Re: [PATCH net-next] net: dsa: remove OF-based MDIO bus registration from DSA core

[Arınç ÜNAL]

On 23.01.2024 18:44, Vladimir Oltean wrote:
> On Mon, Jan 22, 2024 at 08:33:48AM +0300, Arınç ÜNAL wrote:
> > These subdrivers which control switches [with MDIO bus] probed on OF, will
> > lose the ability to register the MDIO bus OF-based:
> >
> > drivers/net/dsa/b53/b53_common.c
> > drivers/net/dsa/lan9303-core.c
> > drivers/net/dsa/realtek/realtek-mdio.c
> > drivers/net/dsa/vitesse-vsc73xx-core.c
> >
> > These subdrivers let the DSA core driver register the bus:
> > - ds->ops->phy_read() and ds->ops->phy_write() are present.
> > - ds->user_mii_bus is not populated.
> >
> > The commit fe7324b93222 ("net: dsa: OF-ware slave_mii_bus") which brought
> > OF-based MDIO bus registration on the DSA core driver is reasonably recent
> > and, in this time frame, there have been no device trees in the Linux
> > repository that started describing the MDIO bus, or dt-bindings defining
> > the MDIO bus for the switches these subdrivers control. So I don't expect
> > any devices to be affected.
>
> IIUC, Luiz made the original patch for the realtek switches. Shouldn't
> we wait until realtek registers ds->user_mii_bus on its own, before
> reverting? Otherwise, you're basically saying that Luiz made the DSA
> core patch without needing it.

My findings point to that. Luiz made the patch to optionally register the
MDIO bus of the MDIO controlled Realtek switches OF-based. So it's not
necessary to wait.

Arınç