[PATCH 1/3] drm/xe/xe_guc_submit: Fix exec queue stop race condition

[Matthew Brost]

On Fri, Mar 29, 2024 at 11:49:27AM -0700, Jonathan Cavitt wrote:
> Reorder the xe_sched_tdr_queue_imm and set_exec_queue_banned calls in
> guc_exec_queue_stop.  This prevents a possible race condition between
> the two events.
> 

Patch LGTM but probably explain the race rather just saying it prevents a race...

With a new commit message:
Reviewed-by: Matthew Brost <matthew.brost at intel.com>

> Suggested-by: Matthew Brost <matthew.brost at intel.com>
> Signed-off-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
> ---
>  drivers/gpu/drm/xe/xe_guc_submit.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
> index 13b7e195c7b57..294f40ab6aaf1 100644
> --- a/drivers/gpu/drm/xe/xe_guc_submit.c
> +++ b/drivers/gpu/drm/xe/xe_guc_submit.c
> @@ -1430,8 +1430,8 @@ static void guc_exec_queue_stop(struct xe_guc *guc, struct xe_exec_queue *q)
>  			    !xe_sched_job_completed(job)) ||
>  			    xe_sched_invalidate_job(job, 2)) {
>  				trace_xe_sched_job_ban(job);
> -				xe_sched_tdr_queue_imm(&q->guc->sched);
>  				set_exec_queue_banned(q);
> +				xe_sched_tdr_queue_imm(&q->guc->sched);
>  			}
>  		}
>  	}
> -- 
> 2.25.1
>