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/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index ae253e0..1f46a8b 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -505,13 +505,20 @@
struct drm_i915_private *dev_priv = dev->dev_private;
int ret = init_ring_common(ring);
- if (INTEL_INFO(dev)->gen > 3) {
+ if (INTEL_INFO(dev)->gen > 3)
I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(VS_TIMER_DISPATCH));
- if (IS_GEN7(dev))
- I915_WRITE(GFX_MODE_GEN7,
- _MASKED_BIT_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) |
- _MASKED_BIT_ENABLE(GFX_REPLAY_MODE));
- }
+
+ /* We need to disable the AsyncFlip performance optimisations in order
+ * to use MI_WAIT_FOR_EVENT within the CS. It should already be
+ * programmed to '1' on all products.
+ */
+ if (INTEL_INFO(dev)->gen >= 6)
+ I915_WRITE(MI_MODE, _MASKED_BIT_ENABLE(ASYNC_FLIP_PERF_DISABLE));
+
+ if (IS_GEN7(dev))
+ I915_WRITE(GFX_MODE_GEN7,
+ _MASKED_BIT_DISABLE(GFX_TLB_INVALIDATE_ALWAYS) |
+ _MASKED_BIT_ENABLE(GFX_REPLAY_MODE));
if (INTEL_INFO(dev)->gen >= 5) {
ret = init_pipe_control(ring);