Bug 437258

Summary: Brightness should never be increased when battery reaches the critical level
Product: [Unmaintained] Powerdevil Reporter: Louis Moureaux <m_louis30>
Component: generalAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: normal CC: 677ee1vp, eduardo.cruz, nate
Priority: NOR    
Version First Reported In: 5.24.4   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Louis Moureaux 2021-05-17 15:10:34 UTC 
SUMMARY

When battery reaches the "critical" level, the screen brightness is automatically adjusted (in the default configuration). If the brightness was already low, this can cause the brightness to be raised, which is exactly the opposite of what you'd want when battery is low.

This was apparently already fixed in the 4.x days (#198463) so it's a regression in Plasma 5.

STEPS TO REPRODUCE

On a laptop:

1. Use default settings
2. Set your brightness to the lowest level, say 5%
3. Wait for your battery to drain to the "critical" level (10%)

OBSERVED RESULT

The screen brightness is raised automatically to 25% (the default setting for "critical" battery).

EXPECTED RESULT

Brightness is never increased. It could be reduced by a factor instead (so 20% would become maybe 10%), because luminosity changes are a very good indicator that power is low.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Kde Neon
(available in About System)
KDE Plasma Version: 5.21.5
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.2
Comment 1 Eduardo 2022-05-11 23:18:17 UTC 
This just happened to me! I was using my laptop with 1% brightness on the bed with my wife sleeping beside me. Suddenly my battery reached the critical level and the brightness increased to 30% which seemed like a flash to my eyes. Luckily my wife didn't wake up.

I'm confirming the bug and updating the version.
Comment 2 Nate Graham 2022-05-14 20:05:52 UTC 

*** This bug has been marked as a duplicate of bug 394945 ***