drm/xe/xe_guc_submit: Fix exec queue stop race condition

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 in which it's possible for xe_sched_tdr_queue_imm to
wake the ufence waiter before the exec queue is banned, causing the
ufence waiter to miss the banned state.

Suggested-by: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Stuart Summers <stuart.summers@intel.com>
Signed-off-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240510194540.3246991-1-jonathan.cavitt@intel.com

diff --git a/drivers/gpu/drm/xe/xe_guc_submit.c b/drivers/gpu/drm/xe/xe_guc_submit.c
index fde527d34f5832f0648cd717c8d07f9c191b3444..3a8e501f2bc25ccd6e0f9f3c3e1c1797974bab5c 100644 (file)
--- a/drivers/gpu/drm/xe/xe_guc_submit.c
+++ b/drivers/gpu/drm/xe/xe_guc_submit.c
@@ -1491,8 +1491,8 @@ 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);
                        }
                }
        }