On Tue, 27 Aug 2013, Udo van den Heuvel wrote: > Hello Alan, > > On 2013-08-23 21:33, Alan Stern wrote: > >> Well, I replaced the motherboard by one of the same type and same BIOS > >> version. > >> And the problem is still here. > >> > >>> kernel:[ 3013.199945] Disabling IRQ #18 > >> > >> So what can we conclude? > >> Kernel bug? > >> Hardware bug? > >> Something else? > > > > Any of the above. On the new hardware, is it still true that > > /proc/interrupts shows IRQ 18 being used by ohci_hcd:usb1, 2, 3, and > > nothing else? > > $ cat /proc/interrupts |grep 18: > 104556 35248 IR-IO-APIC-fasteoi ohci_hcd:usb5, ohci_hcd:usb8, > ohci_hcd:usb9 Different bus numbers, but probably the same controllers. All right. > > Suppose you don't use the webcam, or better yet, unplug it (so that it > > can't possibly be used without your knowledge). If you do, does the > > IRQ still get disabled? > > If I simply stop the `motion` daemon I did not see the errors in the past. > Replacing the pwc webcam did not help. > > rmmod ohci-pci > > modprobe dummy-irq irq=18 > > > > and see if the IRQ line gets disabled after that. > > Can I actually use that irq/ports that way? (as with no usage the > problem does not occur) No, if you unload the ohci-hcd driver then the webcam won't be used. Are you certain that merely stopping the daemon program will prevent the problem? > Also: > > $ lsmod|grep pci > ehci_pci 12432 0 > ehci_hcd 56916 1 ehci_pci > > No ohci_pci, is that a problem? Sorry, for 3.10 it should be ohci_hcd. In 3.11 it changed to ohci_pci. Have you tried getting a USB-2 hub and plugging the webcam into it? That will make a good test: You'll be able to use the webcam without it affecting the ohci-hcd driver. As a second test, you can try plugging everything _except_ the webcam into the hub. > FWIW: on these boards (same type, BIOS, etc) I also see the issue > described at http://marc.info/?l=linux-kernel&m=137749729105329&w=2. > Any correlation? Not that I can see. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
