]> git.ipfire.org Git - people/arne_f/kernel.git/commit
HID: usbhid: fix inconsistent reset/resume/reset-resume behavior
authorAlan Stern <stern@rowland.harvard.edu>
Wed, 23 Mar 2016 16:17:09 +0000 (12:17 -0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 20 Apr 2016 06:40:45 +0000 (15:40 +0900)
commit0caa9766ca3ad03680a539b5023163a36702728d
tree37d535d1b95aaee8b409abad8459abba1ca7c0a4
parent1931344f79a1fe720c0f98ce78df3823bf3bef17
HID: usbhid: fix inconsistent reset/resume/reset-resume behavior

commit 972e6a993f278b416a8ee3ec65475724fc36feb2 upstream.

The usbhid driver has inconsistently duplicated code in its post-reset,
resume, and reset-resume pathways.

reset-resume doesn't check HID_STARTED before trying to
restart the I/O queues.

resume fails to clear the HID_SUSPENDED flag if HID_STARTED
isn't set.

resume calls usbhid_restart_queues() with usbhid->lock held
and the others call it without holding the lock.

The first item in particular causes a problem following a reset-resume
if the driver hasn't started up its I/O.  URB submission fails because
usbhid->urbin is NULL, and this triggers an unending reset-retry loop.

This patch fixes the problem by creating a new subroutine,
hid_restart_io(), to carry out all the common activities.  It also
adds some checks that were missing in the original code:

After a reset, there's no need to clear any halted endpoints.

After a resume, if a reset is pending there's no need to
restart any I/O until the reset is finished.

After a resume, if the interrupt-IN endpoint is halted there's
no need to submit the input URB until the halt has been
cleared.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Daniel Fraga <fragabr@gmail.com>
Tested-by: Daniel Fraga <fragabr@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/hid/usbhid/hid-core.c