The problem is that we call this with a spin lock held.  The call tree
is:
	kaweth_start_xmit() holds kaweth->device_lock.
	-> kaweth_async_set_rx_mode()
	   -> kaweth_control()
	      -> kaweth_internal_control_msg()
The kaweth_internal_control_msg() function is only called from
kaweth_control() which used GFP_ATOMIC for its allocations.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
         int retv;
         int length = 0; /* shut up GCC */
 
-        urb = usb_alloc_urb(0, GFP_NOIO);
+       urb = usb_alloc_urb(0, GFP_ATOMIC);
         if (!urb)
                 return -ENOMEM;