[PATCH net-next v3 1/4] dt-bindings: net: ftgmac100: Add delay properties for AST2600

[Jacky Chou]

> > > > +  - if:
> > > > +      properties:
> > > > +        compatible:
> > > > +          contains:
> > > > +            const: aspeed,ast2600-mac01
> > > > +    then:
> > > > +      properties:
> > > > +        rx-internal-delay-ps:
> > > > +          minimum: 0
> > > > +          maximum: 1395
> > > > +          multipleOf: 45
> > >
> > > I would add a default: 0
> > >
> >
> > Agreed.
> > I will add it in next version.
> >
> > > > +        tx-internal-delay-ps:
> > > > +          minimum: 0
> > > > +          maximum: 1395
> > > > +          multipleOf: 45
> > >
> > > and also here.
> > >
> >
> > Agreed.
> >
> > > > +      required:
> > > > +        - scu
> > > > +        - rx-internal-delay-ps
> > > > +        - tx-internal-delay-ps
> > >
> > > and then these are not required, but optional.
> > >
> >
> > Configure the tx/rx delay in the scu register.
> > At least, the scu handle must be required.
> 
> Sorry, i was unclear. By says 'and then', i was trying to chain it to the previous
> comment, that the delays should default to 0. With defaults set,
> rx-internal-delay-ps and tx-internal-delay-ps become optional. I agree scu is
> required.
> 
> > Here I have one question.
> > In v3 patches series, if the ftgmac driver cannot find one of
> > tx-internal-delay-ps and rx-internal-delay-ps, it will return error in
> > probe stage.
> > If here is optional, does it means that just add warning and not
> > return error when lack one of them and use the default to configure?
> > Or not configure tx/rx delay just return success in probe stage?
> 
> Once you add the default statement, it is clear what delay should be added if
> they property is not listed, 0. No warning is needed.
> 
> What you should find in the end is that most boards just set the new
> compatible and 'rgmii-id', and need nothing else. Only badly designed boards
> tend to need tx-internal-delay-ps and rx-internal-delay-ps.
> 

Thanks for the clarification and detailed explanation.

In the next version, I'll mark "aspeed,ast2600-mac" as deprecated and continue 
using "aspeed,ast2600-mac01" and "aspeed,ast2600-mac23".
I'll also add the default delay values for tx/rx-internal-delay-ps.

In the driver, if those properties are missing, it will use the default values for configuration.
Additionally, I'll treat aspeed-ast2600-evb.dts as a new board using the new
compatible and 'rgmii-id'.

Thanks again for your helpful feedback.

Thanks,
Jacky