Bug 321310

Summary:	brightness on screen display is not shown when changing brightness via Fn keys
Product:	[Frameworks and Libraries] solid	Reporter:	Gandalf Lechner <gandalflechner>
Component:	powermanagement	Assignee:	Dario Freddi <drf>
Status:	RESOLVED UPSTREAM
Severity:	normal	CC:	kde, m2k.networx, rauchwolke
Priority:	NOR
Version:	4.10.5
Target Milestone:	---
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed In:

Description Gandalf Lechner 2013-06-18 08:50:51 UTC

when changing brightness via the slider accessible from the battery icon the on screen display works fine. In both cases, the brightness does change as it should.

I guess this might depend on the setup, so here is what I am using: 
Dell XPS13 "Sputnik" (ubuntu version) with BIOS A07, kernel 3.8.0-26-generic, kubuntu 13.04 fully updated



Reproducible: Always

Comment 1 Jim Jones 2013-09-27 17:47:29 UTC

same here on lenovo x220 and x230

Comment 2 Laurent 2014-01-26 15:41:20 UTC

Same here on Lenovo T440.

Just to clarify things:
- Brightness change via Fn keys: works, but there is no OSD and the slider in the battery widget is not updated.
- via widget slider: OSD is shown and of course the slider is "up-to-date" afterwards

Assumption: The Fn keys "bypass the way through KDE". Can it be that KDE checks if the brighness changing shortcuts are pressed? Because when I remap those shortcuts to "normal" ones (e.g. Ctrl + u etc...), everything works as expected. In that respect, there seem to be two solutions in my eyes:
1. watch the corresponding file in /proc
2. fix the problem at shortcut-level, so that the brightness Fn keys are recognized.

Additional Info: If I try to map Fn + BrightnessUp/Down to other actions, my system does NOT recognize that I just pressed Fn + BrightnessUp/Down and just keeps waiting. Even 'xev' does not register those keys.

Boot params: acpi_osi=
(yes, without anything behind the equality sign)

Regards

Comment 3 Laurent 2014-01-26 16:29:33 UTC

Hi all,
Fixed it for me on Lenovo T440p
https://bugs.kde.org/show_bug.cgi?id=323516#c24
Regards

Comment 4 Kai Uwe Broulik 2015-01-26 21:02:39 UTC

Most likely a driver/ACPI issue.