Re: Panic starting 6.2.x and later 6.1.x kernels

[Limonciello, Mario]

On 3/29/2023 14:20, David R wrote:
> On 29/03/2023 20:17, Limonciello, Mario wrote:
> > On 3/29/2023 14:14, David R wrote:
> > > I note that 6.2.8 still has:
> > >
> > > static bool __init acpi_is_processor_usable(u32 lapic_flags)
> > > {
> > >          if (lapic_flags & ACPI_MADT_ENABLED)
> > >                  return true;
> > >
> > >          if (acpi_support_online_capable && (lapic_flags & 
> > > ACPI_MADT_ONLINE_CAPABLE))
> > >                  return true;
> > >
> > >          return false;
> > > }
> > >
> > > The flag getting set to false won't help unless the patch I tried 
> > > previously is applied ?
> > >
> > > diff 
> > > <https://lore.kernel.org/all/20230327191026.3454-2-eric.devolder@xxxxxxxxxx/#iZ31arch:x86:kernel:acpi:boot.c> --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index 1c38174b5f01..7b5b8ed018b0 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -193,7 +193,13 @@ static bool __init acpi_is_processor_usable(u32 lapic_flags)       if (lapic_flags & ACPI_MADT_ENABLED)
> > >           return true;
> > >   - if (acpi_support_online_capable && (lapic_flags & 
> > > ACPI_MADT_ONLINE_CAPABLE)) + /* + * Prior to MADT.revision 5, the 
> > > presence of the Local x2/APIC + * structure _implicitly_ noted a 
> > > possible hotpluggable cpu. + * Starting with MADT.revision 5, the 
> > > Online Capable bit + * _explicitly_ indicates a hotpluggable cpu. + 
> > > */ + if (!acpi_support_online_capable || (lapic_flags & 
> > > ACPI_MADT_ONLINE_CAPABLE))           return true;
> > >         return false;
> > > --
> >
> > You mean specifically this change:
> > https://lore.kernel.org/all/20230327191026.3454-2-eric.devolder@xxxxxxxxxx/
> >
> > Yes; I suppose that still makes sense.
> Yes, that's the one.
>
> But the fact that  that one worked own its own implies that my system 
> never had the flag set in the first place?
>
> David

Right - your BIOS doesn't support MADT revision 5 which was introduced 
as part of ACPI 6.3.

If you haven't already you should add a Tested-by tag for Eric's patch.

I think both mine and his coupled together should cover both of these 
possible areas of breakage.