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

[Igor Gnatenko]

On Tue, 2013-09-10 at 13:16 +0800, Aaron Lu wrote:
> On 09/10/2013 01:13 PM, Igor Gnatenko wrote:
> > 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 ?
> 
> You need to specify i915.take_over_backlight=1 in kernel cmdline, that
> module option is set to false by default for now.
> 
> Thanks for the test.
> 
> -Aaron
> 
> > 
> > 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
> > 
> 

Thanks for quick answer. Yes. This option do unregister. Thanks. but for
this patch-set I also need "[PATCH 2/3] ACPI / video: Always call
acpi_video_init_brightness() on init" from Matthew (for notifications in
DE).

-- 
Igor Gnatenko
Fedora release 20 (Heisenbug)
Linux 3.11.0-1.fc20.x86_64