CDC_ACM not firing

Question

I've been trying to connect my arduino mega adk to my machine for the past week or so and I can't get it to work as ttyACMx under /dev is being created.

My machine is on Ubuntu 12.04 with the kernel of 3.2.0-32-generic.

Here're the related dmesg:

[ 8294.500275] usb 2-1.1: USB disconnect, device number 3
[ 8306.416596] usb 2-1.1: new full-speed USB device number 4 using ehci_hcd

I've tried the same hardware on a different machine also with ubuntu 12.04 and the same kernel and I've got

cdc_acm 6.2:1.0 ttyACM0: USB ACM device

in my dmesg and it works just fine.

I've checked and cdc_acm is loaded on both the machines. Any idea where this could have gone wrong?

Thanks

Answer 1

So the solution: unplug the arduino, unload cdc_acm and reload cdc_acm

Commands for people unfamiliar with linux:

# rmmod cdc_acm
# modprobe cdc_acm