Re: [PATCH 1/1] serial: fsl_lpuart: RS485 RTS polariy is inverse

From: Jiri Slaby
Date: Thu Aug 04 2022 - 02:51:20 EST


On 02. 08. 22, 18:38, Shenwei Wang wrote:
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.

What commit this fixes? I.e. I am missing a Fixes tag below.

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);

thanks,
--
js
suse labs