This certainly makes sense.  My understanding of the ISA bus is limited to
i386.  But you do agree, that in general, IRQs should not be shared on an
i386 ISA bus?  I think I will submit a pr for i386/isa_machdep.c to
atleast add a kernel option to prevent i386 ISA IRQ sharing.  It certainly
isn't the case that i386 ISA edge triggered interrupts are usually
sharable (as the code would suggest).

Thanks,
	Rick

On Sun, 10 Jan 1999, Martin Husemann wrote:

> > I was under the impression that the ISA bus always used edge triggered
> > interrupts, and that they were not sharable.
> 
> This is not true for all our architectures. The atari uses different
> IRQ's on the ISA bus (I always forget which ones) and the amiga has
> a completely different logic vs. sharing of ISA IRQ's (the details
> of which I also always forget).
> 
> So as a kernel device driver writer: assume nothing about interrupt sharing.
> As someone configuring your kernel for an i386: assume no IRQ on the ISA bus
> can be shared unless explicitly told so by a reliable hardware manual.
> 
> 
> Martin
> 

=========================================================================
Rick Byers                       University of Waterloo, Computer Science
rickb@iaw.on.ca                               http://www.iaw.on.ca/rickb/