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SubjectRe: PCI bookkeeping

> The problem I'm seeing is that at least one driver
> has signed up to handle the wrong IRQ because,
> when it queried that PCI config value, it went
> back and got it from PCI config space rather
> than from the in-kernel data structures where the
> (correct) recalculated value had been stored. So,
> I'm wondering if our Official Approach is to always
> query the in-kernel data structures which have
> been setup so nicely for us, or are we supposed
> to obtain (some or all of) that sort of info from
> PCI space? Or is this all just a bleeding mess?

The only correct way to get the IRQ number for a given PCI card is to look
to the pci_dev structure. This holds for both 2.2 and 2.4 kernels. (The main
reason being that on some architectures the interrupt number doesn't fit
in a single byte.)

If you know of any drivers reading interrupt line information from the
configuration space, please tell us and we'll fix them.

Have a nice fortnight
Martin `MJ' Mares <> <>
"Immanuel doesn't pun, he Kant."
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