Allen Briggs <briggs@NetBSD.org> writes:

> PCI doesn't have a config read or write for anything but 32-bit
> quantities.

Are you sure? Looking at the PCI spec, I don't see anything that
restricts the use of byte lane enables in configuration space, and
some PCI host bridges explicitly document the connection between byte
and word reads on the host side and sub-dword accesses on the PCI
side.

        - Nathan