diff --git a/drivers/serial/mpc52xx_uart.c b/drivers/serial/mpc52xx_uart.c
index 7a3625f52a03b837551697cf2bc23b54bc488d32..efc971d9647b20b7d09f773ba21e12c3b6407437 100644
--- a/drivers/serial/mpc52xx_uart.c
+++ b/drivers/serial/mpc52xx_uart.c
@@ -783,7 +783,9 @@ mpc52xx_uart_int_rx_chars(struct uart_port *port)
 		}
 	}
 
+	spin_unlock(&port->lock);
 	tty_flip_buffer_push(tty);
+	spin_lock(&port->lock);
 
 	return psc_ops->raw_rx_rdy(port);
 }