Hi, first revision integrating Armins feedback. Stuff I did not yet change and did not comment on previously: - Still have to ask Christoffer why the mutex is required - Still using acpi_size instad of size_t in the util functions, because the value is put directly into a struct using acpi_size - Error messages for __wmi_method_acpi_object_out still in that method because they reference method internal variables Let me know if my reasoning is flawed Kind regards, Werner