Mailinglist Archive: opensuse (3337 mails)

< Previous Next >
Re: [SLE] Changing hardware IRQ's
  • From: S Glasoe <srglasoe@xxxxxxxxxxx>
  • Date: Sun, 30 Apr 2006 09:42:13 -0500
  • Message-id: <200604300942.13905.srglasoe@xxxxxxxxxxx>
On Saturday 29 April 2006 8:21 am, Hylton Conacher (ZR1HPC) wrote:
> I have a 9.2 system here where the network card(Realtek 8139) and the
> on-board sound have the same IRQ.
> I know this because it is mentioned when I boot the machine on the
> listing of the HDDs cofigured in the BIOS. In addition RTFM indicated
> that the procinfo command shows the IRQs, relevant details pasted below:
> irq 0: 1495304 timer irq 9: 690 uhci_hcd, uhci_hcd
> irq 1: 1881 i8042 irq 10: 14983 eth0, Ensoniq AudioP
> irq 2: 0 cascade [4] irq 11: 0 acpi
> irq 3: 102 irq 12: 37136 i8042
> irq 4: 8 irq 14: 13890 ide0
> irq 6: 14 irq 15: 18097 ide1
> I would like to move the Ensonique on-board sound device to another IRQ
> but do not know how. What is the 'correct' IRQ for sound devices? I
> think it was 15 but I would prefer to leave te ide items alone.
> Would moving eth0 to a different PCI slot help?

Don't bother. Unless you can actually prove a problem with IRQ sharing, it
doesn't matter. That is why you see the longer PCI hardware ID in which
include PCI bus #, slot#, position on the bus, etc. The actual IRQ is just
another reference point or differentiator along the way.

Pre-1999/2000, the older systems at that time needed correct IRQ settings
and usually would not share IRQs. That is really old-school these days. You
may run into this on pre-400-500 MHz systems but it is less of an issue,
especially in Linux, because the PCI routines are much better about
uniquely identifying each piece of hardware.

There is no single, correct and 'Industry Standard' IRQ for sound devices.
That is dependent on the mainboard hardware, BIOS and how it is presented
to the operating system. Once ID'd, Linux gives it a unique ID to reference
it in the future.

Moving eth0 to another PCI slot may change its IRQ but the system and OS may
keep it at 5 anyway. Again, don't bother. Unless there is a known conflict
you can actually 'prove' is happening because sound and eth0 are sharing an
IRQ it doesn't matter. It used to matter about 10 years ago...


< Previous Next >
Follow Ups