https://bugzilla.kernel.org/show_bug.cgi?id=214205
Bug ID: 214205 Summary: thermal sensor broken after resume, fan speed at 100% speed on Lenovo ThinkPad Carbon X1 4th Gen Product: ACPI Version: 2.5 Kernel Version: 5.14.0-rc7.g61596f4 Hardware: Intel OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: EC Assignee: acpi...@kernel-bugs.osdl.org Reporter: sbra...@suse.com Regression: No On Lenovo ThinkPad Carbon X1 4th Gen, fan speed often raises to max after resume. Reproducibility varies, but recently I get about 85% reproducibility. The problem never appears on boot from poweroff. But when it appears after resume, reboot does not help. Shutdown is required to get fan back to work properly. It can be worked around by repeated suspend/resume many times: cat /proc/acpi/ibm/thermal | ( read t x y ; echo $x ; if test "$x" = -128 ; then systemctl suspend ; fi ) With ~1% probability, a different problem appears: Fan does not stop during resume. It may be related. Another strange ACPI behavior, much less annoying: The computer often forgets wakeup preferences for USB devices during the suspend/wake cycle, e. g. /sys/bus/usb/devices/1-4.2.1.2/power/wakeup goes from enabled to disabled. It is caused by the failed resume of the thermal sensor, which returns -128 instead of the correct value. cat /proc/acpi/ibm/thermal When it fails: temperatures: -128 -128 0 0 0 0 0 0 When OK: temperatures: 47 -128 0 0 0 0 0 0 sensors command shows the same problem. Hardware: ThinkPad X1 Carbon 4th 20FB002UMC BIOS N1FET75W (1.49) 05/25/2021 Output of hwprobe: https://linux-hardware.org/?probe=44d0412dd3 This bug is similar to bug 196129 for 5th Gen. -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug. _______________________________________________ acpi-bugzilla mailing list acpi-bugzilla@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla