Failed IRQ assignment for INT0002 on Braswell

From: Oleksandr Natalenko
Date: Tue Nov 21 2017 - 17:35:36 EST

Hi, Hans.

v4.13 kernel introduced new fancy warning in the dmesg:

kernel: acpi INT0002:00: Device [GPED] is in always present list
kernel: genirq: Flags mismatch irq 9. 00010084 (INT0002) vs. 00002080 (acpi)
kernel: INT0002 Virtual GPIO INT0002:00: Error requesting IRQ 9: -16
kernel: INT0002 Virtual GPIO: probe of INT0002:00 failed with error -16

Looking at git log, I've found that this driver was indeed introduced in v4.13
by the following commit:

commit 63dada87f7ef7d4a536765c816fbbe7c4b9f3c85
Author: Hans de Goede <hdegoede@xxxxxxxxxx>
Date: Mon Jun 12 22:55:46 2017 +0200

platform/x86: Add driver for ACPI INT0002 Virtual GPIO device

I've checked DSDT disassembly for this device, and here is relevant snippet
[1]. The only thing I currently understand there is that IRQ 9 is hard coded
(line 64), but I'm not sure where those flags come from.

The hardware in J3710 CPU on ASRock J3710-ITX motherboard.

Next, I've found that you also faced this warning and posted some RFC patch
[2], but unfortunately I do not see what that discussion ended up with.

It is not that I really need GPIO on this board, but it would be nice to get
rid of this warning. Could you please point me to a possible fix or a way for
further investigation?