Re: MSI support on Linux PCI implementation for Ocotea

Hi ! What is Ocotea ! :)

Did I spell it wrong?? I don't believe Ben doesn't know Ocotea.
Hmmm...Ocotea again? Let me check if I really spelled it wrong. Hey,
it's really Ocotea. ;)

Of course, there is no such MSI support specific for Ocotea.

quoted

1. Obviously MSI is supported in Linux 2.6.x, maybe even in 2.4.x. But
MSI implementation seems to support only IOxAPIC on x86 or IA64
architectures, though the implemenation is in generic drivers/pci
tree.

Exact. And it's also a pile of crap.

;) I'm not in a position where I can either agree or disagree with
you. :D But may I ask if ppc platform can make use of this crap in our
PCI express testing? That is, are the functionalities of this crap
working?

pci host bridges are initialized early, generally in setup_arch() and
the PCI bus is probed later. You can see the code in
arch/powerpc/kernel/pci_{32,64}.c

Now, regarding MSI, as you have noticed, the situation isn't great. I'm
currently in the middle of reworking our interrupt management (and
interrupt numbers allocation layer) and Michael Ellermann is looking at
the MSI issue in parallel.

We don't have a solution yet but are working on it.

It's good to know the development status. What's the relationship
between generic pci driver layer in drivers/pci and architecture
specific implementation? One thing I notice is that architectures
provide pcibios_init() and do resource allocation while the generic
driver provides PCI generic functions such as pci_scan_device().

Thanks,
-Shawn.