Mailinglist Archive: opensuse (5130 mails)

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Re: [SLE] Changing hardware IRQ's
  • From: "Hylton Conacher (ZR1HPC)" <hylton@xxxxxxxxxxxx>
  • Date: Mon, 01 May 2006 18:35:01 +0200
  • Message-id: <445638B5.8010306@xxxxxxxxxxxx>
S Glasoe wrote:
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...
Tnx, Now I feel old as the knowledge I have is about 10-15yrs old.

I'll have a look at the BIOS but otherwise I hope it is not going to be problems.


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