if_stop disable parameter?

[Taylor R Campbell <campbell+netbsd-tech-net%mumble.net@localhost>]

Does the boolean disable parameter to if_stop do anything useful in
any real drivers, or is it just cargo cult copypasta?

If it does something useful, what is it?  What's the contract for
drivers?  Which drivers meaningfully use it?

If not, I propose to get rid of it -- I've fixed several bugs in
drivers that arose from missing cleanup actions in the disable or
!disable case, just by making those actions unconditional, so in my
experience it seems to be a bug magnet.