RE: [PATCH v4 1/6] PCI: starfive: Use regulator APIs instead of GPIO APIs to enable the 3V3 power supply of PCIe slots

Hal Feng
2025-12-04T13:20:28Z

> On 03.12.25 00:31, Bjorn Helgaas wrote:
> On Tue, Dec 02, 2025 at 03:02:48AM +0000, Kevin Xie wrote:
> > ...
>
> > > > On Tue, Nov 25, 2025 at 03:55:59PM +0800, Hal Feng wrote:
> > > > > The "enable-gpio" property is not documented in the dt-bindings
> > > > > and using GPIO APIs is not a standard method to enable or
> > > > > disable PCIe slot power, so use regulator APIs to replace them.
> > > >
> > > > I can't tell from this whether existing DTs will continue to work
> > > > after this change. It looks like previously we looked for an
> > > > "enable-gpios" or "enable-gpio" property and now we'll look for a
> > > > "vpcie3v3-supply" regulator property.
> > > >
> > > > I don't see "enable-gpios" or "enable-gpio" mentioned in any of
> > > > the DT patches in this series, so maybe that property was never
> > > > actually used before, and the code for pcie->power_gpio was actually
> dead?
> > >
> > > pcie->power_gpio is used in the our JH7110 EVB, it share the same
> > > pcie pcie->controller driver with VisionFive2 board. Although
> > > JH7110 was not upstreamed, we still hope to maintain the
> > > compatibility of the driver.
> >
> > Sorry, I missed the background information regarding replacing
> > enable_gpio with regulator APIs. I agree with this change.
>
> OK, thanks. I would still like to have something added to the commit log to the
> effect that this change will break any DTs that use "enable-gpios" or "enable-
> gpio", but that's not a problem because such DTs were only internal to StarFive
> and we are OK with updating them and dealing with the fact that the DT is rev-
> locked with the kernel version (old kernels would require an old DT with
> "enable-gpio" and new kernels require an updated DT with "vpcie3v3-
> supply"). Or DTs using "enable-gpio" never existed in the first place.
>
> Or whatever. I just want the commit log to be clear that "enable-gpio" is no
> longer supported and "vpcie3v3-supply" must be included instead, AND that
> you are aware of the breaking nature of the change and here is why that's not
> an issue.

OK. I send another patch [1] today and add the some description to the commit
log accordingly. Please check it. Thanks for your review.

[1] https://lore.kernel.org/all/20251204064956.118747-1-hal.feng@starfivetech.com/

Best regards,
Hal

>
> We can't make kernel changes that require end users to upgrade the DT when
> they update the kernel or downgrade the DT when rolling back.
>
> Bjorn