Linux Media Controller development
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From: Jean-Francois Moine <moinejf@free.fr>
To: Hans de Goede <hdegoede@redhat.com>
Cc: linux-media@vger.kernel.org
Subject: Re: gspca zc3xx - JPEG quality / frame overflow
Date: Sun, 6 May 2012 20:43:47 +0200	[thread overview]
Message-ID: <20120506204347.6d1a7af9@tele> (raw)
In-Reply-To: <4FA6C024.9090408@redhat.com>

On Sun, 06 May 2012 20:17:08 +0200
Hans de Goede <hdegoede@redhat.com> wrote:

> > - as it is (read the register 11 every 100 ms), the work queue is
> >    usefull when there is no polling of the snapshot button, because the
> >    frame overflow is reported as the bit 0 in the forth byte (data[3])
> >    of the interrupt messages.  
> 
> Interesting, so if the interrupt is enabled, then as soon as an overflow
> happens, we get notified through the interrupt data?
> 
> That may be an alternative to the worker thread, although the current
> solution does work rather well, so I wonder if we should meddle with it.

Hi Hans,

Indeed, your solution works, but it does double polling, and the actual
worker thread asks for a USB exchange each 100 ms. When using only the
interrupt message, there is no overhead.

Regards.

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

      reply	other threads:[~2012-05-06 18:42 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-05 18:54 gspca zc3xx - JPEG quality / frame overflow Jean-Francois Moine
2012-05-06 18:17 ` Hans de Goede
2012-05-06 18:43   ` Jean-Francois Moine [this message]

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