Re: [PATCH v3 RESEND] acpi,pci: warn about duplicate IRQ routing entries returned from _PRT

Mateusz Jończyk
2023-01-23T21:01:46Z

W dniu 23.01.2023 o 21:33, Bjorn Helgaas pisze:
> On Sat, Jan 21, 2023 at 04:33:14PM +0100, Mateusz Jończyk wrote:
>> On some platforms, the ACPI _PRT function returns duplicate interrupt
>> routing entries. Linux uses the first matching entry, but sometimes the
>> second matching entry contains the correct interrupt vector.
>>
>> Print an error to dmesg if duplicate interrupt routing entries are
>> present, so that we could check how many models are affected.
> It shouldn't be too hard to use qemu to figure out whether Windows
> uses the last matching entry, i.e., treating _PRT entries as
> assignments. If so, maybe Linux could just do the same.
>
> Is anybody up for that?
>
> Bjorn

The hardware in question has a working Windows XP installation,
and I could in theory check which interrupt vector it uses - but
I think that such reverse engineering is forbidden by Windows' EULA.

Greetings,
Mateusz