Merge 3.2-rc1 into usb-linus (e3fa252a) · Commits · e / devices / android_kernel_fairphone_FP4

Documentation/usb/URB.txt

+22 −0

Original line number	Original line	Diff line number	Diff line
	@@ -168,6 +168,28 @@ that if the completion handler or anyone else tries to resubmit it
	they will get a -EPERM error. Thus you can be sure that when		they will get a -EPERM error. Thus you can be sure that when
	usb_kill_urb() returns, the URB is totally idle.		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?		1.7. What about the completion handler?

Documentation/usb/usbmon.txt

+3 −3

Original line number	Original line	Diff line number	Diff line
	@@ -183,10 +183,10 @@ An input control transfer to get a port status.
	d5ea89a0 3575914555 S Ci:1:001:0 s a3 00 0000 0003 0004 4 <		d5ea89a0 3575914555 S Ci:1:001:0 s a3 00 0000 0003 0004 4 <
	d5ea89a0 3575914560 C Ci:1:001:0 0 4 = 01050000		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		An output bulk transfer to send a SCSI command 0x28 (READ_10) in a 31-byte
	to a storage device at address 5:		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 >		dd65f0e8 4128379808 C Bo:1:005:2 0 31 >

	* Raw binary format and API		* Raw binary format and API

drivers/usb/Kconfig

+8 −8

Original line number	Original line	Diff line number	Diff line
	@@ -2,14 +2,6 @@
	# USB device configuration		# 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		# many non-PCI SOC chips embed OHCI
	config USB_ARCH_HAS_OHCI		config USB_ARCH_HAS_OHCI
	boolean		boolean
	@@ -63,6 +55,14 @@ config USB_ARCH_HAS_XHCI
	boolean		boolean
	default PCI		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		if USB_SUPPORT

	config USB_COMMON		config USB_COMMON

drivers/usb/core/message.c

+6 −5

Original line number	Original line	Diff line number	Diff line
	@@ -308,7 +308,8 @@ static void sg_complete(struct urb *urb)
	retval = usb_unlink_urb(io->urbs [i]);		retval = usb_unlink_urb(io->urbs [i]);
	if (retval != -EINPROGRESS &&		if (retval != -EINPROGRESS &&
	retval != -ENODEV &&		retval != -ENODEV &&
	retval != -EBUSY)		retval != -EBUSY &&
			retval != -EIDRM)
	dev_err(&io->dev->dev,		dev_err(&io->dev->dev,
	"%s, unlink --> %d\n",		"%s, unlink --> %d\n",
	__func__, retval);		__func__, retval);
	@@ -317,7 +318,6 @@ static void sg_complete(struct urb *urb)
	}		}
	spin_lock(&io->lock);		spin_lock(&io->lock);
	}		}
	urb->dev = NULL;

	/* on the last completion, signal usb_sg_wait() */		/* on the last completion, signal usb_sg_wait() */
	io->bytes += urb->actual_length;		io->bytes += urb->actual_length;
	@@ -524,7 +524,6 @@ void usb_sg_wait(struct usb_sg_request *io)
	case -ENXIO: /* hc didn't queue this one */		case -ENXIO: /* hc didn't queue this one */
	case -EAGAIN:		case -EAGAIN:
	case -ENOMEM:		case -ENOMEM:
	io->urbs[i]->dev = NULL;
	retval = 0;		retval = 0;
	yield();		yield();
	break;		break;
	@@ -542,7 +541,6 @@ void usb_sg_wait(struct usb_sg_request *io)

	/* fail any uncompleted urbs */		/* fail any uncompleted urbs */
	default:		default:
	io->urbs[i]->dev = NULL;
	io->urbs[i]->status = retval;		io->urbs[i]->status = retval;
	dev_dbg(&io->dev->dev, "%s, submit --> %d\n",		dev_dbg(&io->dev->dev, "%s, submit --> %d\n",
	__func__, retval);		__func__, retval);
	@@ -593,7 +591,10 @@ void usb_sg_cancel(struct usb_sg_request *io)
	if (!io->urbs [i]->dev)		if (!io->urbs [i]->dev)
	continue;		continue;
	retval = usb_unlink_urb(io->urbs [i]);		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",		dev_warn(&io->dev->dev, "%s, unlink --> %d\n",
	__func__, retval);		__func__, retval);
	}		}

drivers/usb/core/urb.c

+12 −0

Original line number	Original line	Diff line number	Diff line
	@@ -539,6 +539,10 @@ EXPORT_SYMBOL_GPL(usb_submit_urb);
	* never submitted, or it was unlinked before, or the hardware is already		* never submitted, or it was unlinked before, or the hardware is already
	* finished with it), even if the completion handler has not yet run.		* 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:		* Unlinking and Endpoint Queues:
	*		*
	* [The behaviors and guarantees described below do not apply to virtual		* [The behaviors and guarantees described below do not apply to virtual
	@@ -603,6 +607,10 @@ EXPORT_SYMBOL_GPL(usb_unlink_urb);
	* with error -EPERM. Thus even if the URB's completion handler always		* 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.		* 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		* 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		* half or a completion handler), or when holding a spinlock, or in other
	* situations where the caller can't schedule().		* situations where the caller can't schedule().
	@@ -640,6 +648,10 @@ EXPORT_SYMBOL_GPL(usb_kill_urb);
	* with error -EPERM. Thus even if the URB's completion handler always		* 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.		* 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		* 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		* half or a completion handler), or when holding a spinlock, or in other
	* situations where the caller can't schedule().		* situations where the caller can't schedule().