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SubjectRe: Documentation/i386/IO-APIC.txt (Re: 2.6.11 USB broken on VIA computer (not just ACPI))
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Le mercredi 16 mars 2005 à 11:00 +0100, Xavier Bestel a écrit :
> Le mardi 15 mars 2005 à 21:54 -0800, Andrew Morton a écrit :
> > You may be able to set the thing up by hand with the help of
> > Documentation/i386/IO-APIC.txt.
>
> There's something I don't get in this document's ascii-art:
>
> 8<------------------------------------------------------------------
> ,-. ,-. ,-. ,-. ,-.
> PIRQ4 ----| |-. ,-| |-. ,-| |-. ,-| |--------| |
> |S| \ / |S| \ / |S| \ / |S| |S|
> PIRQ3 ----|l|-. `/---|l|-. `/---|l|-. `/---|l|--------|l|
> |o| \/ |o| \/ |o| \/ |o| |o|
> PIRQ2 ----|t|-./`----|t|-./`----|t|-./`----|t|--------|t|
> |1| /\ |2| /\ |3| /\ |4| |5|
> PIRQ1 ----| |- `----| |- `----| |- `----| |--------| |
> `-' `-' `-' `-' `-'
>
> every PCI card emits a PCI IRQ, which can be INTA,INTB,INTC,INTD:
>
> ,-.
> INTD--| |
> |S|
> INTC--|l|
> |o|
> INTB--|t|
> |x|
> INTA--| |
> `-'
>
> These INTA-D PCI IRQs are always 'local to the card', their real meaning
> depends on which slot they are in. If you look at the daisy chaining diagram,
> a card in slot4, issuing INTA IRQ, it will end up as a signal on PIRQ2 of
> the PCI chipset. [...]
> 8<------------------------------------------------------------------
>
> If I follow the wire from Slot4's INTA, I'm ending on PIRQ4 whereas the
> doc says IRQ2. Do I need glasses, or a new fixed-font ?

Sorry for replying to myself, in fact it seems like somebody reversed
the order of PIRQ[1-4] and INT[A-D] in the ascii-art, but didn't touch
the rest of the text at all. There are several more references to a
"reversed order".

Xav


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