Spurious 8259A Interrupt IRQ 7

Jun 22 09:29:51 p500 kernel: spurious 8259A interrupt: IRQ7.

# cat /proc/interrupts 
           CPU0       
  0:    6486628          XT-PIC  timer
  1:          6          XT-PIC  keyboard
  2:          0          XT-PIC  cascade
  4:     647546          XT-PIC  serial
  5:          0          XT-PIC  Crystal audio controller
  8:          1          XT-PIC  rtc
  9:    3548883          XT-PIC  eth2, eth3
 11:    2601852          XT-PIC  ide2, ide3, eth0, eth1
 12:         38          XT-PIC  PS/2 Mouse
 14:     121950          XT-PIC  ide0
 15:         25          XT-PIC  ide1
NMI:          0 
LOC:    6486487 
ERR:         11
MIS:          0

Is there anyway to narrow down what could be causing this error, as nothing uses IRQ7?

The system is a Dell Optiplex GX1 p.

http://docs.us.dell.com/docs/systems/d_gx1p/irq.htm

It says IRQ7 is the parallel port.

I have the parallel port disabled on in the bios.

http://www.ussg.iu.edu/hypermail/linux/kernel/0301.2/0960.html

An earlier thread on LKML, a lot of different opninions as to if this is a serious problem or not and what to do about it.

Should I take each board out and run the system until I see the message again?

I've only seen this message once.

Today that is.

Using all PCI nics.

kern.warn:Jun 10 23:30:43 p500 kernel: spurious 8259A interrupt: IRQ7. kern.warn:Jun 11 22:29:44 p500 kernel: spurious 8259A interrupt: IRQ7. kern.warn:Jun 14 20:24:34 p500 kernel: spurious 8259A interrupt: IRQ7. kern.warn:Jun 20 00:10:24 p500 kernel: spurious 8259A interrupt: IRQ7.

Could this have anything to do with using the onboard ISA Sound card?

(It uses IRQ5).

I am using Kernel 2.4.21.

linux-2.4.21.tar.bz2 . . . . . . Jun 13 14:52 27865k

And those logs go back to the 10th, before I was running 2.4.20, so it is nothing to do with the kernel.

What did *I* change?

The only Ithing I've recently change wd was: I went from 3 ISA boaerds to PCI

and took out an ol dd ATA/100 board and put in a ATA/133 board (Promise) (both)

the 3isas were 53com 90509s, 2 TP only, 1 aui,bnc,tp

it is the same configuration now but with PCI and 3com 905bs (2), and 1 3com 900 combo (pci)

here is lspci output

00:00.0 Host bridge: Intel Corp. 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (rev 03) 00:01.0 PCI bridge: Intel Corp. 440BX/ZX/DX - 82443BX/ZX/DX AGP bridge (rev 03) 00:07.0 ISA bridge: Intel Corp. 82371AB/EB/MB PIIX4 ISA (rev 02)
00:07.1 IDE interface: Intel Corp. 82371AB/EB/MB PIIX4 IDE (rev 01) 00:07.2 USB Controller: Intel Corp. 82371AB/EB/MB PIIX4 USB (rev 01) 00:07.3 Bridge: Intel Corp. 82371AB/EB/MB PIIX4 ACPI (rev 02)
00:0e.0 Unknown mass storage controller: Promise Technology, Inc. 20269 (rev 02) 00:0f.0 PCI bridge: Digital Equipment Corporation DECchip 21152 (rev 03) 00:11.0 Ethernet controller: 3Com Corporation 3c905B 100BaseTX [Cyclone] (rev 24) 01:00.0 VGA compatible controller: ATI Technologies Inc 3D Rage Pro AGP 1X/2X (rev 5c) 02:09.0 Ethernet controller: 3Com Corporation 3c900 Combo [Boomerang] 02:0a.0 Ethernet controller: 3Com Corporation 3c905B 100BaseTX [Cyclone] (rev 30) 02:0b.0 Ethernet controller: 3Com Corporation 3c905B 100BaseTX [Cyclone] (rev 30)

what would be the best way to determine what is causing his this problem?

IRQ7 is raised if an interrupt appears and then vanishes again before it can be serviced. For 2.4.20/21 at least it can occur from the IDE layer and maybe others

I will put my old ATA/100 board (Promise ATA/100 TX1) back in the box and remove the ATA/133 (Promise TX2) and see if there are any more of these spurious msgs.

Also, I am not sure how the IO-APIC & IRQ routing work, however, with the ATA/100 TX1 (first generation promise controller, the interrupts are shared differently.

Whether this makes a difference or has anything to do with the spurious interrupts/messages, I am not sure.

Before:

# cat /proc/interrupts
CPU0
0: 6486628 XT-PIC timer
1: 6 XT-PIC keyboard
2: 0 XT-PIC cascade
4: 647546 XT-PIC serial
5: 0 XT-PIC Crystal audio controller
8: 1 XT-PIC rtc
9: 3548883 XT-PIC eth2, eth3
11: 2601852 XT-PIC ide2, ide3, eth0, eth1
12: 38 XT-PIC PS/2 Mouse
14: 121950 XT-PIC ide0
15: 25 XT-PIC ide1
NMI: 0
LOC: 6486487
ERR: 11
MIS: 0

After:

CPU0

  0:      22081          XT-PIC  timer
  1:          6          XT-PIC  keyboard
  2:          0          XT-PIC  cascade
  4:       2061          XT-PIC  serial
  5:          0          XT-PIC  Crystal audio controller
  8:          1          XT-PIC  rtc
  9:       4233          XT-PIC  eth2, eth3
 10:         37          XT-PIC  ide2, ide3
 11:       2071          XT-PIC  eth0, eth1
 12:         38          XT-PIC  PS/2 Mouse
 14:       6037          XT-PIC  ide0
 15:         24          XT-PIC  ide1
NMI:          0
LOC:      22032
ERR:          0
MIS:          0

Now to see if I get any more of these spurious interrupts...

I'm also seeing this on my NEC Chrom@ laptop, just at the very end of the boot stage, just before X starts up.