[iMX8] 10 MBit ethernet not working

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?

1 Like

Hello @thomasstauffer ,

I have asked internally about this issue.
Meanwhile, how critical is having 10Mbit Ethernet to you?

Best regards,

At the moment not critical at all, more about how we advertise the devices we are going to sell. But in case there would be a workaround for the software or the hardware, we are still in a phase, where it would be less a problem to change someting (especially regarding the hardware).

Hello @thomasstauffer,
do you consider having 10Mbit Ethernet a requirement for your application? The reason that I ask is it seems to me that this speed is almost not used anymore these days.
Of course, we will be glad to know if there’s an application that requires it, as it will make it easier for us to prioritize the effort we put into trying to find a fix for this issue.

Thank you,

Hello Rafael,

It’s not a strict requirement. For us, this has low priority.