pci address detection

[daggs1-zz]

I have a system with two gpus, one is deactivated.
here are some prints from the os:

# lspci | grep VGA
02:00.0 VGA compatible controller: Matrox Electronics Systems Ltd. MGA G200e [Pilot] ServerEngines (SEP1) (rev 05)
# lspci -t
-[0000:00]-+-00.0
           +-01.0-[01]----00.0
           +-14.0
           +-14.2
           +-16.0
           +-16.1
           +-17.0
           +-1d.0-[02]----00.0
           +-1d.2-[03]----00.0
           +-1d.3-[04]----00.0
           +-1f.0
           +-1f.2
           \-1f.4

I'm trying find the gpu's pci address, I've polled all the handles and found the card, when I execute DevicePathToStr, I get this output:
PciRoot(0)/Pci(0x1D,0x0)/Pci(0x0,0x0)
why the bus isn't displayed? how can I find it?