drm/i915/bxt: Add WaSetClckGatingDisableMedia

Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 64bc77e..920872a 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -134,6 +134,12 @@
 		 */
 		I915_WRITE(TILECTL, I915_READ(TILECTL) | TILECTL_TLBPF);
 	}
+
+	/* WaSetClckGatingDisableMedia:bxt */
+	if (INTEL_REVID(dev) == BXT_REVID_A0) {
+		I915_WRITE(GEN7_MISCCPCTL, (I915_READ(GEN7_MISCCPCTL) &
+					    ~GEN8_DOP_CLOCK_GATE_MEDIA_ENABLE));
+	}
 }
 
 static void i915_pineview_get_mem_freq(struct drm_device *dev)