drm/i915: HSW CRW stability magic

This magic brings stability to HSW CRW machines.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gem.c

@@ -3961,6 +3961,9 @@ i915_gem_init_hw(struct drm_device *dev)
 	if (!intel_enable_gtt())
 		return -EIO;
 
+	if (IS_HASWELL(dev) && (I915_READ(0x120010) == 1))
+		I915_WRITE(0x9008, I915_READ(0x9008) | 0xf0000);
+
 	i915_gem_l3_remap(dev);
 
 	i915_gem_init_swizzling(dev);