Samsung NC10 : max backlight is startup backlight

[Mathieu Marquer]

Binary package hint: acpi

Using Ubuntu Jaunty up-to-date on a Samsung NC10.

The bug : when I start the computer with AC plugged in, max backlight I can set is "normal" maximum backlight. But if I start with AC unplugged, the startup backlight level (reduced backlight, since it has started on battery) is considered as maximum available backlight. I still can make it getting darker, but the maximum backlight level I'll get (with backlight level set as maximum) will be startup backlight level, meaning a reduced backlight level.

Please let me know if you need additionnal informations.

ProblemType: Bug
Architecture: i386
Dependencies:
 libgcc1 1:4.3.3-5ubuntu1 [modified: lib/libgcc_s.so.1]
 gcc-4.3-base 4.3.3-5ubuntu1
 findutils 4.4.0-2ubuntu3 [modified: usr/bin/xargs usr/bin/find usr/bin/oldfind]
 libc6 2.9-4ubuntu2 [modified: lib/ld-2.9.so usr/lib/pt_chown usr/bin/iconv usr/bin/getent usr/bin/getconf usr/bin/localedef usr/bin/locale usr/bin/zdump usr/bin/rpcinfo usr/sbin/zic usr/sbin/iconvconfig]
DistroRelease: Ubuntu 9.04
Package: acpi 1.2-1ubuntu1 [modified: usr/bin/acpi]
ProcEnviron:
 LANG=fr_FR.UTF-8
 SHELL=/bin/bash
SourcePackage: acpi
Uname: Linux 2.6.28-8-generic i686

[Mathieu Marquer (slasher-fun)]

Confirmed by other users. A workaround is to add the backlight control applet to gnome-panel, and then you can set backlight to its real maximum value.

[Kev (ukev)]

I can confirm this bug but could not confirm the workaround. The only workaround that worked for me is to set the backlight control in the bios to "user control" instead the default, because then the brightness is not reduced on battery.

But if i reduce the backlight brightness before booting jaunty (e.g. in bios or in grub with the brightness keys), jaunty will consider this reduced brightness as maximum again.

In Karmic no brightness control works with the nc10.

[papukaija (papukaija)]

The brightness control work perfectly in karmic if you upgrade your bios.

[papukaija (papukaija)]

The minimum required BIOS version is 11Ca because "brightness controls require BIOS 11CA due to the new graphics system. " as seen at https://help.ubuntu.com/community/NC10#Karmic%209.10