xbacklight on intel

[Colin Guthrie]

Jesse Barnes wrote:
> On Tuesday, November 27, 2007 8:08 am Khashayar Naderehvandi wrote:
>>> What does 'xrandr --prop' report when you're running the 2.2 driver?
>> This is what I get:
>>
>> khashayar at dionysos ~ $ xrandr --prop
>> Screen 0: minimum 320 x 200, current 1280 x 768, maximum 1280 x 1280
>> VGA disconnected (normal left inverted right x axis y axis)
>> LVDS connected 1280x768+0+0 (normal left inverted right x axis y axis) 0mm
>> x 0mm
>>         BACKLIGHT_CONTROL: native
>>                 supported: native       legacy       combination
>> kernel
>>         BACKLIGHT: 0 (0x00000000) range:  (0,0)
>>    1280x768       59.2*+   85.0     75.0     70.0     60.0
>>    1280x720       85.0     75.0     70.0     60.0
>>    1152x768       54.8
>>    1024x768       85.0     75.0     70.1     60.0
>>    832x624        74.6
>>    800x600        85.1     72.2     75.0     60.3     56.2
>>    640x480        85.0     72.8     75.0     59.9
>>    720x400        85.0
>>    640x400        85.1
>>    640x350        85.1
>> TMDS disconnected (normal left inverted right x axis y axis)
> 
> So your machine is defaulting to the native register interface.  I wonder if 
> it should be using the legacy interface instead?  Can you try
>   $ xrandr --output LVDS --set BACKLIGHT_CONTROL legacy
> and see if xbacklight works for you then?

Weird...

On mine I just realised my backlight wont work with the built in buttons
(not tried xbacklight) - it just flickers but stays always at 100%.

I have:
        BACKLIGHT_CONTROL: kernel
                supported: native       legacy       combination  kernel

        BACKLIGHT: 100 (0x00000064) range:  (0,100)

Setting it to "legacy" as you stated above caused my X to go into
infinite loop (100% CPU).

I tried stracing the process after ssh'ing in from a separate machine
but all I got was lots of calls with the word alarm in it (SIGALARM,
rt_sigalarm and such like).....

:s

Col