mxs: uart: fix setting RTS from software

commit a6833214cfc6fa8a7c59426af77794cc190c6cfc upstream.

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@pengutronix.de>
Reviewed-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index 6db3baa39a976ec684716623d1d21251eb38b61e..ea513c981b4743813e47c91db384ba12255bdc11 100644 (file)
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -260,10 +260,12 @@ 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;