6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Tvrtko Ursulin tvrtko.ursulin@igalia.com
commit cbc8764e29c2318229261a679b2aafd0f9072885 upstream.
Since drm_sched_entity_modify_sched() can modify the entities run queue, lets make sure to only dereference the pointer once so both adding and waking up are guaranteed to be consistent.
Alternative of moving the spin_unlock to after the wake up would for now be more problematic since the same lock is taken inside drm_sched_rq_update_fifo().
v2: * Improve commit message. (Philipp) * Cache the scheduler pointer directly. (Christian)
Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com Fixes: b37aced31eb0 ("drm/scheduler: implement a function to modify sched list") Cc: Christian König christian.koenig@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: Luben Tuikov ltuikov89@gmail.com Cc: Matthew Brost matthew.brost@intel.com Cc: David Airlie airlied@gmail.com Cc: Daniel Vetter daniel@ffwll.ch Cc: Philipp Stanner pstanner@redhat.com Cc: dri-devel@lists.freedesktop.org Cc: stable@vger.kernel.org # v5.7+ Reviewed-by: Christian König christian.koenig@amd.com Link: https://patchwork.freedesktop.org/patch/msgid/20240924101914.2713-3-tursulin... Signed-off-by: Christian König christian.koenig@amd.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/scheduler/sched_entity.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -599,6 +599,9 @@ void drm_sched_entity_push_job(struct dr
/* first job wakes up scheduler */ if (first) { + struct drm_gpu_scheduler *sched; + struct drm_sched_rq *rq; + /* Add the entity to the run queue */ spin_lock(&entity->rq_lock); if (entity->stopped) { @@ -608,13 +611,16 @@ void drm_sched_entity_push_job(struct dr return; }
- drm_sched_rq_add_entity(entity->rq, entity); + rq = entity->rq; + sched = rq->sched; + + drm_sched_rq_add_entity(rq, entity); spin_unlock(&entity->rq_lock);
if (drm_sched_policy == DRM_SCHED_POLICY_FIFO) drm_sched_rq_update_fifo(entity, submit_ts);
- drm_sched_wakeup(entity->rq->sched); + drm_sched_wakeup(sched); } } EXPORT_SYMBOL(drm_sched_entity_push_job);