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Posts Tagged ‘screen brightness’

Screen brightness work around (part 2)

January 19th, 2014 No comments

As mentioned before I am having some issues with my laptop’s hardware and controlling the screen brightness. Previously my work around was to set acpi_backlight=vender in the grub command line options. While this resulted in having full screen brightness it also removed my ability to use my keyboard function keys to adjust the screen brightness on the fly (not so good when you’re on battery). Removing this option allowed me to manually adjusted my screen brightness again but once again always started the laptop at zero brightness. What to do?

While far from a perfect solution my current work around is to use xdotool to simulate key presses on login which raise the screen brightness for me automatically. Here is the script that I run on startup:

#!/bin/bash
for i in {1..20}
do
     xdotool key XF86MonBrightnessUp
done

While this works great it still isn’t perfect. Because xdotool requires an X session it means I cannot run it before one is created. If you were unaware the login screen, in my case MDM, does not run inside of X (it actually starts X when you successfully login). So while this will automatically brighten my screen it won’t do so until I type in my username and password, leaving me to type into a fully dark screen or manually adjust the brightness up enough to see what I’m doing. Hopefully I’ll have a better solution sooner rather than later…




I am currently running a variety of distributions, primarily Ubuntu 14.04.
Previously I was running KDE 4.3.3 on top of Fedora 11 (for the first experiment) and KDE 4.6.5 on top of Gentoo (for the second experiment).
Check out my profile for more information.

Fix no screen brightness on boot problem

October 14th, 2013 No comments

I recently upgraded my laptop to a brand new Lenovo Y410P and promptly replaced Windows 8 with a Linux install. Unfortunately I immediately ran into a very strange driver(?) issue where, on boot, the computer would default to the absolute lowest screen brightness level. This meant that I would need to manually adjust the screen brightness up just to see the login screen. Thankfully after some help from the excellent people over on the Ubuntu Forums I managed to find a very easy work around.

1) As root open up /etc/default/grub

I did this by simply issuing the following command:

sudo nano /etc/default/grub

2) Find the line that says GRUB_CMDLINE_LINUX= and add “acpi_backlight=vendor” to the list of options.

3) From a terminal run this command to update GRUB

sudo update-grub

4) Reboot!

That’s pretty much it. My computer now boots with the correct screen brightness as one would expect.




I am currently running a variety of distributions, primarily Ubuntu 14.04.
Previously I was running KDE 4.3.3 on top of Fedora 11 (for the first experiment) and KDE 4.6.5 on top of Gentoo (for the second experiment).
Check out my profile for more information.