4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> commit e0bf2d4982fe7d9ddaf550dd023803ea286f47fc upstream. 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@xxxxxxxxxxx> Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port") Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.6+ Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/mvebu-uart.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/tty/serial/mvebu-uart.c +++ b/drivers/tty/serial/mvebu-uart.c @@ -327,8 +327,10 @@ static void mvebu_uart_set_termios(struc if ((termios->c_cflag & CREAD) == 0) port->ignore_status_mask |= STAT_RX_RDY | STAT_BRK_ERR; - if (old) + if (old) { tty_termios_copy_hw(termios, old); + termios->c_cflag |= CS8; + } baud = uart_get_baud_rate(port, termios, old, 0, 460800); uart_update_timeout(port, termios->c_cflag, baud);