Adding a M.2 ethernet port

Regarding robustness, I have downloaded new firmware to my IO card on a running linuxcnc system. It still works and comes back online. One can always wonder how good it was that it was away for half a minute. But nothing crashed, nothing stopped.

Thanks for that document. I had already looked into it and tested what you write there.
Unfortunately it wasn't sufficient on this mini-PC and these realtek network adapters to make the datagrams UNMATCHED go away.
On another system I have it worked fine on the builtin realtek driver though. If I remember, your settings worked on the J1900 I briefly tested.

I am aware of the coalesce settings, but I didn't have to set them to zero on the Intel cards. It worked fine anyway, they are at 3 usecs still.
When I come around to it I will set them to zero in the interfaces file.
I can't find a good way to enter non-energy-efficient mode. It doesn't seem possible (at least easily) to set it in the interfaces file.
If I remember it resets the interfaces when entering or leaving ee mode so nothing I want to do too often.

There are plenty of those mini PC but it is exhausting to search for them. They have product listings with CPU options that are dirt cheap, but after choosing the N100, memory and disk they cost quite a bit more. The one you list look alright, not that I need RS485. Found it on AliX as well. There is now the N150 which is almost identical to the N100. I wouldn't pay much more for that one, maybe a fiver more.

Point 22 refers to eee for intel
Disable energy efficient ethernet. Add this to kernel parameters with isolcpus
igb.EEE=0

Sorry,the document is a bit haphazard as I kept adding stuff as I found it.

Doesn't work. The i226 uses the igc driver.
Neither igc.EEE=on or igc.EEE=off does work, entered just by chance.
As it turns out, eee is disabled by default on the new i226 card so all is good there.

Coalesce is set like this which is perhaps how it always have been done. No need for any tx-usecs, that was the point. In fact, that is an error to add tx-usecs.

 

Yes you are doing it as PCW does it in man hm2_eth
Untested but you could try adding this to /etc/network/interfaces then restart
You can check if enabled with