Max,
On Sat, May 15 2021 at 00:47, Maximilian Luz wrote:
I believe the theory was that, while the PIC is advertised in ACPI, it might be expected to not be used and only present for some legacy reason (therefore untested and buggy). Which I believe led to the question whether we shouldn't prefer IOAPIC on systems like that in general. So I guess it comes down to how you define "systems like that". By Tomas' comment, I guess it should be possible to implement this as "systems that should prefer IOAPIC over legacy PIC" quirk.
I guess all modern machines should have an IOAPIC, so it might also be preferable to expand that definition, maybe over time and with enough testing.
I just double checked and we actually can boot just fine without the PIC even when it is advertised, but disfunctional.
Can you please add "apic=verbose" to the kernel command line and provide full dmesg output for a kernel w/o your patch and one with your patch applied?
Thanks,
tglx