As documented in the data-sheet, the transmitter must be disabled before activating AutoCTS or auto transmitter flow control. Accordingly, the transmitter must be enabled after AutoCTS or auto transmitter flow control gets deactivated.
Signed-off-by: Christoph Vogtländer <[email protected]> --- drivers/tty/serial/max310x.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index fb5a7e0e58e9..adfef6dae4a7 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -860,6 +860,15 @@ static void max310x_set_termios(struct uart_port *port, max310x_port_write(port, MAX310X_XON1_REG, termios->c_cc[VSTART]); max310x_port_write(port, MAX310X_XOFF1_REG, termios->c_cc[VSTOP]); + /* Disable transmitter before enabling AutoCTS or auto transmitter + * flow control + */ + if (termios->c_cflag & CRTSCTS || termios->c_iflag & IXOFF) { + max310x_port_update(port, MAX310X_MODE1_REG, + MAX310X_MODE1_TXDIS_BIT, + MAX310X_MODE1_TXDIS_BIT); + } + port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF); if (termios->c_cflag & CRTSCTS) { @@ -878,6 +887,15 @@ static void max310x_set_termios(struct uart_port *port, } max310x_port_write(port, MAX310X_FLOWCTRL_REG, flow); + /* Enable transmitter after disabling AutoCTS and auto transmitter + * flow control + */ + if (!(termios->c_cflag & CRTSCTS) && !(termios->c_iflag & IXOFF)) { + max310x_port_update(port, MAX310X_MODE1_REG, + MAX310X_MODE1_TXDIS_BIT, + 0); + } + /* Get baud rate generator configuration */ baud = uart_get_baud_rate(port, termios, old, port->uartclk / 16 / 0xffff, -- 2.22.1
