Intel i226 doesn't work correctly on 2.5 Gbps networks

[geerlingguy]

As documented in #2, the i226 NIC on the TimeHAT doesn't seem to get any network connection when I plug it into a 2.5 Gbps network switch. If I manually force the 1 Gbps link speed, it starts working:

ethtool -s eth1 autoneg on speed 1000 duplex full

Also, currently I have to manually force an IPv4 address as DHCP seems to not be working, and since I'm not testing IPv6, I've also disabled IPv6. This might get fixed if I update the firmware for the i226... maybe.

If I plug it into a 1 Gbps switch, it works fine too.

It'd be nice to get 2.5 Gbps speeds, though. So far none of the tricks I've found online seem to work.

[geerlingguy]

So... after some more conversation with Julian St. James today, he said the magjack used on the V2 board revision that I have is actually only rated for 1 Gbps, and that's likely the source of my problems.

It could very well be that, so he's sending over the V4 board revision with the better magjack, and hopefully that'll solve the problem. We'll see!

[geerlingguy]

FYI I tested with a TimeHAT with the new MagJack, and I'm still not able to get packets to flow at 2.5 Gbps.

When I take out my 1 Gbps eth1 if-up.d script, and reboot, with WiFi disabled (sudo nmcli radio wifi off), I wind up with the same issue as before, so I'm not quite sure where it's going wrong. Could still be a driver issue.

dmesg logs show nothing out of the ordinary:

[  221.916726] igc 0000:01:00.0 eth1: NIC Link is Down
[  235.132992] igc 0000:01:00.0 eth1: NIC Link is Up 2500 Mbps Full Duplex, Flow Control: RX
[  235.135252] igc 0000:01:00.0 eth1: Force mode currently not supported
[  238.840993] igc 0000:01:00.0 eth1: NIC Link is Up 2500 Mbps Full Duplex, Flow Control: RX
[  347.919527] warning: `iwconfig' uses wireless extensions which will stop working for Wi-Fi 7 hardware; use nl80211
[  430.428769] igc 0000:01:00.0 eth1: NIC Link is Down
[  439.165036] igc 0000:01:00.0 eth1: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
[  439.167484] igc 0000:01:00.0 eth1: Force mode currently not supported
[  442.733036] igc 0000:01:00.0 eth1: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX

[geerlingguy]

@ahmadexp has suggested I test the card in another PC with the PCIe to FFC adapter card he sent over. A wise idea, that way we can see if it's something Pi specific, or a definitive driver issue (I can test on Ubuntu or Debian maybe first).