On Tue, Oct 10, 2017 at 10:01:35AM +0100, Alan Cox wrote: > > Your concern was that a quirk would require a long list of device IDs > > and we'd have to add new ones. I share that concern, > > I'm not sure I do. The bus topology tells you what is on die, and the > id of the root bridge tells you if it's one of the parts you can do > this. Your a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2") added the most generic version (pci_d3_delay_fixup() uses DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_d3_delay_fixup); so there's no list of device IDs. If this is really a property of the family (BYT/CHT/etc), it makes sense to me to do it that way, but if you think it's better to have a list, that's OK too. The more interesting question to me is whether the quirk should be in an optional driver or in the always-present arch code. My assumption is that putting it in the driver means that if the driver isn't enabled, we're doing unnecessary delays. Bjorn