Re: [PATCH 0/2] opp: core: add regulators enable and disable

From: Viresh Kumar
Date: Mon Sep 05 2022 - 00:35:58 EST


On 03-09-22, 22:35, Clément Péron wrote:
> Today, I compiled my kernel without any program requiring GPU
> computing at boot. This makes the dev_pm_opp_set_rate() to never be
> called and so the regulator is not enabled before the regulator
> framework switches off all the regulators that haven't been enabled.
>
> Unfortunately switching off the GPU regulator makes my board hang..

Why does the board hang? I mean the kernel should boot fine with the
GPU disabled, isn't it ? Or is the regulator shared with some other
critical resource, or something else.

> I'm not sure what is the best approach to fix this.
>
> Is it required that the dev_pm_opp_set_rate() must be called one time
> at the GPU driver init?

Right now, Yes. And it looks like the right approach as well.

> Panfost already calls devfreq_recommended_opp() and dev_pm_opp_put()
> but that doesn't trigger dev_pm_opp_set_rate().

Can you also point to your code ? Which file are you working on ?

--
viresh