[Intel-gfx] [PATCH] drm/i915/execlists: Clear semaphore immediately upon ELSP promotion

[Chris Wilson]

There is no significance to our delay before clearing the semaphore the
engine is waiting on, so release it as soon as we acknowledge the CS
update following our preemption request.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gt/intel_lrc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 16b878d35814..32a30d36eb7b 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1903,6 +1903,9 @@ static void process_csb(struct intel_engine_cs *engine)
 		else
 			promote = gen8_csb_parse(execlists, buf + 2 * head);
 		if (promote) {
+			if (!inject_preempt_hang(execlists))
+				ring_set_paused(engine, 0);
+
 			/* cancel old inflight, prepare for switch */
 			trace_ports(execlists, "preempted", execlists->active);
 			while (*execlists->active)
@@ -1919,9 +1922,6 @@ static void process_csb(struct intel_engine_cs *engine)
 			if (enable_timeslice(execlists))
 				mod_timer(&execlists->timer, jiffies + 1);
 
-			if (!inject_preempt_hang(execlists))
-				ring_set_paused(engine, 0);
-
 			WRITE_ONCE(execlists->pending[0], NULL);
 		} else {
 			GEM_BUG_ON(!*execlists->active);
-- 
2.23.0