Re: i915 backlight

From: Aaron Lu
Date: Fri Aug 02 2013 - 02:35:53 EST


On 08/02/2013 02:25 PM, Josep Lladonosa wrote:
> Hello,
>
> I am using a Lenovo Edge E530 and, with kernel 3.11.0-rc3, I had to
> change to this parameter to the kernel boot:
>
>
> GRUB_CMDLINE_LINUX="acpi_osi=\"!Windows 2012\""

What if you remove the above from kernel command line, and add
video.brightness_switch_enabled=0 to kernel command line, then set the
following in xorg.conf:
$ cat /etc/X11/xorg.conf
Section "Device"
Option "Backlight" "intel_backlight"
Identifier "Card0"
Driver "intel"
BusID "PCI:0:2:0"
EndSection

Does everything work?

If not, please test if manually change brightness level through sysfs
works:
# cd /sys/calss/backlight/intel_backlight
# echo xxx > brightness

And also test if hotkey event is sent out or not by running acpi_listen
and then press the hotkey.

Thanks,
Aaron

>
>
> instead of previous
>
> GRUB_CMDLINE_LINUX="acpi_osi=Linux acpi_backlight=vendor"
>
> to be able to change brightness. In some kernel versions before, it
> worked, but with 15 levels, but in graphical system brightness bar was
> not moving.
>
>
> Now I have, though, 8 possible values for brightness and brightness
> bar shows its correct position.
>
> Josep
>
> On 2 August 2013 08:00, Aaron Lu <aaron.lu@xxxxxxxxx> wrote:
>> On 08/01/2013 04:07 PM, Borislav Petkov wrote:
>>> On Wed, Jul 31, 2013 at 11:16:52PM +0200, Rafael J. Wysocki wrote:
>>>> Does reverting efaa14c help?
>>>
>>> Nope.
>>>
>>> But see my other reply to Aaron.
>>
>> Assume you have specified to use intel_backlight in xorg.conf, does
>> booting with video.brightness_switch_enabled=0 help?
>>
>> Thanks,
>> Aaron
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>
>

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