Hi,
I have a question about enumeration and the distinction between the Host/PCI bridge and a P2P bridge in the Root Complex.
I understand that in the enumeration process you poll Bus 0, Device 0, Function 0 and verify a valid Vendor ID and in my case that the device is a bridge. You then update the Primary bus = 0, Secondary bus = 1, and the Subordinate bus = 1 in the configuration space for BDF 0,0,0. (I realize the subordinate bus can be updated at the end but this is part of the question.) In some explanations of the process that I've read, it says that you also need to update the subordinate bus number on the Host/PCI bridge. How does one do this? It seems to me that using the configuration address/data registers will just update the P2P bridge and not the Host/PCI bridge. Any explanation would be greatly appreciated.
Thanks in advance.