drm/i915: WaRsDoubleRc6WrlWithCoarsePowerGating

Cc: Tom O'Rourke <Tom.O'Rourke@intel.com>
Cc: Akash Goel <akash.goel@intel.com>
Signed-off-by: NSagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: NAlex Dai <yu.dai@intel.com>
[danvet: Fix continuation alignment.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -4854,7 +4854,13 @@ static void gen9_enable_rc6(struct drm_device *dev)
 	I915_WRITE(GEN6_RC_CONTROL, 0);
 
 	/* 2b: Program RC6 thresholds.*/
-	I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16);
+
+	/* WaRsDoubleRc6WrlWithCoarsePowerGating: Doubling WRL only when CPG is enabled */
+	if (IS_SKYLAKE(dev) && !((IS_SKL_GT3(dev) || IS_SKL_GT4(dev)) &&
+				 (INTEL_REVID(dev) <= SKL_REVID_E0)))
+		I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 108 << 16);
+	else
+		I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16);
 	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
 	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
 	for_each_ring(ring, dev_priv, unused)