[hal-info] Dell laptops control brightness in hardware

[Martin Pitt]

hi Rui,

Rui Tiago Matos [2007-11-14 19:37 +0000]:
> On 14/11/2007, Martin Pitt <martin at piware.de> wrote:
> > recently, our power management and laptop expert Matthew Garrett
> > changed the "brightness controlled in HW" to apply to all Dell
> > laptops, not just the D420. We have examined quite a few different
> > Dell models, and so far they all show the same behaviour.
> >
> > This might be a bit gross, but it seems to fix many more cases than it
> > breaks apparently.
> 
> And what about this file[1] which will override the hal-info anyway?

Ah, thanks for pointing this out. This file is not yet in release
20071030, so I missed it. It seems that my patch is moot then.

> Besides, doesn't the existence of the dell backlight addon make it
> software controlled?

You can't, it's hardwired (as Danny pointed out already). AFAIUI, the
file you pointed out just tells hal that it uses the Dell specific
backend for brightness control, which I guess will just read out the
new brightness without actually trying to set it. (I might be wrong
here, I don't know much about the Dell perculiarity).

Thanks,

Martin

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