[PATCH 2/4] dt-bindings: net: dsa: document internal MDIO bus

[Russell King (Oracle)]

On Thu, Sep 14, 2023 at 07:06:11PM +0100, Russell King (Oracle) wrote:
> On Wed, Sep 13, 2023 at 04:59:19PM +0100, Russell King (Oracle) wrote:
> > On Wed, Sep 13, 2023 at 10:42:31AM +0300, Vladimir Oltean wrote:
> > > On Wed, Sep 13, 2023 at 08:52:37AM +0300, Arınç ÜNAL wrote:
> > > > On 12.09.2023 22:34, Vladimir Oltean wrote:
> > > > > On Tue, Sep 12, 2023 at 10:23:51PM +0300, Arınç ÜNAL wrote:
> > > > > > The phylink bindings for user ports I ended up making by looking up the
> > > > > > existing devicetrees are different than the phylink bindings for the shared
> > > > > > (CPU and DSA) ports currently enforced on all switches.
> > > > > > 
> > > > > > My phylink bindings for user ports:
> > > > > > 
> > > > > >              allOf:
> > > > > >                - anyOf:
> > > > > >                    - required: [ fixed-link ]
> > > > > >                    - required: [ phy-handle ]
> > > > > >                    - required: [ managed ]
> > > > > > 
> > > > > >                - if:
> > > > > >                    required: [ fixed-link ]
> > > > > >                  then:
> > > > > >                    not:
> > > > > >                      required: [ managed ]
> > > > > 
> > > > > Right, it should have been anyOf and not oneOf.. my mistake. It is a bug
> > > > > which should be fixed. It's the same phylink that gets used in both cases,
> > > > > user ports and shared ports :)
> > > > 
> > > > One more thing, I don't recall phy-mode being required to be defined for
> > > > user ports as it will default to GMII. I don't believe this is the same
> > > > case for shared ports so phy-mode is required only for them?
> > > 
> > > phy-mode is not strictly required, but I think there is a strong
> > > preference to set it. IIRC, when looking at the DSA device trees, there
> > > was no case where phy-mode would be absent on CPU/DSA ports if the other
> > > link properties were also present, so we required it too. There were no
> > > complaints in 1 year since dsa_shared_port_validate_of() is there. The
> > > requirement can be relaxed to just a warning and no error in the kernel,
> > > and the removal of "required" in the schema, if it helps making it
> > > common with user ports.
> > 
> > However, phylink pretty much requires phy-mode to be specified to be
> > something sane for shared ports, so I wouldn't be in favour of relaxing
> > the checkinng in dsa_shared_port_validate_of()... not unless you're
> > now going to accept the approach I originally proposed to have DSA
> > drivers tell the core (and thus phylink) what phy-mode and other link
> > parameters should be used when they are missing from DT.
> 
> You mean the approach that I picked up using software nodes that got
> thrown out by the software node people? That approach that I picked
> up from you and tried to get merged?
> 
> No, that's not going to happen, and it's not a question of whether
> _I_ am going to accept that approach or not. So don't throw that
> back on me, please.
> 
> If this is something that we want to solve, we need to stop being so
> devisive (your language above is so) and try to come up with a
> solution that is acceptable to everyone... the swnode approach
> doesn't seem to be it.

Oh dear. I must be going mad!

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