diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index d9439e6ab719..954941dd8124 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -274,6 +274,13 @@ static bool atmel_use_dma_rx(struct uart_port *port) return atmel_port->use_dma_rx; } +static bool atmel_use_fifo(struct uart_port *port) +{ + struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); + + return atmel_port->fifo_size; +} + static unsigned int atmel_get_lines_status(struct uart_port *port) { struct atmel_uart_port *atmel_port = to_atmel_uart_port(port); @@ -2090,7 +2097,12 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, mode |= ATMEL_US_USMODE_RS485; } else if (termios->c_cflag & CRTSCTS) { /* RS232 with hardware handshake (RTS/CTS) */ - mode |= ATMEL_US_USMODE_HWHS; + if (atmel_use_dma_rx(port) && !atmel_use_fifo(port)) { + dev_info(port->dev, "not enabling hardware flow control because DMA is used"); + termios->c_cflag &= ~CRTSCTS; + } else { + mode |= ATMEL_US_USMODE_HWHS; + } } else { /* RS232 without hadware handshake */ mode |= ATMEL_US_USMODE_NORMAL;