Some have dual host->PCI bridges for the same logical pci bus (!), eg:
some of the RCC chipsets. This is a 32/64 bit 33/66MHz and dual pci
voltage motherboard so persumably there are electical or signalling
differences but they are otherwise the same logical bus.
The new PCI probe code however was getting somewhat upset about it and
ended up creating two pci bridges to the same logical bus, which caused
devices on that logical bus to appear and be probed twice.
The ACPI data on this box correctly identifies this stuff, so bring on
ACPI! :-)
87051a1025