Fans speed up when screen locks on KDE plasma

Framework Laptop 16 Linux
1

(Manjaro Linux, updated today, KDE Plasma 6.2.5, KDE framework 6.10.0, kernel 6.12.12-2-manjaro, Laptop 16 AMD Ryzen 9 7940HS w/ Radeon 780M)

The system is working great, fans are around 1000 rpm on normal load when the system is in use:

inxi -s
Sensors:
System Temperatures: cpu: 61.9 C mobo: 48.9 C
Fan Speeds (rpm): fan-1: 1083 fan-2: 1081
GPU: device: amdgpu temp: N/A device: amdgpu temp: 38.0 C fan: 0

However, when I manually lock the system or wait for the screen lock/blanking to kick in, the fans speed up and stay there until the screen is unlocked again. Here the output of inxi right after unlocking the laptop:

inxi -s
Sensors:
System Temperatures: cpu: 60.9 C mobo: 42.9 C
Fan Speeds (rpm): fan-1: 2708 fan-2: 2593
GPU: device: amdgpu temp: 30.0 C fan: 0 device: amdgpu temp: N/A

As you can see, no change in temperature, but the fan speeds more than double.

Any idea what causes this?

Is KDE/Plasma actively controlling the fan speed and stops doing that when locked? To my knowledge there is now a kernel module that takes care of fans and overheating, right? It has been years since I had to actively do anything about that on linux, using lm_sensors I remember, so I thought that was not necessary anymore?

Thanks for any help!

2

How old is the installation? Any chance you can log in remotely? Could be baloo doing file indexing while users are logged out.

1 Like
3

Thanks for the tip. I did check baloo, it says indexing is done - and also completely halting it before locking the machine does not help.

It is a single-user laptop btw, rolling release, updated today.

Logging the process activity while locked also suggests it is not any actual CPU activity that leads to increased fan speed. And the general journal log also gives no clues. The increased fan speed also starts immediately after the login screen disappears from the lock screen and continues unchanged until successfully logging back in. Moving the mouse or keyboard inputs do not affect it, screen blank or not does not affect it.

Is there a subsystem that I can tell to increase logging verbosity or something like that to get some more info on what is influencing the fan speed?

4

I’d rather say there is a kernel regression. Try booting an old kernel and see if that fixes it.

5

I was having power draw and resource usage issues on Plasma 6.2, fans ran high all the time. I just recently updated to 6.3 and it seems to have dialed back to a more reasonable amount of computing.

6

Thanks @Jorg_Merten @TechPriestNhyk I did some more investigation after asking on the kde forums, and I eventually found this unresolved bug:

https://bugs.kde.org/show_bug.cgi?id=484323

This fits, and while unresolved there are workarounds like switching to a console tty (Ctrl-Alt-F1) while the screen is locked or triggering a restart of kwin_x11 once during a session with systemctl --user restart plasma-kwin_x11.service

Hopefully, once upgraded to 6.3, I won’t have to do that anymore.

7

I’m running on

6.3 Operating System: KDE neon 6.2
KDE Plasma Version: 6.3.0
KDE Frameworks Version: 6.10.0
Qt Version: 6.8.2
Kernel Version: 6.11.0-17-generic (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7840HS w/ Radeon 780M Graphics
Memory: 60,6 GiB of RAM
Graphics Processor: AMD Radeon 780M
Manufacturer: Framework
Product Name: Laptop 16 (AMD Ryzen 7040 Series)
System Version: AG

and I have no such issues at all. All works as expected.
But yes, you seem to have nailed it!