Bug 436831

Summary: Lowering display brightness to 0% turns screen off only with keyboard shortcut, not with battery plasmoid
Product: [Unmaintained] Powerdevil Reporter: JR <zorael>
Component: generalAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED INTENTIONAL    
Severity: minor CC: kde
Priority: NOR    
Version First Reported In: 5.21.4   
Target Milestone: ---   
Platform: Manjaro   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description JR 2021-05-09 17:12:52 UTC
(This may be the wrong product; please reassign it if so.)

SUMMARY
When lowering the display brightness with your laptop's hotkeys to 0%, the screen is turned off. This arguably makes sense. But when doing the same with the Energy Information ("battery") plasmoid, it behaves instead simply dips to a very low brightness and never turns off.

STEPS TO REPRODUCE
1. Use a laptop
2. Lower display brightness to 0% with keyboard shortcuts
3. Observe the screen turning off
4. Raise brightness again
5. Lower display brightness to 0% with the battery plasmoid

OBSERVED RESULT
A very dark screen, sub-5% brightness.

EXPECTED RESULT
Screen turns off, or at the very least behaves consistently with point 3.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: 5.21.4
KDE Plasma Version: 5.21.4
KDE Frameworks Version: 5.81.0
Qt Version: 5.15.2

ADDITIONAL INFORMATION
Manjaro/Arch x86_64, Dell XPS 9310 (Intel graphics).
Comment 1 Kai Uwe Broulik 2021-05-09 17:26:00 UTC
That is intentional. It is to prevent you from effectively turning the screen off with no way to recover from it should the brightness keys not work on your laptop.
Comment 2 JR 2021-05-10 16:40:38 UTC
This makes sense. Thanks, apologies for the noise.