On Tue, Jan 07, 2025 at 01:16:33PM +0000, Daniel Golle wrote: > On Tue, Jan 07, 2025 at 12:47:14PM +0000, Russell King (Oracle) wrote: > > ... but we don't see link-up reported by the PCS after the PHY comes > > up. Why is that - I think that needs investigation before we proceed > > to patch the issue, because that suggests the PCS isn't seeing > > valid 2500base-X from the PHY. > > The PCS doesn't support in-band status in 2500Base-X mode, or at least > the implementation isn't compatible with those RealTek PHYs. There is in-band for base-X, which involves 16-bit control words to report the capabilities of either end (basically half/full duplex, pause modes). Unlike SGMII, it doesn't contain any status bits for link up, because that is irrelevant. Link-up state in base-X modes comes from the PCS itself, whether the PCS is in sync with the media, and whether it has valid format. This has *nothing* to do with in-band. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!
