Re: [PATCH 1/3] backlight: Allow drivers to update the core, andgenerate events on changes

From: Matthew Garrett
Date: Wed Jul 29 2009 - 11:20:53 EST


On Wed, Jul 29, 2009 at 05:05:24PM +0200, Pavel Machek wrote:
> > No, I mean that the only default policy you could reasonably have in the
> > kernel would be tying the backlight directly to the ALS. And that sucks.
> > You need some degree of smoothing, and that's a job better left to
> > userspace.
>
> How would that be done? Wake up userspace 100times a second so it can
> read an integer and ardd it to running average?

I don't think you'd need more than once a second, possibly modified by
the size of the change since the last measurement. Response doesn't need
to be immediate.

> Is ALS device stupid sensor, or can it do some smoothing/watermarks
> itself?

Generally stupid.

--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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