Re: [PATCH] linux-2.5.69_clear-smi-fix_A1

[john stultz <johnstul@us.ibm.com>]

On Mon, 2003-05-12 at 17:54, Dave Hansen wrote:
> john stultz wrote:
> > 	I've been having problems with ACPI on a box here in our lab. Some of
> > our more recent hardware requires that SMIs are routed through the
> > IOAPIC, thus when we clear_IO_APIC() at boot time, we clear the BIOS
> > initialized SMI pin. This basically clobbers the SMI so we can then
> > never make the transition into ACPI mode. 
> > 
> > This patch simply reads the apic entry in clear_IO_APIC to make sure the
> > delivery_mode isn't dest_SMI. If it is, we leave the apic entry alone
> > and return.
> > 
> > With this patch, the box boots and SMIs function properly.
> 
> So, without the patch, what happens?  Does the thing just completely
> freeze when it tries to turn ACPI on?  Does the machine _require_ that
> you use ACPI?

When trying to boot w/ ACPI the transition fails and the box hobbles
along to different degrees. Normally the interrupt routing is bad and a
scsi or network card fails to init. 

Without ACPI the system boots fine. SMIs are still clobbered, but
they're less critical.

But really, ACPI (and SMIs) should "just work".  ;)

thanks
-john