From: Ramalingam C Date: Tue, 3 Mar 2015 06:41:46 +0000 (+0530) Subject: drm/i915: Fixing mutex deadlock window at eDP DRRS X-Git-Tag: omap-for-v4.1/fixes-rc1~82^2~24^2~73 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3954e733ab0c9449443897f2669e17fff4471a0e;p=pandora-kernel.git drm/i915: Fixing mutex deadlock window at eDP DRRS In invalidate and flush functions of eDP DRRS, if deferred downclock work starts execution at a time window between acquiring the drrs mutex and cancellation of the deferred work (intel_edp_drrs_downclock_work), then deferred work will find drrs mutex locked and wait for the same. Meanwhile the function that acquired mutex drrs invalidate/flush will wait for the completion of the deferred work before releasing the mutex. Thats a deadlock. To avoid such deadlock scenario, this change cancels the deferred work before acquiring the mutex at invalidate and flush functions. Signed-off-by: Ramalingam C Reviewed-by: Rodrigo Vivi Signed-off-by: Daniel Vetter --- Reading git-diff-tree failed