drm/i915: Try to make sure cxsr is disabled around plane enable/disable
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Wed, 24 Jun 2015 19:00:07 +0000 (22:00 +0300)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Mon, 29 Jun 2015 08:58:07 +0000 (10:58 +0200)
commit852eb00dc44ea2b8896e2fa27c6a36a1f697ba5a
treec2e594cd97cdf6c656285e789639c0caf07699c4
parent26e1fe4fbd4c15919f8cfa9440d70eca5a457ba3
drm/i915: Try to make sure cxsr is disabled around plane enable/disable

CxSR (or maxfifo on VLV/CHV) blocks somne changes to the plane control
register (enable bit at least, not quite sure about the rest). So in
order to have the plane enable/disable when we want we need to first
kick the hardware out of cxsr.

Unfortunateloy this requires some extra vblank waits. For the CxSR
enable after the plane update we should eventually use an async
vblank worker, but since we don't have that just do sync vblank
waits. For the disable case we have no choice but to do it
synchronously.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Clint Taylor <Clinton.A.Taylor@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_display.c
drivers/gpu/drm/i915/intel_drv.h
drivers/gpu/drm/i915/intel_pm.c