The screen brightness slider has no effect in Unity. The slider can be moved up and down to the brighter and dimmer positions, but the screen itself does not change one bit. This is on a MacbookPro8,2 and with Ubuntu 11.10.
WORKAROUND: Keys F1 and F2 control the brightness slider.
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AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
ApportVersion: 1.23-0ubuntu3
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC1: lars 1778 F.... pulseaudio
/dev/snd/controlC0: lars 1778 F.... pulseaudio
Card0.Amixer.info:
Card hw:0 'PCH'/'HDA Intel PCH at 0xb0900000 irq 47'
Mixer name : 'Cirrus Logic CS4206'
Components : 'HDA:10134206,106b1d00,00100301'
Controls : 22
Simple ctrls : 13
Card1.Amixer.info:
Card hw:1 'Generic'/'HD-Audio Generic at 0xb0840000 irq 48'
Mixer name : 'ATI R6xx HDMI'
Components : 'HDA:1002aa01,00aa0100,00100200'
Controls : 4
Simple ctrls : 1
Card1.Amixer.values:
Simple mixer control 'IEC958',0
Capabilities: pswitch pswitch-joined penum
Playback channels: Mono
Mono: Playback [on]
CurrentDmesg: Error: command ['sh', '-c', 'dmesg | comm -13 --nocheck-order /var/log/dmesg -'] failed with exit code 1: comm: /var/log/dmesg: Permission denied
DistroRelease: Ubuntu 11.10
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64+mac (20111012)
MachineType: Apple Inc. MacBookPro8,2
Package: linux (not installed)
ProcEnviron:
PATH=(custom, no user)
LANG=en_US.UTF-8
SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.0.0-12-generic root=UUID=4c671a71-6a28-491e-9b3d-7ed360f27405 ro quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Tags: oneiric running-unity
Uname: Linux 3.0.0-12-generic x86_64
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: cdrom dialout lpadmin plugdev sambashare
dmi.bios.date: 09/09/11
dmi.bios.vendor: Apple Inc.
dmi.bios.version: MBP81.88Z.0047.B1E.1109091244
dmi.board.asset.tag: Base Board Asset Tag#
dmi.board.name: Mac-94245A3940C91C80
dmi.board.vendor: Apple Inc.
dmi.board.version: MacBookPro8,2
dmi.chassis.type: 10
dmi.chassis.vendor: Apple Inc.
dmi.chassis.version: Mac-94245A3940C91C80
dmi.modalias: dmi:bvnAppleInc.:bvrMBP81.88Z.0047.B1E.1109091244:bd09/09/11:svnAppleInc.:pnMacBookPro8,2:pvr1.0:rvnAppleInc.:rnMac-94245A3940C91C80:rvrMacBookPro8,2:cvnAppleInc.:ct10:cvrMac-94245A3940C91C80:
dmi.product.name: MacBookPro8,2
dmi.product.version: 1.0
dmi.sys.vendor: Apple Inc.
On the MacBookPro8,2 the keys F1 and F2 control the brightness slider.