Date: Sun, 6 Jul 2008 19:09:24 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Al Viro <viro@ZenIV.linux.org.uk>,
       "Eric W. Biederman" <ebiederm@xmission.com>,
       Marcin Slusarz <marcin.slusarz@gmail.com>,
       LKML <linux-kernel@vger.kernel.org>, Frans Pop <elendil@planet.nl>
Subject: Re: [PATCH] parport/ppdev: fix registration of sysctl entries
Message-ID: <20080706190924.652e7cde@lxorguk.ukuu.org.uk>
In-Reply-To: <20080706200033.0b833508@linux360.ro>
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	<20080706081126.GA28946@ZenIV.linux.org.uk>
	<20080706192233.5df9c65b@linux360.ro>
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> But isn't it incorrect to assume that sharing protocols allow multiple
> separate users? Why not have an userspace server mux/demux requests?

Why do that ?

> The parallel port itself is not designed to be shared, so even if the
> device supports it, it does not mean we should allow independent
> access. We really should have an userspace lib/server to do this.

I suggest you look at the actual hardware examples in more detail. Most of
them are happy to share but need to own the port temporarily. The manner
in which they lock/unlock their use of the port tends to be very specific
to the device so it makes sense to have the current desgign.
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