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

From: Niklas Söderlund <[email-masked]>
Date: Sat, 14 Sep 2024 16:21:36 +0200

Hello,

On 2024-09-14 16:00:01 +0200, Stefan Eichenberger wrote:
> Hi Niklas and Andrew,
> 
> I was able to do a first basic test on my setup. I'm using the MV88Q2110
> and connecting it to a Göpel media converter that I use as a reference.

Thanks for testing this work.

> However, with your patch applied, I can't get a link. When I set a fixed
> link speed of 1GBit/s and the media converter is configured as the
> master, I can normally do: 
> ethtool -s end1 speed 1000 master-slave forced-slave
> After that, the link came up. However, with the changes made, I can't do
> this anymore. Can you reproduce this in your setup?

Without this patch I can't bring up a 1GBit/s link at all, I can only 
setup a 100 MBit/s link with,

    ethtool -s eth1 speed 100 master-slave forced-slave

If I do the same with speed set to a 1000 I never get a link. That's why 
autoneg is a such a boon for me, as with that I do get a 1 Gbit/s link.

As you have the MV88Q2110 datasheets, can you check the register writes 
in mv88q2110_init_seq0 and mv88q2110_init_seq1 for sanity? Maybe 
something is not quiet right there, I have only been able to reveres 
engineer support for autoneg so it's quiet likely.

> What is your setup
> like? Are you connecting two MV88Q2110 physically to each other?

Yes, I hair-pin two MV88Q2110 together.

> out
> of office again next week, afterwards I should be able to do some more
> testing again. I think being able to set fixed link speeds is a must for
> this PHY.

I'm also at LPC next week but I will do some more testing on this and 
see if I can reproduce your finding with a 100 speed link.

-- 
Kind Regards,
Niklas Söderlund