You vs. ACPI

YONETANI Tomokazu noted that there is a kernel environment variable called ‘debug.acpi.disabled’, to which you can specify the following keywords:

   acad bus button children cmbat cpu ec
   isa lid pci pci_link sysresource thermal timer

“acpi” disables everything
“bus” disables “children”
“pci” disables “pci_link”