The ff_memless has a timer running which gets run in an atomic context and
calls the play_effect callback. The callback function for sony uses the
hid_output_raw_report (overwritten by sixaxis_usb_output_raw_report) function
to handle differences in the control message format. It is not safe for an
atomic context because it may sleep later in usb_start_wait_urb.

This "scheduling while atomic" can cause the system to lock up. A workaround is
to make the force feedback state update using work_queues and use the
play_effect function only to enqueue the work item.
Reported-by: NSimon Wood <simon@mungewell.org>
Reported-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NSven Eckelmann <sven@narfation.org>
Signed-off-by: NSimon Wood <simon@mungewell.org>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>