Dear all, I have a problem with IRQs. My pc has a CPU PentiumD945 (dual core) and a 2.6.19smp kernel. I have two video acquisition board (four bt8t8 each) in the only two pci slots of my motherboard. Thus I have a total of 8 bttv modules that are working together, and the /proc/interrupts is as follows: # cat /proc/interrupts CPU0 CPU1 0: 13575 0 IO-APIC-edge timer 1: 2 0 IO-APIC-edge i8042 4: 11 0 IO-APIC-edge serial 8: 1 0 IO-APIC-edge rtc 9: 0 0 IO-APIC-fasteoi acpi 12: 4 0 IO-APIC-edge i8042 14: 22286 0 IO-APIC-edge ide0 17: 7073 2097 IO-APIC-fasteoi uhci_hcd:usb5, eth0 18: 2525 0 IO-APIC-fasteoi bttv0, bttv7 19: 2829 0 IO-APIC-fasteoi bttv1, bttv4 20: 2526 0 IO-APIC-fasteoi bttv2, bttv5 21: 2226 0 IO-APIC-fasteoi bttv3, bttv6 22: 2 0 IO-APIC-fasteoi ehci_hcd:usb1, uhci_hcd:usb4 23: 86 0 IO-APIC-fasteoi uhci_hcd:usb2 24: 0 0 IO-APIC-fasteoi uhci_hcd:usb3 NMI: 0 0 LOC: 13484 13502 ERR: 0 MIS: 0 You can see that IRQ18 is shared between bttv0 and bttv7, IRQ19 between bttv1 and bttv4 and so on. Sometimes it crashes. It seems a matter of conflict in IRQ. With only one video board everything is ok, but with two, they shared irq and something goes wrong... How can I tell to the kernel to not to share the IRQ for these boards ? I think (I don't know if I'm right) that this could be the problem. I even tried with another motherboard, and doing cat /proc/interrupts the situation was the same, except for 'eth0' that was together with bttv0 and bttv7... so it was even worst ! it crashes after few minutes. I tried to read IO-APIC.txt in Documentation/i386/ folder, but I didn't understand how to avoid the coupling of IRQ. Thanks Lapo - To unsubscribe from this list: send the line "unsubscribe linux-smp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html