Laptop screen power management and backlight issue

[sonnik]

I have a pretty typical Centrino-based HP Laptop, which uses an Intel chipset for video. Sometimes, I like just using it for listening to music - and would like the screen to go to sleep.

I've set all my settings up accordingly. I can get a screensaver to run for a minute or two, and the backlight *does* shut off at the specified time.

My problem is, that a few seconds after the backlight shuts off - it turns back on to a black screen.

I haven't really attacked this problem yet, but I may temporarily uninstall gnome-power-manager and rely on xscreensaver to see if that remedies the problem. If that fails, I'll see if there's any of two or three applets or applications that may be causing the display to wake up.

Anyone else seen a similar situation?

[moosetooth]

Originally Posted by sonnik

My problem is, that a few seconds after the backlight shuts off - it turns back on to a black screen.

Same thing happens with my dell inspiron. The screen seems to come back on when the password prompt comes up. I've found if I lock the screen and close the lid, with the password prompt up, the screen will remain off after I close the lid (as long as I don't touch the mouse).

With FC5 my screen wouldn't turn off at all when I closed the lid so I had to add an entry to /etc/acpi/actions to make it happen.

[sonnik]

That's odd in and of itself, I've never ever seen a laptop power a backlight with the lid closed, I figured the laptop's BIOS would prevent that.

I'm not using any password/security - this is just for a laptop at home. I'm not doing any lid action... I just want to screen to go black (backlight off) so I can keep playing music in the dark of the room if I should like to.

It does, but then the backlight powers back up a few (seemingly randomly) seconds afterwards.

[sonnik]

So what I've done to isolate the problem:

- Remove gnome-power-manager
- I had installed some xscreensaver screensavers, which may have installed the xscreensaver daemon, so I deleted that.
- Remove gnome-screen-saver

I tested xscreensaver alone and gnome-power-manager alone.

I noticed using xset -q that dpms was enabled, so I tried gnome-screensaver/gnome-power-manager alone.

Removed all (gnome-power-manager/gnome-screensaver, xscreensaver) and just played with xset dpms.

These were all the locations I could think that would control when the display is put to sleep.

In every possible scenario the backlight turned off, and then turned back on at some random interval.

I switched inittab from 5 to 3 - then ran startx to see if the problem occured when runing having started from run level 3. I tried disabling all non-essential gnome-desktop items.

Can anyone verify that the backlight WILL shut off (and stay off for a few minutes) on their laptop if instructed?

[sonnik]

Found this bug, which seems to describe both of these issues...

https://bugzilla.redhat.com/bugzilla....cgi?id=198307

[moosetooth]

Originally Posted by sonnik

Can anyone verify that the backlight WILL shut off (and stay off for a few minutes) on their laptop if instructed?

It will stay off on my laptop most of the time when I close the lid. I can't figure out what causes it to come on at random though. I'll leave mine sitting for days at a time with the lid closed and the screen will remain off .

[sonnik]

Originally Posted by moosetooth

It will stay off on my laptop most of the time when I close the lid. I can't figure out what causes it to come on at random though. I'll leave mine sitting for days at a time with the lid closed and the screen will remain off .

I've figured out that it's basically my battery discharging and recharging. If you click through the link I provided above, you'll see that any ACPI event will cause the display to wake up.

In my case, battery trickles to 99% and right back to 100% quite often... (this caused a problem with gnome-power-manager and an annoying pop-up some time back).

http://www.sonnik.com/2006/04/annoyi...m_gnomepo.html

Every time this happens, my display wakes up.

Your battery (or ACPI setup) may be more stable than mine, thus the reduced frequency.

[sonnik]

I was asked about this via private message...

http://www.sonnik.com/2006/11/fedora...issu.html#more

... if anyone else is asking for it. Basically, I think we're gonna have to wait until the X.org fix makes it into the Fedora Updates channel.