There is a kernel.org bugreport also

https://bugzilla.kernel.org/show_bug.cgi?id=16036

currently I am using
sudo setpci -s 00:02.0 F4.B=80
to change backlight control.

Well, actually I use lirc daemon to intercept fn-keys and call a
following bash script when screen brightness fn-keys are pressed)

#!/bin/bash
var1=`cat /sys/class/backlight/acpi_video0/max_brightness`
var2=`cat /sys/class/backlight/acpi_video0/actual_brightness`
var3=`echo "16 o 16 i $var2 FF $var1 / * + 1 + p"| /usr/bin/dc `
sudo setpci -s 00:02.0 F4.B=$var3

yep, it works :)


2010/9/22, Luiz Fernando <email address hidden>:
> This is not on kubuntu only - I have exactly the same problem on Ubuntu.
> My laptop is not the same as the reporter's (it's a Samsung R430), but
> it has the same graphics chipset, has the same backlight setting
> problem, I've used the same workaround on Lucid, and now it also doesn't
> work on Maverick. I my case, taking off only "nomodeset" from the kernel
> options allows the system to boot into X, and though the brightness does
> change accordingly when the system is running on AC or battery (whereas
> without "acpi_backlight=vendor" not even that happens), the brightness
> can no longer me set on the Power Management on Gnome Preferences (the
> slider is missing).
>
> --
> [maverick] - Xorg fails to load with "nomodeset" kernel parameter
> https://bugs.launchpad.net/bugs/631412
> You received this bug notification because you are a direct subscriber
> of the bug.
>
> Status in "xserver-xorg-video-intel" package in Ubuntu: New
>
> Bug description:
> Binary package hint: xserver-xorg-video-intel
>
> Some notebooks need the "nomodeset acpi_backlight = vendor" kernel boot time
> option to make screen brigthness adjustable by Fn keys (I have a Toshiba
> Satelltie T130). With this option xorg failes to load. Without this screen
> is always at a maximal brightness. This workaround was OK in lucid, now in
> maverick it doesn't work.
>
> ProblemType: Bug
> DistroRelease: Ubuntu 10.10
> Package: linux-image-2.6.35-19-generic 2.6.35-19.28
> Regression: Yes
> Reproducible: Yes
> ProcVersionSignature: Ubuntu 2.6.35-19.28-generic 2.6.35.3
> Uname: Linux 2.6.35-19-generic x86_64
> AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.23.
> Architecture: amd64
> ArecordDevices:
>  **** List of CAPTURE Hardware Devices ****
>  card 0: Intel [HDA Intel], device 0: CONEXANT Analog [CONEXANT Analog]
>    Subdevices: 1/1
>    Subdevice #0: subdevice #0
> AudioDevicesInUse:
>  USER        PID ACCESS COMMAND
>  /dev/snd/controlC0:  shawkat    1664 F.... pulseaudio
>  /dev/snd/pcmC0D0p:   shawkat    1664 F...m pulseaudio
> CRDA: Error: [Errno 2] Нет такого файла или каталога
> Card0.Amixer.info:
>  Card hw:0 'Intel'/'HDA Intel at 0xf0700000 irq 45'
>    Mixer name	: 'Intel Cantiga HDMI'
>    Components	: 'HDA:14f15066,1179ffe0,00100301
> HDA:80862802,80860101,00100000'
>    Controls      : 13
>    Simple ctrls  : 8
> Date: Mon Sep  6 13:34:04 2010
> InstallationMedia: Kubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100427)
> MachineType: TOSHIBA SATELLITE T130
> ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.35-19-generic
> root=UUID=21b3e6c1-e81f-40a6-afae-cd0946341b37 ro quiet splash
> ProcEnviron:
>  LANGUAGE=
>  PATH=(custom, user)
>  LANG=ru_RU.UTF-8
>  SHELL=/bin/bash
> RelatedPackageVersions: linux-firmware 1.38
> RfKill:
>  0: hci0: Bluetooth
>  	Soft blocked: no
>  	Hard blocked: no
> SourcePackage: linux
> UserAsoundrc:
>  pcm.bluetooth {
>      type bluetooth
>      device 00:1E:7C:00:4D:93
>  }
> dmi.bios.date: 09/29/2009
> dmi.bios.vendor: TOSHIBA
> dmi.bios.version: V1.70
> dmi.board.name: SATELLITE T130
> dmi.board.vendor: TOSHIBA
> dmi.board.version: Not Applicable
> dmi.chassis.asset.tag: No Asset Tag
> dmi.chassis.type: 10
> dmi.chassis.vendor: TOSHIBA
> dmi.chassis.version: N/A
> dmi.modalias:
> dmi:bvnTOSHIBA:bvrV1.70:bd09/29/2009:svnTOSHIBA:pnSATELLITET130:pvrPST3AE-01S01UGR:rvnTOSHIBA:rnSATELLITET130:rvrNotApplicable:cvnTOSHIBA:ct10:cvrN/A:
> dmi.product.name: SATELLITE T130
> dmi.product.version: PST3AE-01S01UGR
> dmi.sys.vendor: TOSHIBA
>
> To unsubscribe from this bug, go to:
> https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/631412/+subscribe
>