Re: [PATCH] arm64: dts: renesas: rzt2h-n2h-evk: Add VCC supply for EEPROM

[Lad, Prabhakar]

Hi Geert,

On Wed, Oct 15, 2025 at 4:36 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>
> Hi Prabhakar,
>
> CC at24, regulator
>
> On Tue, 14 Oct 2025 at 17:33, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> > The R1EX24016 EEPROM on the RZ/T2H-N2H Evaluation Kit is powered from
> > the 3.3V rail. Add the regulator phandle for the VCC supply to reflect
> > this in the device tree and avoid the fallback to the dummy regulator:
> >
> >     at24 0-0050: supply vcc not found, using dummy regulator
> >
> > Fixes: 0176c9e82e10 ("arm64: dts: renesas: rzt2h-n2h-evk-common: Enable EEPROM on I2C0")
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> Thanks for your patch!
>
> > --- a/arch/arm64/boot/dts/renesas/rzt2h-n2h-evk-common.dtsi
> > +++ b/arch/arm64/boot/dts/renesas/rzt2h-n2h-evk-common.dtsi
> > @@ -160,6 +160,7 @@ eeprom: eeprom@50 {
> >                 compatible = "renesas,r1ex24016", "atmel,24c16";
> >                 reg = <0x50>;
> >                 pagesize = <16>;
> > +               vcc-supply = <&reg_3p3v>;
> >         };
> >  };
>
> "vcc-supply" is not a required property, according to the DT bindings,
> and I believe the 3.3V supply can be considered always-on (but see
> below to encounter dragons).
> I was always under the impression that these "supply not found, using
> dummy regulator"-messages are just informational, and can be ignored,
> but they are at the KERN_WARNING level.
> So should we add real dummy supplies to DTS, or not?
>
Agreed, I get your point. Let's drop this patch.

Cheers,
Prabhakar