workaround USB always identified as xHCI after latest ACPI update
After we updated to the latest ACPI code (v6), some external users report that their USB keyboards no longer work. We suspect this is because they are being handled as xHCI devices (which we don't have a driver for yet) instead of as eHCI. We have verified that the temporary fix of disabling the newer Windows releases in the ACPI code will cause the problematic HW to revert to the desired eHCI driver. Once we have a working xHCI driver we can re-enable those Windows releases.
The problem is that the ACPI tables end up having logic where by if they detect a newer Windows version (as declared by the acpica common code), the ACPI code then automatically reroutes the USB ports to the xhci controller (a feature on various Intel chipsets).