Re: [PATCH v2 3/3] dt-bindings: hwinfo: Add mtk-socinfo driver

[AngeloGioacchino Del Regno]

Il 18/09/23 13:59, Krzysztof Kozlowski ha scritto:
> On 18/09/2023 10:47, AngeloGioacchino Del Regno wrote:
> > Il 17/09/23 10:26, Krzysztof Kozlowski ha scritto:
> > > On 15/09/2023 17:26, William-tw Lin wrote:
> > > > dt-binding documentation for mtk-socinfo driver.
> > >
> > > Here and in subject, drop driver and instead descrbe hardware.
> > >
> > > > mtk-socinfo driver provides SoC-related information.
> > > > Such information includes manufacturer information, SoC name,
> > > > SoC segment name, and SoC marketing name.
> > > >
> > > > Signed-off-by: William-tw Lin <william-tw.lin@xxxxxxxxxxxx>
> > > > ---
> > > >    .../bindings/hwinfo/mtk-socinfo.yaml          | 48 +++++++++++++++++++
> > > >    1 file changed, 48 insertions(+)
> > > >    create mode 100644 Documentation/devicetree/bindings/hwinfo/mtk-socinfo.yaml
> > > >
> > > > diff --git a/Documentation/devicetree/bindings/hwinfo/mtk-socinfo.yaml b/Documentation/devicetree/bindings/hwinfo/mtk-socinfo.yaml
> > > > new file mode 100644
> > > > index 000000000000..74f03f1dc404
> > > > --- /dev/null
> > > > +++ b/Documentation/devicetree/bindings/hwinfo/mtk-socinfo.yaml
> > >
> > > Nothing improved.
> > >
> > > This is a friendly reminder during the review process.
> > >
> > > It seems my previous comments were not fully addressed. Maybe my
> > > feedback got lost between the quotes, maybe you just forgot to apply it.
> > > Please go back to the previous discussion and either implement all
> > > requested changes or keep discussing them.
> > >
> > > Thank you.
> > >
> > > > @@ -0,0 +1,48 @@
> > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > > +%YAML 1.2
> > > > +---
> > > > +$id: http://devicetree.org/schemas/hwinfo/mtk-socinfo.yaml#
> > > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > > +
> > > > +title: MediaTek SoC ChipID
> > > > +
> > > > +maintainers:
> > > > +  - William Lin <william-tw.lin@xxxxxxxxxxxx>
> > > > +  - Matthias Brugger <matthias.bgg@xxxxxxxxx>
> > > > +  - Kevin Hilman <khilman@xxxxxxxxxx>
> > > > +  - AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
> > > > +
> > > > +description:
> > > > +  MediaTek SoCs store various product information in eFuses, including
> > > > +  Chip ID and Revision fields, usable to identify the manufacturer,
> > > > +  SoC version, plus segment and marketing names.
> > > > +
> > > > +properties:
> > > > +  compatible:
> > > > +    const: mediatek,socinfo
> > >
> > > What happened to compatibles? No, this is just wrong and no explained.
> > > You ignored other comments as well. Really, that's not the way to go.
> >
> > Practically, having different compatibles for each SoC is not needed, as
> > the only thing that changes between SoCs is the eFuse(s) that you read to
> > get the information - and that's all.
>
>
> And how do you guarantee that no future SoC will have any difference?
> How can you even predict it?

You're right, it's too much long sighted and at some point in the future this
assumption will be *inevitably* wrong.

Thanks,
Angelo

> > So ... we either use this driver with devicetree, giving it the right eFuses
>
> I am talking about bindings, no driver.
>
> > to read from, or we duplicate the mtk-efuse driver, or we statically assign
> > the eFuses in the driver itself and we set compatibles like
> > "mediatek,mt8195-socinfo" to select that... ideas?
>
> Device specific compatibles followed by fallback, just like for every
> other review coming from me.
>  > Best regards,
> Krzysztof