amr driver broken since March 12

[Danny Braniss]

> Danny Braniss wrote:
> > at least for me :-)
> > [and sorry for the cross posting]
> > 
> > old (March 12 , i know need the svn rev number but...)
> 
> None of the commit activity on March 12 is jumping out at me as being 
> suspicious.  However, you are now the second person who has told me 
> about AMR problems in 7.1 recently.  If you have a precise svn change
> number, it would help greatly.
> 
> Scott
my bad. the last working amr/iir is from March 12.
I first detected the problem sometime later, but not later than March 23.
So it has to be changes in that time frame.

both drivers are showing similar symptoms:
	waiting for not busy
the iir goes on for ever, and it's the cam that eventually panics,
 run_interrupt_driven_hooks: still waiting after 300 seconds for xpt_config
(actually not 100% true, depending if WITNESS is on or off, it sometimes
just hangs).
the amr seems to time out:
	amr0: adapter is busy

thanks for looking into the problem,

danny