Date: Tue, 31 Aug 2010 12:23:40 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Rogier Wolff <R.E.Wolff@BitWizard.nl>
Cc: Arnd Bergmann <arnd@arndb.de>, Greg KH <gregkh@suse.de>,
        Jiri Slaby <jslaby@suse.cz>, linux-kernel@vger.kernel.org,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Mike Frysinger <vapier.adi@gmail.com>,
        "Michael H. Warfield" <mhw@wittsend.com>
Subject: Re: [RFC 0/5] tty: move stuff around
Message-ID: <20100831122340.7153388f@lxorguk.ukuu.org.uk>
In-Reply-To: <20100831104205.GA2301@bitwizard.nl>
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> Now I've missed the first part of this discussion... Is there a change
> imminent that requires rewriting of all the drivers?

Mostly locking - it's not a trivial entry point thing. The gs layer for
example was full of races and needed rewriting so just got declared
broken.
 
> (If rewriting serial drivers, PLEASE make it so that the
> userspace-kernel interface just passes a baud rate integer, not the
> one-of-16-possible baudrate-flags. The old stuff can be emulated in a

Did that several years ago. I think you still need to use the ioctl
because several years is apparently a bit short for glibc to get with it
even though a glibc person thought up how to do the new interface 8)

> library. Secondly serial port drivers should NOT have to worry about
> DCD changes and what to do with sleeping processes. The driver should
> have an kernel function to call: "hey, one of the control lines
> changed level. These are the new ones". And "These characters
> arrived". And the driver has an entry point: "please send these
> characters". )

Mostly done. See tty_port_*

Alan
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