Re: [PATCH v2] net: usb: usbnet: restore usb%d name exception for local mac addresses

[Oliver Neukum <oneukum@suse.com>]

On 26.03.25 09:32, Dominique Martinet wrote:
> commit 8a7d12d674ac ("net: usb: usbnet: fix name regression") assumed
> that local addresses always came from the kernel, but some devices hand
> out local mac addresses so we ended up with point-to-point devices with
> a mac set by the driver, renaming to eth%d when they used to be named
> usb%d.
> 
> Userspace should not rely on device name, but for the sake of stability
> restore the local mac address check portion of the naming exception:
> point to point devices which either have no mac set by the driver or
> have a local mac handed out by the driver will keep the usb%d name.
> 
> (some USB LTE modems are known to hand out a stable mac from the locally
> administered range; that mac appears to be random (different for
> mulitple devices) and can be reset with device-specific commands, so
> while such devices would benefit from getting a OUI reserved, we have
> to deal with these and might as well preserve the existing behavior
> to avoid breaking fragile openwrt configurations and such on upgrade.)
> 
> Link: https://lkml.kernel.org/r/20241203130457.904325-1-asmadeus@codewreck.org
> Fixes: 8a7d12d674ac ("net: usb: usbnet: fix name regression")
> Cc: stable@vger.kernel.org
> Tested-by: Ahmed Naseef <naseefkm@gmail.com>
> Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
Acked-by: Oliver Neukum <oneukum@suse.com>