On Sun, Dec 29, 2013 at 12:20:22AM +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > > The device_del(&host_bridge->dev) in pci_stop_root_bus() is > problematic, because it causes all sysfs directories below > the host bridge to be removed recursively and when > pci_remove_root_bus() attempts to remove devices on the root > bus (whose sysfs directories are gone now along with all their > subdirectories), it causes warnings similar to this one to be > printed: > > WARNING: CPU: 0 PID: 6 at fs/sysfs/group.c:214 sysfs_remove_group+0xc6/0xd0() > sysfs group ffffffff819ac5c0 not found for kobject '0001:ff:10.2' > Modules linked in: <irrelevant list> > CPU: 0 PID: 6 Comm: kworker/u512:0 Tainted: G W 3.13.0-rc5+ #11 > Hardware name: > Workqueue: kacpi_hotplug acpi_hotplug_work_fn > 0000000000000009 ffff8808738d3bd8 ffffffff815d84ea ffff8808738d3c20 > ffff8808738d3c10 ffffffff8106594d 0000000000000000 ffffffff819ac5c0 > ffff880871b9d0a8 ffff8a07d1895000 0000000000000103 ffff8808738d3c70 > Call Trace: > [<ffffffff815d84ea>] dump_stack+0x45/0x56 > [<ffffffff8106594d>] warn_slowpath_common+0x7d/0xa0 > [<ffffffff810659bc>] warn_slowpath_fmt+0x4c/0x50 > [<ffffffff8122b52e>] ? sysfs_get_dirent_ns+0x4e/0x70 > [<ffffffff8122c806>] sysfs_remove_group+0xc6/0xd0 > [<ffffffff813b83f3>] dpm_sysfs_remove+0x43/0x50 > [<ffffffff813ae105>] device_del+0x45/0x1c0 > [<ffffffff812e51f6>] pci_remove_bus_device+0x66/0xd0 > [<ffffffff812e5363>] pci_remove_root_bus+0x73/0x80 > [<ffffffff813276ab>] acpi_pci_root_remove+0x42/0x4f > [<ffffffff81323070>] acpi_bus_trim+0x56/0x89 > [<ffffffff81323052>] acpi_bus_trim+0x38/0x89 > [<ffffffff813245df>] acpi_device_hotplug+0x137/0x33b > [<ffffffff8131efba>] acpi_hotplug_work_fn+0x1c/0x27 > [<ffffffff81080f1b>] process_one_work+0x17b/0x460 > [<ffffffff81081ccb>] worker_thread+0x11b/0x400 > [<ffffffff81081bb0>] ? rescuer_thread+0x3e0/0x3e0 > [<ffffffff81088a12>] kthread+0xd2/0xf0 > [<ffffffff81088940>] ? kthread_create_on_node+0x180/0x180 > [<ffffffff815e823c>] ret_from_fork+0x7c/0xb0 > [<ffffffff81088940>] ? kthread_create_on_node+0x180/0x180 > > To avoid that, the host bridge device has to be deleted after all of > its children, so merge pci_stop_root_bus() and pci_remove_root_bus() > into one function, pci_stop_and_remove_root_bus(), that first will > use pci_stop_and_remove_bus_device() to stop and remove all devices > on the root bus and then will delete the host bridge device, remove > its bus and drop the final reference to it. > > Reported-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > --- > > Hi, > > I can't really test this patch, but I don't know how it can break anything. > > The only user of pci_stop_root_bus() and pci_remove_root_bus() is > acpi_pci_root_remove() and the code ordering there seems to be somewhat > arbitrary. If you are aware of any reason why it may not work, please let > me know. :-) Acked-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> -- 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
