On 30.12.18 10:51, Andrew Lunn wrote:

Some of the Marvell Ethernet switches have a similar setup. Some 
ports have both an internal PHY and a SERDES port which can be 
connected to an SFP cage. Whichever gets link first is connected to 
the MAC.

This decision is taken by hardware? I am just wondering how the outcome
would be detected unambiguously by software. (Any documentation?)

I can also imagine a slightly different setup to what you have, the 
MUX is controlled via a GPIO, not MOD_DEF0, so again, you want both 
active until one gets link, although SFP LOS is not very reliable for
this.

Okay, here the decision for the MUX would be taken by software.

So we need a generic solution to this. In your case, the PHY should 
be configured down when the SFP is present, but then made active when
the SFP is unplugged.

That would be the ideal solution for the Omnia.

For the Marvell switch, we need both SFP and PHY active until one 
gets a link, and then the other configured down. So it sounds like
we need some board specific code involved to implement the board 
specific parts.

Such a "generic" solution would be restricted (per MAC) to a maximum of 
one SFP (fiber or copper), and one separate PHY, right? The main 
difference between boards would be the switching logic.

Klaus