diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index e5aba6824e260..c5d7220de529d 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -363,6 +363,53 @@ static void __llist_add(struct llist_node *node, struct llist_head *head) head->first = node; } +static struct i915_request * const * +__engine_active(struct intel_engine_cs *engine) +{ + return READ_ONCE(engine->execlists.active); +} + +static bool __request_in_flight(const struct i915_request *signal) +{ + struct i915_request * const *port, *rq; + bool inflight = false; + + if (!i915_request_is_ready(signal)) + return false; + + /* + * Even if we have unwound the request, it may still be on + * the GPU (preempt-to-busy). If that request is inside an + * unpreemptible critical section, it will not be removed. Some + * GPU functions may even be stuck waiting for the paired request + * (__await_execution) to be submitted and cannot be preempted + * until the bond is executing. + * + * As we know that there are always preemption points between + * requests, we know that only the currently executing request + * may be still active even though we have cleared the flag. + * However, we can't rely on our tracking of ELSP[0] to known + * which request is currently active and so maybe stuck, as + * the tracking maybe an event behind. Instead assume that + * if the context is still inflight, then it is still active + * even if the active flag has been cleared. + */ + if (!intel_context_inflight(signal->context)) + return false; + + rcu_read_lock(); + for (port = __engine_active(signal->engine); (rq = *port); port++) { + if (rq->context == signal->context) { + inflight = i915_seqno_passed(rq->fence.seqno, + signal->fence.seqno); + break; + } + } + rcu_read_unlock(); + + return inflight; +} + static int __await_execution(struct i915_request *rq, struct i915_request *signal, @@ -393,7 +440,7 @@ __await_execution(struct i915_request *rq, } spin_lock_irq(&signal->lock); - if (i915_request_is_active(signal)) { + if (i915_request_is_active(signal) || __request_in_flight(signal)) { if (hook) { hook(rq, &signal->fence); i915_request_put(signal);