[PATCH V3] tty: serial: imx: clear the RTSD status before enable the RTSD irq

[Sherry Sun <sherry.sun@nxp.com>]

From: Fugang Duan <fugang.duan@nxp.com>

Clear RTSD status before enabling the irq event for RTSD in
imx_uart_enable_wakeup function.
Since RTSD can be set as the wakeup source, this can avoid any risk of
false triggering of a wake-up interrupts.

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
changes in V3:
 - Add the Acked-by tag.

changes in V2:
 - Change the subject and the commit message as suggested by Uwe.
---
 drivers/tty/serial/imx.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 90f82e6c54e4..fb75e3e0d828 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -2482,10 +2482,12 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
 
 	if (sport->have_rtscts) {
 		u32 ucr1 = imx_uart_readl(sport, UCR1);
-		if (on)
+		if (on) {
+			imx_uart_writel(sport, USR1_RTSD, USR1);
 			ucr1 |= UCR1_RTSDEN;
-		else
+		} else {
 			ucr1 &= ~UCR1_RTSDEN;
+		}
 		imx_uart_writel(sport, ucr1, UCR1);
 	}
 }
-- 
2.17.1