On Wed, Sep 04, 2019 at 07:35:23AM +0200, Lukas Wunner wrote: > On Tue, Sep 03, 2019 at 10:36:35PM -0600, Kelsey Skunberg wrote: > > Change pci_dev_is_disconnected() call inside pci_dev_is_inaccessible() to: > > > > pdev->error_state == pci_channel_io_perm_failure > > > > Change remaining pci_dev_is_disconnected() calls to > > pci_dev_is_inaccessible() calls. > > I don't think that's a good idea because it introduces a config space read > (for the vendor ID) in places where we don't want that. E.g., after the > check of pdev->error_state, a regular config space read may take place and > if that returns all ones, we may already be able to determine that the > device is inaccessible, obviating the need for a vendor ID check. > Config space reads aren't for free. > > Thanks, > > Lukas Good note. I definitely see why that would be undesirable. Thanks for taking the time to point this out, Lukas. I'll look this over again to see if a better solution can be done, or as Bjorn suggested, at least see if clarification on when to use one vs. the other can be included. Thanks again! -Kelsey
