From: Hui Wang <hui.wang@xxxxxxxxxxxxx> commit 41c606879f89623dd5269eaffea640b915e9e17c upstream. This reverts commit 927728a34f11b5a27f4610bdb7068317d6fdc72a. Once the uart_port->rs485->flag is set to SER_RS485_ENABLED, the port should always work in RS485 mode. If users want the port to leave RS485 mode, they need to call ioctl() to clear SER_RS485_ENABLED. So here we shouldn't clear the RS485 bits in the shutdown(). Fixes: 927728a34f11 ("serial: sc16is7xx: Clear RS485 bits in the shutdown") Signed-off-by: Hui Wang <hui.wang@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220418094339.678144-1-hui.wang@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/sc16is7xx.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1055,12 +1055,10 @@ static void sc16is7xx_shutdown(struct ua /* Disable all interrupts */ sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0); - /* Disable TX/RX, clear auto RS485 and RTS invert */ + /* Disable TX/RX */ sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_RXDISABLE_BIT | - SC16IS7XX_EFCR_TXDISABLE_BIT | - SC16IS7XX_EFCR_AUTO_RS485_BIT | - SC16IS7XX_EFCR_RTS_INVERT_BIT, + SC16IS7XX_EFCR_TXDISABLE_BIT, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT);