When manual_rtsdtr sysfs attribute is written as 1, TTY_PORT_MANUAL_RTSDTR is set, and the call to raise DTR & RTS in tty_port_raise_dtr_rts() is suppressed. However, there is one other place where these signals are also raised on open: uart_port_startup() in drivers/tty/serial/serial_core.c - this other point of raising DTR & RTS also needs to be suppressed if TTY_PORT_MANUAL_RTSDTR is set. Signed-off-by: Mychaela N. Falconia <falcon@xxxxxxxxxxxxxxx> --- drivers/tty/serial/serial_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index b47004a3fb77..e5e00732e8fa 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -236,7 +236,8 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, * Setup the RTS and DTR signals once the * port is open and ready to respond. */ - if (init_hw && C_BAUD(tty)) + if (init_hw && !tty_port_manual_rtsdtr(&state->port) && + C_BAUD(tty)) uart_port_dtr_rts(uport, 1); } -- 2.9.0
