ACPI has an interface for devices who know what their GPE is to enable it for wake, but most of the time a device doesn't know what its GPE is, and it must be determined by calling _PRW. We need to add a function that hides this complexity from drivers. Preferably it will take only the ACPI device handle. We will also need to add a non-ACPI-specific version for other drivers to call.
I have implemented a patch for this feature. the patch is at Bug 1415
*** This bug has been marked as a duplicate of 1415 ***