Public bug reported: I'm running Kubuntu on my Lenovo ThinkPad X1 Carbon (4th generation). Since a recent upgrade to 20.04 LTS, I have the following problem.
Upon wake-up from standby the laptop's fan is sporadically set on max speed (around 7000 RPM) regardless of the actual CPU load. It helps to put the laptop to sleep and wake it up again. Then there is a chance the fan will react normally to CPU load and temperature. Running sensors when the fan is maxed, I get the following: --- $ sensors iwlwifi_1-virtual-0 Adapter: Virtual device temp1: +35.0°C pch_skylake-virtual-0 Adapter: Virtual device temp1: +42.5°C BAT0-acpi-0 Adapter: ACPI interface in0: 16.97 V thinkpad-isa-0000 Adapter: ISA adapter fan1: 6932 RPM temp1: N/A temp2: N/A temp3: +0.0°C temp4: +0.0°C temp5: +0.0°C temp6: +0.0°C temp7: +0.0°C temp8: +0.0°C temp9: +0.0°C temp10: +1.0°C temp11: +0.0°C temp12: +0.0°C temp13: +0.0°C temp14: +0.0°C temp15: +0.0°C temp16: +0.0°C coretemp-isa-0000 Adapter: ISA adapter Package id 0: +43.0°C (high = +100.0°C, crit = +100.0°C) Core 0: +42.0°C (high = +100.0°C, crit = +100.0°C) Core 1: +43.0°C (high = +100.0°C, crit = +100.0°C) acpitz-acpi-0 Adapter: ACPI interface temp1: +48.0°C (crit = +128.0°C) --- And running it when the fan behaves normally, i.e. in accordance with the CPU load, I notice that temp1 is no longer N/A but has a value. ... thinkpad-isa-0000 Adapter: ISA adapter fan1: 3240 RPM temp1: +46.0°C temp2: N/A ... ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: acpi (not installed) ProcVersionSignature: Ubuntu 5.4.0-37.41-generic 5.4.41 Uname: Linux 5.4.0-37-generic x86_64 ApportVersion: 2.20.11-0ubuntu27.2 Architecture: amd64 CasperMD5CheckResult: skip CurrentDesktop: KDE Date: Tue Jun 16 09:17:14 2020 InstallationDate: Installed on 2019-11-22 (206 days ago) InstallationMedia: Kubuntu 19.10 "Eoan Ermine" - Release amd64 (20191017) SourcePackage: acpi UpgradeStatus: Upgraded to focal on 2020-05-09 (37 days ago) ** Affects: ubuntu Importance: Undecided Status: New ** Tags: amd64 apport-bug focal -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1883660 Title: Fan sporadically maxed on wake-up due to unavailable sensor temperature To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+bug/1883660/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs