cat /proc/interrupts gives the following CPU0 CPU1 CPU2 CPU3 CPU4 CPU5 CPU6 CPU7 0: 26 0 0 893152 0 0 0 0 IO-APIC-edge timer 1: 22 0 0 31 5062 0 0 0 IO-APIC-edge i8042 8: 0 0 0 1 0 0 0 0 IO-APIC-edge rtc0 9: 729 0 0 148 0 0 0 0 IO-APIC-fasteoi acpi 12: 74387 0 0 173 0 0 0 0 IO-APIC-edge i8042 16: 11853419 0 0 0 0 0 93 0 IO-APIC-fasteoi ehci_hcd:usb1, brcmsmac 21: 613255 0 0 241 0 0 0 0 IO-APIC-fasteoi ehci_hcd:usb2 40: 1664049 0 0 0 0 0 0 0 HPET_MSI-edge hpet2 41: 0 373735 0 0 0 0 0 0 HPET_MSI-edge hpet3 42: 0 0 244881 0 0 0 0 0 HPET_MSI-edge hpet4 43: 0 0 0 270616 0 0 0 0 HPET_MSI-edge hpet5 44: 0 0 0 0 1035760 0 0 0 HPET_MSI-edge hpet6 45: 0 0 0 0 0 0 0 0 PCI-MSI-edge eth0 46: 6781 5882 0 0 424359 0 0 0 PCI-MSI-edge ahci 47: 0 0 1 0 0 0 0 0 PCI-MSI-edge xhci_hcd 48: 0 0 0 0 0 0 0 0 PCI-MSI-edge xhci_hcd 49: 0 0 0 0 0 0 0 0 PCI-MSI-edge xhci_hcd 50: 0 0 0 0 0 0 0 0 PCI-MSI-edge xhci_hcd 51: 0 0 0 0 0 0 0 0 PCI-MSI-edge xhci_hcd 52: 0 0 0 0 0 0 0 0 PCI-MSI-edge xhci_hcd 53: 0 0 0 0 0 0 0 0 PCI-MSI-edge xhci_hcd 54: 0 0 0 0 0 0 0 0 PCI-MSI-edge xhci_hcd 55: 0 0 0 0 618 0 0 181167 PCI-MSI-edge radeon 56: 0 0 0 0 0 255 940 0 PCI-MSI-edge hda_intel 57: 0 0 0 0 0 624 0 0 PCI-MSI-edge hda_intel NMI: 0 0 0 0 0 0 0 0 Non-maskable interrupts LOC: 146 135 118 101 83 292119 262176 323651 Local timer interrupts SPU: 0 0 0 0 0 0 0 0 Spurious interrupts PMI: 0 0 0 0 0 0 0 0 Performance monitoring interrupts IWI: 0 0 0 0 0 0 0 0 IRQ work interrupts RES: 8835 2130 1206 621 13366 2364 1354 679 Rescheduling interrupts CAL: 848 2123 2403 2402 1147 2676 2523 2331 Function call interrupts TLB: 12484 8516 5371 4185 16856 5432 4059 2812 TLB shootdowns TRM: 0 0 0 0 0 0 0 0 Thermal event interrupts THR: 0 0 0 0 0 0 0 0 Threshold APIC interrupts MCE: 0 0 0 0 0 0 0 0 Machine check exceptions MCP: 58 58 58 58 58 58 58 58 Machine check polls ERR: 0 MIS: 0 The sound cart is on the ehci usb1. I have noticed that my wifi card is using the same IRQ, but on my kernel especially compiled for music, the brcmsmac module is disabled. That's enough to deactivate the hardware from using that interruption, isn't it? lsusb -t /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 5000M /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 480M /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/3p, 480M |__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/8p, 480M |__ Port 2: Dev 7, If 0, Class=hub, Driver=hub/7p, 480M |__ Port 4: Dev 8, If 0, Class=HID, Driver=usbhid, 1.5M |__ Port 4: Dev 8, If 1, Class=HID, Driver=usbhid, 1.5M |__ Port 7: Dev 9, If 0, Class=stor., Driver=usb-storage, 480M |__ Port 5: Dev 4, If 0, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M |__ Port 5: Dev 4, If 1, Class='bInterfaceClass 0x0e not yet handled', Driver=uvcvideo, 480M /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci_hcd/3p, 480M |__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/6p, 480M |__ Port 1: Dev 4, If 0, Class=vend., Driver=snd-usb-audio, 480M |__ Port 1: Dev 4, If 1, Class=vend., Driver=snd-usb-audio, 480M |__ Port 1: Dev 4, If 2, Class=vend., Driver=snd-usb-audio, 480M |__ Port 1: Dev 4, If 3, Class=audio, Driver=snd-usb-audio, 480M |__ Port 1: Dev 4, If 4, Class=app., Driver=snd-usb-audio, 480M