tty: serial: lpuart: Remove unnecessary code from set_mctrl

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.schenker@toradex.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20191017141428.10330-1-philippe.schenker@toradex.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 537896c4d887e278e2ea48d8fcd9abe224ab4944..f3271857621c03cf069d156eb1fc584634cc86a6 100644 (file)
--- 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)