Proposal to remove Token Ring support

[Jason Thorpe <thorpej%me.com@localhost>]

Hey folks --

I am proposing that we remove support for Token Ring.  For those not familiar, Token Ring (referring to IEEE 802.5, in this particular case) is/was a 4Mb/s or 16Mb/s token passing network that, when popular (mid-to-late-80s), had certain advantages over the Ethernet networks of the day. It has long since been eclipsed by Ethernet.

IBM was the primary driving force between 802.5 Token Ring, although Apollo Computer had their own flavor called Apollo Token Ring (sometimes called "Domain Ring" or "Domain Token Ring") that was incompatible with IBM's.

Onno van der Linden wrote our Token Ring code, and ported a Mach driver for the IBM TROPIC Token Ring controller (this controller chip was also used on some 3Com Token Ring boards).  Unfortunately, this code is not MP-safe, and while there were lots of enterprise Token Ring deployments back in the day, Token Ring has been obsolete for quite some time and thus hardware for testing changes to this code is not commonly available (in addition to the interface boards, you need a MAU / concentrator).

I believe it's time to let it go.

Code in question:

net/if_token.h
net/if_tokensubr.c

dev/ic/tropic.c
dev/ic/tropicreg.h
dev/ic/tropicvar.h

dev/isa/if_tr_isa.c

dev/isapnp/if_tr_isapnp.c

dev/mca/if_tr_mca.c

dev/pcmcia/if_tr_pcmcia.c

Are there any objections?

-- thorpej