[Intel-gfx] [PATCH v3 01/20] drm/sched: entity->rq selection cannot fail

[Daniel Vetter]

If it does, someone managed to set up a sched_entity without
schedulers, which is just a driver bug.

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 at intel.com>
Cc: "Christian König" <christian.koenig at amd.com>
Cc: Luben Tuikov <luben.tuikov at amd.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Steven Price <steven.price at arm.com>
Cc: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
Cc: Boris Brezillon <boris.brezillon at collabora.com>
Cc: Jack Zhang <Jack.Zhang1 at 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;
 
-- 
2.32.0