Connecting to "PCI command write" interrupt on 4xx platforms

Benjamin Herrenschmidt benh at kernel.crashing.org
Mon Nov 3 21:57:43 EST 2008


On Mon, 2008-11-03 at 10:10 +0100, Matthias Fuchs wrote:
> 
> Adding this interrupt to the PCI node would make (logical) sense. But
> on PCI adapter (add-in cards) designs we typically disable the PCI node
> of the DT to disable PCI PnP. This should not prevent us from adding the
> interrupt to the node but it looks a little bit weird to take an interrupt
> from a disabled node, right?

You can make a pci-endpoint node that isn't detected as a host bridge.
In fact, I think we have some way to even tell in the DT not to activate
host bridge function on 44x nowadays no ? I dont remember for sure but
it's easy enough to add.

> > the actual PCI bridge, then you can stick an interrupts property in the
> > PCI host bridge node in the DT just fine.
> The PCI node already contains the interrupt-map for the PCI interrupts.

Only relevant for master, not endpoint.

> Doesn't adding a further interrupt property cause some trouble with the PCI interrupts?

Not for endpoint.

Ben.





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