Re: Backlight mystery - anyone shed light? some progress
On 23 Apr 2011, Camaleón wrote:
>
> > This is a laptop (6735s) and is over a year old so not very new. I don't
> > think it has that "feature".
> >
> > It uses the radeon driver.
>
> You will find out in the BIOS screen. If the feature is there, there
> should be an option to toggle it on/off under "system configuration menu/
> buit-in options"
>
> Also, check for a BIOS update, most of these "ACPI things" are usually
> fixed after updating to the latest BIOS.
>
Thanks, Camaleon. I found a lot of people using the same laptop with
Windows who have the same problem. In some cases a bios upgrade fixed
it, in others not. I tried to do this but it requires using an .exe
file, and though I could do this with both wine and dosemu I couldn't
obtain a suitable iso file to do the upgrade. (Also, I was a little
afraid of ending up with an unbootable machine, which a few people
report as happening.)
BUT I have found that by unloading and reloading the video module
(and/or the radeon module) I can sometimes obtain the requisite
backlight file in /sys/devices/virtual .., after which the screen either
becomes bright automatically or I can do it manually. So it seems to be
something to do with the order in which the modules are loaded, though I
can't figure out what. The effect is unpredictable - sometimes it works,
sometimes not.
Anthony
--
Anthony Campbell - ac@acampbell.org.uk
Microsoft-free zone - Using Debian GNU/Linux
http://www.acampbell.org.uk - sample my ebooks at
http://www.smashwords.com/profile/view/acampbell
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