tree e68eba9ed571f0be68d7637ec76d1efbd34f2007
parent da1f2d42974e2f72cb0e53cf60e48254ed00f741
author Takashi Iwai <tiwai@suse.de> 1369240118 +0200
committer Doug Zobel <dzobel1@motorola.com> 1416237136 -0600

firmware: Avoid deadlock of usermodehelper lock at shutdown

When a system goes to reboot/shutdown, it tries to disable the
usermode helper via usermodehelper_disable().  This might be blocked
when a driver tries to load a firmware beforehand and it's stuck by
some reason.  For example, dell_rbu driver loads the firmware in
non-hotplug mode and waits for user-space clearing the loading sysfs
flag.  If user-space doesn't clear the flag, it waits forever, thus
blocks the reboot, too.

As a workaround, in this patch, the firmware class driver registers a
reboot notifier so that it can abort all pending f/w bufs before
issuing usermodehelper_disable().

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Conflicts:
	drivers/base/firmware_class.c

Change-Id: I7ff6c198cd34090e55845b9d4035b1e5dc86226b