Re: [PATCH net] net: pcs: xpcs-rk: limit advertised interfaces

From: Andrew Lunn

Date: Mon Nov 02 2026 - 21:56:12 EST


> Hi Maxime,
>
> You're right that for modes the PCS does implement, the limit belongs
> on the MAC side. The complication is that the compat table describes
> the whole Synopsys IP set, while a given XPCS instance only implements
> a subset of it. That is a historical design issue in pcs-xpcs: the
> table mixes C73, C37, 2500BASE-X and 10GBASE-X entries, but different
> integrations implement different subsets.
>
> On RK3568 the XPCS instance is wired up for the C37 SGMII path only.
> 1000BASE-X is part of the same C37 core, but I don't have a PHY to test
> it against. QSGMII is not implemented in this core. 2500BASE-X and
> 10GBASE-X are separate modes the shared table carries, and neither is
> implemented on this SoC. C73 is not wired up either.
>
> Trimming the mask is not limiting the PCS, it is cutting the shared
> table down to what this instance actually implements. A
> platform-specific glue is the right place to do that.

Are there any registers which describe how the PCS was configured at
syntheses time?

Andrew