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JamieKitson

Member

From: UK

Registered: 2010-10-18

Posts: 161

Website

/sys/class/backlight/acpi_video0/brightness not changing with keyboard

Hi,

I can change my screen brightness by echoing to /sys/class/backlight/acpi_video0/brightness and I can then read that value back out. However, if I change the brightness using the buttons on the keyboard the value I get out remains the same. Is this normal behaviour?

I would like to save the brightness at shutdown and load it at start up, but at the moment the value I load is always the same.

Thanks, Jamie

useradded

Member

From: Edinburgh, UK

Registered: 2010-05-15

Posts: 77

Re: /sys/class/backlight/acpi_video0/brightness not changing with keyboard

I have noticed this oddity as well, and would also appreciate an answer to this.

t1nk3r3r

Member

From: The Pacific Northwest

Registered: 2011-03-22

Posts: 79

Re: /sys/class/backlight/acpi_video0/brightness not changing with keyboard

I do not have this problem on my HP, and this does not seem normal.  However:
Under /sys/class/backlight/acpi_video0 do you also have actual_brightness?
Is something you can try.

As for saving/loading values: a bash-script at shutdown, and some lines in either rc.local or rc.sysinit

kernel 3.2.6-2-ARCH
laptop-mode-tools 1.60-1
acpi 1.6-1
acpid 2.0.14-1

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--------------------------The only wasted day is one in which you learn nothing.--------------------------

JamieKitson

Member

From: UK

Registered: 2010-10-18

Posts: 161

Website

Re: /sys/class/backlight/acpi_video0/brightness not changing with keyboard

This seems to be a bug in asus-wmi-nb:

http://dev.iksaif.net/issues/227