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I am running Ubuntu 14.04 LTS on a Dell Latitude E3440 laptop. My problem is that screen brightness automatically changes depending on content. This means that the screen gets brighter when the contents are white (for example when I open my browser) and it gets dimmer when the contents are dark (for example when I open the terminal). This can easily be seen when I open a white window and a black window and I proceed to move the black window in and out of the screen, so the brightness constantly changes.

I have done a fair amount of research, and the issue seems to have something to do with the power saving feature of the graphics card. This issue seems to be resolved in windows environments, but I have not found a solution for Ubuntu.

This issue appears only when I run the laptop on battery, and disappears as soon as I plug it in. This probably means it has something to do with power saving.

The graphics used is shown as Intel Haswell Mobile in "About this Computer". So I think it doesn't have a dedicated GPU.

All in all, the constant brightness adjustment is quite annoying, to the point that I have to plug my machine in in order to use it for extended periods of time.

This question has been asked before here about 8 months ago with no solution. I am asking this again as I am a new user and don't have enough reputation to comment on it :|

Community
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Ashish Maheshwari
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  • Hello! If you haven't found a solution please follow the instructions on this link and add the details about the card and driver in use. – Torrien Jan 22 '16 at 06:09
  • I think you are correct in your assumption that it is related to power saving feature. Have you tried disabling the power saving mode for "when on battery"? -- ken – ken Feb 11 '16 at 22:11
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    Yeah, I think I tried that. Its been so long and I was so frustrated that I dumped it and asked my company for a Mac. Never have been so peaceful :P – Ashish Maheshwari Feb 14 '16 at 07:42

2 Answers2

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This looks like a Dell-specific "feature" that — if you are lucky — might be disabled in the BIOS menu.

It can go by the name "Dynamic Backlight Control", "adaptive brightness", "Eco light", or "dynamic brightness adjustment".

More info in this other post.

Others suggest that (in a less lucky case) you might need to install some additional driver from Dell.

Levente
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0

Install wildguppy.

You can enable or disable dynamic brighness according to your needs. 

sudo add-apt-repository ppa:fantasyleague0629/wildguppy
sudo apt-get update; sudo apt-get install wildguppy

to make it start on start-up

gedit ~/.config/autostart/wildguppy-gtk.desktop

copy paste the following into the file

[Desktop Entry]
Type=Application
Exec=wildguppy-gtk
Hidden=false
NoDisplay=false
X-GNOME-Autostart-enabled=true
Name[en_US]=WildGuppy
Name=WildGuppy
Comment[en_US]=
Comment=
muru
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