drm/i915: Always recompute watermarks when distrust_bios_wm is set, v2.
authorMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Wed, 31 May 2017 15:42:36 +0000 (17:42 +0200)
committerJani Nikula <jani.nikula@intel.com>
Wed, 7 Jun 2017 13:31:21 +0000 (16:31 +0300)
commit4e3aed844547f63614363a386de126e6304e55fb
tree1f9ba14ae8a000fa7ac902d2345dee54e99d5c9a
parent6ab92afc95c9bd6877cb42e7b24f65be887a5440
drm/i915: Always recompute watermarks when distrust_bios_wm is set, v2.

On some systems there can be a race condition in which no crtc state is
added to the first atomic commit. This results in all crtc's having a
null DDB allocation, causing a FIFO underrun on any update until the
first modeset.

Changes since v1:
- Do not take the connection_mutex, this is already done below.

Reported-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Inspired-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Fixes: 98d39494d375 ("drm/i915/gen9: Compute DDB allocation at atomic
check time (v4)")
Cc: <stable@vger.kernel.org> # v4.8+
Cc: Mahesh Kumar <mahesh1.kumar@intel.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170531154236.27180-1-maarten.lankhorst@linux.intel.com
Reviewed-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
(cherry picked from commit 367d73d2806085bb507ab44c1f532640917fd5ca)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
drivers/gpu/drm/i915/intel_pm.c