Bug 501792

Summary:	Webcam LED permanently turned on without usage (only when plasmashell is running)
Product:	[Plasma] plasmashell	Reporter:	J D <privat>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	kde, nate
Priority:	HI
Version First Reported In:	6.3.3
Target Milestone:	1.0
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description J D 2025-03-20 12:24:52 UTC

SUMMARY
(It was suggested on the Manjaro forums I post this as a bug report here, see original topic: https://forum.manjaro.org/t/plasma-related-webcam-led-permanently-turned-on-without-usage/175870 )

Since the latest stable update, I have a bit of an unsettling issue:
My webcam’s LED is permanently on after reboot.

v4l2-ctl --list-devices
Microsoft® LifeCam Studio(TM): (usb-0000:02:00.0-5):
/dev/video0
/dev/video1
/dev/media0

Checking lsof and fuser shows none of these are actually being used, so there is nothing nefarious going on.
But still, very unsettling.

One way I found to turn off the cam’s LED is to un- and re-plug it.
That will make the LED flash shortly while it’s being “recognized” but then turn off. Which is what used to happen upon startup, but since the recent update the LED will no longer turn off on its own after it turns on during startup.

Another way to turn off the LED - and this is the reason I put this into the KDE Plasma section - is to kill plasmashell. A killall plasmashell will turn the LED off (but also plasma is gone obviously) and a plasmashell --replace will turn it back on permanently.

I did not install anything recently that would be audio/video/webcam related, so I can only guess one of the packages updated with the recent (18th March) update for Manjaro is responsible, likely somehow related to Plasma or one of its widgets as killing that "solves" the issue.

OBSERVED RESULT
See summary.

EXPECTED RESULT
The LED should not be on permanently after plasmashell starts, only blinking shortly (while "detecting/activating" the device) and then be off unless actively used.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Manjaro Linux x86_64, 6.12.19-1-MANJARO
KDE Plasma Version: 6.33

Comment 1 J D 2025-03-20 12:26:16 UTC

Note that this might very well be not a plasmashell issue, but of something it relies on. 
But I don't know anywhere near enough about Plasma internals to determine this.

Comment 2 David Edmundson 2025-03-20 14:37:47 UTC

There's a plasmoid in the system tray "Camera Indicator" can you confirm if disabling that makes a difference?

Comment 3 J D 2025-03-20 14:46:06 UTC

(In reply to David Edmundson from comment #2)
> There's a plasmoid in the system tray "Camera Indicator" can you confirm if
> disabling that makes a difference?

I did that and confirmed in the Add Or Manage Widgets... view that no instances are running anymore (also restarted plasmashell).  
Unfortunately, it made no difference.

Comment 4 Bug Janitor Service 2025-04-04 03:46:43 UTC

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

Thank you for helping us make KDE software even better for everyone!

Comment 5 J D 2025-04-04 05:39:34 UTC

I tried disabling a whole bunch of widgets, but could not find the culprit.

For now, I am hotfixing this with a service script running on autostart that simulates unplugging the camera and plugging it back a good time after startup in via:
```
echo 0 > "$USB_PATH/authorized"
sleep 2
echo 1 > "$USB_PATH/authorized"
```
It's awkward but works.

Comment 6 Nate Graham 2025-04-04 20:50:33 UTC

Very strange. I don't see this on my system, and I imagine most also don't or else it would be a widespread issue with lots of reports about it.

Does it reproduce in a new clean user account on the same system?

Comment 7 Bug Janitor Service 2025-04-19 03:47:15 UTC

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

Thank you for helping us make KDE software even better for everyone!

Comment 8 Bug Janitor Service 2025-05-04 03:47:29 UTC

🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.