Re: pass-through linux ioctl for mfi(4)

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Mon, 17 Sep 2012 09:21:23 -0400
    From:        christos%zoulas.com@localhost (Christos Zoulas)
    Message-ID:  <20120917132123.BCBB797124%rebar.astron.com@localhost>

  | devsw_name2{blk,chr}("mfi", NULL, 0),

That's like driving round the wrong block - backwards...

There's no need to know which particular major(dev) is mfi,
what is needed is to know whether the dev you have is the one
that gets to mfi, which is going at the problem the other way
around.

With suitable error checking added, just use

        cdevsw_lookup(dev)->d_ioctl == mfiioctl

(or whatever its ioctl function is named).

kre