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    brightness controls don't actually work

    Discussion in 'Linux Compatibility and Software' started by Fittersman, Sep 7, 2009.

  1. Fittersman

    Fittersman Wanna trade?

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    Hey, I'm fairly familiar with linux but this one has me stumped.. Maybe someone here will know how to deal with this.

    Basically, when I try to change the brightness with the Fn keys, the event is handled properly (ie. linux thinks the brightness is changing), but when you physically look at the screen it is very clear that the brightness has not changed.

    If I use the brightness Fn buttons, the value in /proc/acpi/video/EVGA/LCD/brightness is updated, but the screen isnt changing.

    I'm using debian and my laptop is in the signature.

    I found a few other DV3 users who have run into this problem, but none have a solution yet. Some are saying it's an acpi event that isn't being handled properly and can't be fixed until a new kernel is released?

    Does anyone know what actually controls the brightness levels? Maybe I could look into that a bit further.
     
    Fittersman, Sep 7, 2009
    #1
  2. rockhopper

    rockhopper Notebook Guru

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    Using the kernel 2.6.30? Try adding one if these to your grub kernel line:

    Code: 
    ACPI_VIDEO=y VIDEO_OUTPUT_CONTROL=y
    or

    Code: 
    acpi_backlight=vendor
     
    rockhopper, Sep 8, 2009
    #2
  3. Fittersman

    Fittersman Wanna trade?

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    Tried those, neither worked.

    I'm using the 2.6.26-2-amd64 kernel
     
    Fittersman, Sep 8, 2009
    #3
  4. archer7

    archer7 Notebook Evangelist

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    Try 2.6.30 if you can.
     
    archer7, Sep 8, 2009
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  5. osomphane

    osomphane Notebook Evangelist

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    My brightness controls did not work because of the ambient light sensor. That got fixed when I inserted a script to turn off the sensor at boot-up. But I think each manufacturer will have a different command to turn it off.
     
    osomphane, Sep 9, 2009
    #5