Messages in this thread | | | Date | Mon, 14 Feb 2005 14:54:56 -0500 | From | Jeff Garzik <> | Subject | Re: avoiding pci_disable_device()... |
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Takashi Iwai wrote: > At Mon, 14 Feb 2005 11:34:13 -0800, > Greg KH wrote: > >>On Mon, Feb 14, 2005 at 08:24:29PM +0100, Takashi Iwai wrote: >> >>>At Mon, 14 Feb 2005 11:06:19 -0800, >>>Greg KH wrote: >>> >>>>>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? >>> >>>How about to add an exclusiveness check in pci_enable_device()? >>>Most drivers suppose that the given pci resources are exclusively >>>available. >> >>You mean only allow pci_enable_device() to work for the first caller of >>it? I don't see how that would help this issue out. > > > Well, for example, add a new pointer to indicate the driver accessing > exclusively. And pci_enable_device() (maybe a new variant would be > better for compatibility) checks whether this is free. > > The second caller wouldn't reach even to pci_request_regions() because > of this check. So, no side-effect of pci_disable_device() in the > error path.
This doesn't work with a driver that is properly using request_resource(), but not using the PCI API.
Jeff
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