----- Original Message ----- > From: "Giulio Benetti" <giulio.bene...@micronovasrl.com> > Sent: Friday, June 1, 2018 7:40:19 AM
> 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.bene...@micronovasrl.com> > --- > 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; Hi Guilio, I ran into this same thing about six months ago, but I was able to accomplish what I needed by assigning a set_mctrl() function in my port definition. Perhaps that would be enough for your case, too? You should see a little lower in this file that set_mctrl is copied to the new port. -Aaron > uart->dma = up->dma; > uart->em485 = up->em485; > > -- > 2.17.0
