Re: PCI Interrupt
From: linux-os \(Dick Johnson\)
Date: Tue Sep 18 2007 - 09:58:48 EST
On Tue, 18 Sep 2007 Duncan.Perrett@xxxxxxxxxx wrote:
>
> I have a CAN PCI card installed on my Ubuntu box.
> I understand that PCI interrupts should be level rather than edge
> triggered.
>
> The output of cat /proc/interrupts is :-
>
> CPU0
> 0: 1614601 IO-APIC-edge timer
> 1: 164 IO-APIC-edge i8042
> 8: 3 IO-APIC-edge rtc
> 9: 1 IO-APIC-level acpi
> 12: 0 IO-APIC-edge CAN-ACx-PCI_01
> 14: 65786 IO-APIC-edge ide0
> 169: 3220 IO-APIC-level eth0, i915@pci:0000:00:02.0
> 177: 46459 IO-APIC-level eth1
> 209: 0 IO-APIC-level uhci_hcd:usb3, eth2
> 217: 2 IO-APIC-level uhci_hcd:usb1, ehci_hcd:usb4
> 225: 697 IO-APIC-level uhci_hcd:usb2
> NMI: 0
> LOC: 1614399
> ERR: 0
> MIS: 0
>
> You see that irq 12 CAN-ACx-PCI_01 is edge triggered.
> Is there any way of forcing the BIOS to see the interrupt as a
> level-triggered one?
It's done in the driver. IRQ12 can be shared, so the driver
needs to request the IRQ as a shared interrupt.
Cheers,
Dick Johnson
Penguin : Linux version 2.6.22.1 on an i686 machine (5588.30 BogoMips).
My book : http://www.AbominableFirebug.com/
_
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