Re: [RFC 3/4] tty: clean up port drain-delay handling

[Peter Hurley <peter@hurleysoftware.com>]

On Wed, 2013-02-13 at 18:27 +0100, Johan Hovold wrote:
> Move port drain-delay handling to a separate function.
> ---
>  drivers/tty/tty_port.c | 29 ++++++++++++++++++-----------
>  1 file changed, 18 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/tty/tty_port.c b/drivers/tty/tty_port.c
> index ffe3689..0a5e955 100644
> --- a/drivers/tty/tty_port.c
> +++ b/drivers/tty/tty_port.c
> @@ -407,6 +407,23 @@ int tty_port_block_til_ready(struct tty_port *port,
>  }
>  EXPORT_SYMBOL(tty_port_block_til_ready);
>  
> +static void tty_port_drain_delay(struct tty_port *port, struct tty_struct *tty)
> +{
> +	unsigned int bps = tty_get_baud_rate(tty);
> +	long timeout;


> +	if (!port->drain_delay)
> +		return;
               ^^^^^^^^^^^^
How about drop this and ...

> +	if (bps > 1200) {
> +		timeout = (HZ * 10 * port->drain_delay) / bps;
> +		timeout = max_t(long, timeout, HZ / 10);
> +	} else {
> +		timeout = 2 * HZ;
> +	}
> +	schedule_timeout_interruptible(timeout);
> +}
> +
>  int tty_port_close_start(struct tty_port *port,
>  				struct tty_struct *tty, struct file *filp)
>  {
> @@ -445,17 +462,7 @@ int tty_port_close_start(struct tty_port *port,
>  	if (test_bit(ASYNCB_INITIALIZED, &port->flags) &&
>  			port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
>  		tty_wait_until_sent_from_close(tty, port->closing_wait);
> -	if (port->drain_delay) {
> -		unsigned int bps = tty_get_baud_rate(tty);
> -		long timeout;
> -
> -		if (bps > 1200)
> -			timeout = max_t(long,
> -				(HZ * 10 * port->drain_delay) / bps, HZ / 10);
> -		else
> -			timeout = 2 * HZ;
> -		schedule_timeout_interruptible(timeout);
> -	}
> +	tty_port_drain_delay(port, tty);

....
	if (port->drain_delay)
		tty_port_drain_delay(port, tty);

>  	/* Flush the ldisc buffering */
>  	tty_ldisc_flush(tty);
>