Subject: Re: [PATCH] net: dsa: mv88e6xxx: fix mdio bus name when using devicetree

From: Andrew Lunn <[email-masked]>
Date: Mon, 1 May 2017 17:20:54 +0200

On Mon, May 01, 2017 at 10:54:04AM -0400, Sylvain Lemieux wrote:
> From: Liam Beguin <[email-masked]>
> 
> mv88e6xxx_mdio_register automatically generates mdio buses for each switch
> discovered in the devicetree. When switch nodes are embedded in other nodes,
> this can cause sysfs naming collisions since full_name may be truncated.
> 
> Only use devicetree node name instead of the full devicetree path
> as the mdio bus name.

Hi Sylvain

I'm not sure this is a good idea. It probably breaks my boards:

:/sys/class/mdio_bus# ls
!mdio-mux!mdio@1!switch@0!mdio	0.1  0.4  400d0000.ethernet-1  fixed-0
!mdio-mux!mdio@2!switch@0!mdio	0.2  0.8  400d1000.ethernet-2  mv88e6xxx-0

np->name is not unique, where as np->full_name is unique.

However, i can understand your problem with truncation. Maybe a better
solution is to detect if truncation is going to happen. If so, use a
concatenation of a hash of np->full_name, and the right hand part of
np->full_name?

	Andrew