USB to LAN adapter not recognized on boot

Question

I bought a cheap VK-QF9700 to connect to my new Raspberry PI Zero. I know the chipset (DM9601) had some problems with the Raspbian kernel that has been recently updated.

The problem I have is that if I power on the Raspberry, wait for the boot to finish and then plug the Ethernet adapter in the Micro USB, everything works fine.

But if I leave the adapter plugged in and try to boot, the adapter does not get recognized.

I run lsusb in rc.local to check if it is detected, but the command just shows me the standard USB Hub without any devices attached.

I tried resetting (with a utility I found around, usbreset) the USB hub, but nothing happens.

Any ideas?

Answer 1

I had the same problem with my usb ethernet adapter but I solved it in my case by removing the settings used to connect the pi over usb to my laptop.

These settings are not default however and I added these myself before.

So for raspbian Jessie this is:

1. Go into your boot partition, it is automaticly mounted at /boot/
2. From config.txt remove dtoverlay=dwc2
3. From cmdline.txt remove modules_load=dwc2,g_ether

For me this solved the problem and after a reboot ethernet directly showed up. However you cannot ssh into the pi anymore using usb, which seem unneccessary anyway because you have an ethernet now.

Answer 2

See my post: https://forums.raspberrypi.com/viewtopic.php?t=334055 and my reply. I have the same problem with different USB to network adapters (UGREEN / BELKIN), but in my case it only is a problem when booting from an USB SSD. The Belkin adapter should work out of the box conform the rpi compatibilty list.

When I boot from SD-card no problems. You can check it with the dmesg command.