From: Christian König Date: Fri, 9 Aug 2019 15:27:21 +0000 (+0200) Subject: drm/scheduler: use job count instead of peek X-Git-Tag: v5.4-rc1~329^2~1^2 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e1b4ce25dbc93ab0cb8ed0f236a3b9ff7b03802c;p=platform%2Fkernel%2Flinux-rpi.git drm/scheduler: use job count instead of peek The spsc_queue_peek function is accessing queue->head which belongs to the consumer thread and shouldn't be accessed by the producer This is fixing a rare race condition when destroying entities. Signed-off-by: Christian König Acked-by: Andrey Grodzovsky Reviewed-by: Monk.liu@amd.com Signed-off-by: Alex Deucher --- diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 35ddbec1375a..671c90f34ede 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -95,7 +95,7 @@ static bool drm_sched_entity_is_idle(struct drm_sched_entity *entity) rmb(); /* for list_empty to work without lock */ if (list_empty(&entity->list) || - spsc_queue_peek(&entity->job_queue) == NULL) + spsc_queue_count(&entity->job_queue) == 0) return true; return false; @@ -281,7 +281,7 @@ void drm_sched_entity_fini(struct drm_sched_entity *entity) /* Consumption of existing IBs wasn't completed. Forcefully * remove them here. */ - if (spsc_queue_peek(&entity->job_queue)) { + if (spsc_queue_count(&entity->job_queue)) { if (sched) { /* Park the kernel for a moment to make sure it isn't processing * our enity.