Re: [PATCH v2] drm/sched: drm_sched_job_cleanup(): correct false doc

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 04.03.25 um 15:13 schrieb Philipp Stanner:
> drm_sched_job_cleanup()'s documentation claims that calling
> drm_sched_job_arm() is a "point of no return", implying that afterwards
> a job cannot be cancelled anymore.
>
> This is not correct, as proven by the function's code itself, which
> takes a previous call to drm_sched_job_arm() into account. In truth, the
> decisive factors are whether fences have been shared (e.g., with other
> processes) and if the job has been submitted to an entity already.
>
> Correct the wrong docstring.
>
> Signed-off-by: Philipp Stanner <phasta@kernel.org>
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
> Changes in v2:
>   - Also adjust comment about arm inside function's body. (Tvrtko)
> ---
>  drivers/gpu/drm/scheduler/sched_main.c | 12 +++++++-----
>  1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index c634993f1346..7e71e89cea89 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -1013,11 +1013,13 @@ EXPORT_SYMBOL(drm_sched_job_has_dependency);
>   * Cleans up the resources allocated with drm_sched_job_init().
>   *
>   * Drivers should call this from their error unwind code if @job is aborted
> - * before drm_sched_job_arm() is called.
> + * before it was submitted to an entity with drm_sched_entity_push_job().
>   *
> - * After that point of no return @job is committed to be executed by the
> - * scheduler, and this function should be called from the
> - * &drm_sched_backend_ops.free_job callback.
> + * Since calling drm_sched_job_arm() causes the job's fences to be initialized,
> + * it is up to the driver to ensure that fences that were exposed to external
> + * parties get signaled. drm_sched_job_cleanup() does not ensure this.
> + *
> + * This function must also be called in &struct drm_sched_backend_ops.free_job
>   */
>  void drm_sched_job_cleanup(struct drm_sched_job *job)
>  {
> @@ -1028,7 +1030,7 @@ void drm_sched_job_cleanup(struct drm_sched_job *job)
>  		/* drm_sched_job_arm() has been called */
>  		dma_fence_put(&job->s_fence->finished);
>  	} else {
> -		/* aborted job before committing to run it */
> +		/* aborted job before arming */
>  		drm_sched_fence_free(job->s_fence);
>  	}
>