To my knowledge, the only devices capable of sharing interrupts are PCI
cards (I could be wrong, but this is all I have seen). The PCI BIOS
apparently does some magic whereby it manages requests to different
devices set for the same interrupt.
I have also seen flakey performance with some off-brand NICs using shared
interrupts under Linux.
Regards,
Thomas Cameron, RHCE, CNE, MCP, MCT
Three-Sixteen Technical Services, Inc.
A subsidiary of TeamLinux Corporation
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In science it often happens that scientists say, 'You know that's a really
good argument; my position is mistaken,' and then they actually change
their minds and you never hear that old view from them again. They really
do it. It doesn't happen as often as it should, because scientists are
human and change is sometimes painful. But it happens every day. I
cannot recall the last time something like that happened in politics or
religion.
-- Carl Sagan, 1987 CSICOP keynote address
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On Tue, 20 Jun 2000, Paul Sack <[EMAIL PROTECTED]> wrote:
> I think the problem *is* that they share irq's. It might help if you told
> us what devices are occuping these ttyS's. Sometimes devices can share
> irq's, sometimes not. It's generally a good idea to avoid that if
> possible. I have seen computers where irq's are shared but sharing irq's
> has not worked on either of the 2 boxen on which I have tried.
>
> --
> Labor, n.:
> One of the processes by which A acquires property for B.
> -- Ambrose Bierce, "The Devil's Dictionary"
>
> On Tue, 20 Jun 2000, Nolan Darilek wrote:
>
> > Ok, guess it's time for my "problem of the month" post. :)
> >
> > I've recently been attempting to access /dev/ttyS0, but for some
> > strange reason, Linux always reports that it's busy. Odd -- I have
> > /dev/ttyS0-2, and ttyS1 and 2 are the only two ports being used.
> >
> > So I ran fuser/lsof to learn what might be grabbing the port. fuser
> > shows that ttyS1-2 are being accessed, but not ttyS0.
> >
> > On a hunch, I killed my PPP connection (which uses ttyS2), and
> > amazingly, ttyS0 became available. Anyhow, I can't quite figure out
> > how my modem's use of ttyS2 could effect ttyS0. Here is what dmesg
> > says about my serial ports:
> >
> > Serial driver version 4.27 with no serial options enabled
> > ttyS00 at 0x03f8 (irq = 4) is a 16550A
> > ttyS01 at 0x02f8 (irq = 3) is a 16550A
> > ttyS02 at 0x03e8 (irq = 4) is a 16550A
> >
> > So, it looks as if there shouldn't be any conflicts, except for the
> > IRQs being shared by both, but doesn't the fact that they're using
> > different addresses make that possible? If not, what should I do to
> > fix this?
> >
> > ---------------------------------------------------------------------------
> > Send administrative requests to [EMAIL PROTECTED]
> >
>
> ---------------------------------------------------------------------------
> Send administrative requests to [EMAIL PROTECTED]
>
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