LCD hardware fading

David Zeuthen david at fubar.dk
Mon Jan 30 09:01:13 PST 2006


On Sun, 2006-01-29 at 13:16 -0500, David Zeuthen wrote:
> On Sun, 2006-01-29 at 12:09 -0500, David Zeuthen wrote:
> > On Sun, 2006-01-29 at 17:03 +0000, Richard Hughes wrote:
> > > How do you disable the fading? I was under the impression that this was
> > > done by hardware attached to the lcd backlight, rather than the kernel
> > > doing anything remotely clever.
> > 
> > For IBM just look at the "cleverness" in ibm-acpi.c:brightness_write() -
> > the patch should be simple to write. Hopefully upstream will take it...
> 
> FYI I've submitted a patch for this on LKML
> 
>  http://lkml.org/lkml/2006/1/29/96/index.html

So the patch was rejected because some hardware only works with changing
the value one at a time...

Richard, remind me why this is a problem? It seems that if we're fading
from g-p-m _anyway_ we still get the same effect (e.g. we take only one
step at a time). Is it perhaps because you are not waiting for the
return value of the previous SetLCDBrightness() call before invoking the
next?

Cheers,
David




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