Re: [PATCH] drm/xe: Fix NPD when saving default context

[Matthew Brost <matthew.brost@intel.com>]

On Wed, May 28, 2025 at 02:42:22PM -0700, Lucas De Marchi wrote:
> xef is only valid if it's a job from userspace.  For in-kernel jobs it
> causes a NPD like below:
> 
>         <4> [] RIP: 0010:xe_sched_job_create+0xbd/0x390 [xe]
> 	...
>         <4> [] Call Trace:
>         <4> []  <TASK>
>         <4> []  __xe_bb_create_job+0xa2/0x240 [xe]
>         <4> []  ? find_held_lock+0x31/0x90
>         <4> []  ? xa_find_after+0x12c/0x250
>         <4> []  xe_bb_create_job+0x6e/0x380 [xe]
>         <4> []  ? xa_find_after+0x136/0x250
>         <4> []  ? __drm_dev_dbg+0x7d/0xb0
>         <4> []  xe_gt_record_default_lrcs+0x542/0xb00 [xe]
> 
> Since drm_file starts with 1 for the unique id, just use 0 for the
> in-kernel jobs.
> 
> Fixes: 2956554823ce ("drm/sched: Store the drm client_id in drm_sched_fence")
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
> Cc: Philipp Stanner <phasta@kernel.org>
> Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> ---
>  drivers/gpu/drm/xe/xe_sched_job.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_sched_job.c b/drivers/gpu/drm/xe/xe_sched_job.c
> index 5921293b25db3..d21bf8f269640 100644
> --- a/drivers/gpu/drm/xe/xe_sched_job.c
> +++ b/drivers/gpu/drm/xe/xe_sched_job.c
> @@ -114,7 +114,7 @@ struct xe_sched_job *xe_sched_job_create(struct xe_exec_queue *q,
>  	xe_exec_queue_get(job->q);
>  
>  	err = drm_sched_job_init(&job->drm, q->entity, 1, NULL,
> -				 q->xef->drm->client_id);
> +				 q->xef ? q->xef->drm->client_id : 0);
>  	if (err)
>  		goto err_free;
>  
> 
> 
>