Brightness control fails in Ubuntu 14.04

Asked by Triyambakesh Mohanty on 2014-08-16

I have recently upgraded the laptop OS from LTS 12.04 to LTS 14.04 in Acer Aspire 5740. Earlier, the brightness control was controled by a plugin 'Kamal Mostafa mjgbacklight'. Soon after upgrade to 14.04, the brightness control fails. Kindly resolve.

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Solved by:
Manfred Hampl
Last query:
Last reply:

What is the output of :

sudo lshw -C display; lsb_release -a; uname -a


       description: VGA compatible controller
       product: Core Processor Integrated Graphics Controller
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 12
       width: 64 bits
       clock: 33MHz
       capabilities: msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:41 memory:f0000000-f03fffff memory:d0000000-dfffffff ioport:1800(size=8)
LSB Version: core-2.0-ia32:core-2.0-noarch:core-3.0-ia32:core-3.0-noarch:core-3.1-ia32:core-3.1-noarch:core-3.2-ia32:core-3.2-noarch:core-4.0-ia32:core-4.0-noarch:core-4.1-ia32:core-4.1-noarch:security-4.0-ia32:security-4.0-noarch:security-4.1-ia32:security-4.1-noarch
Distributor ID: Ubuntu
Description: Ubuntu 14.04.1 LTS
Release: 14.04
Codename: trusty
Linux triyambakesh-laptop 3.13.0-34-generic #60-Ubuntu SMP Wed Aug 13 15:49:09 UTC 2014 i686 i686 i686 GNU/Linux

OmgUbuntu has a guide on how to install the Intel driver installed. It may help

Dear Actionparsnip, Thank you for guiding me in setting up the Intel Driver from OMGUBUNTU ( I have followed the instructions exactly what is given in the page ( & downloaded - 'Graphics Installer 1.0.6 for Ubuntu* 14.04, 32-bit' that is compatible to my system. Installation was done with complete set up & execution of 'Signatures - Ubuntu*' in Terminal, given in the same web page. But, there is no respose. Still the brightness remains 100%.

I also tried setting up Brightness Indicator from the page OMGUBUNTU. This also didnot work. ( Kindly suggest me. Thanks again.

I am facing problem during prolonged work on my laptop due to failure in brightness control. Please help me out solving this problem. Also my Battery gets exhausted very fast.

Launchpad Janitor (janitor) said : #6

This question was expired because it remained in the 'Open' state without activity for the last 15 days.

I could not configure anything for brightness. Kindly, provide me with solution for this. Thanks.

Thankyou very much Manfred, my problem got fixed solution given on by Abhishek. Thanks a lot.

For intel_backlight

sudo touch /usr/share/X11/xorg.conf.d/20-intel.conf

sudo gedit /usr/share/X11/xorg.conf.d/20-intel.conf

Add lines in text:

Section "Device"
        Identifier "card0"
        Driver "intel"
        Option "Backlight" "intel_backlight"
        BusID "PCI:0:2:0"

Save it. Log out and log in back.

Problem Solved. Thanks Manfred for providing me this link.

Thanks Manfred Hampl, that solved my question.