Bug 187960

Summary: Powerdevil doesn't update brightness slider state when changing brightness by acpi hotkeys
Product: [Unmaintained] solid Reporter: Kamil Neczaj <kneczaj>
Component: powermanagement-daemonAssignee: Dario Freddi <drf>
Status: RESOLVED FIXED    
Severity: normal CC: daniel.rocher, highwaystar.ru, neitzke, remur, sznurek, vmatare+kdebug, wstephenson
Priority: NOR    
Version: unspecified   
Target Milestone: ---   
Platform: unspecified   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: Tests Solid's signals for brightness and AC Adapter status.

Description Kamil Neczaj 2009-03-24 01:06:35 UTC 
Version:            (using KDE 4.2.1)
OS:                Linux
Installed from:    Unlisted Binary Package

When I change the LCD brightness in my laptop using Fn key and then click on the battery icon, the slider is showing the wrong brightness state.
Comment 1 Łukasz Dąbek 2009-04-14 11:51:29 UTC 
Same for me (KDE 4.2.2, Arch Linux, Acer Aspire 5315).

I turned out, that Solid can't get current brightness level (Solid::Control::PowerManager::brightness() always returns 0), but HAL can (dbus-send --system --print-reply --dest=org.freedesktop.Hal /org/freedesktop/Hal/devices/computer_backlight org.freedesktop.Hal.Device.LaptopPanel.GetBrightness returns good value).

I can set brightness by PowerDevil's slider, and it changes automaticly when I'm setting a new profile.

Is this fixed in 4.3?
Comment 2 Łukasz Dąbek 2009-04-14 12:10:16 UTC 
Created attachment 32821 [details]
Tests Solid's signals for brightness and AC Adapter status.
Comment 3 Łukasz Dąbek 2009-04-14 12:12:13 UTC 
Ok, upper one was bug in my distro - now Solid reports good brightness, but it doesn't delivers signal brightnessChanged when I'm changing brightness by ACPI keys or PowerDevil applet. I sent small test program.
Comment 4 Kamil Neczaj 2009-05-31 22:31:44 UTC 
Still in kde 4.2.87
Comment 5 Kamil Neczaj 2009-06-07 16:30:34 UTC 
I have Asus A6JC notebook
Comment 6 Victor Mataré 2009-08-17 19:01:03 UTC 
works for me now with 4.3
Comment 7 Kamil Neczaj 2009-08-18 00:10:11 UTC 
For me doesn't.
Comment 8 Daniel Rocher 2009-11-03 23:53:01 UTC 
I've same problem (KDE4.3, Ubuntu 9.10, ASPIRE 5735Z). I tested your little program :

Solid reports good brightness, but it doesn't delivers signal brightnessChanged when I'm changing brightness by PowerDevil's slider.

change brightness works:
- With plasma_applet_battery
- When I change profile
Comment 9 Daniel Rocher 2009-11-04 00:00:57 UTC 
*** This bug has been confirmed by popular vote. ***
Comment 10 Daniel Rocher 2009-11-06 00:04:32 UTC 
I use an alternative solution (Its not very good, but it's works): http://rocher.daniel.free.fr/wiki/wakka.php?wiki=KdeBrightness
Comment 11 Will Stephenson 2009-11-23 12:48:33 UTC 
Confirmed on openSUSE 11.2.
Comment 12 Dario Freddi 2009-11-30 11:57:17 UTC 
This bug unfortunately is a mixture of stuff from ACPI and HAL and it's still hard to say if the brightnessChanged signal is actually delivered. There should be also a duplicate of this one around
Comment 13 Karsten König 2009-12-03 14:08:28 UTC 
This is not in most recent kernels, so currently powerdevil has no chance of beeing notified unless it polls the brightness level itself

http://thread.gmane.org/gmane.linux.acpi.devel/40383
Comment 14 Dario Freddi 2010-11-09 17:18:29 UTC 
Should be fixed with UPower backend in 4.6