drm/i915: Disable AsyncFlip performance optimisations
This is a required workarounds for all products, especially on gen6+
where it causes the command streamer to fail to parse instructions
following a WAIT_FOR_EVENT. We use WAIT_FOR_EVENT for synchronising
between the GPU and the display engines, and so this bit being unset may
cause hangs.
References: https://bugzilla.kernel.org/show_bug.cgi?id=52311
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Reviewed-by: Imre Deak <imre.deak@intel.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 b401788..59afb7e 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -533,6 +533,7 @@
#define MI_MODE 0x0209c
# define VS_TIMER_DISPATCH (1 << 6)
# define MI_FLUSH_ENABLE (1 << 12)
+# define ASYNC_FLIP_PERF_DISABLE (1 << 14)
#define GEN6_GT_MODE 0x20d0
#define GEN6_GT_MODE_HI (1 << 9)