Re: Interrupt sharing.

Ricky Beam (
Thu, 13 Feb 1997 20:23:45 -0500 (EST)

Letting the chips far where they may, I quote Steven N. Hirsch:
>If memory serves, the kernel could care less how many devices share an

Well, actually it can... if I remember correctly, the driver can request
that it be the only driver for the IRQ. But I've not looked at that stuff
for eons (in the Linux time continium.)

>But, if multiple cards all try to activate one interrupt with multiple
>drivers - look out! Without getting into the issues of tri-stated busses,
>edge-triggered vs. level-triggered, etc, it simply won't work.

Suffice it to say you run the rick of letting the smoke out of the chips.

>PCI, EISA and MicroChannel will cheerfully support interrupt sharing.

"Support" and "funtionality" are two different things... #9-771 and any other
device can generally support shared PCI-IRQs, but it tends to lock up the
machine under certain conditions (read: dragging large full-speed animations
around the screen... Mod4Win keeps on playing tho' :-))