Comment 18 for bug 810093

I installed the RC9 and the daily 3.1 kernel. For some reason I was unable to do a normal boot (boot just freezes with new kernel just like in this bug report: https://bugs.launchpad.net/ubuntu/+source/lightdm/+bug/856810). So I testet it in Safe-Mode (modprobe samsung-laptop, echo number > /sys/devices/platform/samsung/backlight/samsung/brightness ). Result:
The driver is still broken. Here is a quote from Greg Kroah-Hartman who describes the bug:
[quote]
On some Samsung laptops the brightness regulation works slightly different.
All SABI commands except for set_brightness work as expected. The behaviour
of set_brightness is as follows:

- Setting a new brightness will only step one level toward the new brightness
  level. For example, setting a level of 5 when the current level is 2 will
  result in a brightness level of 3.
- A spurious KEY_BRIGHTNESS_UP or KEY_BRIGHTNESS_DOWN event is also generated
  along with the change in brightness.
- Neither of the above two issues occur when changing from/to brightness
  level 0.
[/quote]

The patch in #15 are two of his patches that fix the backlight bug here. (I patched samsung-laptop and did a diff against the original from linux-source)