The patch below does not apply to the 3.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8687634b7908c42eb700e0469e110e02833611d1 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre <[email protected]> Date: Mon, 11 May 2015 13:00:31 +0200 Subject: [PATCH] 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 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 <[email protected]> Signed-off-by: Nicolas Ferre <[email protected]> Cc: [email protected] # 3.2+ Signed-off-by: Greg Kroah-Hartman <[email protected]> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index b1fcddd6652a..2a8f528153e7 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -316,8 +316,7 @@ 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"); @@ -355,8 +354,7 @@ 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; } @@ -2062,8 +2060,7 @@ 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) */ -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
