On Thursday, January 30, 2014 03:39:02 PM Yinghai Lu wrote: > On Thu, Jan 30, 2014 at 3:39 PM, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote: > > On Thursday, January 30, 2014 08:56:05 AM Yinghai Lu wrote: > >> > >> --047d7b5d2ea4eb937804f132eedf > >> Content-Type: text/plain; charset=ISO-8859-1 > >> > >> >> The latest mainline kernel "hangs" when Thunderbolt devices are > >> >> hot-unplugged to the system. I can't see any oops but after hot-unplug I'm > >> >> getting huge amounts of messages like: > >> >> > >> >> [ 352.717001] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717011] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717021] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717032] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717041] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717051] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717061] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717070] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717083] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717094] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717104] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717113] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717124] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717133] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717143] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717153] pci 0000:02:00.0: PME# disabled > >> >> [ 352.717162] pci 0000:02:00.0: PME# disabled > >> > > >> > that mean pci_stop_dev() get called again and again ? > >> > >> please check if attached patch could help. > > > > Well, it looks like what happens is an endless loop in > > acpiphp_glue.c:disable_slot(). > > > > dev_in_slot() returns the first device in the list, so > > pci_stop_and_remove_bus_device() is called for it, but it > > doesn't remove the device from bus->devices any more, so > > dev_in_slot() will return the same device next time and > > so on forever. > > > ... > > > > So the above won't help in my opinion. > > > > I wonder, however, if this patch helps instead: > > > > https://patchwork.kernel.org/patch/3540701/ > > > > I thought it would be 3.15 material, but it very well can go in earlier if > > it happens to address this particular problem. > > Agree, that should fix the problem. > > but please use list_for_each_entry_safe_reverse > instead. > > please refer to pciehp changelog in > > commit 29ed1f29b68a8395d5679b3c4e38352b617b3236 > Author: Yinghai Lu <yinghai@xxxxxxxxxx> > Date: Fri Jul 19 12:14:16 2013 -0700 > > PCI: pciehp: Fix null pointer deref when hot-removing SR-IOV device > > Hot-removing a device with SR-IOV enabled causes a null pointer dereference > in v3.9 and v3.10. > > This is a regression caused by ba518e3c17 ("PCI: pciehp: Iterate over all > devices in slot, not functions 0-7"). When we iterate over the > bus->devices list, we first remove the PF, which also removes all the VFs > from the list. Then the list iterator blows up because more than just the > current entry was removed from the list. > > ac205b7bb7 ("PCI: make sriov work with hotplug remove") works around a > similar problem in pci_stop_bus_devices() by iterating over the list in > reverse, so the VFs are stopped and removed from the list first, before the > PF. > > This patch changes pciehp_unconfigure_device() to iterate over the list in > reverse, too. > > [bhelgaas: bugzilla, changelog] > Reference: https://bugzilla.kernel.org/show_bug.cgi?id=60604 So I gather all of bus->devices list walks during which devices may be removed should be done in the reverse order, right? -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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
