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Re: CVS commit: src/sys/arch/x86 said:
> Matthias Drochner wrote:
> > add an experimental implementation of PCI MSIs (Message Signaled
> > Interrupts)
> Can you replace the magic numbers with symbols from pcireg.h ? You may
> need to add the symbols, of course.

There are already some symbols for MSIs, but incomplete and
too cryptic. Just placeholders as it looks.

> struct pci_attach_args * is const virtually everywhere, shouldn't it be
> a const argument to pci_msi_establish(), too?

OK, this makes sense. The API might change, though...

> > There seem to be buggy chips around which announce MSI support
> > but don't correctly implement it
> Might be helpful for other developers to see a heads-up about those
> chips.

It worked for the two chips I tested with. I only found per-chip-version
quirk bits in OSes which have been implementing MSIs for longer. And
a remark in some Intel southbridge manual.

[power management]
> This may be the responsibility of pci_child_suspend()/pci_child_resume()?

This would be easy to add, but the code there is also somewhat clumsy,
and adding actions depending on capability records would add more runtime
overhead than necessary. Suspend/resume shouldn't waste cycles, just
for the user experience.

I'll be on travel for almost 3 weeks, starting next monday. I hope
to do some bits of this before. There are some structural changes
necessary to common x86 interrupt code as said. The PCI interrupt
mapping code also doesn't work too well which is not surprising
if you look at the code structure, or non-structure.
This will take a while.

best regards

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