Re: 2.6.38-rc2: acpi backlight control missing

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Friday, January 28, 2011, Thomas Meyer wrote:
> Am Samstag, den 22.01.2011, 20:43 +0100 schrieb Rafael J. Wysocki:
> > On Saturday, January 22, 2011, Thomas Meyer wrote:
> > > with 2.6.38-rc2 the acpi backlight is gone:
> > > 
> > > any ideas?
> > 
> > Not really, but Matthew may have some (CCed).
> 
> Okay, found the problem.
> 
> This commit broke my backlight:
> 
> commit 677bd810eedce61edf15452491781ff046b92edc
> Author: Zhang Rui <rui.zhang@intel.com>
> Date:   Mon Dec 6 15:04:21 2010 +0800
> 
>     ACPI video: remove output switching control
> 
> This is because in function
> "acpi_is_video_device()" (drivers/acpi/video_detect.c) the backlight
> device is only checked when some video capabilities were found, but by
> removing the check for the VIDEO_OUTPUT_SWITCHING (that seems to be the
> only video capability on my system) the check for the backlight device
> isn't done anymore.
> 
> by reverting above commit, the backlight is back again.

Is it the same issue as https://bugzilla.kernel.org/show_bug.cgi?id=27702 ?
In case it is, can you test the patch in there, please?

Rafael