serial: 8250_dwlib: remove redundant sanity check for RS485 flags

Before the drivers rs485_config() function is called the serial core
already ensures that only one of both options RTS on send or RTS after send
is set. So remove the concerning sanity check in the driver function to
avoid redundancy.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com>
Link: https://lore.kernel.org/r/20220710164442.2958979-8-LinoSanfilippo@gmx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_dwlib.c b/drivers/tty/serial/8250/8250_dwlib.c
index 2c3b146..dbe4d44 100644 (file)
--- a/drivers/tty/serial/8250/8250_dwlib.c
+++ b/drivers/tty/serial/8250/8250_dwlib.c
@@ -187,16 +187,10 @@ static int dw8250_rs485_config(struct uart_port *p, struct ktermios *termios,
        if (rs485->flags & SER_RS485_ENABLED) {
                tcr |= DW_UART_TCR_RS485_EN;
 
-               if (rs485->flags & SER_RS485_RX_DURING_TX) {
+               if (rs485->flags & SER_RS485_RX_DURING_TX)
                        tcr |= DW_UART_TCR_XFER_MODE_DE_DURING_RE;
-               } else {
-                       /* HW does not support same DE level for tx and rx */
-                       if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
-                           !(rs485->flags & SER_RS485_RTS_AFTER_SEND))
-                               return -EINVAL;
-
+               else
                        tcr |= DW_UART_TCR_XFER_MODE_DE_OR_RE;
-               }
                dw8250_writel_ext(p, DW_UART_DE_EN, 1);
                dw8250_writel_ext(p, DW_UART_RE_EN, 1);
        } else {