Date: Thu, 17 Jun 2010 21:49:15 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Howard Chu <hyc@symas.com>
Cc: linux-kernel@vger.kernel.org, Greg KH <greg@kroah.com>
Subject: Re: [PATCH] tty: Add EXTPROC support for LINEMODE
Message-ID: <20100617214915.3478e501@lxorguk.ukuu.org.uk>
In-Reply-To: <4C1A7F72.6020907@symas.com>
References: <E1OObIu-0004K2-3K@lirone.symas.net>
	<20100615202924.24446d28@lxorguk.ukuu.org.uk>
	<4C17DA85.40803@symas.com>
	<4C1A7F72.6020907@symas.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1057
Lines: 28

> >> For Alpha this value should match OSF if possible.
> 
> OSF didn't define this flag, nor did it assign that particular bit to any 
> purpose. Is that good enough?

Fine

> > Are you suggesting that this is completely unfixable/unworkable? Would it be
> > sufficient to use kernel_termios_to_user_termios() ?

I don't see a way to fix it sanely

> >
> Actually using kernel_termios_to_user_termios_1(). In all supported 
> architectures this structure is basically aligned with but smaller than the 
> userland struct termios.

The relationship isn't quite so simple and it may change in the future,
so this seems to be a very bad idea. Besides which syscalls are *cheap*
so simply notifying someone to reread the terminal data they care about
should be fine. In that sense it seems SVR4 got it right.

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/