> 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