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

[Bertrik Sikken]

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

Kind regards,
Bertrik Sikken