On Sun, 10 Jan 1999, Rick Byers wrote:

> 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).
> 
But e.g. a multi port serial card could have 8 16550s connected to the
same IRQ, so preventing shared irqs would not be a good idea.

The usual restriction is that you cannot have two (or more) ISA-cards
sharing the same irq.


Tom
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Tom Javen                    |   Innotrac Diagnostics Oy
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