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screen brightness setting isn't saved

Posted: Fri Jan 11, 2013 12:00 am
by jms
Hi, I'm able to adjust my screen brightness settings just fine, the only issue I have is that they don't save after the computer reboots or hibernates. It always resets the screen to maximum brightness.

How can I fix this so that my screen brightness is saved permanently? Thanks.

Re: screen brightness setting isn't saved

Posted: Mon Jan 21, 2013 10:42 pm
by aviatorgeek
I have the same problem. Linux Mint 14 "Nadia" with Cinnamon on Asus N56V. I set the brightness to desired level using the Brightness and Lock settings. If any of the following happens, the screen resets to full brightness:
- let the screen timeout and lock (screen turns off to save power)
- standby / resume
- hibernate / resume

Incidentally I also note a problem with the brightness control applet: it "inverses" the brightness setting each time I click it:
- click brightness control applet
- set brightness to 30% (ok)
- click brightness control applet again: brightness switches to 70% (100% - 30%)
- set brightness to 40% (ok)
- click brightness control applet again: brightness switches to 60% (100% - 40%)

Is this a known bug?

Re: screen brightness setting isn't saved

Posted: Wed Jan 23, 2013 4:23 pm
by hasson
same issue here...

A partial solution

Posted: Mon Sep 23, 2013 12:17 pm
by HanekDaikaen
I could save a certain value of brightness adding the line:

Code: Select all

echo 0 > /sys/class/backlight/acpi_video0/brightness
to the file /etc/rc.local as seen below:

Code: Select all

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.
echo 0 > /sys/class/backlight/acpi_video0/brightness                          <·······
exit 0
It turns brightness to minimum when initiating.
Other values of brightness can be set by changing the number after "echo". Numbers allowed go from 0 (minimum) to a maximum value indicated in the file /sys/class/backlight/acpi_video0/max_brigthness

- Note that acpi_video0 could have another name.
- I can't guarantee it will work on every machine. I know it worked for me (Toshiba laptop, intel integrated graphics and linux mint 15)

I hope it helps.