> 
> > > Anybody (Bill Studenmund?) know why lev4intr just does an rte instead of
> > > jra rei like the other handlers?
> > No clue. What happens if you stick in a jra _ASM_LABEL(rei)?
> 
> I was thinking about having zshard and the non-serial level 4
> interrupts return different codes and only go through rei for
> non-serial interrupts.  I don't know if that's a good idea or
> not.  It might be better to just go through the rei.  I'm not
> so much worried about the effect on serial performance on the
> AVs so much as I am worried about the performance impact on
> the slower machines...  A 33.6Kbps modem going full-throttle
> on one of the two ports is what?  1000s of interrupts/sec?

Since each byte has a start and stop bit, take the bit rate
and divide by 10 for the max byte rate. So we're talking anywhere
from 3000 to 5760 interrupts per second. That's why I haven't enabled
115200 or 230400 baud, even though we could do it. The older macs
would just melt.

I think different return values would be fine, one indicating just
rei out, another indicating you should call the softint stuff.

Take care,

Bill