Hello,

On 06/08/2015 12:11 PM, Uwe Kleine-K?nig wrote:

Hello,

On Mon, Jun 01, 2015 at 10:51:06AM +0530, Bhuvanchandra DV wrote:

quoted

The LPUART does not provide manual control of RTS/CTS signals,
those can only be controlled by the hardware directly. Therefore
manual control of those signals through mctrl can not be provided.
The current implementation enables/disables the automatic control,
which is not what mctrl should do, hence remove the incorrect
implementation.

Signed-off-by: Bhuvanchandra DV <redacted>
---
  drivers/tty/serial/fsl_lpuart.c | 63 +++++------------------------------------
  1 file changed, 7 insertions(+), 56 deletions(-)

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 08ce76f..532cfb7 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c

@@ -822,64 +822,15 @@ static unsigned int lpuart32_tx_empty(struct uart_port *port)

  static unsigned int lpuart_get_mctrl(struct uart_port *port)
  {
-	unsigned int temp = 0;
-	unsigned char reg;
-
-	reg = readb(port->membase + UARTMODEM);
-	if (reg & UARTMODEM_TXCTSE)
-		temp |= TIOCM_CTS;
-
-	if (reg & UARTMODEM_RXRTSE)
-		temp |= TIOCM_RTS;
-
-	return temp;

 From reading the commit log I would expect that you only touch the
set_mctrl function, but not get_mctrl. Assuming your code change is
right, can you mention this in the commit log please? The bits
UARTMODEM_TXCTSE and UARTMODEM_RXRTSE only control the automatic mode?

OK, will use 'get/set_mctrl' instead of 'mctrl' in the commit log.
Yes, those bits are only responsible for enabling/disabling the auto 
hardware flow control, not for controlling the RTS/CTS signals directly.

What is the problem you're fixing here? I'm not sure how such an UART
should be handled, but I imagine that you want to make use of automatic
mode in some cases. Greg?

Fixing the implementation of hardware flow control wrt LPUART hardware.

Best regards
Uwe

Best regards,
Bhuvan