On Thu, Aug 02, 2018 at 09:45:44AM -0400, Alexei Colin wrote:

If I move RapidIO option to drivers/Kconfig, then it won't appear under
the Bus Options/System Support menu, along with other choices for the
system bus (PCI, PCMCIA, ISA, TC, ...).

It's not like anyone cares.  And FYI, moving all those to
drivers/Kconfig is osmething I will submit for the next merge window.

Alex explains above that RapidIO
may be selected as a system bus on some architectures, and users expect
it to be in the menu in which it has been for some time now.  What
problem is the current organization causing?

A "system bus" seems like a rather outdated concept to start with.