[PATCH 4/5] post-submit

[Chris Wilson]

---
 drivers/gpu/drm/i915/gt/intel_lrc.c | 37 +++++++++++++----------------
 1 file changed, 16 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index e866b8d721ed..73ae3862f34b 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -3163,26 +3163,16 @@ static void queue_request(struct intel_engine_cs *engine,
 	set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
 }
 
-static void __submit_queue_imm(struct intel_engine_cs *engine)
-{
-	struct intel_engine_execlists * const execlists = &engine->execlists;
-
-	if (reset_in_progress(execlists))
-		return; /* defer until we restart the engine following reset */
-
-	__execlists_submission_tasklet(engine);
-}
-
-static void submit_queue(struct intel_engine_cs *engine,
+static bool submit_queue(struct intel_engine_cs *engine,
 			 const struct i915_request *rq)
 {
 	struct intel_engine_execlists *execlists = &engine->execlists;
 
 	if (rq_prio(rq) <= execlists->queue_priority_hint)
-		return;
+		return false;
 
 	execlists->queue_priority_hint = rq_prio(rq);
-	__submit_queue_imm(engine);
+	return true;
 }
 
 static bool ancestor_on_hold(const struct intel_engine_cs *engine,
@@ -3196,20 +3186,22 @@ static void flush_csb(struct intel_engine_cs *engine)
 {
 	struct intel_engine_execlists *el = &engine->execlists;
 
-	if (READ_ONCE(el->pending[0]) && tasklet_trylock(&el->tasklet)) {
-		if (!reset_in_progress(el))
-			process_csb(engine);
-		tasklet_unlock(&el->tasklet);
+	if (!tasklet_trylock(&el->tasklet)) {
+		tasklet_hi_schedule(&el->tasklet);
+		return;
 	}
+
+	if (!reset_in_progress(el))
+		execlists_submission_tasklet((unsigned long)engine);
+
+	tasklet_unlock(&el->tasklet);
 }
 
 static void execlists_submit_request(struct i915_request *request)
 {
 	struct intel_engine_cs *engine = request->engine;
 	unsigned long flags;
-
-	/* Hopefully we clear execlists->pending[] to let us through */
-	flush_csb(engine);
+	bool submit = false;
 
 	/* Will be called from irq-context when using foreign fences. */
 	spin_lock_irqsave(&engine->active.lock, flags);
@@ -3224,10 +3216,13 @@ static void execlists_submit_request(struct i915_request *request)
 		GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root));
 		GEM_BUG_ON(list_empty(&request->sched.link));
 
-		submit_queue(engine, request);
+		submit = submit_queue(engine, request);
 	}
 
 	spin_unlock_irqrestore(&engine->active.lock, flags);
+
+	if (submit)
+		flush_csb(engine);
 }
 
 static void __execlists_context_fini(struct intel_context *ce)
-- 
2.20.1