[Intel-gfx] [REGRESSION BISECTED] backlight control stops workin with 3.14 and later

[Jani Nikula]

On Sun, 17 Aug 2014, Bertrik Sikken <bertrik at sikken.nl> wrote:
> On 15-8-2014 3:43, Jani Nikula wrote:
>> On Thu, 14 Aug 2014, Bertrik Sikken <bertrik at sikken.nl> wrote:
>
>>> Attached is dmesg output from booting kernel 3.14-2 (debian unstable)
>>> with drm.debug=0xe and the samsung_laptop module enabled, from my
>>> Samsung N150plus netbook.
>> 
>> Have you tried 3.15?
>
> I've built the v3.15 kernel (using the .config file from debian
> unstable and doing make oldconfig).
>
> The backlight is at maximum brightness after boot and I can't control
> it using the backlight buttons, nor by writing to
> /sys/class/backlight/samsung/brightness
> (say half the value or 1/10th of max_brightness)
>
> Backlight does work when writing
> /sys/class/backlight/intel_backlight/brightness

How about disabling samsung backlight module with 3.15?

BR,
Jani.


>
> Kind regards,
> Bertrik Sikken

-- 
Jani Nikula, Intel Open Source Technology Center