drm/i915: WaRsUseTimeoutMode

Enable TO mode for RC6 for SKL till D0 and BXT till A0.

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: Fixup line continuation alignment.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_pm.c

@@ -4871,6 +4871,13 @@ static void gen9_enable_rc6(struct drm_device *dev)
 		rc6_mask = GEN6_RC_CTL_RC6_ENABLE;
 	DRM_INFO("RC6 %s\n", (rc6_mask & GEN6_RC_CTL_RC6_ENABLE) ?
 			"on" : "off");
+
+	if ((IS_SKYLAKE(dev) && INTEL_REVID(dev) <= SKL_REVID_D0) ||
+	    (IS_BROXTON(dev) && INTEL_REVID(dev) <= BXT_REVID_A0))
+		I915_WRITE(GEN6_RC_CONTROL, GEN6_RC_CTL_HW_ENABLE |
+			   GEN7_RC_CTL_TO_MODE |
+			   rc6_mask);
+	else
 		I915_WRITE(GEN6_RC_CONTROL, GEN6_RC_CTL_HW_ENABLE |
 			   GEN6_RC_CTL_EI_MODE(1) |
 			   rc6_mask);