Re: [PATCH v1 09/16] thermal: gov_step_wise: Use trip thresholds instead of trip temperatures

Lukasz Luba
2024-04-19T19:11:45Z

On 4/10/24 17:43, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> In principle, the Step-Wise governor should take trip hystereses into

s/hystereses/hysteresis/

> account. After all, once a trip has been crossed on the way up,
> mitigation is still needed until it is crossed on the way down.
>
> For this reason, make it use trip thresholds that are computed by
> the core when trips are crossed, so as to apply mitigations in the
> hysteresis rages of trips that were crossed on the way up, but have
> not been crossed on the way down yet.
>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
> drivers/thermal/gov_step_wise.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> Index: linux-pm/drivers/thermal/gov_step_wise.c
> ===================================================================
> --- linux-pm.orig/drivers/thermal/gov_step_wise.c
> +++ linux-pm/drivers/thermal/gov_step_wise.c
> @@ -62,7 +62,8 @@ static unsigned long get_target_state(st
> }
>
> static void thermal_zone_trip_update(struct thermal_zone_device *tz,
> - const struct thermal_trip *trip)
> + const struct thermal_trip *trip,
> + int trip_threshold)
> {
> int trip_id = thermal_zone_trip_id(tz, trip);
> enum thermal_trend trend;
> @@ -72,13 +73,13 @@ static void thermal_zone_trip_update(str
>
> trend = get_tz_trend(tz, trip);
>
> - if (tz->temperature >= trip->temperature) {
> + if (tz->temperature >= trip_threshold) {

So this value in 'trip_threshold' might be lower than older
'trip->temperature', but not necessarily. Anyway, all good here.

> throttle = true;
> trace_thermal_zone_trip(tz, trip_id, trip->type);
> }
>
> dev_dbg(&tz->device, "Trip%d[type=%d,temp=%d]:trend=%d,throttle=%d\n",
> - trip_id, trip->type, trip->temperature, trend, throttle);
> + trip_id, trip->type, trip_threshold, trend, throttle);
>
> list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
> if (instance->trip != trip)
> @@ -131,7 +132,7 @@ static void step_wise_manage(struct ther
> trip->type == THERMAL_TRIP_HOT)
> continue;
>
> - thermal_zone_trip_update(tz, trip);
> + thermal_zone_trip_update(tz, trip, td->threshold);
> }
>
> list_for_each_entry(instance, &tz->thermal_instances, tz_node)
>
>
>

LGTM w/ spelling fixed.

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>