turning off the LCD backlight
Fraser Wright
APM BIOS. Does anyone know of a way to get the backlight to turn off when
X blanks the screen?
"xset dpms force off" only blanks the screen but the backlight stays on.
I have a 2.4.20 kernel patched with the 20021212 ACPI kernel patch.
any suggestions?
Fraser
Hugo Haas
[2003-04-03 01:52+0000] (comp.os.linux.portable)
AFAICT it is a problem with all the Evos.
You can see my notes about that at:
http://larve.net/people/hugo/2002/12/evo410
Maybe try the following patch and see if it works:
http://article.gmane.org/gmane.linux.laptop/27
I didn't try it and am actually curious to know what it exactly does.
Good luck.
--
Hugo Haas - http://larve.net/people/hugo/
David Efflandt
I don't know about Compaq, but with my Sony, I have not figured out how to
do anything about the backlight in X, but in the console, my BIOS seems to
blank the screen and turn off backlight without doing anything special
(laptop itself is not going into suspend on AC power). So I just switch
to a console if leaving it unattended. It is ACPI, but I have not gotten
into that yet, since suspend (but not standby) seemed to work with apmd or
keyboard (BIOS) Fn keys.
On the other hand with my desktop, I can put my monitor to sleep into
powersave mode in X with dpms, but not in the frame buffer console
(setterm powersave modes do not work). So then I leave it in X if
unattended.
--
David Efflandt - All spam ignored http://www.de-srv.com/
http://www.autox.chicago.il.us/ http://www.berniesfloral.net/
http://cgi-help.virtualave.net/ http://hammer.prohosting.com/~cgi-wiz/
Fraser Wright
I've since found a hack to turn off the backlight of Radeon Mobility, it
seems to work without problems:
Others looking to fix this problem should try:
http://fdd.com/software/radeon/
You'll want to start the lightwatch.pl script (i got it working using
sudo) after you start xscreensaver. Your .xsession seems like a good place
to start it. It works too!
I heard mentioned somewhere that X 4.3 might have proper support for
turning off the backlight of the radeon mobility. But i haven't tried it.
APM doesn't work on my laptop because it is one of new breed of laptops
that just use ACPI, and don't support APM.
Thanks for the suggestions though people.
Fraser
Hugo Haas
[2003-04-03 08:40+0000] (comp.os.linux.portable)
> I've since found a hack to turn off the backlight of Radeon Mobility, it
> seems to work without problems:
>
> Others looking to fix this problem should try:
>
> http://fdd.com/software/radeon/
>
> You'll want to start the lightwatch.pl script (i got it working using
> sudo) after you start xscreensaver. Your .xsession seems like a good place
> to start it. It works too!
It works well, thanks.
FYI, since I don't use xscreensaver, I have gone for a more
lightweight solution:
xautolock -time 3 -locker "/usr/local/bin/radeontool light off"
The problem is that then you need to be able to turn it back on, which
I did with hotkeys.
One interesting thing is that the external video output is always
turned back on if I switch consoles, but that's another problem.