Am 08.07.21 um 19:37 schrieb Daniel Vetter:
If it does, someone managed to set up a sched_entity without schedulers, which is just a driver bug.
NAK, it is perfectly valid for rq selection to fail.
See drm_sched_pick_best():
if (!sched->ready) { DRM_WARN("scheduler %s is not ready, skipping", sched->name); continue; }
This can happen when a device reset fails for some engine.
Regards, Christian.
We BUG_ON() here because in the next patch drm_sched_job_init() will be split up, with drm_sched_job_arm() never failing. And that's the part where the rq selection will end up in.
Note that if having an empty sched_list set on an entity is indeed a valid use-case, we can keep that check in job_init even after the split into job_init/arm.
Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: "Christian König" christian.koenig@amd.com Cc: Luben Tuikov luben.tuikov@amd.com Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Steven Price steven.price@arm.com Cc: Andrey Grodzovsky andrey.grodzovsky@amd.com Cc: Boris Brezillon boris.brezillon@collabora.com Cc: Jack Zhang Jack.Zhang1@amd.com
drivers/gpu/drm/scheduler/sched_entity.c | 2 +- drivers/gpu/drm/scheduler/sched_main.c | 3 +-- 2 files changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c index 79554aa4dbb1..6fc116ee7302 100644 --- a/drivers/gpu/drm/scheduler/sched_entity.c +++ b/drivers/gpu/drm/scheduler/sched_entity.c @@ -45,7 +45,7 @@
- @guilty: atomic_t set to 1 when a job on this queue
is found to be guilty causing a timeout
- Note: the sched_list should have at least one element to schedule
- Note: the sched_list must have at least one element to schedule
the entity- Returns 0 on success or a negative error code on failure.
diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c index 33c414d55fab..01dd47154181 100644 --- a/drivers/gpu/drm/scheduler/sched_main.c +++ b/drivers/gpu/drm/scheduler/sched_main.c @@ -586,8 +586,7 @@ int drm_sched_job_init(struct drm_sched_job *job, struct drm_gpu_scheduler *sched;
drm_sched_entity_select_rq(entity);
- if (!entity->rq)
return -ENOENT;
BUG_ON(!entity->rq);
sched = entity->rq->sched;