Re: atmel_serial: fix RTS high after initialization in RS485 mode

[Andrew Morton <akpm@linux-foundation.org>]

On Sun, 24 Oct 2010 12:48:29 +0200
Claudio Scordino <claudio@evidence.eu.com> wrote:

> Hi Nicolas,
> 
> 	when working in RS485 mode, the atmel_serial driver keeps RTS
> high after the initialization of the serial port. It goes low only after
> the first character has been sent. 
> 
> This patch fixes this behavior. It has been already tested by Arkadiusz (CC:-ed).
> 
> Best regards,
> 
> 	Claudio
> 
> 
> atmel_serial: RTS line low after initialization of the serial port
> 
> Signed-off-by: Claudio Scordino <claudio@evidence.eu.com>
> Signed-off-by: Arkadiusz Bubala <arkadiusz.bubala@gmail.com>
> ---
>  drivers/serial/atmel_serial.c |    9 +++++++++
>  1 files changed, 9 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/serial/atmel_serial.c b/drivers/serial/atmel_serial.c
> index 3892666..85aa66f 100644
> --- a/drivers/serial/atmel_serial.c
> +++ b/drivers/serial/atmel_serial.c
> @@ -1732,6 +1732,15 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev)
>  	device_init_wakeup(&pdev->dev, 1);
>  	platform_set_drvdata(pdev, port);
>  
> +	if (port->rs485.flags & SER_RS485_ENABLED) {
> +		unsigned int control = 0;
> +		unsigned int mode = 0;
> +		control |= ATMEL_US_RTSEN;
> +		mode |= ATMEL_US_USMODE_NORMAL;
> +		UART_PUT_MR(&port->uart, mode);
> +		UART_PUT_CR(&port->uart, control);
> +	}
> +
>  	return 0;
>  

That was a lot of code!  How about just this?

	if (port->rs485.flags & SER_RS485_ENABLED) {
		UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL);
		UART_PUT_CR(&port->uart, ATMEL_US_RTSEN);
	}