Re: APIC Error when doing apic_pm_suspend

[Mikael Pettersson]

Zwane Mwaikambo writes:
 > I get an APIC error 0x40 when resuming from an apm -s. If i'm correct
 > that would be an illegal register access wouldn't it? I tried putting
 > enter/exit printks in the apic_pm_resume/suspend functions and it showed
 > that both returned before the APIC error printk. Is there anyway of finding out
 > which register access it was? I "thought" it would be one of the
 > apic_writes in the pm functions but looks like i might be wrong.
 > 
 > The kernel is compiled with local APIC and gets detected and enabled on
 > boot (UP machine).

No, 0x40 is an illegal vector error. It's a (semi-) known quirk in the P6 family
of processors that you get this error when writing a null vector to any of the
LVT entries, even if you are also setting the mask bit at the same time.
Both the clear_local_APIC() call at PM suspend and the reinitialisation at PM
resume can trigger this.

The "error" is mostly harmless. Ignore it for now, I'll do a patch to silence it later.

/Mikael