Hi Lukasz,
On Tuesday 24 Nov 2020 at 16:10:23 (+0000), Lukasz Luba wrote:
> Intelligent Power Allocation (IPA) is built around the PID controller
> concept. The initialization code tries to setup the environment based on
> the information available in DT or estimate the value based on minimum
> power reported by each of the cooling device. The estimation will have an
> impact on the PID controller behaviour via the related 'k_po', 'k_pu',
> 'k_i' coefficients and also on the power budget calculation.
>
> This change prevents the situation when 'k_i' is relatively big compared
> to 'k_po' and 'k_pu' values. This might happen when the estimation for
> 'sustainable_power' returned small value, thus 'k_po' and 'k_pu' are
> small.
>
> Signed-off-by: Lukasz Luba <lukasz.l...@arm.com>
> ---
> drivers/thermal/gov_power_allocator.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/thermal/gov_power_allocator.c
> b/drivers/thermal/gov_power_allocator.c
> index b29e21c56a4f..2e20085ed217 100644
> --- a/drivers/thermal/gov_power_allocator.c
> +++ b/drivers/thermal/gov_power_allocator.c
> @@ -134,6 +134,7 @@ static void estimate_pid_constants(struct
> thermal_zone_device *tz,
> int ret;
> int switch_on_temp;
> u32 temperature_threshold;
> + s32 k_i;
>
> ret = tz->ops->get_trip_temp(tz, trip_switch_on, &switch_on_temp);
> if (ret)
> @@ -159,8 +160,11 @@ static void estimate_pid_constants(struct
> thermal_zone_device *tz,
> tz->tzp->k_pu = int_to_frac(2 * sustainable_power) /
> temperature_threshold;
>
> - if (!tz->tzp->k_i || force)
> - tz->tzp->k_i = int_to_frac(10) / 1000;
> + if (!tz->tzp->k_i || force) {
> + k_i = tz->tzp->k_pu / 10;
> + tz->tzp->k_i = k_i > 0 ? k_i : 1;
> + }
> +
> /*
> * The default for k_d and integral_cutoff is 0, so we can
> * leave them as they are.
> --
I see this patch did not change so:
Reviewed-by: Ionela Voinescu <ionela.voine...@arm.com>
> 2.17.1
>
