Subject: Re: [PATCH v1 net-next 6/7] dt-bindings: net: add generic ethernet-switch-port binding

From: Colin Foster <[email-masked]>
Date: Wed, 26 Oct 2022 21:06:08 -0700

On Wed, Oct 26, 2022 at 12:44:21PM -0500, Rob Herring wrote:
> On Mon, Oct 24, 2022 at 10:03:54PM -0700, Colin Foster wrote:
> > The dsa-port.yaml binding had several references that can be common to all
> > ethernet ports, not just dsa-specific ones. Break out the generic bindings
> > to ethernet-switch-port.yaml they can be used by non-dsa drivers.
> > 
> > Signed-off-by: Colin Foster <[email-masked]>
> > Suggested-by: Vladimir Oltean <[email-masked]>
> > ---
> >  .../devicetree/bindings/net/dsa/dsa-port.yaml | 26 +----------
> >  .../bindings/net/ethernet-switch-port.yaml    | 44 +++++++++++++++++++
> >  .../bindings/net/ethernet-switch.yaml         |  4 +-
> >  MAINTAINERS                                   |  1 +
> >  4 files changed, 50 insertions(+), 25 deletions(-)
> >  create mode 100644 Documentation/devicetree/bindings/net/ethernet-switch-port.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/net/dsa/dsa-port.yaml b/Documentation/devicetree/bindings/net/dsa/dsa-port.yaml
> > index 10ad7e71097b..c5144e733511 100644
> > --- a/Documentation/devicetree/bindings/net/dsa/dsa-port.yaml
> > +++ b/Documentation/devicetree/bindings/net/dsa/dsa-port.yaml
> > @@ -4,7 +4,7 @@
> >  $id: http://devicetree.org/schemas/net/dsa/dsa-port.yaml#
> >  $schema: http://devicetree.org/meta-schemas/core.yaml#
> >  
> > -title: Ethernet Switch port Device Tree Bindings
> > +title: DSA Switch port Device Tree Bindings
> >  
> >  maintainers:
> >    - Andrew Lunn <[email-masked]>
> > @@ -15,12 +15,9 @@ description:
> >    Ethernet switch port Description
> >  
> >  allOf:
> > -  - $ref: /schemas/net/ethernet-controller.yaml#
> > +  - $ref: /schemas/net/ethernet-switch-port.yaml#
> >  
> >  properties:
> > -  reg:
> > -    description: Port number
> > -
> >    label:
> >      description:
> >        Describes the label associated with this port, which will become
> > @@ -57,25 +54,6 @@ properties:
> >        - rtl8_4t
> >        - seville
> >  
> > -  phy-handle: true
> > -
> > -  phy-mode: true
> > -
> > -  fixed-link: true
> > -
> > -  mac-address: true
> > -
> > -  sfp: true
> > -
> > -  managed: true
> > -
> > -  rx-internal-delay-ps: true
> > -
> > -  tx-internal-delay-ps: true
> > -
> > -required:
> > -  - reg
> > -
> >  # CPU and DSA ports must have phylink-compatible link descriptions
> >  if:
> >    oneOf:
> > diff --git a/Documentation/devicetree/bindings/net/ethernet-switch-port.yaml b/Documentation/devicetree/bindings/net/ethernet-switch-port.yaml
> > new file mode 100644
> > index 000000000000..cb1e5e12bf0a
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/net/ethernet-switch-port.yaml
> > @@ -0,0 +1,44 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/net/ethernet-switch-port.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Ethernet Switch port Device Tree Bindings
> > +
> > +maintainers:
> > +  - Andrew Lunn <[email-masked]>
> > +  - Florian Fainelli <[email-masked]>
> > +  - Vivien Didelot <[email-masked]>
> > +
> > +description:
> > +  Ethernet switch port Description
> > +
> > +$ref: ethernet-controller.yaml#
> > +
> > +properties:
> > +  reg:
> > +    description: Port number
> > +
> > +  phy-handle: true
> > +
> > +  phy-mode: true
> > +
> > +  fixed-link: true
> > +
> > +  mac-address: true
> > +
> > +  sfp: true
> > +
> > +  managed: true
> > +
> > +  rx-internal-delay-ps: true
> > +
> > +  tx-internal-delay-ps: true
> > +
> > +required:
> > +  - reg
> > +
> > +additionalProperties: true
> > +
> > +...
> > diff --git a/Documentation/devicetree/bindings/net/ethernet-switch.yaml b/Documentation/devicetree/bindings/net/ethernet-switch.yaml
> > index fbaac536673d..f698857619da 100644
> > --- a/Documentation/devicetree/bindings/net/ethernet-switch.yaml
> > +++ b/Documentation/devicetree/bindings/net/ethernet-switch.yaml
> > @@ -36,7 +36,9 @@ patternProperties:
> >          type: object
> >          description: Ethernet switch ports
> >  
> > -        $ref: /schemas/net/dsa/dsa-port.yaml#
> > +        allOf:
> > +          - $ref: /schemas/net/dsa/dsa-port.yaml#
> > +          - $ref: ethernet-switch-port.yaml#
> 
> dsa-port.yaml references ethernet-switch-port.yaml, so you shouldn't 
> need both here.
> 
> I imagine what you were trying to do here was say it is either one of 
> these, not both. I don't think this is going work for the same reasons I 
> mentioned with unevaluatedProperties.

Oh, that was definitely a mistake for me to reference
ethernet-switch-port.yaml. And that was exactly requested of me when
Vladimir helped guide me down this path:

"""
6. The ethernet-switch.yaml will have "$ref: ethernet-switch-port.yaml#"
   and "$ref: dsa-port.yaml". The dsa-port.yaml schema will *not* have
   "$ref: ethernet-switch-port.yaml#", just its custom additions.
   I'm not 100% on this, but I think there will be a problem if:
   - dsa.yaml references ethernet-switch.yaml
     - ethernet-switch.yaml references ethernet-switch-port.yaml
   - dsa.yaml also references dsa-port.yaml
     - dsa-port.yaml references ethernet-switch-port.yaml
   because ethernet-switch-port.yaml will be referenced twice. Again,
   not sure if this is a problem. If it isn't, things can be simpler,
   just make dsa-port.yaml reference ethernet-switch-port.yaml, and skip
   steps 2 and 3 since dsa-port.yaml containing just the DSA specifics
   is no longer problematic.
"""

I might have been testing to see if this was necessary and since I
didn't notice any dt_binding_check errors this might have slipped into
the patch set. But my intent was to reference both here and remove the
reference in dsa-port.yaml.

> Rob