Re: PCI init issues

Ivan Kokshaysky
2003-03-04T22:37:05Z

On Tue, Mar 04, 2003 at 10:54:21AM -0800, Linus Torvalds wrote:
> Well, I'd say it looks like the MP table _claims_ that only pin0 is
> connected. Remember: the claim was that this machine worked on WinXP.

It seems that "IRQ redirection table" is gathered directly from
IO_APIC hardware (I may be wrong though), and it conforms to other
data...

> So there are at least two potential reasons for that:
>
> - The MP table is simply wrong, and WinXP gets the routing information
> from somewhere else (ie most likely ACPI)
>
> - The MP table is right, and only pin0 is connected, and WinXP only uses
> pin0 (ie it puts the card in some state where all irqs are shared
> across all of the four tulip chips).
>
> Maybe somebody can come up with other schenarios.

- XP is able to reprogramm the IO_APIC so that all four pins are
routed properly.

Sounds a bit heretical, I know. :-)

Ivan.