Bug 453985

Summary:	Keyboard brightness slider is present in battery applet despite my keyboard does not have such feature
Product:	[Unmaintained] Powerdevil	Reporter:	Patrick Silva <bugseforuns>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED UPSTREAM
Severity:	normal	CC:	kde, nate, tinozzo123
Priority:	NOR
Version First Reported In:	master
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	screenshot

Description Patrick Silva 2022-05-18 13:20:29 UTC

SUMMARY
The keyboard of my laptop does not have brightness feature, but the slider to adjust it is present in the battery applet anyway.

STEPS TO REPRODUCE
1. run Plasma on a laptop without keyboard brightness feature
2. click on battery applet in the system tray
3. 

OBSERVED RESULT
the slider to adjust the keyboard brightness is present

EXPECTED RESULT
the slider to adjust the keyboard brightness is only present when this feature is supported

SOFTWARE/OS VERSIONS
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.24.80
KDE Frameworks Version: 5.95.0
Qt Version: 5.15.4
Graphics Platform: Wayland

Comment 1 Nate Graham 2022-05-18 16:01:27 UTC

Does it appear in the KCM too? Or just the System Tray applet?

Comment 2 Patrick Silva 2022-05-18 16:22:05 UTC

Created attachment 148960 [details]
screenshot

There is 'Keyboard backlight' slider in the KCM. Please see the attached screenshot.

Comment 3 Nate Graham 2022-05-19 17:34:53 UTC

Thanks!

Comment 4 Martino Fontana 2022-06-21 08:15:56 UTC

This might be a kernel problem instead of Powerdevil's.
I think that Powerdevil is simply checking that `/sys/class/leds/platform::kbd_backlight` exists. If it does, then it's a problem of the kernel module that your laptop is using.

Comment 5 Nate Graham 2022-06-21 16:29:27 UTC

On my system, that folder is located at /sys/class/leds/tpacpi::kbd_backlight.

Is it there for you?

Comment 6 Martino Fontana 2022-06-21 16:47:58 UTC

(In reply to Nate Graham from comment #5)
> On my system, that folder is located at
> /sys/class/leds/tpacpi::kbd_backlight.
> 
> Is it there for you?

Seems like your laptop is a ThinkPad.
My laptop is an IdeaPad (which does have a keyboard backlight) and the folder name is different (`/sys/class/leds/platform::kbd_backlight`).
Still, the fact that your folder exists in the first place seems like a kernel bug, you should report it to https://bugzilla.kernel.org. (Product: drivers, Component: Platform_x86, if I'm not wrong)
Also, for issues like this, you should say what your laptop model is.

Comment 7 Patrick Silva 2022-06-21 16:52:46 UTC

/sys/class/leds/platform::kbd_backlight exists on my neon unstable.

Comment 8 Martino Fontana 2022-06-21 16:56:27 UTC

(I confused persons, I replied to Nate thinking they were the OP, sorry)
Anyway, the second half of the reply I sent to the wrong person applies to the OP.

Comment 9 Patrick Silva 2022-06-21 17:17:04 UTC

I have just updated my kernel to version 5.18.4 and the bug persists.

Comment 10 Nate Graham 2022-06-22 15:54:04 UTC

(In reply to Patrick Silva from comment #7)
> /sys/class/leds/platform::kbd_backlight exists on my neon unstable.

Seems like a kernel bug indeed. Because if you don't have a backlit keyboard, that shouldn't exist. I would recommend that you report this upstream at https://bugzilla.kernel.org/