drm/dp: move hw_mutex up the call stack
authorRob Clark <robdclark@gmail.com>
Thu, 25 Feb 2016 21:15:05 +0000 (16:15 -0500)
committerDave Airlie <airlied@redhat.com>
Fri, 1 Apr 2016 03:17:36 +0000 (13:17 +1000)
commit7779c5e23c5132c22a219f1f5554ef81dd15ee91
treec1cc30db8f783716b01241bd44f2e314d82680ae
parent5456248d6647c61d333961ab919cec0350cdcb83
drm/dp: move hw_mutex up the call stack

1) don't let other threads trying to bang on aux channel interrupt the
defer timeout/logic
2) don't let other threads interrupt the i2c over aux logic

Technically, according to people who actually have the DP spec, this
should not be required.  In practice, it makes some troublesome Dell
monitor (and perhaps others) work, so probably a case of "It's compliant
if it works with windows" on the hw vendor's part..

v2: rebased to come before DPCD/AUX logging patch for easier backport
to stable branches.

Reported-by: Dave Wysochanski <dwysocha@redhat.com>
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1274157
Cc: stable@vger.kernel.org
Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drivers/gpu/drm/drm_dp_helper.c