Enabling verbose ACPI debug messages might do it: https://www.kernel.org/doc/Documentation/acpi/debug.txt https://www.kernel.org/doc/Documentation/acpi/debug.t

Enabling verbose ACPI debug messages might do it: https://www.kernel.org/doc/Documentation/acpi/debug.txt https://www.kernel.org/doc/Documentation/acpi/debug.txt I'm not exactly sure what options you'd need to enable/disable to just catch useful info. Hopefully you don't need to enable everything, which may produce enough (realtime) logspam to make journald use a noticeable amount of CPU.