Re: dsa: mv88e6xxx: serdes link without phy

[Chris Packham]

On 2/10/20 1:36 am, Andrew Lunn wrote:
>>> Can you run 1000Base-X over these links?
>> With some reading "1000base-x" does seem the right thing to say here.
>> It's even what is reflected in the CMODE field for those ports.
> One more thing you might need is
>
> managed = "in-band-status";
>
>>> If you can, it is probably
>>> worth chatting to Russell King about using inband-signalling, and what
>>> is needed to make it work without having back to back SFPs. If i
>>> remember correctly, Russell has said not much is actually needed.
>> That'd be ideal. The sticking point seems to be allowing it to have no PHY.
> I think there is more to it than that. This is new ground to some
> extent.

managed = "in-band-status"; helps to convince things that there isn't a 
PHY. I need to update mv88e6xxx_mac_link_up to not force the link when 
mode == MLO_AN_INBAND.

I also have a problem with mv88e6xxx_serdes_pcs_get_state expecting 
mv88e6xxx_serdes_get_lane() to return a lane number. Implementing 
mv88e6xxx_serdes_get_lane() for the mv88e6097 causes a lot of other code 
paths to trigger which didn't before. I think I'm close to getting 
something sensible working for my hardware but I'm off on leave for a 
week so I just wanted to get this out before I go.