Re: [PATCH 18/47] drm/i915: Disable preempt busywait when using GuC scheduling

[John Harrison]

On 6/24/2021 00:04, Matthew Brost wrote:

Disable preempt busywait when using GuC scheduling. This isn't need as

needed

the GuC control preemption when scheduling.

controls

With the above fixed:
Reviewed-by: John Harrison <john.c.harri...@intel.com>

Cc: John Harrison <john.c.harri...@intel.com>
Signed-off-by: Matthew Brost <matthew.br...@intel.com>
---
  drivers/gpu/drm/i915/gt/gen8_engine_cs.c | 6 ++++--
  1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c 
b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
index 87b06572fd2e..f7aae502ec3d 100644
--- a/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/gen8_engine_cs.c
@@ -506,7 +506,8 @@ gen8_emit_fini_breadcrumb_tail(struct i915_request *rq, u32 
*cs)
        *cs++ = MI_USER_INTERRUPT;

*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;

-       if (intel_engine_has_semaphores(rq->engine))
+       if (intel_engine_has_semaphores(rq->engine) &&
+           !intel_uc_uses_guc_submission(&rq->engine->gt->uc))
                cs = emit_preempt_busywait(rq, cs);

rq->tail = intel_ring_offset(rq, cs);

@@ -598,7 +599,8 @@ gen12_emit_fini_breadcrumb_tail(struct i915_request *rq, 
u32 *cs)
        *cs++ = MI_USER_INTERRUPT;

*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;

-       if (intel_engine_has_semaphores(rq->engine))
+       if (intel_engine_has_semaphores(rq->engine) &&
+           !intel_uc_uses_guc_submission(&rq->engine->gt->uc))
                cs = gen12_emit_preempt_busywait(rq, cs);

rq->tail = intel_ring_offset(rq, cs);