On Mon, Sep 09, 2013 at 10:15:07AM -0600, Bjorn Helgaas wrote: >On Mon, Sep 9, 2013 at 1:00 AM, Wei Yang <weiyang@xxxxxxxxxxxxxxxxxx> wrote: >> On Fri, Sep 06, 2013 at 05:09:41PM -0600, Bjorn Helgaas wrote: >>>[+cc Kenji, Alex] >>> >>>Did you trip over a case where a root bus has bus->self != NULL? >>>I'd like to know more details about the case where: >>> >>> (bus->parent == NULL) && (bus->self != NULL) >> >> I found one case that (bus->self == NULL) and this bus is not root bus. >> >> Not sure, this case will meet your requirement? > >I'm definitely interested in that case as well. Can you include a >complete "lspci -vv" output for the case where this happens? I don't *see* it. I notice this during the code reading. So yes, this happens when a virtual bus is created for SR-IOV. Sounds this is the *only* case for (bus->self == NULl)? >I suspect this happens with SR-IOV when we create "virtual" buses, >i.e., in virtfn_add_bus(). I think maybe I'll update the comment at >pci_is_root_bus() with a note about why we want to use it instead of >testing for "bus->self == NULL". > >I think we still have other tree traversal issues related to those >virtual buses, e.g., the ones I mentioned here [1]. But those are a >separate problem. > >Bjorn > >[1] http://lkml.kernel.org/r/CAErSpo5sFfr=O-Pp=PyaxGauaEajaTr2aK-EQ_rTVUk1zyz8cA@xxxxxxxxxxxxxx Here comes another problem I met recently. On some platforms, like powernv, each pci-dev has a dev-tree node to represent it. The dev-tree node is set by pci_set_of_node() during pci_scan_device(). In pci_set_of_node(), it searchs for the node with the same devfn in its parent. Here comes the question, who should be the VF's parent. Would be a conflict for the devfn between PF and VF? -- Richard Yang Help you, Help me -- 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
