Re: dsa: mv88e6xxx: serdes link without phy

From: Andrew Lunn
Date: Wed Sep 30 2020 - 21:24:22 EST


>                         port@8 {
>                                 reg = <8>;
>                                 label = "internal8";
>                                 phy-mode = "rgmii-id";
>                                 fixed-link {
>                                         speed = <1000>;
>                                         full-duplex;
>                                 };
>                         };
>                         port@9 {
>                                 reg = <9>;
>                                 label = "internal9";
>                                 phy-mode = "rgmii-id";
>                                 fixed-link {
>                                         speed = <1000>;
>                                         full-duplex;
>                                 };
>                         };

>
> The problem is that by declaring ports 8 & 9 as fixed link the driver
> sets the ForcedLink in the PCS control register. Which mostly works.
> Except if I add a chassis controller while the system is running (or one
> is rebooted) then the newly added controller doesn't see a link on the
> serdes.

Hi Chris

You say SERDES here, but in DT you have rgmii-id?

Can you run 1000Base-X over these links? 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.

Andrew