[PATCH] drm/xe: Take job list lock in xe_sched_first_pending_job

[Nirmoy Das <nirmoy.das@intel.com>]

Access to the pending_list should always happens under job_list_lock.

Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Cc: Matthew Brost <matthew.brost@intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
---
 drivers/gpu/drm/xe/xe_gpu_scheduler.h | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gpu_scheduler.h b/drivers/gpu/drm/xe/xe_gpu_scheduler.h
index 64b2ae6839db..c250ea773491 100644
--- a/drivers/gpu/drm/xe/xe_gpu_scheduler.h
+++ b/drivers/gpu/drm/xe/xe_gpu_scheduler.h
@@ -71,8 +71,14 @@ static inline void xe_sched_add_pending_job(struct xe_gpu_scheduler *sched,
 static inline
 struct xe_sched_job *xe_sched_first_pending_job(struct xe_gpu_scheduler *sched)
 {
-	return list_first_entry_or_null(&sched->base.pending_list,
-					struct xe_sched_job, drm.list);
+	struct xe_sched_job *job;
+
+	spin_lock(&sched->base.job_list_lock);
+	job = list_first_entry_or_null(&sched->base.pending_list,
+				       struct xe_sched_job, drm.list);
+	spin_unlock(&sched->base.job_list_lock);
+
+	return job;
 }
 
 static inline int
-- 
2.46.0