On Wed, Oct 23, 2024 at 04:15:31PM +0200, Philipp Stanner wrote:
> drm_sched_job_init()'s name suggests that after the function succeeded,
> parameter "job" will be fully initialized. This is not the case; some
> members are only later set, notably drm_sched_job.sched by
> drm_sched_job_arm().
>
> Document that drm_sched_job_init() does not set all struct members.
>
> Document the lifetime of drm_sched_job.sched.
>
> Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx>
Reviewed-by: Matthew Brost <matthew.brost@xxxxxxxxx>
> ---
> drivers/gpu/drm/scheduler/sched_main.c | 4 ++++
> include/drm/gpu_scheduler.h | 8 ++++++++
> 2 files changed, 12 insertions(+)
>
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index dab8cca79eb7..8c1c4739f36d 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -771,6 +771,10 @@ EXPORT_SYMBOL(drm_sched_resubmit_jobs);
> * Drivers must make sure drm_sched_job_cleanup() if this function returns
> * successfully, even when @job is aborted before drm_sched_job_arm() is called.
> *
> + * Note that this function does not assign a valid value to each struct member
> + * of struct drm_sched_job. Take a look at that struct's documentation to see
> + * who sets which struct member with what lifetime.
> + *
> * WARNING: amdgpu abuses &drm_sched.ready to signal when the hardware
> * has died, which can mean that there's no valid runqueue for a @entity.
> * This function returns -ENOENT in this case (which probably should be -EIO as
> diff --git a/include/drm/gpu_scheduler.h b/include/drm/gpu_scheduler.h
> index ab161289d1bf..95e17504e46a 100644
> --- a/include/drm/gpu_scheduler.h
> +++ b/include/drm/gpu_scheduler.h
> @@ -340,6 +340,14 @@ struct drm_sched_fence *to_drm_sched_fence(struct dma_fence *f);
> struct drm_sched_job {
> struct spsc_node queue_node;
> struct list_head list;
> +
> + /**
> + * @sched:
> + *
> + * The scheduler this job is or will be scheduled on. Gets set by
> + * drm_sched_job_arm(). Valid until drm_sched_backend_ops.free_job()
> + * has finished.
> + */
> struct drm_gpu_scheduler *sched;
> struct drm_sched_fence *s_fence;
>
> --
> 2.47.0
>
