On Thu, 2016-11-17 at 17:11 +0100, Wim Osterholt wrote: > Nov 17 15:07:51 localhost kernel: Check point 10 > Nov 17 15:07:51 localhost kernel: BUG: unable to handle kernel NULL pointer dereference at 00000249 > Nov 17 15:07:51 localhost kernel: IP: [] acm_probe+0x559/0xe53 [cdc_acm] > Nov 17 15:07:51 localhost kernel: *pde = 00000000 > Nov 17 15:07:51 localhost kernel: Oops: 0000 [#1] SMP I don't understand it, bit please test the attached patch with dynamic debugging for cdc-acm and the kernel log level at maximum. And please repost "lsusb -v" for your device. Regards Oliver