diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
index 89362d733d6230331c6bead3c8bbce3ef9d28563..8f58f7ff0dd7db29af5c749dbeda386b8c6c10b9 100644
--- a/drivers/serial/atmel_serial.c
+++ b/drivers/serial/atmel_serial.c
@@ -877,6 +877,10 @@ static int atmel_startup(struct uart_port *port)
 		}
 	}
 
+	/* Save current CSR for comparison in atmel_tasklet_func() */
+	atmel_port->irq_status_prev = UART_GET_CSR(port);
+	atmel_port->irq_status = atmel_port->irq_status_prev;
+
 	/*
 	 * Finally, enable the serial port
 	 */