I915_PRIORITY_INVALID
node->attr.priority = I915_PRIORITY_INVALID;
if (attr->priority == I915_PRIORITY_INVALID)
GEM_BUG_ON(prio == I915_PRIORITY_INVALID);
if (request->sched.attr.priority == I915_PRIORITY_INVALID) {
int last_prio = I915_PRIORITY_INVALID;
GEM_BUG_ON(rq_prio(rq) == I915_PRIORITY_INVALID);