Arch Linux

ellipsis

Member

Registered: 2012-07-05

Posts: 3

Actual backlight brightness locked on Samsung ATIV book 8

After the most recent kernel update, the screen brightness of my laptop was locked to the maximum level. The values from /sys/class/intel_backlight are:

/sys/class/intel_backlight/actual_brightness    46
/sys/class/intel_backlight/max_brightness       46
/sys/class/intel_backlight/brightness           4648

and that's the only directory in /sys/class/backlight. I can write values to /sys/class/intel_backlight/brightness fine, and the changes are reflected in the actual_brightness file, but the actual backlight brightness doesn't change unless I write 0, in which case it turns off until I write something 1 or above again. xbacklight works to change the values shown, but doesn't change the actual backlight brightness. I also tried using

acpi_backlight=vendor video.use_native_backlight=1

in my kernel parameters, but all that happened was that the brightness was locked at a lower level than before.

Does anyone have any suggestions on how to fix this?

Vins

Member

From: Italy

Registered: 2005-12-14

Posts: 67

Re: Actual backlight brightness locked on Samsung ATIV book 8

Same issue here, I had to install the linux-lts kernel. It looks like everything works fine with kernel ver 3.14.