diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 046bedca7b8f5..55108db5b64bf 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2414,7 +2414,8 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, * We probably don't need a spinlock around this, but */ spin_lock_irqsave(&port->lock, flags); - port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR); + port->mctrl &= TIOCM_DTR; + port->ops->set_mctrl(port, port->mctrl); spin_unlock_irqrestore(&port->lock, flags); /*