commit 647e1715166a38238455897589539884a3a4c282
author Manoj Kumar AVM <manojavm@codeaurora.org> Wed Jan 20 16:36:41 2016 -0800
committer Gerrit - the friendly Code Review server <code-review@localhost> Mon Jan 25 12:02:51 2016 -0800
tree b4659b71f281bbacb69c00b956892a2987cb9ea6
parent 46ef281e94bfe764309b78f3e3b89274c59d6ae6

hwc: Fix mutex deadlock in GetVsyncPeriod

Existing implementation of GetVsyncPeriod use sequence locker entry mechanism.

This can potentially lead to deadlock for below scenario:
1. During hotplug connection, locker_.sequence_wait_ is set in GetVsyncPeriod.
2. Dumpsys() utility acquires HWComposer::mDrawLock and waits till
   locker_.sequence_wait_ is reset.
3. SurfaceFlinger::SetupHWComposer() waits on HWComposer::mDrawLock.

This results in deadlock.

Fix deadlock by using scope lock of locker_ in GetVsyncPeriod.

Change-Id: Iea1e2bd53ef4434c40af6062eb9dd5fa9354db4a
CRs-Fixed: 962964