From 6e853d1593afa65bcddaa991b1b4fef508262317 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre Date: Mon, 11 May 2015 13:00:31 +0200 Subject: tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_send MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 8687634b7908c42eb700e0469e110e02833611d1 upstream. In RS485 mode, we may want to set the delay_rts_after_send value to 0. In the datasheet, the 0 value is said to "disable" the Transmitter Timeguard but this is exactly the expected behavior if we want no delay... Moreover, if the value was set to non-zero value by device-tree or earlier ioctl command, it was impossible to change it back to zero. Reported-by: Sami Pietikäinen Signed-off-by: Nicolas Ferre Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/atmel_serial.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 27dade29646b..5ca1dfb0561c 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -315,8 +315,7 @@ static int atmel_config_rs485(struct uart_port *port, if (rs485conf->flags & SER_RS485_ENABLED) { dev_dbg(port->dev, "Setting UART to RS485\n"); atmel_port->tx_done_mask = ATMEL_US_TXEMPTY; - if ((rs485conf->delay_rts_after_send) > 0) - UART_PUT_TTGR(port, rs485conf->delay_rts_after_send); + UART_PUT_TTGR(port, rs485conf->delay_rts_after_send); mode |= ATMEL_US_USMODE_RS485; } else { dev_dbg(port->dev, "Setting UART to RS232\n"); @@ -354,8 +353,7 @@ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) /* override mode to RS485 if needed, otherwise keep the current mode */ if (port->rs485.flags & SER_RS485_ENABLED) { - if ((port->rs485.delay_rts_after_send) > 0) - UART_PUT_TTGR(port, port->rs485.delay_rts_after_send); + UART_PUT_TTGR(port, port->rs485.delay_rts_after_send); mode &= ~ATMEL_US_USMODE; mode |= ATMEL_US_USMODE_RS485; } @@ -2061,8 +2059,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, /* mode */ if (port->rs485.flags & SER_RS485_ENABLED) { - if ((port->rs485.delay_rts_after_send) > 0) - UART_PUT_TTGR(port, port->rs485.delay_rts_after_send); + UART_PUT_TTGR(port, port->rs485.delay_rts_after_send); mode |= ATMEL_US_USMODE_RS485; } else if (termios->c_cflag & CRTSCTS) { /* RS232 with hardware handshake (RTS/CTS) */ -- cgit v1.2.3