Until someone tests or otherwise provides specific information on
a
given machine we're just guessing about how it's wired up.
What specific information are we talking about here? I have the 82YM in front of me and could help investigate.
We need to know what magic set of quirks makes the thing work. Are you saying that your patch doesn't actually do that?
It does.
Maybe the non-quirk check (ll. 395-403, seems to be using ACPI) is too specific? But I'm a bit out of my depth here, so I can't investigate that by myself.