From: Ville Syrj?l? <ville.syrjala at linux.intel.com> WaDisable4x2SubspanOptimization isn't listed for VLV in the workaround database, but BSpec says that the relevant bit must be set. Add a comment to remind people of this. Signed-off-by: Ville Syrj?l? <ville.syrjala at linux.intel.com> --- drivers/gpu/drm/i915/intel_pm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index ce78928..f1ff216 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -4846,6 +4846,10 @@ static void valleyview_init_clock_gating(struct drm_device *dev) I915_WRITE(MI_ARB_VLV, MI_ARB_DISPLAY_TRICKLE_FEED_DISABLE); + /* + * BSpec says this must be set, even though + * WaDisable4x2SubspanOptimization isn't listed for VLV. + */ I915_WRITE(CACHE_MODE_1, _MASKED_BIT_ENABLE(PIXEL_SUBSPAN_COLLECT_OPT_DISABLE)); -- 1.8.1.5
