linux-kernel - Re: [PATCH 1/2] soc: qcom: rpmhpd: Use corner in power

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Message-ID: <CAE-0n50EvG4qV0n+Ag+dvFxKKasnUzwH=MA+f-jsgDdBqaqziQ@mail.gmail.com>
Date:   Thu, 8 Jul 2021 00:21:32 +0000
From:   Stephen Boyd <swboyd@...omium.org>
To:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        Rajendra Nayak <rnayak@...eaurora.org>,
        Ulf Hansson <ulf.hansson@...aro.org>
Cc:     linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] soc: qcom: rpmhpd: Use corner in power_off

Quoting Bjorn Andersson (2021-07-02 17:54:15)
> rpmhpd_aggregate_corner() takes a corner as parameter, but in
> rpmhpd_power_off() the code requests the level of the first corner
> instead.
>
> In all (known) current cases the first corner has level 0, so this
> change should be a nop, but in case that there's a power domain with a
> non-zero lowest level this makes sure that rpmhpd_power_off() actually
> requests the lowest level - which is the closest to "power off" we can
> get.
>
> While touching the code, also skip the unnecessary zero-initialization
> of "ret".
>
> Fixes: 279b7e8a62cc ("soc: qcom: rpmhpd: Add RPMh power domain driver")
> Signed-off-by: Bjorn Andersson <bjorn.andersson@...aro.org>
> ---

I think this is why qcom folks talk about "virtual corner" and "physical
corner" because there's the one in command DB and the one in hardware.
Maybe we should change rpmhpd_aggregate_corner() to call the argument
'vcorner'? Unfortunately we can't really build a type system here to
make this problem easy to catch with a mismatched type, unless there's
some sort of typedef trick we can play?

Reviewed-by: Stephen Boyd <swboyd@...omium.org>