Re: [PATCH net 2/2] net: stmmac: qcom-ethqos: advertise supported SerDes interfaces

[Mohd Ayaan Anwar]

On Thu, Sep 17, 2026 at 07:36:42AM +0200, Maxime Chevallier wrote:
> On 9/17/26 06:29, Thomas Karpiniec wrote:
> > This POC did show that STMMAC_FLAG_SERDES_SUPPORTS_2500M enabled phylink to configure the integrated PCS for 2500BASE-X and a 2.5 Gbps link came up with no apparent issues.
> 
> Maybe the blind spot is inband aneg. Mohd, you were quite involved in
> this, do you remember where we stand on that front ?
> 

That sounds about right. Let me go through the older emails and the logs
I had captured at the time to jog my memory.

Thomas, it would be useful to know if switching between 1G and 2.5G
causes any PCS instability. I remember that particular test case causing
a lot of SerDes link flapping.

Note that I was testing the QCS9100 board which has the AQR115C PHY (and
due to its rate matching capabilities, phylink presents all speeds by
default, unlike QCA8081).

In parallel, I will try to test out boards with both of these PHYs as
well.

	Ayaan