Re: [PATCH net-next RFC v4 2/5] net: Expose available time stamping layers to user space.

Köry Maincent
2023-09-06T09:22:08Z

On Tue, 5 Sep 2023 22:29:51 +0200
Andrew Lunn <andrew@lunn.ch> wrote:

> > Maybe we should try to enumerate the use cases, I don't remember now
> > but I think the concern was that there may be multiple PHYs?
>
> You often see a Marvell 10G PHY between a MAC and an SFP cage. You can
> then get a copper SFP module which has a PHY in it.
>
> So:
>
> "Linux" NIC: [DMA MAC][PHY][PHY]
>
> And just to make it more interesting, you sometimes see:
>
> [MAC] - MII MUX -+---[PHY][PHY]
> |
> +---[PHY]
>
> This is currently not supported, but there is work in progress to
> address this, by giving each PHY and ID, and extending the netlink
> ethtool so you can enumerate PHYs and individually configure them.

Yes, I have talked to maxime about his PHY ID support patch series.

> And i pointed out maybe the worst case scenario:
>
> [MAC][PHY][PHY][MAC]switch core[MAC][PHY][PHY]

always more complex! :)