drm/i915/bxt: Add WaDisableThreadStallDopClockGating

Signed-off-by: Nick Hoath <nicholas.hoath@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index de8c074..98424e2 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1041,8 +1041,15 @@
 
 static int bxt_init_workarounds(struct intel_engine_cs *ring)
 {
+	struct drm_device *dev = ring->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
 	gen9_init_workarounds(ring);
 
+	/* WaDisableThreadStallDopClockGating:bxt */
+	WA_SET_BIT_MASKED(GEN8_ROW_CHICKEN,
+			  STALL_DOP_GATING_DISABLE);
+
 	return 0;
 }