The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From e0bf2d4982fe7d9ddaf550dd023803ea286f47fc Mon Sep 17 00:00:00 2001

From: Jan Kiszka jan.kiszka@siemens.com Date: Sun, 26 Aug 2018 19:49:32 +0200 Subject: [PATCH] serial: mvebu-uart: Fix reporting of effective CSIZE to userspace

Apparently, this driver (or the hardware) does not support character length settings. It's apparently running in 8-bit mode, but it makes userspace believe it's in 5-bit mode. That makes tcsetattr with CS8 incorrectly fail, breaking e.g. getty from busybox, thus the login shell on ttyMVx.

Fix by hard-wiring CS8 into c_cflag.

Signed-off-by: Jan Kiszka jan.kiszka@siemens.com Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Cc: stable stable@vger.kernel.org # 4.6+ Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c index d04b5eeea3c6..170e446a2f62 100644 --- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -511,6 +511,7 @@ static void mvebu_uart_set_termios(struct uart_port *port, termios->c_iflag |= old->c_iflag & ~(INPCK | IGNPAR); termios->c_cflag &= CREAD | CBAUD; termios->c_cflag |= old->c_cflag & ~(CREAD | CBAUD); + termios->c_cflag |= CS8; }

spin_unlock_irqrestore(&port->lock, flags);