it must insure that the
	612	+ * completion handler cannot deallocate the URB.
	613	+ *
606	614	* This routine may not be used in an interrupt context (such as a bottom
607	615	* half or a completion handler), or when holding a spinlock, or in other
608	616	* situations where the caller can't schedule().
...	...	@@ -639,6 +647,10 @@
639	647	* After and while the routine runs, attempts to resubmit the URB will fail
640	648	* with error -EPERM. Thus even if the URB's completion handler always
641	649	* tries to resubmit, it will not succeed and the URB will become idle.
	650	+ *
	651	+ * The URB must not be deallocated while this routine is running. In
	652	+ * particular, when a driver calls this routine, it must insure that the
	653	+ * completion handler cannot deallocate the URB.
642	654	*
643	655	* This routine may not be used in an interrupt context (such as a bottom
644	656	* half or a completion handler), or when holding a spinlock, or in other
...	...	@@ -1574,7 +1574,6 @@
1574	1574	DBG (dev, "%s %d\n", __func__, dev->state);
1575	1575
1576	1576	/* dev->state must prevent interference */
1577		-restart:
1578	1577	spin_lock_irq (&dev->lock);
1579	1578	while (!list_empty(&dev->epfiles)) {
1580	1579	struct ep_data *ep;
...	...	@@ -132,7 +132,36 @@
132	132	#undef COMPLIANT_DEV
133	133	#undef USUAL_DEV
134	134
	135	+#ifdef CONFIG_LOCKDEP
135	136
	137	+static struct lock_class_key us_interface_key[USB_MAXINTERFACES];
	138	+
	139	+static void us_set_lock_class(struct mutex *mutex,
	140	+ struct usb_interface *intf)
	141	+{
	142	+ struct usb_device *udev = interface_to_usbdev(intf);
	143	+ struct usb_host_config *config = udev->actconfig;
	144	+ int i;
	145	+
	146	+ for (i = 0; i < config->desc.bNumInterfaces; i++) {
	147	+ if (config->interface[i] == intf)
	148	+ break;
	149	+ }
	150	+
	151	+ BUG_ON(i == config->desc.bNumInterfaces);
	152	+
	153	+ lockdep_set_class(mutex, &us_interface_key[i]);
	154	+}
	155	+
	156	+#else
	157	+
	158	+static void us_set_lock_class(struct mutex *mutex,
	159	+ struct usb_interface *intf)
	160	+{
	161	+}
	162	+
	163	+#endif
	164	+
136	165	#ifdef CONFIG_PM /* Minimal support for suspend and resume */
137	166
138	167	int usb_stor_suspend(struct usb_interface *iface, pm_message_t message)
...	...	@@ -895,6 +924,7 @@
895	924	*pus = us = host_to_us(host);
896	925	memset(us, 0, sizeof(struct us_data));
897	926	mutex_init(&(us->dev_mutex));
	927	+ us_set_lock_class(&us->dev_mutex, intf);
898	928	init_completion(&us->cmnd_ready);
899	929	init_completion(&(us->notify));
900	930	init_waitqueue_head(&us->delay_wait);