Re: Documentation/i386/IO-APIC.txt (Re: 2.6.11 USB broken on VIAcomputer (not just ACPI))

[Xavier Bestel]

Le mercredi 16 mars 2005 Ã 11:00 +0100, Xavier Bestel a Ãcrit :
> Le mardi 15 mars 2005 Ã 21:54 -0800, Andrew Morton a Ãcrit :
> > 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


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/