Re: IRQ 2,9

. Tethys (
Wed, 12 Feb 1997 12:01:48 +0000

>> So, is there a reason why this information is incomplete (as at 2.0.27
>> on x86 -- I haven't checked since then)?
>Well, for the serial ports (yawn! have we got to say this again),
>the interrupt isn't reserved unless the serial port is in use.
>The driver won't grab irq 4 or 3 (or whatever) until it needs it.
>That's a design feature, not a bug.
>By default, the parallel printer driver doesn't use interrupts,
>so it won't grab irq 7 or 5 (or whatever) unless you
> a) load the lp driver - if its a module
> and
> b) tell it to use interrupts
>That's another design feature, not a bug.

Sounds OK, but given that it's a multi-boot machine, I can't assign
anything to those interrupts, as that would cause a conflict under
the crap from Redmond. It would be handy to know what the IRQ settings
are on a card, even if it's not currently being used by linux. Thus,
/proc/interrupts might say something like:

5 WD-8003
7 parallel port (unused)

Is this even possible? (the cards in question are mostly old ISA non-PnP,
with jumper settings for IRQ/base address).


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