RS485 can modify mctrl on startup, especially when RTS_AFTER_SEND is on TIOCM_RTS is set, then need to keep it set when registering port. Copy mctrl to new port too. Signed-off-by: Giulio Benetti <giulio.benetti@xxxxxxxxxxxxxxxx> --- drivers/tty/serial/8250/8250_core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index c8c2b260c681..c8e62fbd6570 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -993,6 +993,7 @@ int serial8250_register_8250_port(struct uart_8250_port *up) uart->port.unthrottle = up->port.unthrottle; uart->port.rs485_config = up->port.rs485_config; uart->port.rs485 = up->port.rs485; + uart->port.mctrl = up->port.mctrl; uart->dma = up->dma; uart->em485 = up->em485; -- 2.17.0 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html