> -----Original Message-----
> From: Mike Smith [SMTP:[email protected]]
> Sent: Friday, May 21, 1999 2:16 AM
> To: Joel Ray Holveck
> Cc: Doug Rabson; Peter Wemm; Tommy Hallgren;
> [email protected]
> Subject: Re: Lazy SPLs
>
> >
> > Why mask out the interrupts at all, instead of queuing them in
> handler
> > level?
>
> Level-triggered interrupts are persistent conditions, not queueable
> events. They typically require device-driver level intervention to be
>
> cleared. This is a major error in the PCI design (no surprises
> there).
>
[ML] Whoa there! That's the MAJOR advantage of PCI design.
Open collector, active low, level triggered interrupts are the only
possibility for interupt line sharing without programmatically
accessible registers on card which say "yes, I am still interrupting".
Active high, edge triggered interrupts are an abomination (there
is no way to reliably share the interrupt line and you cannot even wire
or it). They are the reason why one never has enough interrupt lines on
ISA.
> --
> \\ The mind's the standard \\ Mike Smith
> \\ of the man. \\ [email protected]
> \\ -- Joseph Merrick \\ [email protected]
>
>
>
>
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