Ethernet communication does not work between two boards with an iMX8M Plus Quad, when manually lowered to 10 MBit. It also does not work if just one verdin board is connected to a GBit network. It works without any issue (no Tx/Rx errors, ca. 95 MByte/s in GBit mode) when manually switched back to 1 GBit or 100 MBit.
1 GBit (works fine)
ethtool -s eth0 speed 1000 duplex full
100 MBit (works fine)
ethtool -s eth0 speed 100 duplex full
10 MBit (does not work anymore, no ping, no TCP, Linux just reports that the link is up)
ethtool -s eth0 speed 10 duplex full autoneg off
ethtool -s eth0 speed 10 duplex half autoneg off
ethtool -s eth0 speed 10 duplex full autoneg on
ethtool -s eth0 speed 10 duplex half autoneg on
According to the Ethernet PHY (KSZ9131) documentation 10 MBit should also be supported. ethtool also reports that 10baseT/Half 10baseT/Full are both supported. Anyone any idea what the issue could be?