Sima requested that in a discussion, just copy&paste my explanation from
the mail.
Signed-off-by: Christian König <christian.koenig@xxxxxxx>
---
drivers/gpu/drm/scheduler/sched_entity.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/scheduler/sched_entity.c b/drivers/gpu/drm/scheduler/sched_entity.c
index 58c8161289fe..571e2f2365a1 100644
--- a/drivers/gpu/drm/scheduler/sched_entity.c
+++ b/drivers/gpu/drm/scheduler/sched_entity.c
@@ -166,8 +166,21 @@ bool drm_sched_entity_is_ready(struct drm_sched_entity *entity)
* drm_sched_entity_error - return error of last scheduled job
* @entity: scheduler entity to check
*
- * Opportunistically return the error of the last scheduled job. Result can
- * change any time when new jobs are pushed to the hw.
+ * Drivers should use this function in two ways:
+ *
+ * 1. In it's prepare callback so that when one submission fails all following
+ * from the same ctx are marked with an error number as well.
+ *
+ * This is intentionally done in a driver callback so that driver decides if
+ * they want subsequent submissions to fail or not. That can be helpful for
+ * example for in kernel paging queues where submissions don't depend on each
+ * other and a failed submission shouldn't cancel all following.
+ *
+ * 2. In it's submission IOCTL to reject new submissions and inform userspace
+ * that it needs to kick of some error handling.
+ *
+ * Returns the error of the last scheduled job. Result can change any time when
+ * new jobs are pushed to the hw.
*/
int drm_sched_entity_error(struct drm_sched_entity *entity)
{
--
2.34.1
