USB: add quirk for devices with broken LPM
authorAlan Stern <stern@rowland.harvard.edu>
Thu, 10 Dec 2015 20:27:21 +0000 (15:27 -0500)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 11 Dec 2015 23:40:51 +0000 (15:40 -0800)
commitad87e03213b552a5c33d5e1e7a19a73768397010
treeabe42750b32a52d20a35bbd5635279a06d12390c
parentf69115fdbc1ac0718e7d19ad3caa3da2ecfe1c96
USB: add quirk for devices with broken LPM

Some USB device / host controller combinations seem to have problems
with Link Power Management.  For example, Steinar found that his xHCI
controller wouldn't handle bandwidth calculations correctly for two
video cards simultaneously when LPM was enabled, even though the bus
had plenty of bandwidth available.

This patch introduces a new quirk flag for devices that should remain
disabled for LPM, and creates quirk entries for Steinar's devices.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Steinar H. Gunderson <sgunderson@bigfoot.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/hub.c
drivers/usb/core/quirks.c
include/linux/usb/quirks.h