drm/i915: WaRsDisableCoarsePowerGating

WaRsDisableCoarsePowerGating: Coarse Power Gating (CPG) needs to be
disabled for platforms prior to BXT B0 and SKL GT3/GT4 till E0.

v2: Added GT3/GT4 Check.

Change-Id: Ia3c4c16e050c88d3e259f601054875c812d69c3a
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: Alex Dai <yu.dai@intel.com>
[danvet: Align continuation properly.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -4877,11 +4877,14 @@ static void gen9_enable_rc6(struct drm_device *dev)
 
 	/*
 	 * 3b: Enable Coarse Power Gating only when RC6 is enabled.
-	 * WaDisableRenderPowerGating:skl,bxt - Render PG need to be disabled with RC6.
+	 * WaRsDisableCoarsePowerGating:skl,bxt - Render/Media PG need to be disabled with RC6.
 	 */
-	I915_WRITE(GEN9_PG_ENABLE, (rc6_mask & GEN6_RC_CTL_RC6_ENABLE) ?
-			GEN9_MEDIA_PG_ENABLE : 0);
-
+	if ((IS_BROXTON(dev) && (INTEL_REVID(dev) < BXT_REVID_B0)) ||
+	    ((IS_SKL_GT3(dev) || IS_SKL_GT4(dev)) && (INTEL_REVID(dev) <= SKL_REVID_E0)))
+		I915_WRITE(GEN9_PG_ENABLE, 0);
+	else
+		I915_WRITE(GEN9_PG_ENABLE, (rc6_mask & GEN6_RC_CTL_RC6_ENABLE) ?
+				(GEN9_RENDER_PG_ENABLE | GEN9_MEDIA_PG_ENABLE) : 0);
 
 	intel_uncore_forcewake_put(dev_priv, FORCEWAKE_ALL);