linux-kernel - Re: [PATCH] regulator: qcom_smd: Keep one rpm handle for all vregs

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Date: Wed, 3 Jan 2024 20:31:37 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Konrad Dybcio <konrad.dybcio@...aro.org>
Cc: Bjorn Andersson <andersson@...nel.org>, Liam Girdwood <lgirdwood@...il.com>, 
	Mark Brown <broonie@...nel.org>, Marijn Suijten <marijn.suijten@...ainline.org>, 
	linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] regulator: qcom_smd: Keep one rpm handle for all vregs

On Wed, 3 Jan 2024 at 12:03, Konrad Dybcio <konrad.dybcio@...aro.org> wrote:
>
> On 27.12.2023 12:48, Dmitry Baryshkov wrote:
> > On 27/12/2023 03:29, Konrad Dybcio wrote:
> >> For no apparent reason (as there's just one RPM per SoC), all vregs
> >> currently store a copy of a pointer to smd_rpm. Introduce a single,
> >> global one to save up on space in each definition.
> >>
> >> bloat-o-meter reports:
> >>
> >> Total: Before=43944, After=43924, chg -0.05%
> >>
> >> plus sizeof(ptr) on every dynamically allocated regulator :)
> >>
> >> Signed-off-by: Konrad Dybcio <konrad.dybcio@...aro.org>
> >> ---
>
> [...]
>
> >>   @@ -1440,11 +1438,10 @@ static int rpm_reg_probe(struct platform_device *pdev)
> >>       const struct rpm_regulator_data *vreg_data;
> >>       struct device_node *node;
> >>       struct qcom_rpm_reg *vreg;
> >> -    struct qcom_smd_rpm *rpm;
> >>       int ret;
> >>   -    rpm = dev_get_drvdata(pdev->dev.parent);
> >> -    if (!rpm) {
> >> +    smd_vreg_rpm = dev_get_drvdata(pdev->dev.parent);
> >> +    if (!smd_vreg_rpm) {
> >
> > I thought about having a mutex around (I don't remember if secondary PMICs and/or chargers can be routed through RPM or not).
>
> A mutex for assigning this?

Yep.

>
> Konrad
> >
> > Then I went on checking other RPM and SMD-RPM drivers.
> >
> > clk-rpm: global variable, field
> > clk-smd-rpm: struct field
> > regulator_qcom-smd-rpm: struct field
> >
> > Probably it's worth using the same approach in all four drivers?
>
>


-- 
With best wishes
Dmitry