diff --git a/drivers/tty/serial/sirfsoc_uart.c b/drivers/tty/serial/sirfsoc_uart.c
index 1d0d47f2a8c2..48cceaf5338a 100644
--- a/drivers/tty/serial/sirfsoc_uart.c
+++ b/drivers/tty/serial/sirfsoc_uart.c
@@ -344,7 +344,8 @@ static void sirfsoc_uart_enable_ms(struct uart_port *port)
 	if (sirfport->uart_reg->uart_type == SIRF_REAL_UART) {
 		wr_regl(port, ureg->sirfsoc_afc_ctrl,
 				rd_regl(port, ureg->sirfsoc_afc_ctrl) |
-				SIRFUART_AFC_TX_EN | SIRFUART_AFC_RX_EN);
+				SIRFUART_AFC_TX_EN | SIRFUART_AFC_RX_EN |
+				SIRFUART_AFC_CTRL_RX_THD);
 		if (!sirfport->is_atlas7)
 			wr_regl(port, ureg->sirfsoc_int_en_reg,
 					rd_regl(port, ureg->sirfsoc_int_en_reg)