drm/i915: HSW FBC WaFbcAsynchFlipDisableFbcQueue

Display register 420B0h bit 22 must be set to 1b for the entire time that
Frame Buffer Compression is enabled.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index a7fc13d..d485586 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -980,6 +980,13 @@
 #define IVB_FBC_RT_BASE			0x7020
 
 
+#define _HSW_PIPE_SLICE_CHICKEN_1_A	0x420B0
+#define _HSW_PIPE_SLICE_CHICKEN_1_B	0x420B4
+#define   HSW_BYPASS_FBC_QUEUE		(1<<22)
+#define HSW_PIPE_SLICE_CHICKEN_1(pipe) _PIPE(pipe, + \
+					     _HSW_PIPE_SLICE_CHICKEN_1_A, + \
+					     _HSW_PIPE_SLICE_CHICKEN_1_B)
+
 /*
  * GPIO regs
  */