GBit NIC on Nanopi M2

[nicolas314]

Hello!
I just bought a NanoPi-M2 and installed Debian from scratch, recompiled everything using wiki instructions:
http://wiki.friendlyarm.com/wiki/index.php/NanoPi_M2

I observe problems with the GBit NIC stability, which drops signal after a few minutes. The problem looks exactly like what is described here:
http://linux-sunxi.org/Ethernet

For reliable Gigabit networking (1000Mbit operation), several sunxi devices require an important tweak that adjusts the relative timing of the clock and data signals to the PHY, in order to compensate for differing trace lengths on the PCB (details). Among others, this includes Banana Pi/Pro, Cubietruck, Lamobo R1, pcDuino3 Nano and Orange Pi/Mini. Recent mainline U-Boot uses CONFIG_GMAC_TX_DELAY to initialize these devices accordingly. If a necessary GMAC TX delay isn't set, then GBit Ethernet operation might be unreliable or won't work at all. 10/100 Mbit/sec negotiation is unaffected, so misconfigured devices could actually work (faster) when connected to a Fast Ethernet port instead of a GBit Ethernet port.

A simple workaround is to reduce the NIC speed to 100mbps with:
ethtool -s eth0 speed 100 duplex full

It is a bit silly not to use the full interface speed. Any idea how this could be improved?

[jjm]

Hi,
You can use iperf tool to test the Ethernet，but first you need use a gigabit Ethernet router.

[nicolas314]

Hi,
You can use iperf tool to test the Ethernet，but first you need use a gigabit Ethernet router.

This is not a problem of performance. When the NIC works in GBit (default mode) it only maintains connections alive for 30 seconds or so under Debian. Switching speed back to 100MBit/s removes all stability issues. Of course I tested on a GBit network.

Any ideas?