Am 02.10.20 um 08:55 schrieb Boris Brezillon:
If we don't initialize the entity to idle and the entity is never scheduled before being destroyed we end up with an infinite wait in the destroy path.
Good catch, of hand I would say that this is valid.
v2:
- Add Steven's R-b
Signed-off-by: Boris Brezillon boris.brezillon@collabora.com Reviewed-by: Steven Price steven.price@arm.com
Reviewed-by: Christian König christian.koenig@amd.com
Should I pick it up for drm-misc-next? (Or maybe even -fixes?).
Thanks, Christian.
This is something I noticed while debugging another issue on panfrost causing the scheduler to be in a weird state where new entities were no longer scheduled. This was causing all userspace threads trying to close their DRM fd to be blocked in kernel space waiting for this "entity is idle" event. I don't know if that fix is legitimate (now that we fixed the other bug we don't seem to end up in that state anymore), but I thought I'd share it anyway.
drivers/gpu/drm/scheduler/sched_entity.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 146380118962..f8ec277a6aa8 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -73,6 +73,9 @@ int drm_sched_entity_init(struct drm_sched_entity *entity,
init_completion(&entity->entity_idle);
- /* We start in an idle state. */
- complete(&entity->entity_idle);
- spin_lock_init(&entity->rq_lock); spsc_queue_init(&entity->job_queue);