How to disable low display brightness when power fail?

[Unga]

>________________________________

> From: "illoai at gmail.com" <illoai at gmail.com>
>To: Unga <unga888 at yahoo.com> 
>Cc: "freebsd-questions at freebsd.org" <freebsd-questions at freebsd.org> 
>Sent: Tuesday, February 4, 2014 12:16 PM
>Subject: Re: How to disable low display brightness when power fail?
> 
>
>On 4 February 2014 04:55, Unga <unga888 at yahoo.com> wrote:
>> Hi all
>>
>> I have a laptop running FreeBSD 9.2 and KDE4.
>>
>>
>> When main A/C power fails, this laptop immediately reduces the display brightness. When power restores, it also immediately restore the full brightness.
>>
>> Because of this I cannot show a presentation without power.
>>
>> Therefore, how to disable becoming low bright when no main A/C power?
>>
>> I prefer a xorg.conf entry.
>
>Have a look at acpi_video(4).
>
>http://www.freebsd.org/cgi/man.cgi?query=acpi_video&sektion=4
>


Hi

There are no hw.acpi.video.X variables in this laptop:


sysctl -a | grep hw.acpi.video


This laptop uses Intel open source driver.

Regards
Unga