RE: Serial custom speed deprecated?

From: "Stuart MacDonald" <stuartm@connecttech.com>
To: "'Rogier Wolff'" <R.E.Wolff@BitWizard.nl>,
	"'Alan Cox'" <alan@lxorguk.ukuu.org.uk>
Cc: "'linux-os \(Dick Johnson\)'" <linux-os@analogic.com>,
	"'Krzysztof Halasa'" <khc@pm.waw.pl>,
	"'David Woodhouse'" <dwmw2@infradead.org>,
	<linux-serial@vger.kernel.org>,
	"'LKML'" <linux-kernel@vger.kernel.org>
Subject: RE: Serial custom speed deprecated?
Date: Mon, 28 Aug 2006 10:14:30 -0400	[thread overview]
Message-ID: <000901c6caac$478bfca0$294b82ce@stuartm> (raw)
In-Reply-To: <20060827065210.GA6932@bitwizard.nl>

From: On Behalf Of Rogier Wolff
> Note that IMHO, we should have started hiding this mess from /drivers/
> a long time ago. The tty layer should convert the B_9600 thingies to
> "9600", the integer, and then call the set_termios function. The
> driver should be prohibited from looking at how the the baud rate came
> to be 9600, and attempt to approach the requested baud rate as good as
> possible. It might return a flag somewhere: Not exact. In the example
> above, the resulting baud rate is about 1.4 baud off: 9598.6. This is
> not a problem in very many cases.
> 
> Once this is in place, you lose a lot of "figure out the baud rate
> integer from the B_xxx settings" code in all the drivers, as well as
> that we get to provide a new interface to userspace without having to
> change ALL drivers at the same time. This decouples the drivers from
> the kernel<->userspace interface.

I'll second the motion. :-)

..Stu