reduce backlight brightness / dim display when idle

[DaveAbrahams]

Binary package hint: gnome-power-manager

These options are unexplained in documentation and it's not even clear that they work as intended. If you choose "help" from the g-p-m menu, you'll see screenshots that don't show these options in the "On Batter Power" tab. It's unclear what the difference is between reducing the backlight brightness and dimming the display, and when I make the transition from AC to battery the display is dimmed once. I never see any idle dimming. There's no description of how long I have to leave the computer alone before it is considered "idle". When I click "reduce backlight brightness" there is no perceivable effect.

I'm fairly certain there's a functionality bug here, but it's hard to tell because there's certainly a documentation bug. Any behavior at all short of a crash could be considered legitimate when the features aren't documented!

I'm using Ubuntu Hardy 8.04 with all the latest updates.

If more info is needed, please ask.

[Pedro Villavicencio (pedro)]

Thanks for taking the time to report this bug and helping to make Ubuntu better. Could you please attach the resulting log file of: gnome-power-bugreport.sh &> gpm.log to the report? You might also want to take a look to the Debugging instructions located at https://wiki.ubuntu.com/DebuggingGNOMEPowerManager for submit any other logs related to your problem.Thanks in advance.

[DaveAbrahams (boostpro)]

I've attached the log. As for looking at the debugging guide, I don't see how it could be of any use until I know how the features are supposed work when they're working correctly.

[Ted Gould (ted)]

Typically the reason that idle dimming won't work is that your particular hardware doesn't support dimming through HAL only through the video driver. Could you see if the brightness applet works for adjusting the backlight level?

[DaveAbrahams (boostpro)]

Works just fine for dimming the laptop's LCD. When the laptop is driving external monitors, it doesn't work, but I'm essentially never driving external monitors when I'm on battery anyway.

[Jayson Rowe (jayson.rowe)]

Since it's been a very long time since any additional info was added to this bug, I'm just checking to see if this is still an issue, and find out what additional work should be done on this bug.

[DaveAbrahams (boostpro)]

Yes, it's still an issue.

The first piece of work to be done on the bug is to fix the documentation:

* fill in the missing details about the intended behavior of this interface.
* explain what "dimming" really means
* Fix the screenshots

Once that's done, maybe we have a hope of seeing whether the functionality conforms to the specification.

[Gilles Schintgen (shigi)]

I can only concur that this is still an issue. Why is it still marked as INCOMPLETE? What's the missing info?

I'm using the Ubuntu Netbook Remix 1.01 (lpia, based on 8.04) on an Ideapad s10e and the screen is never dimmed. I think (but can't be sure due to inexistent documentation!) what it should look like: when I'm running a "normal" 8.04 (from USB, using unetbootin) the screen is dimmed to complete blackness after a few seconds of inactivity.

I'd really like to debug/fix this issue since it could probably save quite some energy. However I don't know where to start looking since this feature seems to be neither documented nor configurable (timeout, how much dimming). Where do I find this "brightness applet" that was mentioned in comment #3?

[Gilles Schintgen (shigi)]

Oh well, I got confused from all the different versions I'm currently running. In 8.04 (netbook remix 1.01) screen dimming is not yet implemented and the Ubuntu version in which it was working was actually 8.10. So as far as I am concerned it's working as intended, but still it's neither documented nor configurable. Anyway, I'm very sorry for the noise.

[Andy (arwilliamsuk)]

Is this still a problem? Certainly on my netbook for both 9.10 and the alpha 2 10.04, my screen dims correctly on battery power if I leave the keyboard and mouse unattended for a short period of time i.e. when computer is idling. Was gonna suggest close it out if fixed in the later releases of the software.

[Sebastien Bacher (seb128)]

Thanks for the bug report. This particular bug has already been reported, but feel free to report any other bugs you find.