[PATCH v3 RESEND] mxs: uart: allow setting RTS from software

[Steffen Trumtrar]

With the patch "serial: mxs-auart: fix the wrong RTS hardware flow control" the
mainline mxs-uart driver now sets RTSEN only when hardware flow control is
enabled via software. It is not possible any longer to set RTS manually via
software. However, the manual modification is a valid operation.
Regain the possibility to set RTS via software and only set RTSEN when hardware
flow control is explicitly enabled via settermios cflag CRTSCTS.

Signed-off-by: Steffen Trumtrar <s.trumtrar at pengutronix.de>
Reviewed-by: Huang Shijie <b32955 at freescale.com>

Cc: stable at vger.kernel.org
---
 drivers/tty/serial/mxs-auart.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index 6db23b0..9f63f88 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -412,10 +412,12 @@ static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl)
 
 	u32 ctrl = readl(u->membase + AUART_CTRL2);
 
-	ctrl &= ~AUART_CTRL2_RTSEN;
+	ctrl &= ~(AUART_CTRL2_RTSEN | AUART_CTRL2_RTS);
 	if (mctrl & TIOCM_RTS) {
 		if (tty_port_cts_enabled(&u->state->port))
 			ctrl |= AUART_CTRL2_RTSEN;
+		else
+			ctrl |= AUART_CTRL2_RTS;
 	}
 
 	s->ctrl = mctrl;
-- 
1.7.10.4