Unity Screen Brightness Settings not Preserved on Reboot

[Tim Edwards]

Whenever Unity starts it sets the screen brightness to maximum, even when the laptop is on battery. Lowering the screen brightness doesn't persist across reboots.

To reproduce:
1. Start laptop (in this case a Lenovo Yoga 2 Pro) in battery mode (i.e. disconnected from the AC adaptor)
2. Unity will start in maximum brightness. Lower brightness using keyboard brightness keys.
3. Shutdown laptop and start it back up again (still with the AC adapter disconnected)

Expected result:
The screen brightness settings should be preserved across reboots

Actual result:
After each new start Unity sets the screen brightness to maximum, meaning the user has to remember to manually reduce it or the battery will be quickly used up

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity 7.2.3+14.04.20140826-0ubuntu1
ProcVersionSignature: Ubuntu 3.13.0-40.69-generic 3.13.11.10
Uname: Linux 3.13.0-40-generic x86_64
.tmp.unity.support.test.0:

ApportVersion: 2.14.1-0ubuntu3.5
Architecture: amd64
CompizPlugins: [core,bailer,detection,composite,opengl,compiztoolbox,decor,imgpng,mousepoll,vpswitch,unitymtgrabhandles,gnomecompat,regex,move,grid,place,wall,animation,snap,resize,fade,session,expo,workarounds,scale,ezoom,unityshell]
CompositorRunning: compiz
CompositorUnredirectDriverBlacklist: '(nouveau|Intel).*Mesa 8.0'
CompositorUnredirectFSW: true
CurrentDesktop: Unity
Date: Sat Nov 29 11:59:31 2014
DistUpgraded: Fresh install
DistroCodename: trusty
DistroVariant: ubuntu
GraphicsCard:
 Intel Corporation Haswell-ULT Integrated Graphics Controller [8086:0a16] (rev 0b) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Device [17aa:3978]
InstallationDate: Installed on 2014-09-16 (73 days ago)
InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2)
MachineType: LENOVO 20266
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-3.13.0-40-generic.efi.signed root=/dev/mapper/MainVG-root ro video.use_native_backlight=1 quiet splash vt.handoff=7
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 03/25/2014
dmi.bios.vendor: LENOVO
dmi.bios.version: 76CN35WW
dmi.board.asset.tag: No Asset Tag
dmi.board.name: Yoga2
dmi.board.vendor: LENOVO
dmi.board.version: 31900058STD
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo Yoga 2 Pro
dmi.modalias: dmi:bvnLENOVO:bvr76CN35WW:bd03/25/2014:svnLENOVO:pn20266:pvrLenovoYoga2Pro:rvnLENOVO:rnYoga2:rvr31900058STD:cvnLENOVO:ct10:cvrLenovoYoga2Pro:
dmi.product.name: 20266
dmi.product.version: Lenovo Yoga 2 Pro
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.11.2+14.04.20140714-0ubuntu1
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.52-1
version.libgl1-mesa-dri: libgl1-mesa-dri 10.1.3-0ubuntu0.2
version.libgl1-mesa-dri-experimental: libgl1-mesa-dri-experimental N/A
version.libgl1-mesa-glx: libgl1-mesa-glx 10.1.3-0ubuntu0.2
version.xserver-xorg-core: xserver-xorg-core 2:1.15.1-0ubuntu2.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev 1:2.8.2-1ubuntu2
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:7.3.0-1ubuntu3.1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.910-0ubuntu1.3
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.10-1ubuntu2
xserver.bootTime: Fri Nov 28 23:10:38 2014
xserver.configfile: default
xserver.errors:

xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
 product id 16970
 vendor SDC
xserver.version: 2:1.15.1-0ubuntu2.1

[sucipto (show-cheap)]

Same issue here,
Asus X45A

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.