Screen brightness not adjusted when switching from AC to battery

[papukaija]

I upgraded my Samsung NC 10 to Oneiric recently. Since then, switching between AC and battery power has no effect to screen brightness. Adjusting the brightness manually works but is quite annoying.

I added the regression tag since this didn't happen in Natty and older.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: gnome-settings-daemon 3.2.0-0ubuntu5
ProcVersionSignature: Ubuntu 3.0.0-12.20-generic 3.0.4
Uname: Linux 3.0.0-12-generic i686
ApportVersion: 1.23-0ubuntu3
Architecture: i386
Date: Mon Oct 31 01:00:12 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu-Netbook-Remix 9.10 "Karmic Koala" - Release i386 (20091028.4)
SourcePackage: gnome-settings-daemon
UpgradeStatus: Upgraded to oneiric on 2011-10-01 (29 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Danny Wood (danwood76)]

This is a rather annoying issue.

Looking through all the power manager settings it seems they have removed the brightness_battery and brightness_ac settings that used to achieve this. Hopefully it will be back in 12.04

Until then a possible solution is to write a script that sets the back-light brightness on ac -> battery and back.

[papukaija (papukaija)]

Please dont move this bug to g-p-m as "If you're running Oneiric you'll notice that the Power Management was moved to GNOME Settings Daemon, thus all the bugs affecting GNOME Power Manager in Oneiric are about the statistics ui and not the daemon. " [1] Thanks.

[1] https://wiki.ubuntu.com/DebuggingGNOMEPowerManager

[Scott Sweeny (ssweeny)]

Judging by upstream design documents[1], this feature has been changed by the GNOME folks to only dim the screen when idle on battery power. The tickbox for "Dim screen to save power" in the "Brightness and Lock" capplet in Gnome Control Center toggles the "idle-dim-battery" GSettings key, and on battery power your screen should dim after (by default) 30 seconds of idle time.

I'm going to talk with upstream about clarifying the tickbox label, but otherwise I don't think this feature will be coming back as it was.

[1] https://live.gnome.org/Design/SystemSettings/Screen

[Danny Wood (danwood76)]

What is irritating about this is the backlight on laptops is usually the highest power item.

So on battery I want it to always be low power to maximise the battery life, I don't want it to continuously go bright when I touch my laptop as this consumes excess battery.

As I can't have that my display is always dim at the moment, so even on AC I am having a dim display and not utilising the screens ability.

It makes sense to have two power modes, on battery, and on AC. It makes absolutely no sense to use virtually the same settings on both. The GNOME guys are consistently going to far to reduce configuration.

[Victor Tuson Palau (vtuson)]

this worked for me in the nexus 7

[Victor Tuson Palau (vtuson)]

Matt - can you double check that this applies to Nexus 7, as mentioned this works in my system

[Sean Feole (sfeole)]

Scott, you may want to change the status of https://bugzilla.gnome.org/show_bug.cgi?id=688179 from "Need Info" back to "Unconfirmed" so the bug is back in their queue.