When gracefully stopping the controller, the driver was continuing if
*either* RX or TX had stopped.  We need to wait for both, or the
controller could get into an invalid state.
Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
                tempval |= (DMACTRL_GRS | DMACTRL_GTS);
                gfar_write(®s->dmactrl, tempval);
 
-               while (!(gfar_read(®s->ievent) &
-                        (IEVENT_GRSC | IEVENT_GTSC)))
-                       cpu_relax();
+               spin_event_timeout(((gfar_read(®s->ievent) &
+                        (IEVENT_GRSC | IEVENT_GTSC)) ==
+                        (IEVENT_GRSC | IEVENT_GTSC)), -1, 0);
        }
 }