[U-Boot] [PATCH 2/2] RFC: Add XON/XOFF support

[Graeme Russ <graeme.russ@gmail.com>]

Hi Simon,

On 25/10/11 14:52, Simon Glass wrote:
> This is just for testing - please try it out and report back with results.
> For me it works on Minicom but not ser2net.
> 
> This needs to be controlled by an environment variable, CONFIG option or
> both. We may need a way of specifying flow control on a per-device basis.
> We may need to do something special for X-modem transfers, etc. This might
> turn out to be a can of worms.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
>  common/command.c |    1 +
>  common/console.c |   12 ++++++++++++
>  common/main.c    |    3 +++
>  include/common.h |    2 ++
>  4 files changed, 18 insertions(+), 0 deletions(-)
> 
> diff --git a/common/command.c b/common/command.c
> index acc1c15..7b7c24e 100644
> --- a/common/command.c
> +++ b/common/command.c
> @@ -492,6 +492,7 @@ int cmd_call(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>  {
>  	int result;
>  
> +	console_suspend_input();

Not the best name, but I cannot think of better right now

>  	result = (cmdtp->cmd)(cmdtp, flag, argc, argv);
>  	if (result)
>  		debug("Command failed, result=%d", result);
> diff --git a/common/console.c b/common/console.c
> index f17875e..eeb58e6 100644
> --- a/common/console.c
> +++ b/common/console.c
> @@ -199,6 +199,18 @@ static inline void console_doenv(int file, struct stdio_dev *dev)
>  }
>  #endif /* defined(CONFIG_CONSOLE_MUX) */
>  
> +void console_suspend_input(void)
> +{
> +	/* Send XOFF to tell the other end to stop sending */
> +	console_putc(stdout, 'S' - '@');

Uugh - #define XON and XOFF please

> +}
> +
> +void console_resume_input(void)
> +{
> +	/* Send XON to tell the other end to start sending */
> +	console_putc(stdout, 'Q' - '@');
> +}
> +
>  /** U-Boot INITIAL CONSOLE-NOT COMPATIBLE FUNCTIONS *************************/
>  
>  int serial_printf(const char *fmt, ...)
> diff --git a/common/main.c b/common/main.c
> index 3b60d27..b030176 100644
> --- a/common/main.c
> +++ b/common/main.c
> @@ -948,6 +948,7 @@ int readline_into_buffer (const char *const prompt, char * buffer)
>  
>  		if (prompt)
>  			puts (prompt);
> +		console_resume_input();

Not needed - move to getc()

>  		rc = cread_line(prompt, p, &len);
>  		return rc < 0 ? rc : len;
> @@ -967,6 +968,8 @@ int readline_into_buffer (const char *const prompt, char * buffer)
>  	}
>  	col = plen;
>  
> +	console_resume_input();

Not needed (in getc())

> +
>  	for (;;) {
>  #ifdef CONFIG_BOOT_RETRY_TIME
>  		while (!tstc()) {	/* while no incoming data */
> diff --git a/include/common.h b/include/common.h
> index a1683a2..970ec0d 100644
> --- a/include/common.h
> +++ b/include/common.h
> @@ -738,6 +738,8 @@ int	ctrlc (void);
>  int	had_ctrlc (void);	/* have we had a Control-C since last clear? */
>  void	clear_ctrlc (void);	/* clear the Control-C condition */
>  int	disable_ctrlc (int);	/* 1 to disable, 0 to enable Control-C detect */
> +void console_suspend_input(void);
> +void console_resume_input(void);
>  
>  /*
>   * STDIO based functions (can always be used)

What about the secondart 'rx_flush()' I mentioned?

Regards,

Graeme