Re: [Intel-wired-lan] [PATCH v2 2/2] e1000e: fix link fluctuations problem

[Sasha Neftin]

On 10/05/2024 15:32, Andrew Lunn wrote:
> > > It would be interesting to see what the link partner sees. What does
> > > it think the I219-LM is advertising? Is it advertising 1000BaseT_Half?
> >
> > i219 parts come with LSI PHY. 1000BASE-T half-duplex is not supported.
> > 1000BASET half-duplex not advertised in IEEE 1000BASE-T Control Register 9.
>
> That is the theory. But in practice? What does the link partner really
> see? I've come across systems which get advertisement wrong. However,
> in that case, i suspect it is the software above the PHY, not the PHY
> itself which was wrong.
>
> 	Andrew

Not only in the theory. On the link partner IEEE 1000BASE-T Status 
Register - Address 10, Link Partner 1000BASE-T Half-Duplex Capability is 
0. (1000BAS-T HD not advertised). I believe here is some false positive 
indication during the auto-negotiation process.(this is not related to 
the link fluctuation)

Sasha