Re: [PATCH v3 06/12] x86/amd_nb: Use topology info to get AMD node count

[Michal Pecio]

On Thu, 23 Oct 2025 11:22:29 -0500, Mario Limonciello wrote:
> As this is an ancient BIOS this reminds me of some related commits:
> 
> aa06e20f1be6 ("x86/ACPI: Don't add CPUs that are not online capable")
> a74fabfbd1b70 ("x86/ACPI/boot: Use FADT version to check support for 
> online capable")
> 
> Does reverting that second one help?

Not sure if it's worth trying? My BIOS predates the ACPI 6.3 spec by
several years and (if I understand correctly) MADT revision is 1.

It seems Yazen guessed right: they list 6 APICs and mark absent ones
as not enabled. But I don't think we can assume any ACPI 6.3 flags to
be valid here.

I wonder if some quick check could recognize those consumer CPUs and
simply ignore hotplug there? AFAIK it was never a thing on AM3.

Michal