Every time I reboot my machine the brightness goes back to 100% in Gnome. I wish it would keep the last setting. Is there anyway?
This is supposed to be configurable in the energy options, set the brightness to the desired level and it will always be used. If you use a laptop you will also need to configure the level for battery mode as well...
I found that Gnome has some issues about lcd panel brightness, e.g. if I run on battery mode and set the brightness manually to a given level and leave the laptop unattended for 10 seconds it will go back to the preset brightness when I take control back. Same goes when on A/C mode except it takes longer so goes unnoticed more easily. I believe all those settings should be saved somewhere and restored - at least for A/C mode.
EDIT: For gnome3 this does not work (at least for me).
Here is a quick workaround for that :-
edit the /etc/rc.local file by typing
sudo gedit /etc/rc.local in terminal
comment out the
this is necessary otherise it wont work !
after this add the following line in the file
such that it looks like this :-
replace 0 with the required brightness value ( ranges from 0 to 10 )
save the file and exit.
now try testing the setting by typing this command in terminal
if the brightness changes to minimum , you have got it right ! reboot to see the changes.
Note :- you may have to replace acpi_video0 with your device code if you have a different one ( its mostly acpi_video0 ). Most of u wont need to do so.
The file /etc/rc.local should look like this:
Per @zerdo: In my dell studio 1558 the brightness setting is stored in
Also, per @Nick :
If this is the only answer you read, note that the 0 in
To adjust screen brightness in 11.10, you will need to access the "System Settings":
If Ubuntu isn't remembering your adjustment, you may use an application or you may need to use the workaround for GNOME: Brightness setting not saved in Ubuntu 11.10
This function, the backlight control, is dependent on your bios and kernel version.
Try these four things.
Kernel (boot) options
When you boot, at the grub screen, hit e to edit. To the kernel line add
As you can see, you may need to google search for your settings.
If that works, edit
Edit the "GRUB_CMDLINE_LINUX_DEFAULT" line so it looks like this
Save your edit, update grub
If that does not work, you can try to manually set the brightness.
Note: Path may vary with hardware / kernel version, may be
The output of that command varies a bit with hardware, 1 -> 10 , 1 -> 12 , 1 -> 100 ??? Choose a value and set it (choose the value for your hardware).
If that works, add it to
Add in your setting above "exit 0"
You can also try
You then adjust with the command line
Again, add that to
Add in, above "exit 0"
You can try to set your brightness with
The general syntax is
You identify your pci bus address with
If you get your setting wrong, most likely you will just loose your display, and have to reboot. As this is a hardware setting, you really need to identify your hardware and research the settings first.
Acer extensa - https://bugs.launchpad.net/ubuntu/+source/linux/+bug/518002
There seems to be a bug report abaout this:
For me, it has worked to place:
Or, as others suggested,
The "Screen" option of "System Settings" works OK, and in
I found the solution to my problem:
Add the next option under your "Device" section in
This worked for my NVIDIA card (Ubuntu 11.10 x64 on Toshiba Satellite L745-SP4142CL)
It worked for me with the following spesifications:
Here is a great work around I found, credit and thanks to thaelim on Ubuntu forum How to get effective display brightness management under Unity/Gnome Shell just download the script edit the perimeters at the beginning of the script and save it when your done to your home folder. Heres the download of the full script brightmanager.py
These are the variable perimeters to change to your desired settings, as you can see I like mine at 20 all the time with no idle timeout.
After saving then open a terminal and enter
Then open up startup applications from the dash, click on the add button, name your start up application, and enter your command as:
replacing "david" with your home folders name, then add a description and click add, logout, and back in, and your done, you now have brightness settings for battery, AC, and idle.
You will want to do this for each user and each user should have their own copy of the script in their home folder with their own desired settings in the beginning of the script.
I found a workaround from Andrew, It helps.
The command above should display an output similar to this:
where "acpi_videoX" is "acpi_video0" or "acpi_video1". This is the acpi_video that controls the brightness, so remember it for the next steps.
If the command above doesn't display any output and you have a folder called "intel_backlight" under "/sys/class/backlight/", then use "intel_backlight" as the ACPI interface for the next steps.
where "acpi_videoX" is the ACPI interface which controls your laptop's brightness, which you find out under step 1.
Remember this value for the next step.
And in this file, paste this:
here, you need to:
replace BRIGHTNESS_VALUE with the brightness value you got under step 3;
replace acpi_videoX with the ACPI Interface that controls your laptop's brightness, which you found out under step 1.
Then save the file.
protected by Community♦ Nov 1 '11 at 19:26
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