drm/i915: Fix serialisation of pipecontrol write vs semaphore signal

In order for the MI_SEMAPHORE_SIGNAL command to wait until after the
pipecontrol writing the signal value is complete, we have to pause the
CS inside the PIPE_CONTROL with the CS_STALL bit.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461932305-14637-4-git-send-email-chris@chris-wilson.co.uk
This commit is contained in:
Chris Wilson 2016-04-29 13:18:24 +01:00
parent 215a7e3210
commit f9a4ea35b8

View File

@ -1307,7 +1307,7 @@ static int gen8_rcs_signal(struct drm_i915_gem_request *signaller_req,
intel_ring_emit(signaller, GFX_OP_PIPE_CONTROL(6));
intel_ring_emit(signaller, PIPE_CONTROL_GLOBAL_GTT_IVB |
PIPE_CONTROL_QW_WRITE |
PIPE_CONTROL_FLUSH_ENABLE);
PIPE_CONTROL_CS_STALL);
intel_ring_emit(signaller, lower_32_bits(gtt_offset));
intel_ring_emit(signaller, upper_32_bits(gtt_offset));
intel_ring_emit(signaller, seqno);
@ -1489,7 +1489,6 @@ gen8_ring_sync(struct drm_i915_gem_request *waiter_req,
intel_ring_emit(waiter, MI_SEMAPHORE_WAIT |
MI_SEMAPHORE_GLOBAL_GTT |
MI_SEMAPHORE_POLL |
MI_SEMAPHORE_SAD_GTE_SDD);
intel_ring_emit(waiter, seqno);
intel_ring_emit(waiter,