On Wed, Jun 12, 2013 at 12:20 AM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: > On Tue, Apr 2, 2013 at 1:10 PM, Bjorn Helgaas <bhelgaas@xxxxxxxxxx> wrote: >> On Mon, Apr 1, 2013 at 6:03 PM, Yinghai Lu <yinghai@xxxxxxxxxx> wrote: >>>> commit 96e5d01cd536458435ef0678d9fa3dc542afb41f >>>> Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> >>>> Date: Mon Apr 1 15:47:39 2013 -0600 >>>> >>>> Revert "PCI/ACPI: Request _OSC control before scanning PCI root bus" >>>> >>>> This reverts commit 8c33f51df406e1a1f7fa4e9b244845b7ebd61fa6. >>>> >>>> Conflicts: >>>> drivers/acpi/pci_root.c >>>> >>>> Reference: https://bugzilla.kernel.org/show_bug.cgi?id=55211 >>>> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> >>> >>> Acked-by: Yinghai Lu <yinghai@xxxxxxxxxx> >>> >>> stable need this reverting too. >> >> I updated the changelog and added this to my for-linus branch, headed for v3.9. > > We may need to revert this reverting for 3.10. > > Today noticed that acpiphp jump in before pciehp on one setup. > > current code from acpi_pci_root_add we have > 1. pci_acpi_scan_root > ==> pci devices enumeration and bus scanning. > ==> pci_alloc_child_bus > ==> pcibios_add_bus > ==> acpi_pci_add_bus > ==> acpiphp_enumerate_slots > ==> ...==> register_slot > ==> device_is_managed_by_native_pciehp > ==> check osc_set with > OSC_PCI_EXPRESS_NATIVE_HP_CONTROL > 2. _OSC set request > > so we always have acpiphp hotplug slot registered at first. > > so either we need to > A. revert reverting about _OSC > B. move pcibios_add_bus down to pci_bus_add_devices() > as acpiphp and apci pci slot driver are some kind of drivers for pci_bus > C. A+B It doesn't surprise me at all that there are problems in the _OSC code and the acpiphp/pciehp interaction. That whole area is a complete disaster. It'd really be nice if somebody stepped up and reworked it so it makes sense. But this report is useless to me. I don't have time to work out what the problem is and how it affects users and come up with a fix. My advice is to simplify the path first, and worry about fixing the bug afterwards. We've already done several iterations of fiddling with things, and I think all we're doing is playing "whack-a-mole" and pushing the bugs around from one place to another. Bjorn -- 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
