Patch "serial: imx: Update cached mctrl value when changing RTS" has been added to the 4.14-stable tree

Patch "serial: imx: Update cached mctrl value when changing RTS" has been added to the 4.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    serial: imx: Update cached mctrl value when changing RTS

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     serial-imx-update-cached-mctrl-value-when-changing-rts.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Dec  6 18:04:41 CET 2017
From: Ian Jamison <ian.dev@arkver.com>
Date: Thu, 21 Sep 2017 10:13:12 +0200
Subject: serial: imx: Update cached mctrl value when changing RTS

From: Ian Jamison <ian.dev@arkver.com>


[ Upstream commit a0983c742a5885f82afb282166f83f1d3d8addf4 ]

UART core function uart_update_mctrl relies on a cached value of
modem control lines. This was used but not updated by local RTS
control functions within imx.c. These are used for RS485 line
driver enable signalling. Having an out-of-date value in the cached
mctrl can result in the transmitter being enabled when it shouldn't
be.

Fix this by updating the mctrl value before applying it.

Signed-off-by: Ian Jamison <ian.dev@arkver.com>
Origin: id:8195c96e674517b82a6ff7fe914c7ba0f86e702b.1505375165.git.ian.dev@arkver.com
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/imx.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -334,7 +334,8 @@ static void imx_port_rts_active(struct i
 {
 	*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
 
-	mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS);
+	sport->port.mctrl |= TIOCM_RTS;
+	mctrl_gpio_set(sport->gpios, sport->port.mctrl);
 }
 
 static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2)
@@ -342,7 +343,8 @@ static void imx_port_rts_inactive(struct
 	*ucr2 &= ~UCR2_CTSC;
 	*ucr2 |= UCR2_CTS;
 
-	mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS);
+	sport->port.mctrl &= ~TIOCM_RTS;
+	mctrl_gpio_set(sport->gpios, sport->port.mctrl);
 }
 
 static void imx_port_rts_auto(struct imx_port *sport, unsigned long *ucr2)


Patches currently in stable-queue which might be from ian.dev@arkver.com are

queue-4.14/serial-imx-update-cached-mctrl-value-when-changing-rts.patch