diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 326020f86f75..9c57486c2e7f 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -1910,6 +1910,12 @@ uart_set_options(struct uart_port *port, struct console *co, if (flow == 'r') termios.c_cflag |= CRTSCTS; + /* + * some uarts on other side don't support no flow control. + * So we set * DTR in host uart to make them happy + */ + port->mctrl |= TIOCM_DTR; + port->ops->set_termios(port, &termios, NULL); co->cflag = termios.c_cflag;