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

[Johan Hovold <jhovold@gmail.com>]

On Wed, Feb 13, 2013 at 08:39:31PM -0500, Peter Hurley wrote:
> 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);

Yeah, I agree. Checking at the call site would perhaps be more clear in
this case.

Thanks,
Johan