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From: Tomi Valkeinen <tomi.valkeinen@ti.com>
To: linux-fbdev@vger.kernel.org
Subject: Re: How to use backlight device with fb device
Date: Thu, 15 Sep 2011 09:18:05 +0000	[thread overview]
Message-ID: <1316078285.1880.55.camel@deskari> (raw)
In-Reply-To: <1316072820.1880.51.camel@deskari>

On Thu, 2011-09-15 at 08:58 +0000, Florian Tobias Schandinat wrote:
> Hi Tomi,
> 
> On 09/15/2011 07:47 AM, Tomi Valkeinen wrote:
> > Hi,
> > 
> > I'm a bit confused how a backlight device and a fb device should be
> > "connected".
> > 
> > In this particular case the OMAP 4430SDP board has an LCD panel
> > controlled by omapfb (and omapdss on the lower level) with a backlight
> > controlled by pwm_backlight (and twl6030-pwm on the lower level).
> > 
> > Both omapfb and pwm_backlight work fine, but they don't know anything
> > about each other, so, for example, blanking the fb via omapfb leaves the
> > backlight on.
> > 
> > Is there something I'm missing, or is the only solution to have some
> > custom code to connect the fb and the bl, and handle it that way?
> 
> I don't know anything about backlight but recently there was a patch that
> affected the same area you mention so it might give an idea
> "[PATCH] FB: add early fb blank feature."
> http://marc.info/?l=linux-fbdev&m\x131554458720940&w=2

Ah, thanks for pointing that out.

I seem to have dropped from linux-fbdev list and hadn't received that
post. For some reason I seem to get dropped from linux mailing lists,
this is getting a bit frustrating...

 Tomi



      parent reply	other threads:[~2011-09-15  9:18 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-09-15  7:47 How to use backlight device with fb device Tomi Valkeinen
2011-09-15  8:58 ` Florian Tobias Schandinat
2011-09-15  9:18 ` Tomi Valkeinen [this message]

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