From 7ecc77011c6fb40d3eef7c6a0ebcec61e69b3ec3 Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Delgado Date: Mon, 6 Nov 2017 11:49:12 +0100 Subject: [PATCH] serial: 8250_fintek: Return -EINVAL on invalid configuration Hardware does not support having the same RTS level during RX and TX when RS485 mode is on (URA in Fintek terminology). The manufacturer has also confirmed that the delays are not enabled if the RS485 mode is not enabled. Therefore we should return -EINVAL if the user wants to have the same value for RTS_ON_SEND and RTS_AFTER_SEND. Cc: "Ji-Ze Hong (Peter Hong)" Cc: Lukas Wunner Signed-off-by: Ricardo Ribalda Delgado Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_fintek.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c index be7029f2391e..6c7910d8e136 100644 --- a/drivers/tty/serial/8250/8250_fintek.c +++ b/drivers/tty/serial/8250/8250_fintek.c @@ -197,10 +197,17 @@ static int fintek_8250_rs485_config(struct uart_port *port, if (!pdata) return -EINVAL; - if (rs485->flags & SER_RS485_ENABLED) + /* Hardware do not support same RTS level on send and receive */ + if (!(rs485->flags & SER_RS485_RTS_ON_SEND) == + !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) + return -EINVAL; + + if (rs485->flags & SER_RS485_ENABLED) { memset(rs485->padding, 0, sizeof(rs485->padding)); - else + config |= RS485_URA; + } else { memset(rs485, 0, sizeof(*rs485)); + } rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND; @@ -215,12 +222,6 @@ static int fintek_8250_rs485_config(struct uart_port *port, config |= RXW4C_IRA; } - if ((!!(rs485->flags & SER_RS485_RTS_ON_SEND)) == - (!!(rs485->flags & SER_RS485_RTS_AFTER_SEND))) - rs485->flags &= ~SER_RS485_ENABLED; - else - config |= RS485_URA; - if (rs485->flags & SER_RS485_RTS_ON_SEND) config |= RTS_INVERT;