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

serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTS

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: serial-imx-only-wakeup-via-rtsden-bit-if-the-system-has-rts-cts.patch and it can be found in the queue-4.4 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 38b1f0fb42f772b8c9aac53593883a18ff5eb9d7 Mon Sep 17 00:00:00 2001

From: Fabio Estevam fabio.estevam@nxp.com Date: Thu, 4 Jan 2018 15:58:34 -0200 Subject: serial: imx: Only wakeup via RTSDEN bit if the system has RTS/CTS

From: Fabio Estevam fabio.estevam@nxp.com

commit 38b1f0fb42f772b8c9aac53593883a18ff5eb9d7 upstream.

The wakeup mechanism via RTSDEN bit relies on the system using the RTS/CTS lines, so only allow such wakeup method when the system actually has RTS/CTS support.

Fixes: bc85734b126f ("serial: imx: allow waking up on RTSD") Signed-off-by: Fabio Estevam fabio.estevam@nxp.com Reviewed-by: Martin Kaiser martin@kaiser.cx Acked-by: Fugang Duan fugang.duan@nxp.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/tty/serial/imx.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-)

--- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -2057,12 +2057,14 @@ static void serial_imx_enable_wakeup(str val &= ~UCR3_AWAKEN; writel(val, sport->port.membase + UCR3);

- val = readl(sport->port.membase + UCR1); - if (on) - val |= UCR1_RTSDEN; - else - val &= ~UCR1_RTSDEN; - writel(val, sport->port.membase + UCR1); + if (sport->have_rtscts) { + val = readl(sport->port.membase + UCR1); + if (on) + val |= UCR1_RTSDEN; + else + val &= ~UCR1_RTSDEN; + writel(val, sport->port.membase + UCR1); + } }

static int imx_serial_port_suspend_noirq(struct device *dev)

Patches currently in stable-queue which might be from fabio.estevam@nxp.com are

queue-4.4/serial-imx-only-wakeup-via-rtsden-bit-if-the-system-has-rts-cts.patch