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Since I first installed Ubuntu 11.10, I noticed that volume and screen brightness get reset every time Ubuntu starts.

Why is this so? And what ways are there to keep brightness and volume levels after rebooting?

I have found some scripts that change the screen-brightness at login. But this is not a good solution since

  • login is slower because it seems to wait until the screen brightness is at the level specified by the script. After entering the password I see the screen brightness go down gradually. Only after this is complete (~1 or 2 seconds) does the background disappear and Unity come up.
  • The screenbrightness is not remembered but instead redefined at login. So it gets remembered for the first part of the boot, then set to MAX and then again re-set to normal value by the script. My boot process is as follows:
    desired brightness: 2 (13,33%) / Max brightness: 15 (100%)
    1. Bios / brightness: OK
    2. GRUB (violet background color, white text) / brightness: OK
    3. Ubuntu loading screen with the dots / brightness: MAX (win7 loads with OK-brightness)
    4. User Login / brightness: MAX
    5. Unity starts / brightness: OK
  • It seems to be more like a temporary patch than a actual solution.

I'm looking for solutions that set the desired brightness permanently and consistently throughout the whole boot-process

After updating to 12.04 the behavior is the same.

I tried

  • setpci -s 02:00.0 F4.B=XX
    The value of F4.B is always '0' regardless of what value I try to set it to (tried 0, ff, f, 5, etc)
  • The solution in this answer does not have any noticeable effect: Desktop doesn't remember brightness settings after a reboot
    The variables at /sys/class/backlight/acpi_video0/ get changed if I use Fn+UP and Fn+DOWN

Any help is appreciated. Thanks!

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Did you found the answer to this question. I am getting the same problem please help. –  Murtaza Munshi Dec 27 '13 at 12:09
    
@MurtazaMunshi Unfortunately not. I still have the same issue. –  leugim Dec 28 '13 at 15:19
    
Damn....Why isn't anyone helping us over here. –  Murtaza Munshi Dec 29 '13 at 15:10

2 Answers 2

Have you tried the following?

Open Terminal (Press Ctrl+Alt+T) and type:

sudo gedit /etc/rc.local

Add this before the last line "exit 0":

echo 4 > /sys/class/backlight/acpi_video0/brightness
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I edited /etc/rc.local but it has no effect ... I did a few reboots to make sure. The value of /sys/class/backlight/acpi_video0/brightness is always 15 after reboot. –  leugim Jun 20 '12 at 14:57
    
Have you other folders in /sys/class/backlight/ besides acpi_video0 ? For example, I've got /sys/class/backlight/intel_backlight/brightness too, and I would add also echo 4 > /sys/class/backlight/intel_backlight/brightness to /etc/rc.local –  jasmines Jun 20 '12 at 15:01
    
Thank you for taking the time to look into this! I have just that one acpi_video0 folder nothing else. It has a litlle black arrow, though as if it were a shortcut? –  leugim Jun 20 '12 at 15:24
    
Yes, it's a symlink. If you want to know the original folder, just type ls -la /sys/class/backlight/, but this won't help much. –  jasmines Jun 20 '12 at 15:29

This method will not slow down anything. Press Ctrl+Alt+t for openeing terminal then use -

cat /sys/class/backlight/acpi_video0/max_brightness

it will give you the maximum brightness value, to change it for after booting open-

sudo gedit /etc/rc.local

and add the line shown below before exit , look at the screenshort I have attached-

echo 0 > /sys/class/backlight/acpi_video0/brightness

Change 0 to the value you want in the start as got from previous command output.

as shown here-here changing

Now just save it and restart. Hope it helped you.

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