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>
1 file changed