isp(4) broken in RELENG_9

[Matthew Jacob]

So, it's working in 9.1 but not in 9?

Since any fix to 9.0 would be in 9.1 are we just concerned with 
understanding what happened, or is there a specific reason we need to 
know what changed so that a specific fix to 9.0 is needed?

I'm sure that there is a bug in isp where it can ask for more than a 
page's worth of queue space mapping but can't deal with things if you 
get more than 1 segment descriptor back. I need to fix that, but I won't 
be able to get to that for a couple of weeks.

It's possible that the FC-TAPE changes triggered this because that threw 
more of a load on the control space. I'll try and calculate a change to 
MAXISPREQUEST to re-fit within a page some time today.

-matt