The setting of RS485 RTS polarity is inverse in the current driver. When the property of 'rs485-rts-active-low' is enabled in the dts node, the RTS signal should be LOW during sending. Otherwise, if there is no such a property, the RTS should be HIGH during sending. Signed-off-by: Nicolas Diaz <nicolas.diaz@xxxxxxx> Signed-off-by: Shenwei Wang <shenwei.wang@xxxxxxx> --- drivers/tty/serial/fsl_lpuart.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index afa0f941c862f..abc3a3674bc39 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1394,9 +1394,9 @@ static int lpuart_config_rs485(struct uart_port *port, struct ktermios *termios, * Note: UART is assumed to be active high. */ if (rs485->flags & SER_RS485_RTS_ON_SEND) - modem &= ~UARTMODEM_TXRTSPOL; - else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) modem |= UARTMODEM_TXRTSPOL; + else if (rs485->flags & SER_RS485_RTS_AFTER_SEND) + modem &= ~UARTMODEM_TXRTSPOL; } writeb(modem, sport->port.membase + UARTMODEM); -- 2.25.1
