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

Bjorn Helgaas
2023-01-23T20:33:10Z

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