Re: [PATCH V5 2/3] thermal/drivers/cpu_cooling: Introduce the cpu idle cooling driver

From: Martin Kepplinger
Date: Thu Dec 12 2019 - 03:17:31 EST

On 11.12.19 23:43, Daniel Lezcano wrote:
> The cpu idle cooling device offers a new method to cool down a CPU by
> injecting idle cycles at runtime.
> It has some similarities with the intel power clamp driver but it is
> actually designed to be more generic and relying on the idle injection
> powercap framework.
> The idle injection duration is fixed while the running duration is
> variable. That allows to have control on the device reactivity for the
> user experience.
> An idle state powering down the CPU or the cluster will allow to drop
> the static leakage, thus restoring the heat capacity of the SoC. It
> can be set with a trip point between the hot and the critical points,
> giving the opportunity to prevent a hard reset of the system when the
> cpufreq cooling fails to cool down the CPU.
> With more sophisticated boards having a per core sensor, the idle
> cooling device allows to cool down a single core without throttling
> the compute capacity of several cpus belonging to the same clock line,
> so it could be used in collaboration with the cpufreq cooling device.
> Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>

Tested-by: Martin Kepplinger <martin.kepplinger@xxxxxxx>