From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Thu, 15 Sep 2011 09:18:05 +0000 Subject: Re: How to use backlight device with fb device Message-Id: <1316078285.1880.55.camel@deskari> List-Id: References: <1316072820.1880.51.camel@deskari> In-Reply-To: <1316072820.1880.51.camel@deskari> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-fbdev@vger.kernel.org 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&m1554458720940&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