Date: Sat, 7 Mar 2009 17:38:19 -0800
From: Arjan van de Ven <arjan@infradead.org>
To: Tilman Schmidt <tilman@imap.cc>
Cc: davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
       Paul Bolle <pebolle@tiscali.nl>, Hansjoerg Lipp <hjlipp@web.de>
Subject: Re: [PATCH 1/2] gigaset: return -ENOSYS for unimplemented functions
Message-ID: <20090307173819.36d352c8@infradead.org>
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	<49B30FC4.5040305@imap.cc>
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	<49B3176A.7000004@imap.cc>
Organization: Intel
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On Sun, 08 Mar 2009 01:55:06 +0100
Tilman Schmidt <tilman@imap.cc> wrote:

> Am 08.03.2009 01:35 schrieb Arjan van de Ven:
> > On Sun, 08 Mar 2009 01:22:28 +0100
> > Tilman Schmidt <tilman@imap.cc> wrote:
> > 
> >> Am 07.03.2009 23:26 schrieb Arjan van de Ven:
> [...]
> >>> ENODEV is what would be more appropriate.
> >> Not at all. ENODEV means "no such device", which would be quite
> >> wrong. The device does exist and is in all probability working
> >> perfectly fine. It just doesn't implement that particular ioctl.
> > 
> > then -ENOTTY is the right answer
> 
> Interesting, though slightly surprising proposition.
> "Not a typewriter" is certainly correct. :-)
> 
> "Not a tty device", however, which I take is the customary
> interpretation, much less clearly so. The device most certainly
> is a tty device. It just happens to know a few additional ioctl
> commands which may or may not be implemented, depending on the
> kernel config.
> 
> Not to question your authority, but I would really like a second
> opinion on that issue before I adopt your proposition, simply to
> minimize the risk of getting another objection from someone else
> who feels that ENOTTY is inappropriate in that situation.


from the ioctl manpage:

ERRORS
	[snip]

       ENOTTY The specified request does not apply to the kind of
       object that the descriptor d references.


-- 
Arjan van de Ven 	Intel Open Source Technology Centre
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