Re: [PATCH] net: phy: phy_ethtool_ksettings_set: Allow any supported speed

[Andrew Lunn]

On Tue, Dec 03, 2024 at 02:05:07PM +0000, Dennis Ostermann wrote:
> Hi,
> 
> according to IEE 802.3-2022, ch. 125.2.4.3, Auto-Negotiation is optional for 2.5GBASE-T1
> 
> > 125.2.4.3 Auto-Negotiation, type single differential-pair media
> > Auto-Negotiation (Clause 98) may be used by 2.5GBASE-T1 and 5GBASE-T1 devices to detect the
> > abilities (modes of operation) supported by the device at the other end of a link segment, determine common
> > abilities, and configure for joint operation. Auto-Negotiation is performed upon link startup through the use
> > of half-duplex differential Manchester encoding.
> > The use of Clause 98 Auto-Negotiation is optional for 2.5GBASE-T1 and 5GBASE-T1 PHYs
> 
> So, purposed change could make sense for T1 PHYs.

The proposed change it too liberal. We need the PHY to say it supports
2.5GBASE-T1, not 2.5GBASE-T. We can then allow 2.5GBASE-T1 to not use
autoneg, but 2.5GBASE-T has to use autoneg.

	Andrew