Bug 513451

Summary: CPU Temperature (°C) doesn't show in chart when Automatic data range is enabled and sensor reports no maximum value, shows only text value
Product: [Plasma] plasmashell Reporter: gamecuber
Component: System Monitor widgetsAssignee: Plasma Bugs List <plasma-bugs-null>
Status: RESOLVED DOWNSTREAM    
Severity: minor CC: ahiemstra, nate, notmart
Priority: NOR    
Version First Reported In: 6.4.2   
Target Milestone: 1.0   
Platform: Fedora RPMs   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Widget with auto data range OFF, with the data range 0-100°C showing the chart properly and a widget with auto data range ON not showing it on the chart.

Description gamecuber 2025-12-16 20:25:48 UTC
Created attachment 187709 [details]
Widget with auto data range OFF, with the data range 0-100°C showing the chart properly and a widget with auto data range ON not showing it on the chart.

SUMMARY


STEPS TO REPRODUCE
1. Create a new System Monitor widget with multiple sensor metrics with different units, such as % used, GB used, °C temperature and time. 
2. All metrics show correctly, with both text and graphical values, except for the CPU temperature.
(tested with horizontal bar display style)

OBSERVED RESULT
The CPU temperature shows only a text value, with the chart empty.

EXPECTED RESULT
The CPU temperature shows a value on the chart

SOFTWARE/OS VERSIONS
Operating System: Fedora Linux 43
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.17.11-300.fc43.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 7900X 12-Core Processor

ADDITIONAL INFORMATION
I had it working perfectly on my previous computer with an intel CPU. Making a widget only with temperatures and the data range set to 0-100°C shows the value on the chart properly.
Comment 1 Arjen Hiemstra 2025-12-17 11:48:06 UTC
The automatic data range is based on what the sensor reports as its maximum value. If it reports a bogus value then there is unfortunately not a lot we can do on our side. You can check what the command `sensors` outputs to see what values are reported.
Comment 2 gamecuber 2025-12-17 20:27:24 UTC
(In reply to Arjen Hiemstra from comment #1)
> The automatic data range is based on what the sensor reports as its maximum
> value. If it reports a bogus value then there is unfortunately not a lot we
> can do on our side. You can check what the command `sensors` outputs to see
> what values are reported.

checking the cpu temperature sensor through that command it seems like it doesn't even report a maximum value, could that be the issue?

k10temp-pci-00c3
Adapter: PCI adapter
Tctl:         +48.6°C  
Tccd1:        +40.1°C  
Tccd2:        +37.2°C
Comment 3 Nate Graham 2025-12-18 22:05:22 UTC
I guess that makes sense. Without a maximum value, there's no way for it to display a representation of where the data falls between the min and max values.