Ubuntu 12.04 LTS set max lcd brightness on every boot

[SiRiusCb]

I'm on:
Linux 3.2.0-12-generic-pae #20-Ubuntu SMP Sat Jan 28 01:10:59 UTC 2012 i686

I solve the issue editing the file
/etc/rc.local
adding this line "echo 4 > /sys/class/backlight/acpi_video0/brightness" (without quotes)
(i use 4 because is value in the middle, in fact 0 is the lower and 8 is the higher)

Probably there are a better ways to solve this issue (i hope...)
---
ApportVersion: 1.91-0ubuntu1
Architecture: i386
DistroRelease: Ubuntu 12.04
Package: gnome-power-manager 3.2.1-2 [modified: usr/bin/gnome-power-statistics]
PackageArchitecture: i386
ProcVersionSignature: Ubuntu 3.2.0-15.24-generic-pae 3.2.5
Tags: precise
Uname: Linux 3.2.0-15-generic-pae i686
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/923940/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[Fabio Marconi (fabiomarconi)]

Hello
Please run in a terminal
apport-collect 923940
Thanks
Fabio
---
Ubuntu Bug Squad volunteer triager
http://wiki.ubuntu.com/BugSquad

[SiRiusCb (xlat)]

apport information

[SiRiusCb (xlat)]

apport information

[SiRiusCb (xlat)]

@fabiomarconi

[SiRiusCb (xlat)]

@fabiomarconi

Il comando "apport-collect 923940" serve a launchpad per aggiornare/integrare lo status del Bug Report?

P.S Specifico che sono italiano, ma probabilmente si capiva dall'inglese maccheronico del 1° post

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Clément (cochon)]

Hello

Also affected here.
LCD doesn't only set brightness max on every boot but every time screen goes sleep. Pretty anoying.

I can't modify /sys/class/backlight/acpi_video0/brightness with the echo command. I got the answer : "bash: /sys/class/backlight/acpi_video0/brightness: Permission denied".
If it worked, would the modification be definitive ?

Best

[SiRiusCb (xlat)]

@cochon
Sorry,but it's my fault i have confused file /sys/class/backlight/acpi_video0/brightness
with /etc/rc.local
See "Bug Description" now corrected in top of page.

>https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/923940/+attachment/2701793/+files/rc.local

[Clément (cochon)]

Sorry SiRiusCb but it doesn't change anything on my system. /sys/class/backlight/acpi_video0/brightness keeps 10 as value. /etc/rc.local is nevertheless executable.
What did I miss ?

Best

[SiRiusCb (xlat)]

My stat with the ACL of rc.local is in attachment.
if you have follow correctly the instruction to modify the rc.local all should be ok

[Clément (cochon)]

Weird !
There is barely a difference.

  Fichier : «/etc/rc.local»
   Taille : 358 Blocs : 8 ES blocs : 4096 fichier
Device : 805h/2053d Inode : 263548 Liens : 1
Accès : (0775/-rwxrwxr-x) UID : ( 0/ root) GID : ( 0/ root)
Accès : 2012-04-22 16:24:12.345009945 +0200
Modi. : 2012-04-15 20:05:12.584086535 +0200
Chgt  : 2012-04-15 20:05:12.608074533 +0200
Créé  : -

[Clément (cochon)]

I used to lower down brightness around 2. Then after about 15 to 20 seconds of inactivity, the screen used to set itself automatically to 5 and then to 10 suddenly after touching the touchpad. I had to lower down brightness manually every times.

Problem solved by disabling the "lower luminosity to save battery" option in the luminosity/locking options of the gnome parameter menu.

[Sami Jaktholm (sjakthol)]

I'm no expert but a working command you can use to change the display brightness temporarily as a normal user is:
    echo somevalue | sudo tee /sys/class/backlight/acpi_video0/brightness

For example if you want to set the brightness to 2, run following:
    echo 2 | sudo tee /sys/class/backlight/acpi_video0/brightness

If the command is run as root (like it's done if added to rc.local), you can just use the echo x > ... command. If this doesn't work during startup, it's very likely that the case is what Steve Langasek describes in another bug report:
    "And even if you get it to work at the commandline, this setting may be getting overridden by the desktop after rc.local runs."

[Jeff Gregoire (jfgregoire)]

As a temporary patch, you can try the following:

- Create a file (any name) under /etc/pm/power.d with the following content:

# Brightness adjustment

case $1 in
        true)

                # 20% screen brightness on battery
                echo 2 > /sys/class/backlight/acpi_video0/brightness
        ;;
        false)
                # 80% screen brightness on AC
                echo 8 > /sys/class/backlight/acpi_video0/brightness
        ;;
esac

exit 0

- Make it executable "chmod +x myscript" assuming "myscript" is the name of your file.

Of course, you will need to reboot. This will adjust the brightness at 20 % when on battery and 80% when on AC power.

[Asheesh (asheeshranjan1)]

I had the same issue. I use xbacklight to solve the issue.

Add xbacklight to your startup applications with the desired brightness setting and problem worked around.

[SiRiusCb (xlat)]

Il 13/01/2013 06:14, Asheesh ha scritto:
> I had the same issue. I use xbacklight to solve the issue.
>
> Add xbacklight to your startup applications with the desired brightness
> setting and problem worked around.
>
Probably my workaround is very similar !

[Hugin (g-schwartzmann)]

Jeff Gregoire (jfgregoire) wrote on 2012-06-11:

> - Create a file (any name) under /etc/pm/power.d with the following content:

> # Brightness adjustment

Thanks for this solution, it works ;-)