mpparse.c question

From: Manfred (
Date: Fri Feb 02 2001 - 11:04:20 EST

I've started cleaning up mpparse.c/ioapic.c for the addition of acpi
support, but I got stuck in the mess of global variables.

What's the purpose of of the irq_2_pin in io_apic.c?

I assume that I overlook something, but afaics the code allows one
physical interrupt source (e.g. INTA from device 9 on pci bus 0) to
arrive at multiple ioapic pins.

Can that happen, is that important?

Silly question: Why can't we ignore all but the first pin? If we don't
enable the additional pins, we don't have to disable them during

disable_irq() and enable_irq() seem to be the only users of irq_2_pin.

Btw, is is correct that the isa irq's are always connected to the first
io apic? find_isa_irq_pin() doesn't handle that, and the caller just
access io apic 0.

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This archive was generated by hypermail 2b29 : Wed Feb 07 2001 - 21:00:15 EST