PCI IRQs and IO-APIC

Hi,

I am using a 2.4.20 Linux kernel with an Intel SDS2 motherboard. By default, USB doesn't function as is shown by this /proc/interrupts

CPU0 CPU1

  0:     146457     142403    IO-APIC-edge  timer
  1:          1          1    IO-APIC-edge  keyboard
  2:          0          0          XT-PIC  cascade
  4:        616        690    IO-APIC-edge  serial
  7:          0          0    IO-APIC-edge  parport0
 14:          0          2    IO-APIC-edge  ide0
 16:      27394      27504   IO-APIC-level  aic7xxx
 17:          9          7   IO-APIC-level  aic7xxx
 18:      10562      10579   IO-APIC-level  eth0
 19:       6871       6786   IO-APIC-level  eth1
 22:     446759     445440   IO-APIC-level  ide2, ide3
 23:       8089       7770   IO-APIC-level  mxser
 24:        229        213   IO-APIC-level  EMU10K1
 25:          9          7   IO-APIC-level  aic7xxx
 28:         10          6   IO-APIC-level  aic7xxx
 33:          0          0            none  usb-ohci
NMI:          0          0
LOC:     288724     288714
ERR:          0
MIS:          0

Booting with the noapic option does fix this and only gives 16 IRQs so many devices wind up sharing. The other thing I tried was the ACPI patch at www.sf.net/projects/acpi and that also fixed the problem with the APIC enabled.

CPU0 CPU1

  0:    3142365    3090327    IO-APIC-edge  timer
  1:          1          1    IO-APIC-edge  keyboard
  2:          0          0          XT-PIC  cascade
  4:        221        216    IO-APIC-edge  serial
  7:         21         10    IO-APIC-edge  parport0
  9:          2          4   IO-APIC-level  acpi
 10:          2          0    IO-APIC-edge  usb-ohci
 14:          2          0    IO-APIC-edge  ide0
 16:     152211     153488   IO-APIC-level  aic7xxx
 17:          9          7   IO-APIC-level  aic7xxx
 18:     271568     270316   IO-APIC-level  eth0
 19:       8492       8638   IO-APIC-level  eth1
 22:      26577      25716   IO-APIC-level  ide2, ide3
 23:     213562     200629   IO-APIC-level  mxser
 24:      12651      12583   IO-APIC-level  EMU10K1
 25:         11          5   IO-APIC-level  aic7xxx
 28:          9          7   IO-APIC-level  aic7xxx
NMI:          0          0
LOC:    6231968    6231965
ERR:          0
MIS:          0

Regards,
Shane