[Intel-gfx] [PATCH 2/2] ACPI / video / i915: Remove ACPI backlight if firmware expects Windows 8

[Igor Gnatenko]

On Tue, 2013-09-10 at 11:27 +0800, Aaron Lu wrote:
> On 09/09/2013 07:44 PM, Igor Gnatenko wrote:
> > On Mon, 2013-09-09 at 16:42 +0800, Aaron Lu wrote:
> >> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> >> index f466980..75fba17 100644
> >> --- a/drivers/gpu/drm/i915/i915_dma.c
> >> +++ b/drivers/gpu/drm/i915/i915_dma.c
> >> @@ -1650,7 +1650,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
> >>  	if (INTEL_INFO(dev)->num_pipes) {
> >>  		/* Must be done after probing outputs */
> >>  		intel_opregion_init(dev);
> >> -		acpi_video_register();
> >> +		__acpi_video_register(i915_take_over_backlight);
> >>  	}
> >>  
> >>  	if (IS_GEN5(dev))
> > 
> > I can't compile:
> > 
> > 
> > DEBUG: drivers/gpu/drm/i915/i915_dma.c: In function 'i915_driver_load':
> > DEBUG: drivers/gpu/drm/i915/i915_dma.c:1661:3: error: implicit
> > declaration of function
> > '__acpi_video_register' [-Werror=implicit-function-declaration]
> > DEBUG:    __acpi_video_register(i915_take_over_backlight);
> > DEBUG:    ^
> > DEBUG: cc1: some warnings being treated as errors
> > DEBUG: make[4]: *** [drivers/gpu/drm/i915/i915_dma.o] Error 1
> > DEBUG: make[3]: *** [drivers/gpu/drm/i915] Error 2
> > DEBUG: make[2]: *** [drivers/gpu/drm] Error 2
> > DEBUG: make[1]: *** [drivers/gpu] Error 2
> > DEBUG: make: *** [drivers] Error 2
> > 
> 
> The two patches are based on top of Rafael's linux-next tree. I just
> tried it again, no compile problem for me. I also tried on today Linus'
> master tree, as there are some updates from i915, two conflicts exist.
> I've just resolved them and will update it in next revision.
> If you want to try it now, please use:
> https://github.com/aaronlu/linux acpi_video_rework
> 
> Thanks,
> Aaron

Thanks. this patch fixes my problems w/ compilation. I've tested this
two patches and after apply I have:
$ tree /sys/class/backlight/
/sys/class/backlight/
|-- acpi_video0
-> ../../devices/pci0000:00/0000:00:02.0/backlight/acpi_video0
`-- intel_backlight
-> ../../devices/pci0000:00/0000:00:02.0/drm/card0/card0-LVDS-1/intel_backlight

2 directories, 0 files

I think it's didn't unregistered.. I may forget. I need to apply one of
patch from Matthew ?

Some strings from logs:
DMI: LENOVO 23205NG/23205NG, BIOS G2ET92WW (2.52 ) 02/22/2013
thinkpad_acpi: Standard ACPI backlight interface available, not loading
native one
-- 
Igor Gnatenko
Fedora release 20 (Heisenbug)
Linux 3.11.0-1.fc20.x86_64