I need to capture at 25 frame per second from each channel... So 25 x 8 total frames per second on the pci. So do you think I have to change the motherboard ? What is important ? the chipset ? is there specification I need ? -----Messaggio originale----- Da: linux-kernel-owner@xxxxxxxxxxxxxxx [mailto:linux-kernel-owner@xxxxxxxxxxxxxxx] Per conto di Robert Hancock Inviato: venerdì 2 febbraio 2007 0.30 A: Lapo TIN Cc: linux-smp@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx Oggetto: Re: smp and irq conflict Lapo TIN wrote: > 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. Usually the IRQ routing is hard-wired on the motherboard, so there's no way to avoid the devices sharing IRQs. Unless the driver is badly buggy this should not cause problems anyway. What kind of video bit rate are you capturing? 8 video capture chips is a pretty heavy load on the PCI bus, maybe something just gets overwhelmed? -- Robert Hancock Saskatoon, SK, Canada To email, remove "nospam" from hancockr@xxxxxxxxxxxxx Home Page: http://www.roberthancock.com/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ - 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
