linux-kernel - Re: [PATCH 0/8] arm64: dts: qcom: x1e: mark l12b and l15b always-on

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Message-ID: <Z8gLwSkMocE-KrbH@hovoldconsulting.com>
Date: Wed, 5 Mar 2025 09:30:57 +0100
From: Johan Hovold <johan@...nel.org>
To: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
Cc: Johan Hovold <johan+linaro@...nel.org>,
	Bjorn Andersson <andersson@...nel.org>,
	Konrad Dybcio <konradybcio@...nel.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>, devicetree@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/8] arm64: dts: qcom: x1e: mark l12b and l15b always-on

On Tue, Mar 04, 2025 at 06:07:32PM +0100, Konrad Dybcio wrote:
> On 27.02.2025 9:13 AM, Johan Hovold wrote:
> > The l12b and l15b supplies are used by components that are not (fully)
> > described (and some never will be) and must never be disabled.
> > 
> > Mark the regulators as always-on to prevent them from being disabled,
> > for example, when consumers probe defer or suspend.
> > 
> > Note that there are likely votes from other processors for these rpmh
> > regulators (at least for l15b) but the OS should not rely on that in any
> > case.
> > 
> > Included is also a patch that adds the missing HID supplies for the
> > T14s. It was a corresponding change for the CRD that made me look into
> > this to make sure these supplies were not disabled during suspend or on
> > probe deferrals.

> This looks good, too bad SL7 was left out :( I'll take care of that
> myself

Thanks for catching that. It seems my grep pattern was too specific
given that you had dropped the voltages from the SL7 regulator labels
whereas every other X1 board copy-pasted the CRD which had them:

	vreg_l12b_1p2: ldo12 {

	vreg_l12b: ldo12 {

Like you, I'd prefer if they were not there (especially since they are
not even correct with 3 V rails having "2p9" suffixes), but I see now
that this pattern have been used also for some older Qualcomm machines.

Perhaps we can drop them throughout, at least for X1, for consistency.

> Reviewed-by: Konrad Dybcio <konrad.dybcio@....qualcomm.com>

Thanks for reviewing.

Johan