linux-kernel - Re: [PATCH v2 3/8] clk: qcom: gpucc-sc8280xp: Add external supply for GX gdsc

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Date: Mon, 8 Jan 2024 10:23:08 -0800
From: Bjorn Andersson <quic_bjorande@...cinc.com>
To: Konrad Dybcio <konrad.dybcio@...aro.org>
CC: Bjorn Andersson <andersson@...nel.org>,
        Michael Turquette
	<mturquette@...libre.com>,
        Stephen Boyd <sboyd@...nel.org>, Rob Herring
	<robh+dt@...nel.org>,
        Krzysztof Kozlowski
	<krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>, Taniya Das <quic_tdas@...cinc.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        Johan Hovold <johan+linaro@...nel.org>,
        Catalin Marinas
	<catalin.marinas@....com>,
        Will Deacon <will@...nel.org>, <linux-arm-msm@...r.kernel.org>,
        <linux-clk@...r.kernel.org>, <devicetree@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <linux-pm@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        "Dmitry
 Baryshkov" <dmitry.baryshkov@...aro.org>
Subject: Re: [PATCH v2 3/8] clk: qcom: gpucc-sc8280xp: Add external supply
 for GX gdsc

On Wed, Dec 27, 2023 at 02:07:52AM +0100, Konrad Dybcio wrote:
> On 22.12.2023 05:39, Bjorn Andersson wrote:
> > On SA8295P and SA8540P the GFX rail is powered by a dedicated external
> > regulator, instead of the rpmh-controlled "gfx.lvl".
> > 
> > Define the "vdd-gfx" as the supply regulator for the GDSC, to cause the
> > gdsc logic to look for, and control, this external power supply.
> > 
> > Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> > Signed-off-by: Bjorn Andersson <quic_bjorande@...cinc.com>
> > ---
> Worth noting the regulator framework will create a virtual supply
> for the normal 8280
> 

You're right. No functional harm, but that's not very nice.

I don't think we have any benefit from having a dummy supply, if the DT
author failed to provide a proper one, so it seems reasonable to switch
gdsc to devm_regulator_get_optional().

Regards,
Bjorn

> Reviewed-by: Konrad Dybcio <konrad.dybcio@...aro.org>
> 
> Konrad