Re: [PATCH v6 11/11] of: mdio: Prevent of_mdiobus_register from scanning mdio-mux nodes

From: Rob Herring
Date: Thu Oct 05 2017 - 18:09:34 EST


On Wed, Sep 27, 2017 at 09:50:46PM -0700, Florian Fainelli wrote:
>
>
> On 09/27/2017 07:12 AM, Andrew Lunn wrote:
> > On Wed, Sep 27, 2017 at 09:34:14AM +0200, Corentin Labbe wrote:
> >> Each child node of an MDIO node is scanned as a PHY when calling
> >> of_mdiobus_register() givint the following result:
> >> [ 18.175379] mdio_bus stmmac-0: /soc/ethernet@1c30000/mdio/mdio-mux has invalid PHY address
> >> [ 18.175408] mdio_bus stmmac-0: scan phy mdio-mux at address 0
> >> [ 18.175450] mdio_bus stmmac-0: scan phy mdio-mux at address 1
> >> [...]
> >> [ 18.176420] mdio_bus stmmac-0: scan phy mdio-mux at address 30
> >> [ 18.176452] mdio_bus stmmac-0: scan phy mdio-mux at address 31
> >>
> >> Since mdio-mux nodes are not PHY, this patch a way to to not scan
> >> them.
> >
> > Hi Corentin
> >
> > I still don't like this, but ...
>
> Me neither, even more so as I don't understand the reasoning behind
> putting the mux as a child node of the MDIO bus controller in the first
> place.

If no one agrees with me, then you shouldn't just accept my answers. I'm
not always right.

Looking at this some more, why can't mdio-mux-mmio be used? Then there
is nothing to review or discuss. If you want to extend that then make it
clear this is just extending/inheriting already defined bindings.

That being said, if we were starting over I would probably do mux
designs differently with DT hierarchy reflecting the mux hierarchy, but
that ship has sailed.

Rob