tree fee788fb13479ebe013eae8c9a4b621d6ccd3057
parent b4a133da2eaccb844a7beaef16ffd9c76a0d21d3
author NeilBrown <neilb@suse.de> 1333275570 +1000
committer Jiri Kosina <jkosina@suse.cz> 1333417356 +0200

APM: fix deadlock in APM_IOC_SUSPEND ioctl

I found the Xorg server on my ARM device stuck in the 'msleep()' loop
in apm_ioctl.

I suspect it had attempted suspend immediately after resuming and lost
a race.
During that msleep(10);, a new suspend cycle must have started and
changed ->suspend_state to SUSPEND_PENDING, so it was never seen to
be SUSPEND_DONE and the loop could never exited.  It would have moved on
to SUSPEND_ACKTO but never been able to reach SUSPEND_DONE.

So change the loop to only run while SUSPEND_ACKED rather than until
SUSPEND_DONE.  This is much safer.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>