[2.6.7] Ehci controller interrupts like crazy on nforce2

Here it is: another nforce2 hardware bug. The ehci controller seems to send a massive number of interrupts to the kernel (264379 per second). This uses about 5 to 10% of the cpu. This shows up in top in the "hi"(hard interrupts) indicator. Nothing unusual shows up in the kernel log. My system has an Asus A7N8X Nforce2 Board with an Athlon XP 2800+ mounted on it.

[joe@omega3:~]$ cat /proc/interrupts ; sleep 1; cat /proc/interrupts
          CPU0
 0:     583513          XT-PIC  timer
 1:       1279    IO-APIC-edge  i8042
 7:     137293    IO-APIC-edge  parport0
 8:          0    IO-APIC-edge  rtc
 9:          0   IO-APIC-level  acpi
14:      41463    IO-APIC-edge  ide0
15:         23    IO-APIC-edge  ide1
17:          9   IO-APIC-level  EMU10K1
18:      18584   IO-APIC-level  eth0
20:  121541873   IO-APIC-level  ehci_hcd
21:          0   IO-APIC-level  ohci_hcd
22:          0   IO-APIC-level  ohci_hcd
NMI:          0
LOC:     583348
ERR:          0
MIS:          0
          CPU0
 0:     584760          XT-PIC  timer
 1:       1280    IO-APIC-edge  i8042
 7:     137578    IO-APIC-edge  parport0
 8:          0    IO-APIC-edge  rtc
 9:          0   IO-APIC-level  acpi
14:      41505    IO-APIC-edge  ide0
15:         23    IO-APIC-edge  ide1
17:          9   IO-APIC-level  EMU10K1
18:      18641   IO-APIC-level  eth0
20:  121806252   IO-APIC-level  ehci_hcd
21:          0   IO-APIC-level  ohci_hcd
22:          0   IO-APIC-level  ohci_hcd
NMI:          0
LOC:     584595
ERR:          0
MIS:          0
[joe@omega3:~]$

Any help or random thougths are welcome.

Happy Hacking,
Joe

Well, I have the same system (board is Deluxe version) and no such situation.

Hmm, I don't have this though. "IO-APIC-edge timer" is the closest in my box.

[snip]

[snip]

Well, the "usual answer" is try enable/disable PREEMPT, upgrade BIOS. Also IO-APIC and APIC as a whole.

Here is my board:

$ cat /proc/interrupts 
          CPU0       
 0:  415667195    IO-APIC-edge  timer
 1:     184380    IO-APIC-edge  i8042
 8:          2    IO-APIC-edge  rtc
 9:          0   IO-APIC-level  acpi
14:     865112    IO-APIC-edge  ide0
15:       9195    IO-APIC-edge  ide1
19:   31371344   IO-APIC-level  nvidia
20:    8356973   IO-APIC-level  ehci_hcd, NVidia nForce2, eth0
21:          0   IO-APIC-level  ohci_hcd
22:     798076   IO-APIC-level  ohci_hcd
NMI:          0 LOC:  415691931 ERR:          0
MIS:          0
$ bash -c 'cat /proc/interrupts ; sleep 1; cat /proc/interrupts'|  grep ehci
20:    8357517   IO-APIC-level  ehci_hcd, NVidia nForce2, eth0
20:    8357530   IO-APIC-level  ehci_hcd, NVidia nForce2, eth0

|| ~~~~~~~~~~~~~~~~~~~~~~ ||
(  ) http://ThinRope.net/ (  )
|| ______________________ ||

I've seen this problem on my board (Epox 8RDA3+) as well. The root cause seems to be interrupt link devices enabled without regard for the actual device status. A recent patch that delayed IRQ assignment to device activiation time fixed this for me; you might want to try a fresh -mm or -bk kernel.

Hope that helps,

Daniel.

2.6.7-bk21 fixed this problem for me, thanks

it sure did.

Happy Hacking,
Joe