Bug 506866

Summary: KDE System Monitor seems very confused about sensors of Raspberry Pi 5
Product: [Applications] plasma-systemmonitor Reporter: Ellie <el>
Component: generalAssignee: KSysGuard Developers <ksysguard-bugs>
Status: REOPENED ---    
Severity: normal CC: ahiemstra, kde.bugs, plasma-bugs-null
Priority: NOR    
Version First Reported In: 6.4.2   
Target Milestone: ---   
Platform: postmarketOS   
OS: Linux   
See Also: https://gitlab.postmarketos.org/postmarketOS/pmaports/-/issues/3750
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Screenshot showing the missing sensor data and an error message showing up when opening system monitor

Description Ellie 2025-07-10 13:54:57 UTC
Created attachment 183126 [details]
Screenshot showing the missing sensor data and an error message showing up when opening system monitor

SUMMARY

KDE System Monitor seems very confused about sensors of Raspberry Pi 5, and doesn't show any useful information other than the process table. This is an OpenRC system, however on my x64 OpenRC install of postmarketOS+Alpine with KDE, the system monitor works. Therefore, something about this seems to be specific to a Raspberry Pi 5. I already poked the distribution about this, but they seem to be clueless as well. My apologies if this turns out to be a distribution and packaging issue after all.

STEPS TO REPRODUCE

1. Open KDE system monitor with a KDE install on Raspberry Pi 5 using Alpine or postmarketOS (I haven't tested Raspberry Pi OS)

OBSERVED RESULT

No sensor data is shown, not even free memory.

EXPECTED RESULT

The sensor data works.

SOFTWARE/OS VERSIONS

Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: postmarketOS Edge based on Alpine Edge (ARM64, bug might be limited to this architecture)
KDE Plasma Version: 6.4.2
KDE Frameworks Version: 6.15.0
Qt Version: 6.8.3

ADDITIONAL INFORMATION
Comment 1 Arjen Hiemstra 2025-07-10 15:31:29 UTC
Make sure that ksystemstats is installed and can be launched using D-Bus autolaunch. From the looks of it, it's not running thus you'll not get any sensors.
Comment 2 Ellie 2025-07-14 02:04:40 UTC
Currently, it does seem to be running:

$ ps aux | grep stats
13076 user     0:15 /usr/bin/ksystemstats
13083 user     0:00 grep stats
$
Comment 3 Arjen Hiemstra 2025-08-07 10:30:33 UTC
Ok, next step would be running `kstatsviewer --list` to get a list of the sensors known to ksystemstats.
Comment 4 Bug Janitor Service 2025-08-22 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 5 Bug Janitor Service 2025-09-06 03:48:20 UTC
🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.
Comment 6 Ellie 2025-10-04 16:19:40 UTC
I've had to format and reinstall the system for various reasons, and the problem still occurs on a Raspberry Pi 5. This suggests to me it's not a customization issue since this is a fresh install with wiped config.

I tried to prompt kstatviewer but it seems like Alpine and postmarketOS don't ship it at all. There seems to be no way to install and launch it.
Comment 7 Ellie 2025-10-04 16:23:00 UTC
This time around however, ksystemstats doesn't seem to be running after booting and unlocking a session. What is the usual way this is meant to be automatically launched? I've had some issues with the home being briefly readonly with this install https://discuss.kde.org/t/i-broke-my-kwallet-auto-login/40205 and it seems like this can cause some initial setup steps of a KDE session not to happen.
Comment 8 Arjen Hiemstra 2025-10-07 11:20:04 UTC
Normally, D-Bus should autolaunch ksystemstats when something requests stats from it. Unfortunately there isn't an easy way to verify that that's working, other than launching `kstatsviewer --list` or something similar and seeing if that starts ksystemstats.
Comment 9 Arjen Hiemstra 2025-10-07 12:48:36 UTC
*** Bug 484384 has been marked as a duplicate of this bug. ***
Comment 10 Ellie 2025-11-02 17:26:03 UTC
Running kstatsviewer --list will start ksystemstats, but then it just reports no sensors available:

$ ps aux | grep ksystem
24585 user     0:00 grep ksystem
$ kstatsviewer --list
No sensors available.
$ ps aux | grep ksystem
24589 user     0:30 /usr/bin/ksystemstats
24599 user     0:00 grep ksystem
$ kstatsviewer --list
No sensors available.
$
Comment 11 Ellie 2025-11-02 17:38:54 UTC
(I think I previously mistyped the command as kstatviewer instead of kstatsviewer, hence why I erroneously believed it to be missing.)
Comment 12 Ellie 2025-11-02 17:41:14 UTC
Here's the output of "sensors", which shows that the kernel seems to have some sensors available that are operational:

# sensors
rpi_volt-isa-0000
Adapter: ISA adapter
in0:              N/A  

pwmfan-isa-0000
Adapter: ISA adapter
fan1:        2447 RPM

cpu_thermal-virtual-0
Adapter: Virtual device
temp1:        +56.8°C  

rp1_adc-isa-0000
Adapter: ISA adapter
in1:           2.02 V  
in2:           2.57 V  
in3:           1.43 V  
in4:           1.44 V  
temp1:        +47.3°C  

nvme-pci-10100
Adapter: PCI adapter
Composite:    +29.9°C  (low  =  -5.2°C, high = +82.8°C)
                       (crit = +84.8°C)
Sensor 1:     +29.9°C  (low  = -273.1°C, high = +65261.8°C)

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