[Bug 320874] Re: [asus] /sys/devices/virtual/backlight/acpi_video0/brightness has it backwards

[Leann Ogasawara]

Thanks Khashayar,

I'm just including the upstream git commit id for the Ubuntu kernel team
to reference.  Thanks.

ogasawara at yoji:~/linux-2.6$ git log -p
935e5f290ec1eb0f1c15004421f5fd3154380fd5

commit 935e5f290ec1eb0f1c15004421f5fd3154380fd5

Author: Zhang Rui <rui.zhang at intel.com>

Date:   Thu Dec 11 16:24:52 2008 -0500


    ACPI: video: Fix reversed brightness behavior on ThinkPad SL series


    Section B.6.2 of ACPI 3.0b specification that defines _BCL method

    doesn't require the brightness levels returned to be sorted.

    At least ThinkPad SL300 (and probably all IdeaPads) returns the

    array reversed (i.e. bightest levels have lowest indexes), which

    causes the brightness management behave in completely reversed

    manner on these machines (brightness increases when the laptop is

    idle, while the display dims when used).


    Sorting the array by brightness level values after reading the list

    fixes the issue.


    http://bugzilla.kernel.org/show_bug.cgi?id=12037


    Signed-off-by: Zhang Rui <rui.zhang at intel.com>

    Tested-by: Lubomir Rintel <lkundrak at v3.sk>

    Signed-off-by: Len Brown <len.brown at intel.com>


** Changed in: linux (Ubuntu)
   Importance: Undecided => Medium
       Status: New => Triaged

-- 
[asus] /sys/devices/virtual/backlight/acpi_video0/brightness has it backwards
https://bugs.launchpad.net/bugs/320874
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