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Date: Tue, 3 Feb 2009 20:47:07 +0100
From: Jean-Francois Moine <moinejf@free.fr>
To: kilgota@banach.math.auburn.edu
Cc: Adam Baker <linux@baker-net.org.uk>, linux-media@vger.kernel.org,
	Alan Stern <stern@rowland.harvard.edu>
Subject: Re: [PATCH] Add support for sq905 based cameras to gspca
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On Tue, 3 Feb 2009 13:54:15 -0600 (CST)
kilgota@banach.math.auburn.edu wrote:

> > Indeed, the problem is there! You must have only one process
> > reading the webcam! I do not see how this can work with these 2
> > processes...  
> 
> The problem, then, would seem to me to boil down to the question of 
> whether that is up to us. Apparently, a decision like that is not up
> to us, but rather it is up to the compiler and to the rest of the
> kernel to decide. Which, incidentally, appears to me to be a very
> logical way to arrange things. Presumably, a dual- or multi-core
> machine gives certain advantages, or it ought to, but it also
> requires certain accommodations.

Yes, a multiprocessor machine is a plus, but, you must run only one
process to handle streaming. If you have not seen it yet, this is done
changing the line 373 of sq905.c (if I have the same source as yours)
from:

	dev->work_thread = create_workqueue(MODULE_NAME);
to
	dev->work_thread = create_singlethread_workqueue(MODULE_NAME);

-- 
Ken ar c'hentan	|	      ** Breizh ha Linux atav! **
Jef		|		http://moinejf.free.fr/