Re: PCI, ACPI, IRQ, IOAPIC: reroute PCI interrupt to legacy boot interrupt equivalent

Ingo Molnar
2009-01-12T11:37:37Z

* Stefan Assmann <sassmann@suse.de> wrote:

> Why can these IRQ lines be brought down by Boot Interrupts? Because
> there's no handler installed on the primary IO-APIC IRQ line that can
> take care of them and after too many unhandled IRQs the line will be
> shut down by the kernel.

The failure mode can be quite nasty: ranging from non-working USB (and
other) devices to hard lockups due to screaming IRQs.

Ingo