There are platforms (such as the platform used by ARM-based t2a instances in Google Cloud) where the PCI device at 00:00:0 is not a host-to-pci bridge but PCI bus 0 is still present and should be enumerated. This change ensures that PCI bus 0 is always enumerated.
Enumeration of a PCI bus is being optimized by avoiding probing device functions 1 to 7 in a given device slot when device function 0 does not exist in that slot.
There are platforms (such as the platform used by ARM-based t2a instances in Google Cloud) where the PCI device at 00:00:0 is not a host-to-pci bridge but PCI bus 0 is still present and should be enumerated. This change ensures that PCI bus 0 is always enumerated. Enumeration of a PCI bus is being optimized by avoiding probing device functions 1 to 7 in a given device slot when device function 0 does not exist in that slot.