Re: [PATCH v3] x86: i8237: Register based on FADT legacy boot flag

From: Alan Cox
Date: Mon Mar 26 2018 - 10:52:47 EST


> Please explain WHY 2017 is the cut-off date. I still have no clue how
> that
> is decided aside of being a random number.

Because if it's prior to 2017 then it'll almost certainly have those
registers even if the firmware says otherwise. After that point we
think the firmware is going to give valid answers (although the 0xFF
check is actually the important one in reality).

Alan