Re: [PATCH v4 1/3] dt-bindings: net: add Realtek RTL8125 PCIe Ethernet

[Krzysztof Kozlowski]

On Wed, Jun 17, 2026 at 06:43:42PM +0200, Heiner Kallweit wrote:
> On 17.06.2026 14:58, Ricardo Pardini via B4 Relay wrote:
> > From: Ricardo Pardini <ricardo@xxxxxxxxxxx>
> > 
> > Add a binding for fixed/soldered Realtek RTL8125 PCIe Ethernet
> > controller.
> > 
> > The "pciVVVV,DDDD" compatibles are the Open Firmware PCI Bus Binding
> > spelling, auto-derived from PCI-SIG vendor/device IDs, but they still
> > need a binding when used in a board DT - analogous to "usbVVVV,PPPP"

Ricardo,

No, they do not need. They are already documented, they already have a
binding, see: dtschema/schemas/pci/pci-device.yaml


> > compatibles documented in their own bindings (e.g. microchip,lan95xx)
> > so board DTs attaching properties (fixed MAC, nvmem cell, ...) to
> > these PCI function nodes can be validated.
> > 
> > Suggested-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
> > Signed-off-by: Ricardo Pardini <ricardo@xxxxxxxxxxx>
> > ---
> >  .../devicetree/bindings/net/realtek,rtl8125.yaml   | 43 ++++++++++++++++++++++
> >  MAINTAINERS                                        |  1 +
> >  2 files changed, 44 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/net/realtek,rtl8125.yaml b/Documentation/devicetree/bindings/net/realtek,rtl8125.yaml
> > new file mode 100644
> > index 0000000000000..eee13fbc1e6a6
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/net/realtek,rtl8125.yaml
> > @@ -0,0 +1,43 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/net/realtek,rtl8125.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Realtek RTL8125 2.5 Gigabit PCIe Ethernet Controller
> > +
> > +maintainers:
> > +  - Heiner Kallweit <hkallweit1@xxxxxxxxx>
> > +
> > +description:
> > +  The Realtek RTL8125 is a 2.5GBASE-T Ethernet controller with a PCIe host
> > +  interface.
> > +
> > +allOf:
> > +  - $ref: ethernet-controller.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    const: pci10ec,8125
> 
> IIRC we came to the conclusion that the compatible string isn't used in the
> relevant code path. Then why add it here? Is there an alignment on this?

Heiner, it is used - in the DTS.

> If it should be added here, then an explaining comment would be helpful.

Commit msg should explain that.  The compatible is used, so it
must be documented and in fact already is, so you need to specify them
ONLY if device nodes have some other properties, like being an ethernet
controller.

I assume that this is the case here, although that should be mentioned
in the commit msg.

Best regards,
Krzysztof