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    SubjectRe: avoiding pci_disable_device()...
    On Sun, Feb 13, 2005 at 08:42:55PM -0500, Jeff Garzik wrote:
    >
    > Currently, in almost every PCI driver, if pci_request_regions() fails --
    > indicating another driver is using the hardware -- then
    > pci_disable_device() is called on the error path, disabling a device
    > that another driver is using
    >
    > To call this "rather rude" is an understatement :)
    >
    > Fortunately, the ugliness is mitigated in large part by the PCI layer
    > helping to make sure that no two drivers bind to the same PCI device.
    > Thus, in the vast majority of cases, pci_request_regions() -should- be
    > guaranteed to succeed.
    >
    > However, there are oddball cases like mixed PCI/ISA devices (hello IDE)
    > or cases where a driver refers a pci_dev other than the primary, where
    > pci_request_regions() and request_regions() still matter.

    But this is a very small subset of pci devices, correct?

    > As a result, I have committed the attached patch to libata-2.6. In many
    > cases, it is a "semantic fix", addressing the case
    >
    > * pci_request_regions() indicates hardware is in use
    > * we rudely disable the in-use hardware
    >
    > that would not occur in practice.
    >
    > But better safe than sorry. Code cuts cut-n-pasted all over the place.
    >
    > I'm hoping one or two things will happen now:
    > * janitors fix up the other PCI drivers along these lines
    > * improve the PCI API so that pci_request_regions() is axiomatic

    Do you have any suggestions for how to do this?

    thanks,

    greg k-h
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