gianfar: Wait for both RX and TX to stop

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: NAndy Fleming <afleming@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/gianfar.c

@@ -1511,9 +1511,9 @@ static void gfar_halt_nodisable(struct net_device *dev)
 		tempval |= (DMACTRL_GRS | DMACTRL_GTS);
 		gfar_write(&regs->dmactrl, tempval);
 
-		while (!(gfar_read(&regs->ievent) &
-			 (IEVENT_GRSC | IEVENT_GTSC)))
-			cpu_relax();
+		spin_event_timeout(((gfar_read(&regs->ievent) &
+			 (IEVENT_GRSC | IEVENT_GTSC)) ==
+			 (IEVENT_GRSC | IEVENT_GTSC)), -1, 0);
 	}
 }