diff --git a/drivers/gpu/drm/i915/gem/i915_gem_context.c b/drivers/gpu/drm/i915/gem/i915_gem_context.c
index a179e170c936..9f1dc96b10a6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -403,7 +403,7 @@ static struct intel_engine_cs *active_engine(struct intel_context *ce)
 	if (!ce->timeline)
 		return NULL;
 
-	rcu_read_lock();
+	mutex_lock(&ce->timeline->mutex);
 	list_for_each_entry_reverse(rq, &ce->timeline->requests, link) {
 		if (i915_request_completed(rq))
 			break;
@@ -413,7 +413,7 @@ static struct intel_engine_cs *active_engine(struct intel_context *ce)
 		if (engine)
 			break;
 	}
-	rcu_read_unlock();
+	mutex_unlock(&ce->timeline->mutex);
 
 	return engine;
 }