On Friday, January 31, 2014 12:53:01 PM Mika Westerberg wrote: > On Fri, Jan 31, 2014 at 01:38:42AM +0100, Rafael J. Wysocki wrote: > > On Friday, January 31, 2014 12:59:06 AM Rafael J. Wysocki wrote: > > > 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. > > > > > > OK, I will. > > > > Mika, below is an updated patch to try. > > > > --- > > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > Subject: ACPI / hotplug / PCI: Simplify disable_slot() > > > > After recent PCI core changes related to the rescan/remove locking, > > the ACPIPHP's disable_slot() function is only called under the > > general PCI rescan/remove lock, so it doesn't have to use > > dev_in_slot() any more to avoid race conditions. Make it simply > > walk the devices on the bus and drop the ones in the slot being > > disabled and drop dev_in_slot() which has no more users. > > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > Thanks for the fix. > > Unfortunately, it now crashes here after I re-plug the TBT chain (I have > both of your patches applied): > > int sysfs_create_bin_file(struct kobject *kobj, > const struct bin_attribute *attr) > { > BUG_ON(!kobj || !kobj->sd || !attr); <-- > > Since I don't have proper serial console to that machine, all I see is the > end of the backtrace :-( > > Here is a hand copied backtrace from the screen: > > pci_create_sysfs_dev_files() > pci_bus_add_device() > pci_bus_add_devices() > enable_slot() > acpiphp_check_bridge() > hotplug_event() > ... So I think what happens is that we leak the struct pci_dev during removal and the proper cleanup is never done. Can you please add a debug printk into pci_release_dev() and see if that's ever called after TBT unplug? -- 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
