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    SubjectRe: [PATCH RFC v5] net: add PCINet driver
    On Thursday 15 January 2009, Ira Snyder wrote:
    > Some sort of Broadcom chipset, I think. Full dmesg and lspci output are
    > appended.
    > The PCI bridge does mention MSI, so maybe it does support it. Would
    > using the DMA from the host mean that the guest system couldn't use the
    > DMA controller at all? All of the channels share the same interrupt line
    > on the guest. I need one channel on the DMA controller on the guest to
    > do realtime transfers from some data processing FPGAs on the board.

    The PCI-CompactPCI bridge supports MSI, but that does not imply that
    the host does. My limited understanding of x86 tells me that you need
    to enable the I/O-APIC in order to use MSI. Your log shows two relavant

    [ 0.000000] Local APIC disabled by BIOS -- you can enable it with "lapic"
    [ 2.146845] IO APIC resources could be not be allocated.

    I think you first need to enable the local APIC, then find out what the
    problem with the IO APIC is. If possible, try enabling ACPI (sic) in the
    BIOS in order to get the APIC support.

    If you get that to work, you can use the interrupt line of the DMA controller
    to signal interrupts to the FSL machine, while using DMA transfers to the
    MSI address for sending interrupts to the host machine.

    Arnd <><

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      Last update: 2009-01-15 22:11    [W:0.020 / U:6.004 seconds]
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