On 16/09/2020 10:42, Chris Wilson wrote:
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@xxxxxxxxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 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);
}
I did not immediately get this one. Do we really need two pulses or
maybe we could re-order the code a bit and just undo the heartbeat park
if pulse after parking did not work?
Regards,
Tvrtko