Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8687634b authored by Nicolas Ferre's avatar Nicolas Ferre Committed by Greg Kroah-Hartman
Browse files

tty/serial: at91: RS485 mode: 0 is valid for delay_rts_after_send 



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: default avatarSami Pietikäinen <Sami.Pietikainen@wapice.com>
Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Cc: stable@vger.kernel.org  # 3.2+
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fa8cd0f6

drivers/tty/serial/atmel_serial.c

+3 −6
Original line number Diff line number Diff line
@@ -316,7 +316,6 @@ 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);

		mode |= ATMEL_US_USMODE_RS485;

	} else {
@@ -355,7 +354,6 @@ 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);

		mode &= ~ATMEL_US_USMODE;

		mode |= ATMEL_US_USMODE_RS485;
@@ -2062,7 +2060,6 @@ 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);

		mode |= ATMEL_US_USMODE_RS485;

	} else if (termios->c_cflag & CRTSCTS) {