6.17-stable review patch. If anyone has any objections, please let me know.
------------------
From: Philipp Stanner phasta@kernel.org
commit e0023c8a74028739643aa14bd201c41a99866ca4 upstream.
nouveau_sched_fini() uses a memory barrier before wait_event(). wait_event(), however, is a macro which expands to a loop which might check the passed condition several times. The barrier would only take effect for the first check.
Replace the barrier with a function which takes the spinlock.
Cc: stable@vger.kernel.org # v6.8+ Fixes: 5f03a507b29e ("drm/nouveau: implement 1:1 scheduler - entity relationship") Acked-by: Danilo Krummrich dakr@kernel.org Signed-off-by: Philipp Stanner phasta@kernel.org Link: https://patch.msgid.link/20251024161221.196155-2-phasta@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/gpu/drm/nouveau/nouveau_sched.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/nouveau/nouveau_sched.c +++ b/drivers/gpu/drm/nouveau/nouveau_sched.c @@ -482,6 +482,17 @@ nouveau_sched_create(struct nouveau_sche return 0; }
+static bool +nouveau_sched_job_list_empty(struct nouveau_sched *sched) +{ + bool empty; + + spin_lock(&sched->job.list.lock); + empty = list_empty(&sched->job.list.head); + spin_unlock(&sched->job.list.lock); + + return empty; +}
static void nouveau_sched_fini(struct nouveau_sched *sched) @@ -489,8 +500,7 @@ nouveau_sched_fini(struct nouveau_sched struct drm_gpu_scheduler *drm_sched = &sched->base; struct drm_sched_entity *entity = &sched->entity;
- rmb(); /* for list_empty to work without lock */ - wait_event(sched->job.wq, list_empty(&sched->job.list.head)); + wait_event(sched->job.wq, nouveau_sched_job_list_empty(sched));
drm_sched_entity_fini(entity); drm_sched_fini(drm_sched);