drm/i915: enable HiZ Raw Stall Optimization on IVB

The optimization helps IVB too.  No piglit regression.

Signed-off-by: Chia-I Wu <olv@lunarg.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 1a1eec64ecfb..3c79b6342883 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4866,6 +4866,10 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
 
         gen7_setup_fixed_func_scheduler(dev_priv);
 
+        /* enable HiZ Raw Stall Optimization */
+        I915_WRITE(CACHE_MODE_0_GEN7,
+                   _MASKED_BIT_DISABLE(HIZ_RAW_STALL_OPT_DISABLE));
+
         /* WaDisable4x2SubspanOptimization:ivb */
         I915_WRITE(CACHE_MODE_1,
                    _MASKED_BIT_ENABLE(PIXEL_SUBSPAN_COLLECT_OPT_DISABLE));