linux-kernel - Re: [PATCH v5 14/18] PCI/pwrctl: add a power control driver for WCN7850

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Date: Tue, 20 Feb 2024 12:22:42 +0100
From: Bartosz Golaszewski <brgl@...ev.pl>
To: Mark Brown <broonie@...nel.org>
Cc: Marcel Holtmann <marcel@...tmann.org>, Luiz Augusto von Dentz <luiz.dentz@...il.com>, 
	"David S . Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, 
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>, Conor Dooley <conor+dt@...nel.org>, 
	Kalle Valo <kvalo@...nel.org>, Bjorn Andersson <andersson@...nel.org>, 
	Konrad Dybcio <konrad.dybcio@...aro.org>, Liam Girdwood <lgirdwood@...il.com>, 
	Catalin Marinas <catalin.marinas@....com>, Will Deacon <will@...nel.org>, 
	Bjorn Helgaas <bhelgaas@...gle.com>, Saravana Kannan <saravanak@...gle.com>, 
	Geert Uytterhoeven <geert+renesas@...der.be>, Arnd Bergmann <arnd@...db.de>, 
	Neil Armstrong <neil.armstrong@...aro.org>, Marek Szyprowski <m.szyprowski@...sung.com>, 
	Alex Elder <elder@...aro.org>, Srini Kandagatla <srinivas.kandagatla@...aro.org>, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Abel Vesa <abel.vesa@...aro.org>, 
	Manivannan Sadhasivam <mani@...nel.org>, Lukas Wunner <lukas@...ner.de>, 
	Dmitry Baryshkov <dmitry.baryshkov@...aro.org>, linux-bluetooth@...r.kernel.org, 
	netdev@...r.kernel.org, devicetree@...r.kernel.org, 
	linux-kernel@...r.kernel.org, linux-wireless@...r.kernel.org, 
	linux-arm-msm@...r.kernel.org, linux-arm-kernel@...ts.infradead.org, 
	linux-pci@...r.kernel.org, linux-pm@...r.kernel.org, 
	Bartosz Golaszewski <bartosz.golaszewski@...aro.org>
Subject: Re: [PATCH v5 14/18] PCI/pwrctl: add a power control driver for WCN7850

On Mon, Feb 19, 2024 at 6:50 PM Mark Brown <broonie@...nel.org> wrote:
>
> On Fri, Feb 16, 2024 at 09:32:11PM +0100, Bartosz Golaszewski wrote:
>
> > +static struct pci_pwrctl_wcn7850_vreg pci_pwrctl_wcn7850_vregs[] = {
> > +     {
> > +             .name = "vdd",
> > +             .load_uA = 16000,
> > +     },
>
> I know a bunch of the QC stuff includes these load numbers but are they
> actually doing anything constructive?  It keeps coming up that they're
> causing a bunch of work and it's not clear that they have any great
> effect on modern systems.
>

Yes, we have what is called a high-power mode and a low-power mode in
regulators and these values are used to determine which one to use.

> > +static int pci_pwrctl_wcn7850_power_on(struct pci_pwrctl_wcn7850_ctx *ctx)
> > +{
> > +     int ret;
> > +
> > +     ret = regulator_bulk_enable(ctx->pdata->num_vregs, ctx->regs);
> > +     if (ret)
> > +             return ret;
> > +
> > +     ret = clk_prepare_enable(ctx->clk);
> > +     if (ret)
> > +             return ret;
>
> This won't disable the regulators on error.

Indeed. Thanks for catching this.

Bart