Currently flow control is not working due to lpuart32_set_mctrl that is clearing TXCTSE bit in all cases. This bit gets earlier setup by lpuart32_set_termios.
As I read in Documentation set_mctrl is also not meant for hardware flow control rather than gpio setting and clearing a RTS signal. Therefore I guess it is safe to remove the whole code in lpuart32_set_mctrl. This was tested with console on a i.MX8QXP SoC. Signed-off-by: Philippe Schenker <philippe.schen...@toradex.com> Reviewed-by: Fugang Duan <fugang.d...@nxp.com> --- Changes in v2: - Added Fugang Duan's review drivers/tty/serial/fsl_lpuart.c | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 537896c4d887..f3271857621c 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -1333,18 +1333,7 @@ static void lpuart_set_mctrl(struct uart_port *port, unsigned int mctrl) static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl) { - unsigned long temp; - - temp = lpuart32_read(port, UARTMODIR) & - ~(UARTMODIR_RXRTSE | UARTMODIR_TXCTSE); - - if (mctrl & TIOCM_RTS) - temp |= UARTMODIR_RXRTSE; - - if (mctrl & TIOCM_CTS) - temp |= UARTMODIR_TXCTSE; - lpuart32_write(port, temp, UARTMODIR); } static void lpuart_break_ctl(struct uart_port *port, int break_state) -- 2.23.0