The bios assigns the interrupt. Linux does not, sooooo......................, figure
how your bios
assigns the irq (one way is by slot). It is likely that you have not opted for
extended pci options in
your bios which include these assignments.
Tom Berkley
Svante Signell wrote:
> No response so far, trying again.
>
> Anyone knows how IRQ 5 is chosen both for my eth0 (tulip, external
> card) driver and sound (maestro, on motherboard) on my Compaq Presario
> 5640/5670 when other interrupts are available: 4,6,7,9,10,11?
>
> Also the graphics card is allocated to IRQ5:
> 01:00.0 VGA compatible controller: 3Dfx Interactive, Inc. Voodoo Banshee (rev 03)
>(prog-if 00 [VGA])
> Subsystem: Guillemot Corporation Maxi Gamer Phoenix
> Flags: VGA palette snoop, 66Mhz, fast devsel, IRQ 5
>
> How to steer away one of the units from IRQ 5 to avoid interrupt
> sharing/conflicts? In the documentation to both the tulip and maestro driver I
> have not found any option to control the IRQ. What unit takes care of
> allocating IRQ's if the card driver does not require one, the kernel
> or the BIOS?
>
> The BIOS for this computer has very limited number of options, and as
> mentioned above the sound hardware is on the motherboard. Also only
> two PCI slots are available (one with the ethernet card, the other
> with a PCTV card, IRQ 3), so shuffling cards is not much to try.