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    SubjectRe: [PATCH/RFC] PCI prepare/activate instead of enable to avoid IRQ storm and rogue DMA access
    On Wed, Mar 14, 2007 at 06:34:11PM -0400, Jeff Garzik wrote:
    > Russell King wrote:
    > >pci_enable_device() doesn't deal with this; in most PCI setups I've
    > >seen, there is no control at PCI level over whether a device generates
    > >an interrupt on the bus. Certainly the memory and io command enables
    >
    > PCI grew an interrupt enable while you weren't looking:
    > PCI_COMMAND_INTX_DISABLE

    That's fine for devices which conform to the later PCI specs, but not
    all do.

    > It was added in PCI 2.3 I think.

    Correct.

    > Older PCI devices certainly do not have this standardized bit.

    No PCI device that I have has that bit - including the raid card I
    bought last year...

    In any case, relying on such a new control bit to implement this kind
    of functionality would result in a very hit and miss result; Linux
    tends to get used on things other than the bleeding edge of hardware
    technology.

    --
    Russell King
    Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
    maintainer of:
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