drm/panthor: Defer scheduler entitiy destruction to queue release

Commit de8548813824 ("drm/panthor: Add the scheduler logical block")
handled destruction of a group's queues' drm scheduler entities early
into the group destruction procedure.

However, that races with the group submit ioctl, because by the time
entities are destroyed (through the group destroy ioctl), the submission
procedure might've already obtained a group handle, and therefore the
ability to push jobs into entities. This is met with a DRM error message
within the drm scheduler core as a situation that should never occur.

Fix by deferring drm scheduler entity destruction to queue release time.

Fixes: de8548813824 ("drm/panthor: Add the scheduler logical block")
Signed-off-by: Adrián Larumbe <adrian.larumbe@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20250919164436.531930-1-adrian.larumbe@collabora.com

diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
index 8f17394cc82aad9eaf01e473cd9d3dea46fa3d61..df76653e649a30806a28221099c3553824d7de0b 100644 (file)
--- a/drivers/gpu/drm/panthor/panthor_sched.c
+++ b/drivers/gpu/drm/panthor/panthor_sched.c
@@ -886,8 +886,7 @@ static void group_free_queue(struct panthor_group *group, struct panthor_queue *
        if (IS_ERR_OR_NULL(queue))
                return;
 
-       if (queue->entity.fence_context)
-               drm_sched_entity_destroy(&queue->entity);
+       drm_sched_entity_destroy(&queue->entity);
 
        if (queue->scheduler.ops)
                drm_sched_fini(&queue->scheduler);
@@ -3558,11 +3557,6 @@ int panthor_group_destroy(struct panthor_file *pfile, u32 group_handle)
        if (!group)
                return -EINVAL;
 
-       for (u32 i = 0; i < group->queue_count; i++) {
-               if (group->queues[i])
-                       drm_sched_entity_destroy(&group->queues[i]->entity);
-       }
-
        mutex_lock(&sched->reset.lock);
        mutex_lock(&sched->lock);
        group->destroyed = true;