[Intel-gfx] [PATCH 3/4] drm/i915/gt: Always send a pulse down the engine after disabling heartbeat

[Chris Wilson]

Currently, we check we can send a pulse prior to disabling the
heartbeat to verify that we can change the heartbeat, but since we may
re-evaluate execution upon changing the heartbeat interval we need another
pulse afterwards to refresh execution.

Fixes: 9a40bddd47ca ("drm/i915/gt: Expose heartbeat interval via sysfs")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: <stable at vger.kernel.org> # v5.7+
---
 drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
index 8ffdf676c0a0..d09df370f7cd 100644
--- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c
@@ -192,10 +192,12 @@ int intel_engine_set_heartbeat(struct intel_engine_cs *engine,
 	WRITE_ONCE(engine->props.heartbeat_interval_ms, delay);
 
 	if (intel_engine_pm_get_if_awake(engine)) {
-		if (delay)
+		if (delay) {
 			intel_engine_unpark_heartbeat(engine);
-		else
+		} else {
 			intel_engine_park_heartbeat(engine);
+			intel_engine_pulse(engine); /* recheck execution */
+		}
 		intel_engine_pm_put(engine);
 	}
 
-- 
2.20.1