@rmaclachlan If it's an ACPI issue and since Lenovo doesn't seem to be very cooperative, one could try to downgrade the firmware to a working version (i.e. one that runs fans at normal speed) and dump the ACPI table. Then upgrade to the latest firmware, dump the ACPI tables again, and then compare them.
I don't know ACPI much but I can have a look if you can share them.
The ACPI tools should be already installed on any XCP-ng host.
- Dump the ACPI tables in binary format
Do so in an empty folder as this produces numerous files
# acpidump -b
- Decompile the
dsdt.dat
file
# iasl -e ssdt*.dat -d dsdt.dat
- Do the same operations for both firmwares and share the
dsdt.dsl
files.
The files are pretty big so don't hesitate to compress them before sharing.