Backlight issue for hotkeys on Dell inspiron laptop

[Ima]

I work on a Dell Inspiron laptop. The backlight is not working on Ubuntu. Is there any known issues like this with Ubuntu on Dell machines?

I've tried some solutions such as changing grub like the following sample but still it's not working.

sudo gedit /etc/default/grub
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_backlight=vendor"
sudo update-grub
Also, I installed xbacklight, but I can only set a value for it once and then I have to restart if I want to decrease the backlight.

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
NonfreeKernelModules: fglrx wl
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: ima 1893 F.... pulseaudio
 /dev/snd/controlC0: ima 1893 F.... pulseaudio
Card0.Amixer.info:
 Card hw:0 'Intel'/'HDA Intel at 0xfbf00000 irq 48'
   Mixer name : 'IDT 92HD81B1X5'
   Components : 'HDA:111d7605,10280447,00100105'
   Controls : 16
   Simple ctrls : 9
Card1.Amixer.info:
 Card hw:1 'Generic'/'HD-Audio Generic at 0xfbe40000 irq 49'
   Mixer name : 'ATI R6xx HDMI'
   Components : 'HDA:1002aa01,00aa0100,00100200'
   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: Mon Mar 10 21:21:41 2014
HibernationDevice: RESUME=UUID=2ed0b425-01e4-4d67-95e8-b667c73cc6df
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
MachineType: Dell Inc. Inspiron N5010
MarkForUpload: True
ProcEnviron:
 LANGUAGE=en_AU:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
ProcFB: 0 VESA VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-60-generic root=UUID=726c79d3-d245-4127-b65e-9ef72cca6b5c ro quiet splash 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 1.79.10
SourcePackage: linux
StagingDrivers: mei
UpgradeStatus: Upgraded to precise on 2014-02-15 (23 days ago)
dmi.bios.date: 11/17/2010
dmi.bios.vendor: Dell Inc.
dmi.bios.version: A10
dmi.board.name: 0YXXJJ
dmi.board.vendor: Dell Inc.
dmi.board.version: A10
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Inc.
dmi.chassis.version: A10
dmi.modalias: dmi:bvnDellInc.:bvrA10:bd11/17/2010:svnDellInc.:pnInspironN5010:pvrA10:rvnDellInc.:rn0YXXJJ:rvrA10:cvnDellInc.:ct8:cvrA10:
dmi.product.name: Inspiron N5010
dmi.product.version: A10
dmi.sys.vendor: Dell Inc.

[Brad Figg (brad-figg)]

This change was made by a bot.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v3.14 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

If you are unable to test the mainline kernel, for example it will not boot, please add the tag: 'kernel-unable-to-test-upstream'.
Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.14-rc6-trusty/