Re: IDE + SMP Lockup (no OOPS) in 2.2.12, 2.2.10

Jes Sorensen (Jes.Sorensen@cern.ch)
30 Sep 1999 09:28:02 +0200


>>>>> "Rogier" == Rogier Wolff <R.E.Wolff@BitWizard.nl> writes:

Rogier> Alan Cox wrote:
>> > My question is: what is the right behavior for sharing an irq in
>> a > situation like this? Is it considered not something you can
>> do, or

>> PCI IRQ sharing should be bulletproof. Anything else is a bug - be
>> it firmware or software

Rogier> Hardware, firmware or software.

Rogier> (The BP6 has several features not commonly found anywhere else
Rogier> (dual celeron, quad IDE ports), so to me it is entirely
Rogier> possible that there is a hardware bug somewhere.)

If the interrupts get delivered then it is most likely a driver bug. A
hardware bug would either give you bogus interrupts (which the driver
is supposed to check for by reading the interrupt status register of
the device, before doing _any_ processing on the card) or you get no
interrupts and you have a real problem.

Most of the interrupt sharing problems I have seen have been due to
driver writers forgetting to check whether an interrupt actually came
from the device before they start processing it.

Jes

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