> I am a little confused by the interrupt level assignments I found
> while playing with the zs driver.   Compare these:
> 
> Level	Sunos-4.1.1	NetBSD-current
> -----	-----------	--------------
> 1	net/softclk	softclk
> 2	spl2(spare)	bio/tty/vm
> 3	le/splimp	le/net
> 4	(spare) 	(spare)
> 5	clock/tty	clock
> 6	splzs		splzs/splimp
> 7	(nmi)		(nmi)
> 
> I am most surprised to see tty at a lower priority than net.
> Wouldn't one rather miss an ethernet packet than tty input?
> Is the interrupt level design dictated by anything outside of
> the sys/arch/sun3 area?  Why is it so different from SunOS?
> 
> Gordon Ross

Level	Sunos-4.1.1	NetBSD-current	sun3 hardware
-----	-----------	--------------	-------------
1	net/softclk	softclk		system enab reg 1
2	spl2(spare)	bio/tty/vm	scsi or system enab reg 2
3	le/splimp	le/net		ether or system enab reg 3
4	(spare) 	(spare)		video (not used)
5	clock/tty	clock		clock
6	splzs		splzs/splimp	serial chip
7	(nmi)		(nmi)		

spltty() was primarily chosen to be this value as its relative
priority seemed irrelevant once you go to the spltty()/splzs() split.
There was another stupid reason in that there was currently nothing on
spl2() that actually worked, and thus i could test stuff w/o breaking
other things.

Anyway, you can re-arrange these any way you like.  Hell you can even
make it configurable.

bleh,
Adam Glass

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