Samsung NP300V5A -- no backlight brightness change

English Hardware
1

Fn + F2(down) and Fn + F3(up) don’t change brightness level of backlight on my Samsung NP300V5A laptop. I have OpenSUSE 12.3 with bumblebee installed as described in Wiki ( Repo URL: Index of /repositories/home:/Overman79:/Laptop/openSUSE_12.3 ).

With no special setup, I can’t lower brightness, and have 3 entries under /sys/class/backlight:


acpi0_backlight
acpi1_backlight
intel_backlight

Haven’t tried to manipulate them through console.

With acpi_backlight=vendor, I can’t up brightness, and have 2 entries:


intel_backlight
samsung

Changing brightness with *intel_backlight *through console seems OK, but changing it with samsung don’t work, I can set only 0 or 1 brightness level(same with Fn-##)


dmesg | grep samsung
   16.423716] samsung_laptop: enabled workaround for brightness stepping quirk
   16.424060] samsung_laptop: detected SABI interface: SwSmi@

Some related links:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/810093
https://lists.ubuntu.com/archives/kernel-team/2011-December/018086.html

2

I have solve problem for me, by deleting strange workaround from samsung-laptop.c and recompiling module. Will contact with developer of this module for future investigation.

Diff:http://zalil.ru/34466753

3

Have just noticed, that there is special Laptop section on forum. I think this thread should be moved there.

4

It seems that nobody has read this thread, but I must notice, that baclight was fixed for the last kernel in Tumbleweed.