drm/i915/gen9: Add WaSetDisablePixMaskCammingAndRhwoInCommonSliceChicken

In Indirect context w/a batch buffer,
+WaSetDisablePixMaskCammingAndRhwoInCommonSliceChicken

v2: SKL revision id was used for BXT, copy paste error found during
internal review (Bob Beckett).

v3: explain why part of the WA is in Per ctx batch (Mika)

Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index b7e1629..83ed0f7 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1292,6 +1292,16 @@
 	struct drm_device *dev = ring->dev;
 	uint32_t index = wa_ctx_start(wa_ctx, *offset, CACHELINE_DWORDS);
 
+	/* WaSetDisablePixMaskCammingAndRhwoInCommonSliceChicken:skl,bxt */
+	if ((IS_SKYLAKE(dev) && (INTEL_REVID(dev) <= SKL_REVID_B0)) ||
+	    (IS_BROXTON(dev) && (INTEL_REVID(dev) == BXT_REVID_A0))) {
+		wa_ctx_emit(batch, index, MI_LOAD_REGISTER_IMM(1));
+		wa_ctx_emit(batch, index, GEN9_SLICE_COMMON_ECO_CHICKEN0);
+		wa_ctx_emit(batch, index,
+			    _MASKED_BIT_ENABLE(DISABLE_PIXEL_MASK_CAMMING));
+		wa_ctx_emit(batch, index, MI_NOOP);
+	}
+
 	/* WaDisableCtxRestoreArbitration:skl,bxt */
 	if ((IS_SKYLAKE(dev) && (INTEL_REVID(dev) <= SKL_REVID_D0)) ||
 	    (IS_BROXTON(dev) && (INTEL_REVID(dev) == BXT_REVID_A0)))