drm/i915: leave rc6 enabled at suspend time v4

This allows the system to enter the lowest power mode during system freeze.

v2: delete force wake timer at suspend (Imre)
v3: add GT work suspend function (Imre)
v4: use uncore forcewake reset (Daniel)

Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 458b778..704dfe3 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -529,7 +529,7 @@
 		drm_irq_uninstall(dev);
 		dev_priv->enable_hotplug_processing = false;
 
-		intel_disable_gt_powersave(dev);
+		intel_suspend_gt_powersave(dev);
 
 		/*
 		 * Disable CRTCs directly since we want to preserve sw state
@@ -548,8 +548,8 @@
 
 	i915_save_state(dev);
 
+	intel_uncore_forcewake_reset(dev, false);
 	intel_opregion_fini(dev);
-	intel_uncore_fini(dev);
 
 	console_lock();
 	intel_fbdev_set_suspend(dev, FBINFO_STATE_SUSPENDED);