Re: [PATCH 2/2] acpi: Disable IRQ 0 through I/O APIC for some HPsystems

From: Maciej W. Rozycki
Date: Mon Jul 07 2008 - 07:43:58 EST


On Mon, 7 Jul 2008, Ingo Molnar wrote:

> > Please note two things:
> > (1) The whole acpi_dmi_table[] thing originally depended on __i386__, so it
> > wouldn't work on x86-64 no matter what. I removed that dependecy, but
> > I have no idea why it was there and so I'm not sure if that's correct.

Well spottedd -- perhaps the x86-64 was though to be perfect. ;)

> > (2) The clear_IO_APIC_pin(apic1, pin1) done if
> > disable_irq0_through_ioapic is true is absolutely essential. The
> > symptoms are 100% reproducible without it.
>
> thanks, applied to tip/x86, to give this some more testing.
>
> the clear_IO_APIC_pin() is the most worrisome aspect of the change - but
> since we are already in limited quirk mode, does it hurt? Maciej, any
> preferences?

It makes absolutely no sense and should be harmful to call
clear_IO_APIC_pin(apic1, pin1) here, because both apic1 and pin1 should be
equal to -1 here. If it has to be called, then I suppose the DMI matching
did not work and the workaround has not been enabled.

Rafael, can you please provide a full bootstrap log obtained with all the
changes, but *without* this part? Also, can you please verify DMI IDs of
your system (dmidecode or /sys/class/dmi, I am told)?

I do think we should record DMI vendor and name information in the
bootstrap log. It won't take a lot of space and will be more useful than
some other IDs we never use for anything else, which we obtain from some
other tables.

Maciej
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