IRQS on 6 Slot Macs
geert at linux-m68k.org
Wed Nov 5 09:30:06 EST 2003
On Tue, 4 Nov 2003, Jeff Walther wrote:
> At 20:14 +1100 11/04/2003, Benjamin Herrenschmidt wrote:
> >> After all, one can, in theory, add 1024 PCI slots to a machine using
> >> PPBs. There aren't going to be 1024 interrupts available.
> >Why ? Some iSeries have up to 2048 irq lines afaik ;)
> By iSeries, do you mean iBook and iMac? Or is that something else?
iSeries are the big IBM boxes formerly known as AS/400.
> I think I can find GC's connection to MESH as well, but I'm
> uncertain. I believe that MESH is just a licensed NEC (now LSI
> Logic) 53CF96 and I have the pinout for the 53CF96 so tracing
NCR, I assume?
> I haven't dug into that, but I'd like to know how they made that
> work. Does an Enet card require an interrupt? Does it ever master
> the PCI bus?
Ethernet prefers to have an interrupt, else it becomes quite slow :-)
Most modern Ethernet interfaces do bus mastering. Old NE2000 clones don't.
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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