Re: [PATCH V2 3/4] thermal/drivers/cpu_cooling: Introduce the cpu idle cooling driver

From: Viresh Kumar
Date: Tue Dec 03 2019 - 03:24:48 EST


On 02-12-19, 21:28, 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 cycle is fixed while the running cycle 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>
> ---
> V2:
> - Remove idle_duration_us field and use idle_inject API instead (Viresh Kumar)
> - Fixed function definition wheh CPU_IDLE_COOLING is not set
> - Inverted the initialization in the init function (Viresh Kumar)
> ---
> drivers/thermal/cpuidle_cooling.c | 233 ++++++++++++++++++++++++++++++

This needs to go in MAINTAINERS file btw :)

--
viresh