On Wed, Apr 6, 2011 at 3:34 PM, Dave Phillips <dlphillips@xxxxxxxxxx> wrote: > Greetings, > > I've been working with Ardour3 on my laptop, a machine with an AMD Turion X2 > CPU and an nVidia 8200M integrated video chipset. Recently I started > monitoring my test recordings through the headphone output of my UA25 and I > notice that when I move the mouse it creates scratchy sounds, though > QJackCtl reports no xruns and my recordings are unaffected. I verified the > problem with Ardour2 and Mixbus. It doesn't occur when I use the integrate > audio chipset (snd-hda-intel, wahoo). > > Running 'cat /proc/interrupts' reports that usb1/usb3 share interrupt 17 and > usb2/usb4 share interrupt 16. I've tried switching ports around but that > didn't get rid of the noise. Any further suggestions ? > > Best, > > dp What does lsusb and lsusb -t tell you? Are these two USB devices on different buses using different controllers & different interrupts? With no audio running if you move the mouse and watch /proc/interrupts you should be able to see which interrupt is being used. HEre are a couple of measurements. The first is a baseline. The second is the system sitting quiet for 1 minute. Note that Int16 didn't change. The third is after me moving the mouse for 1 minute. Clearly Int16 jumped a lot, as expected. I don't have a USB audio device but you can run the same tests using USB audio and not using the mouse. (much) This is a 12-core SMP machine which is why there are so many 0's in each row. Hope this helps, Mark cat /proc/interrupts | grep usb c2stable ~ # date && cat /proc/interrupts | grep usb Wed Apr 6 15:48:00 PDT 2011 16: 506693 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi ahci, uhci_hcd:usb3 18: 35414 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb8 19: 0 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb5, uhci_hcd:usb7 21: 0 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb4 23: 2 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi ehci_hcd:usb2, uhci_hcd:usb6 c2stable ~ # date && cat /proc/interrupts | grep usb Wed Apr 6 15:49:00 PDT 2011 16: 506693 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi ahci, uhci_hcd:usb3 18: 35471 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb8 19: 0 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb5, uhci_hcd:usb7 21: 0 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb4 23: 2 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi ehci_hcd:usb2, uhci_hcd:usb6 c2stable ~ # date && cat /proc/interrupts | grep usb Wed Apr 6 15:50:00 PDT 2011 16: 513590 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi ahci, uhci_hcd:usb3 18: 35534 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb8 19: 0 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb5, uhci_hcd:usb7 21: 0 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi uhci_hcd:usb4 23: 2 0 0 0 0 0 0 0 0 0 0 0 IO-APIC-fasteoi ehci_hcd:usb2, uhci_hcd:usb6 c2stable ~ # - Mark _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user