In message <8B976F40-EF76-4EA1-9D4D-091F9D431D80@3am-software.com>, Matt Thomas
 writes:
>Are you zeroing it?  Don't.  the softc the kernel gives is already  
>zeroed
>and device struct at the beginning is filled in.  zeroing it would cause
>the kernel to crash.

I was zeroing some data in it, but as you note, unneeded.

Turns out, though, mostly my problem was I'd reversed "parent" and "self".

-s