Re: [net-next 3/3] net: phy: marvell-88q2xxx: Enable auto negotiation for mv88q2110

[Stefan Eichenberger <eichest@gmail.com>]

Hi Andrew and Niklas,

On Sat, Sep 14, 2024 at 04:50:02PM +0200, Andrew Lunn wrote:
> > master, I can normally do: 
> > ethtool -s end1 speed 1000 master-slave forced-slave
> 
> You might want to try adding 'autoneg off'
> 
> If the new default is to perform autoneg, speed 1000 tells it to try
> to autoneg only advertising 1000. If the link partner is not actually
> performing autoneg, it will never succeed.
> 
> This is the regression i was talking about. For this device, due to
> its history, we might want to default to autoneg off.
> 
> 	Andrew


You were right about the autoneg off. I wasn't able to turn it off in my
first trial because when autoneg is not working I also have to set the
duplex mode. So the following four things worked:
ethtool -s end1 autoneg off duplex full speed 1000 master-slave forced-slave
ethtool -s end1 autoneg off duplex full speed 1000 master-slave forced-master
ethtool -s end1 autoneg off duplex full speed 100 master-slave forced-slave
ethtool -s end1 autoneg off duplex full speed 100 master-slave forced-master

So for our use case everything is working fine now and we can live with
the fact that autoneg is the default.

Tested with a mv88q2110 device.

Tested-by: Stefan Eichenberger <eichest@gmail.com>

Thanks,
Stefan