On Tue, Aug 05, 2025 at 09:59:57AM +0200, Alexander Wilhelm wrote:

I have a ping running in the background and can observe that MAC frames and
TX-RMON packets are continuously increasing. However, the PHY statistics remain
unchanged. I suspect the current SGMII frames originate from U-Boot, as I load
the firmware image via `netboot`. These statistics were recorded at 2.5G speed,
but the same behavior is also visible at 1G.

Do you think the issue still lies within the MAC driver, or could it be related
to the Aquantia driver or firmware?

So the claim is that in U-Boot, the exact same link with the exact same
PHY firmware works, right? Yet in Linux, MAC transmit counters increase,
but nothing comes across on the PHY side of the MII link? What about
packets sent from the link partner (the remote board connected to the PHY)?
Do packets sent from that board result in an increase of PHY counters,
and MAC RX counters?

For sure this is the correct port ("ffe4e6000.ethernet" corresponds to fm1-mac4,
port name in U-Boot would be "FM1@DTSEC4")? What SoC is this on? T1 something?
What SRDS_PRTCL_S1 value is in the RCW? I'd like to trace back the steps
in order to establish that the link works at 2.5G with autoneg disabled
on both ends. It seems to me there is either a lack of connectivity
between the MAC used in Linux and the PHY, or a protocol mismatch.

Could you please also apply this PHY debugging patch and let us know
what the Global System Configuration registers contain after the
firmware applies the provisioning?