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Date:   Wed, 19 Oct 2022 14:49:06 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Geert Uytterhoeven <geert@linux-m68k.org>
Cc:     Madalin Bucur <madalin.bucur@nxp.com>,
        Sean Anderson <sean.anderson@seco.com>,
        Andrew Davis <afd@ti.com>,
        "David S . Miller" <davem@davemloft.net>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Jakub Kicinski <kuba@kernel.org>,
        Eric Dumazet <edumazet@google.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Camelia Alexandra Groza <camelia.groza@nxp.com>
Subject: Re: [PATCH net] net: fman: Use physical address for userspace
 interfaces
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> > root@localhost:~# grep 1ae /etc/udev/rules.d/72-fsl-dpaa-persistent-networking.rules
> > SUBSYSTEM=="net", DRIVERS=="fsl_dpa*", ATTR{device_addr}=="1ae0000", NAME="fm1-mac1"
> > SUBSYSTEM=="net", DRIVERS=="fsl_dpa*", ATTR{device_addr}=="1ae2000", NAME="fm1-mac2"
> > SUBSYSTEM=="net", DRIVERS=="fsl_dpa*", ATTR{device_addr}=="1ae4000", NAME="fm1-mac3"
> > SUBSYSTEM=="net", DRIVERS=="fsl_dpa*", ATTR{device_addr}=="1ae6000", NAME="fm1-mac4"
> > SUBSYSTEM=="net", DRIVERS=="fsl_dpa*", ATTR{device_addr}=="1ae8000", NAME="fm1-mac5"
> > SUBSYSTEM=="net", DRIVERS=="fsl_dpa*", ATTR{device_addr}=="1aea000", NAME="fm1-mac6"
> 
> So you rely on the physical address.
> It's a pity this uses a custom sysfs file.
> Can't you obtain this information some other way?
> Anyway, as this is in use, it became part of the ABI.

I agree about the ABI thing. Please add this to the commit messages as
a justification.

It would also be good to move user space away from this. You should be
able to use the port id in the place of the physical address. That is
what is used by Ethernet switches etc, in the udev rules for giving
switch ports names.

       Andrew