Usbgadget ecm not enumerated - there is no l4tbr0 in `ifconfig`


The custom board is recognized in device mode. I can use it as a USB gadget with ACM - that means I can hook up to the board through /dev/ttyACM0. The USB gadget for mass storage also works like a charm.

However, the USB Gadget-ethernet/ECM choice doesn’t show up. i checked it with the 'ifconfig' command and all I see is eth0, lo, rndis0, and usb0 - no sign of l4tbr0.

i checked /opt/nvidia/l4t-usb-device-mode/, and enable_ecm=1 → it is enabled.

You can take a look at the Device Tree below for more info.
kernel_tegra194-p3668-0001-p3509-0000_edit.dts (393.6 KB)
the original for your reference:
kernel_tegra194-p3668-0001-p3509-0000_ori.dts (393.6 KB)

Best regards,

Would like to get detail of the use-case. You have a host PC connecting to Xavier NX developer kit and Xavier NX runs in device mode. And you would like to use ethernet on Xavier NX developer kit to connect to internet. Do we understand the use-case correctly?

Hello DaneLLL,

Indeed, you’re right.
The Ethernet I was referring to is actually Ethernet over USB, operating in device mode. This allows me to obtain the address, similar to what’s achievable with the development board. However, this capability seems to be unavailable to me following the modifications to the device tree. Interestingly, USB-ACM & USB-MassStorage functionality continues to work despite these changes.

Looks like the use-case does not work on default release. Probably certain configs needs to be enabled. We will check and also other users may share experience.

Another use-case is to connect to a Android phone to use USB tethering. Jetson device is in host mode and the phone is in device mode. This is reported before but shall work fine on latest Jetpack 4.6.4 and 5.1.2.
Android USB tethering not working

1 Like

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.