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@chris-wilson.co.uk Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: stable@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 */}
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