From: Shenwei Wang shenwei.wang@nxp.com
stable inclusion from stable-v5.10.142 commit 6ccd69141b9facbd6c23f53fef268c09344365b6 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6CSFH
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 846651eca073e2e02e37490a4a52752415d84781 upstream.
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.
Fixes: 03895cf41d18 ("tty: serial: fsl_lpuart: Add support for RS-485") Cc: stable stable@kernel.org Signed-off-by: Nicolas Diaz nicolas.diaz@nxp.com Signed-off-by: Shenwei Wang shenwei.wang@nxp.com Link: https://lore.kernel.org/r/20220805144529.604856-1-shenwei.wang@nxp.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Jialin Zhang zhangjialin11@huawei.com Reviewed-by: Zheng Zengkai zhengzengkai@huawei.com --- 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 52a603a6f9b8..9070741153e3 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1376,9 +1376,9 @@ static int lpuart32_config_rs485(struct uart_port *port, * 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; }
/* Store the new configuration */