Re: [APIC] Avoid change apic_id failure panic

[William Lee Irwin III <wli@holomorphy.com>]

Herbert Xu <herbert@gondor.apana.org.au> wrote:
>> I've received two reports at http://bugs.debian.org/251207 where
>> ioapic caused machines to lock up during booting due to the
>> change apic_id panic in arch/i386/kernel/io_apic.c.
>> Since it appears that we can avoid panicking at all, I think we
>> should replace the panic calls with the following patch which
>> attempts to continue after the failure.
>> I've also done the same thing to the other panic() call in the
>> same function.

On Thu, Jun 03, 2004 at 04:20:45PM -0700, Andrew Morton wrote:
> Well.  Question is, why are we getting insame APIC ID's in there in the
> first place?

They're usually not insane. xAPIC's have 8-bit physical ID's, not 4-bit,
but no one's bothered tracking whether the APIC's found were serial APIC
or xAPIC, and then dispatching on that in the IO-APIC physid check to
avoid unnecessarily renumbering the things or panicking.

This is my longstanding complaint regarding APIC_BROADCAST_ID being wrong.


-- wli