[Intel-gfx] [PATCH 11/51] drm/i915: Disable preempt busywait when using GuC scheduling

Matthew Brost
2021-07-16T20:00:15Z

Disable preempt busywait when using GuC scheduling. This isn't needed as
the GuC controls preemption when scheduling.

v2:
(John H):
- Fix commit message

Cc: John Harrison <john.c.harrison@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@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);
--
2.28.0