Re: [PATCH v5 5/8] blockdev: Add a new IF type IF_OTHER

[Peter Maydell]

On Thu, 28 Jul 2022 at 15:50, Markus Armbruster <armbru@redhat.com> wrote:
> Kevin Wolf <kwolf@redhat.com> writes:
> >
> > But if you have more than one device, it becomes hard to predict which
> > device gets which backend - it depends on the initialisation order in
> > the code then,
>
> Really?  Board code should use IF_OTHER devices just like it uses the
> other interface types, namely connecting each frontend device to a
> backend device with a well-known and fixed interface type and index (or
> bus and unit instead, where appropriate).

I think part of the problem is that unlike the typical disk
interface, where there is some idea of bus-and-unit-number or
index number that it makes sense to expose to users, these
"miscellaneous storage" devices don't have any particular index
concept -- in the real hardware there are just a random set of
devices that are connected in various places. So you're requiring
users to look up the documentation for "index 0 is this eeprom,
index 1 is that other eeprom, index 2 is ...".

thanks
-- PMM