Re: [PATCH v3 0/7] Add support for Allwinner H6 DVFS

Maxime Ripard
2020-04-20T08:45:57Z

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Hi,

On Sun, Apr 19, 2020 at 03:50:04PM +0200, Clément Péron wrote:
> Now that required drivers are merged we can contibute on DVFS
> support for Allwinner H6.
>
> This serie is based on Yangtao Li serie[0] and Ondřej Jirman work[1].
>
> Most of the OPP tables are taken from original vendor kernel[2].
> Plus there are new CPU frequencies at 1.6GHz, 1.7GHz and 1.8GHz.
>
> I wrote a simple script to randomly set a frequency during
> a random time[3]. This script is quite stressfull and set some high
> frequency without checking temperature. This can result on behavior
> that whould not occurs with the real cpufreq framework.
> As Maxime point out I also tested with cpufreq-ljt-stress-test
> (found here https://github.com/ssvb/cpuburn-arm).
> This script doesn't trigger any issue.
> I also test that that offlining CPU0 and doing DVFS on other CPUs
> works. As CPU regulator is only set for CPU0.
>
> The GPU devfreq was drop as the regulator is still not properly
> drive by panfrost driver[4].
> I will re-introduce it later.
>
> Ondřej Jirman has an Orange Pi 3, Jernej has a PineH64 and a Tanix
> TX6 boards and I have a Beelink GS1 board so I have enable these
> boards. But CPU Devfreq is really touchy has it depends on:
> board design, SoC speed_grade and environement which can affect
> thermal cooling and have different behavior for different user.
>
> If people can test this serie and give feedback, I will try to
> introduce this in LibreElec tree, so LE community can test it.

Applied all of them, thanks!
Maxime

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