On Tue, 2015-06-23 at 18:02 -0500, Bjorn Helgaas wrote: > On Tue, Jun 23, 2015 at 5:46 PM, Benjamin Herrenschmidt > <benh@xxxxxxxxxxxxxxxxxxx> wrote: > > On Tue, 2015-06-02 at 15:55 +0100, Lorenzo Pieralisi wrote: > >> While at it, do you think it is reasonable to also claim the bridge > >> windows (resources) in the respective pci_read_bridge_* calls ? > > > > No, don't claim in read. There's a clear distinction between gathering > > resources and claiming them, and we need to keep that. > > > > Some fixups might happen in between the two for example. > > Are there any existing fixups like that? Concrete examples would help > figure out the best way forward. Not off the top of my mind, it's been a long time since I wrote the resource claiming stuff in arch/powerpc but it does make me nervous. We collect resources when probing and we claim in the survey, those have been historically very distinct steps. > Most arches call pci_read_bridge_bases() from pcibios_fixup_bus(). I > think that's a poor place to do it because it's code that normally > doesn't have to be arch-specific. Resource claiming is also usually > done from arch code, and it shouldn't be arch-specific either. Claiming as in putting in the resource tree etc... is different from actually reading the values from the HW and is traditionally done much later, no ? > If we move both the read and claim into generic code, then we might > need to make sure there's a fixup phase in between or something. Well, then there's a more general argument to be made as to whether we want the claiming to be "merged" as part of the probing/reading I suppose... Then there's also the case where everything gets fully reassigned, like powernv, where the "read" phase is really only about sizing device BARs... Cheers, Ben. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
