> I'm pretty sure the spec disallows routing-to-self so doing a P2P
> transaction in that sense isn't going to work unless the device
> specifically supports it and intercepts the traffic before it gets to
> the port.
This is correct. Unless the device intercepts the TLP before it hits the
root-port then this would be considered a "route to self" violation and an
error event would occur. The same holds for the downstream port on a PCI switch
(unless route-to-self violations are disabled which violates the spec but which
I have seen done in certain applications).
Stephen