On 31/03/2021 18:33, Lukasz Luba wrote:
> When the temperature is below the first activation trip point the cooling
> devices are not checked, so they cannot maintain fresh statistics. It
> leads into the situation, when temperature crosses first trip point, the
> statistics are stale and show state for very long period.
Can you elaborate the statistics you are referring to ?
I can understand the pid controller needs temperature but I don't
understand the statistics with the cooling device.
> This has impact
> on IPA algorithm calculation and wrong decisions. Thus, check the cooling
> devices even when the temperature is low, to refresh these statistics.
>
> Signed-off-by: Lukasz Luba <lukasz.l...@arm.com>
> ---
> drivers/thermal/gov_power_allocator.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/thermal/gov_power_allocator.c
> b/drivers/thermal/gov_power_allocator.c
> index 2802a0e13c88..0cbd10cab193 100644
> --- a/drivers/thermal/gov_power_allocator.c
> +++ b/drivers/thermal/gov_power_allocator.c
> @@ -575,15 +575,27 @@ static void allow_maximum_power(struct
> thermal_zone_device *tz)
> {
> struct thermal_instance *instance;
> struct power_allocator_params *params = tz->governor_data;
> + u32 req_power;
>
> mutex_lock(&tz->lock);
> list_for_each_entry(instance, &tz->thermal_instances, tz_node) {
> + struct thermal_cooling_device *cdev = instance->cdev;
> +
> if ((instance->trip != params->trip_max_desired_temperature) ||
> (!cdev_is_power_actor(instance->cdev)))
> continue;
>
> instance->target = 0;
> mutex_lock(&instance->cdev->lock);
> + /*
> + * Call for updating the cooling devices local stats and avoid
> + * periods of dozen of seconds when those have not been
> + * maintained. The long period would come into the first check
> + * when lower threshold is crossed. Thus, limit it to single
> + * one longer polling period.
> + */
> + cdev->ops->get_requested_power(cdev, &req_power);
> +
> instance->cdev->updated = false;
> mutex_unlock(&instance->cdev->lock);
> thermal_cdev_update(instance->cdev);
>
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