pci_intr_alloc() vs pci_intr_establish() - retry type?

[Jaromír Doleček <jaromir.dolecek%gmail.com@localhost>]

I see several drivers (e.g. xhci(4), ahcisata(4), bge(4), nvme(4))
retry the pci_intr_alloc()+pci_intr_establish() with 'lower' types
when pci_intr_establish() fails.

Is this a real case, can it actualy happen that pci_intr_alloc()
returns the interrupt handlers, but pci_intr_establish() would fail
for it?

If it's not a real case, it would be nice to remove all that boilerplate code.

Jaromir