Insert any h/w into ohci usb port, run two scripts in parallel:

$ while true; do rmmod ohci; modprobe ohci; done

$ while true; do lsusb; done > /dev/null

It's better to run 2-3 lsusb loops simultaneously. lsusb script outputs:

cannot read device descriptor No such device (19)
cannot read device descriptor No such device (19)
cannot open /proc/bus/usb/002/001, No such file or directory (2)

And kernel silently hangs in several minutes. Verified on x86_64 and ppc64 machines.