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    SubjectRe: [PATCH 0/6] PCI legacy I/O port free driver (take2)

    > Here, there are many PCI devices that provide both I/O port and MMIO
    > interface, and some of those devices can be handled without using I/O
    > port interface. The reason why such devices provide I/O port interface
    > is for compatibility to legacy OSs. So this kind of devices should
    > work even if enough I/O port resources are not assigned. The "PCI
    > Local Bus Specification Revision 3.0" also mentions about this topic
    > (Please see p.44, "IMPLEMENTATION NOTE"). On the current linux,
    > unfortunately, this kind of devices don't work if I/O port resources
    > are not assigned, because pci_enable_device() for those devices fails.

    Which is where the real problem is ... I'm afraid you are doing a
    workaround for the wrong issue... do we really need to assign all
    resources to the device at pci_enable_device() time ? Yeah, I know, that
    sounds gross... but think about it... doesn't pci_request_region(s) look
    like a better spot ? Or maybe we should change pci_enable_device()
    itself to take a mask of BARs that are relevant. That would help dealing
    with a couple of other cases of devices where some BARs really need to
    be ignored...

    The later is probably the best approach without breaking everything, by
    having a new pci_enable_resources(mask) that would take a mask of BARs
    to enable, with pci_enable_device() becoming just a call to the former
    for all BARs ....


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      Last update: 2006-02-23 03:39    [W:0.019 / U:64.488 seconds]
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