No backlight found on system with Lubuntu 12.04

[Kokel]

Labtop HP Pavilion HDX 9150EF with Lubuntu 12.04.4 LTS, Kernel Linux 3.2.0-60-generic (x86_64) has acceptable visual quality but lacks brillance and is somewhat dark.

This is first time Linux is installed on this machine.

Open source Radeon drivers installed according to: http://doc.ubuntu-fr.org/radeon

XFCE manager does not dim the display.

Brightness control created according to: http://www.omgubuntu.co.uk/2013/04/brightness-control-ubuntu
return the message "no backlights were found on your system".

Grub file changed according to: http://www.refreshit.info/2012/08/solved-brightness-increase-and-decrease.html#.Uzp8ch_I0fA
but with no effect.

According to reporting Backlight Bugs from https://wiki.ubuntu.com/Kernel/Debugging/Backlight
I checked that backlight control does not work and there are no entries in /sys/class/backlight.

Therefore it should be an ACPI issue if I understand correctly.

Is there a way to activate or manage backlight on this system to recover original brillance?

Best regards,
Nicolas

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-60-generic 3.2.0-60.91
ProcVersionSignature: Ubuntu 3.2.0-60.91-generic 3.2.55
Uname: Linux 3.2.0-60-generic x86_64
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 2.0.1-0ubuntu17.6
Architecture: amd64
ArecordDevices:
 **** List of CAPTURE Hardware Devices ****
 card 0: Intel [HDA Intel], device 0: STAC92xx Analog [STAC92xx Analog]
   Subdevices: 1/1
   Subdevice #0: subdevice #0
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: nicolas 1883 F.... pulseaudio
 /dev/snd/controlC0: nicolas 1883 F.... pulseaudio
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xe8404000 irq 51'
   Mixer name : 'SigmaTel STAC9271D'
   Components : 'HDA:83847627,30d4103c,00100201'
   Controls : 23
   Simple ctrls : 12
Card1.Amixer.info:
 Card hw:1 'HDMI'/'HDA ATI HDMI at 0xe8310000 irq 52'
   Mixer name : 'ATI R6xx HDMI'
   Components : 'HDA:1002aa01,00aa0100,00100000'
   Controls : 6
   Simple ctrls : 1
Card1.Amixer.values:
 Simple mixer control 'IEC958',0
   Capabilities: pswitch pswitch-joined penum
   Playback channels: Mono
   Mono: Playback [on]
Date: Tue Apr 1 10:42:45 2014
HibernationDevice: RESUME=UUID=30f70a08-6eeb-4713-a061-ec58ec336dc4
InstallationMedia: Lubuntu 12.04 "Precise Pangolin" - Release amd64 (20120423)
MachineType: Hewlett-Packard HP Pavilion HDX9000 Notebook PC
MarkForUpload: True
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-60-generic root=UUID=5e9ec670-275b-41d9-99b1-9bf72e010269 ro quiet splash pcie_aspm=force acpi_backlight=vendor vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-3.2.0-60-generic N/A
 linux-backports-modules-3.2.0-60-generic N/A
 linux-firmware 1.94
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 08/28/2008
dmi.bios.vendor: Hewlett-Packard
dmi.bios.version: 68DVD Ver. F.40
dmi.board.name: 30D4
dmi.board.vendor: Hewlett-Packard
dmi.board.version: KBC Version 86.17
dmi.chassis.asset.tag: CNU7413YH1
dmi.chassis.type: 10
dmi.chassis.vendor: Hewlett-Packard
dmi.modalias: dmi:bvnHewlett-Packard:bvr68DVDVer.F.40:bd08/28/2008:svnHewlett-Packard:pnHPPavilionHDX9000NotebookPC:pvrF.40:rvnHewlett-Packard:rn30D4:rvrKBCVersion86.17:cvnHewlett-Packard:ct10:cvr:
dmi.product.name: HP Pavilion HDX9000 Notebook PC
dmi.product.version: F.40
dmi.sys.vendor: Hewlett-Packard

[Brad Figg (brad-figg)]

This change was made by a bot.

[Kokel (nicolaskokel)]

I created a 80-backlight.conf file according to the Intel HD Graphic Controllers section of page
 https://wiki.ubuntu.com/Kernel/Debugging/Backlight
and then the brightness script is now working, but it does not improve the brightness farther.

Probably I got used to the high brightness and brillance of an LCD monitor I am using as an external display.
It must be the lower screen quality of the labtop display which made think of a backlight bug.

This ticket can be closed.

Sorry for annoyance.

Nicolas