MLK-17005: linux-imx: serial: fsl_lpuart: Clear LOOP mode when requested

The LOOP mode remained always set after first use.
If the ioctl tiocmset gets called with TIOCMBIC for TIOCM_LOOP,
UARTCTRL_LOOPS needs to be cleared in the LPUART control register.

Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Acked-by: Fugang Duan <fugang.duan@nxp.com>

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 3971bc0..b89a1bc 100644 (file)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1126,6 +1126,9 @@ static void lpuart32_set_mctrl(struct uart_port *port, unsigned int mctrl)
        temp = lpuart32_read(port->membase + UARTCTRL);
        if (mctrl & TIOCM_LOOP)
                temp |= UARTCTRL_LOOPS;
+       else
+               temp &= ~UARTCTRL_LOOPS;
+
        lpuart32_write(temp, port->membase + UARTCTRL);
 }