Re: [PATCH 1/2] of: net: Add helper function of_get_ethdev_label()

Andrew Lunn
2022-01-07T16:55:32Z

On Fri, Jan 07, 2022 at 04:29:31PM +0000, Russell King (Oracle) wrote:
> On Fri, Jan 07, 2022 at 05:12:21PM +0100, Pali Rohár wrote:
> > Adds a new helper function of_get_ethdev_label() which sets initial name of
> > specified netdev interface based on DT "label" property. It is same what is
> > doing DSA function dsa_port_parse_of() for DSA ports.
> >
> > This helper function can be useful for drivers to make consistency between
> > DSA and netdev interface names.
> >
> > Signed-off-by: Pali Rohár <pali@kernel.org>
>
> Doesn't this also need a patch to update the DT binding document
> Documentation/devicetree/bindings/net/ethernet-controller.yaml ?
>
> Also it needs a covering message for the series, and a well thought
> out argument why this is required. Consistency with DSA probably
> isn't a good enough reason.
>
> >From what I remember, there have been a number of network interface
> naming proposals over the years, and as you can see, none of them have
> been successful... but who knows what will happen this time.

I agree with Russell here. I doubt this is going to be accepted.

DSA is special because DSA is very old, much older than DT, and maybe
older than udev. The old DSA platform drivers had a mechanism to
supply the interface name to the DSA core. When we added a DT binding
to DSA we kept that mechanism, since that mechanism had been used for
a long time.

Even if you could show there was a generic old mechanism, from before
the days of DT, that allowed interface names to be set from platform
drivers, i doubt it would be accepted because there is no continuity,
which DSA has.

Andrew