[ltp] xbacklight = 1?

Arno Trautmann linux-thinkpad@linux-thinkpad.org
Fri, 13 Jun 2008 14:12:03 +0200

Yves-Alexis Perez wrote:
> On Fri, Jun 13, 2008 at 09:53:34AM +0200, Arno Trautmann wrote:
>> Hi,
>> I hope, this is the right list for this question and you can give me a  
>> hint; it’s about xbacklight:
>> I have a X61s, Arch Linux, using xbacklight. When I don’t use the  
>> machine for some minutes, the screen turns black. ok, great so far.
>> Returning to the keyboard, the screen turns bright, wonderful. But  
>> mostly it is going to brightnes level 100. Good, so I do a
>> xbacklight = 0
>> because I’m fine with the remaining brightnes at level 0. But if I enter  
>> this, the screen doesn‘t change at all, but stays bright. If I type a
>> xbacklight = 1,
>> it turns to level 1 and is dark. Now I can put it back to 100, and then  
>> putting it to 0 succeeds… this ist quite a strange thing I really would  
>> like to understand. Some kind of bug – but where? xbacklight, hardware  
>> or anything else? It’s not a serious problem, just a bit annoying.
> I have the same thing on a T61 running debian sid. I think the problem
> is in the Xorg intel driver, which doesn't read the firmware backlight
> value before setting it, or something like that.

Ah… so it thinks, it still has the value 0 and thus doesn’t change 
anything? Sonds good, thanks!