Re: [PATCH net-next] net: dsa: honor "max-speed" for implicit PHYs on user ports

Vladimir Oltean
2024-12-19T19:36:28Z

On Thu, Dec 19, 2024 at 06:50:18PM +0000, Sverdlin, Alexander wrote:
> There are still switch drivers in tree, which only implement .phy_read/.phy_write
> callbacks (which means, they rely on .user_mii_bus ?), even gigabit-capable,
> such as vsc73xx, rtl8365mb, rtl8366rb... But I'm actually interested in an
> out of tree driver for a new generation of lantiq_gsw hardware, under
> Maxlinear branch, which is planned to be submitted upstream at some point.
>
> The relevant question is then, is it acceptable API (.phy_read/.phy_write),
> or any new gigabit-capable driver must use some form of mdiobus_register
> to populate the MDIO bus explicitly itself?

See the documentation patches which I never managed to finish for general
future directions:
https://patchwork.kernel.org/project/netdevbpf/patch/20231208193518.2018114-4-vladimir.oltean@nxp.com/

Not explicitly having a phy-handle should be seen a legacy feature,
which we are forced to keep for compatibility with existing drivers.