| Message ID | 37552283.kG1L4S8Daa@vostro.rjw.lan |
|---|---|
| State | Not Applicable |
| Headers | show |
On Sun, Dec 29, 2013 at 12:20:22AM +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > 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@jp.fujitsu.com> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > > 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@linuxfoundation.org> -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sat, Dec 28, 2013 at 3:20 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > 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@jp.fujitsu.com> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > > 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. :-) > > Thanks, > Rafael > > --- > drivers/acpi/pci_root.c | 4 +--- > drivers/pci/remove.c | 23 ++++------------------- > include/linux/pci.h | 3 +-- > 3 files changed, 6 insertions(+), 24 deletions(-) > > Index: linux-pm/drivers/acpi/pci_root.c > =================================================================== > --- linux-pm.orig/drivers/acpi/pci_root.c > +++ linux-pm/drivers/acpi/pci_root.c > @@ -611,12 +611,10 @@ static void acpi_pci_root_remove(struct > { > struct acpi_pci_root *root = acpi_driver_data(device); > > - pci_stop_root_bus(root->bus); > - > device_set_run_wake(root->bus->bridge, false); > pci_acpi_remove_bus_pm_notifier(device); > > - pci_remove_root_bus(root->bus); > + pci_stop_and_remove_root_bus(root->bus); > > kfree(root); > } We have patches that need to stop ioapic and iommu between pci_stop_root_bus and pci_remove_root_bus. Please check if the problem still happen after http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=c4a0a5d964e90b93eb4101c3927b788e083e530f http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=e3b439e1d315aff59c1b4f0fc43c5cd2d82b4138 or just try: git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git pci/deletion Thanks Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sunday, December 29, 2013 07:30:18 PM Yinghai Lu wrote: > On Sat, Dec 28, 2013 at 3:20 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > > > 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@jp.fujitsu.com> > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > --- > > > > 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. :-) > > > > Thanks, > > Rafael > > > > --- > > drivers/acpi/pci_root.c | 4 +--- > > drivers/pci/remove.c | 23 ++++------------------- > > include/linux/pci.h | 3 +-- > > 3 files changed, 6 insertions(+), 24 deletions(-) > > > > Index: linux-pm/drivers/acpi/pci_root.c > > =================================================================== > > --- linux-pm.orig/drivers/acpi/pci_root.c > > +++ linux-pm/drivers/acpi/pci_root.c > > @@ -611,12 +611,10 @@ static void acpi_pci_root_remove(struct > > { > > struct acpi_pci_root *root = acpi_driver_data(device); > > > > - pci_stop_root_bus(root->bus); > > - > > device_set_run_wake(root->bus->bridge, false); > > pci_acpi_remove_bus_pm_notifier(device); > > > > - pci_remove_root_bus(root->bus); > > + pci_stop_and_remove_root_bus(root->bus); > > > > kfree(root); > > } > > > We have patches that need to stop ioapic and iommu between > pci_stop_root_bus and pci_remove_root_bus. > > Please check if the problem still happen after > > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=c4a0a5d964e90b93eb4101c3927b788e083e530f > > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=e3b439e1d315aff59c1b4f0fc43c5cd2d82b4138 The second one should fix the problem. Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Monday, December 30, 2013 01:51:28 PM Rafael J. Wysocki wrote: > On Sunday, December 29, 2013 07:30:18 PM Yinghai Lu wrote: > > On Sat, Dec 28, 2013 at 3:20 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > > > > > 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@jp.fujitsu.com> > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > > --- > > > > > > 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. :-) > > > > > > Thanks, > > > Rafael > > > > > > --- > > > drivers/acpi/pci_root.c | 4 +--- > > > drivers/pci/remove.c | 23 ++++------------------- > > > include/linux/pci.h | 3 +-- > > > 3 files changed, 6 insertions(+), 24 deletions(-) > > > > > > Index: linux-pm/drivers/acpi/pci_root.c > > > =================================================================== > > > --- linux-pm.orig/drivers/acpi/pci_root.c > > > +++ linux-pm/drivers/acpi/pci_root.c > > > @@ -611,12 +611,10 @@ static void acpi_pci_root_remove(struct > > > { > > > struct acpi_pci_root *root = acpi_driver_data(device); > > > > > > - pci_stop_root_bus(root->bus); > > > - > > > device_set_run_wake(root->bus->bridge, false); > > > pci_acpi_remove_bus_pm_notifier(device); > > > > > > - pci_remove_root_bus(root->bus); > > > + pci_stop_and_remove_root_bus(root->bus); > > > > > > kfree(root); > > > } > > > > > > We have patches that need to stop ioapic and iommu between > > pci_stop_root_bus and pci_remove_root_bus. BTW, what *exactly* do they need to be stopped between? After these two patches: > > Please check if the problem still happen after > > > > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=c4a0a5d964e90b93eb4101c3927b788e083e530f > > > > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=e3b439e1d315aff59c1b4f0fc43c5cd2d82b4138 pci_stop_root_bus() is just a walk over devices on the root bus stopping them and pci_remove_root_bus() starts with the removal of those devices. Surely, those two list walks can be combined into one? Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Dec 30, 2013 at 5:15 AM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > On Monday, December 30, 2013 01:51:28 PM Rafael J. Wysocki wrote: >> > We have patches that need to stop ioapic and iommu between >> > pci_stop_root_bus and pci_remove_root_bus. > > BTW, what *exactly* do they need to be stopped between? After these two patches: need to stop regular pci drivers before stop "driver" for ioapic/dmar. > >> > Please check if the problem still happen after >> > >> > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=c4a0a5d964e90b93eb4101c3927b788e083e530f >> > >> > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=e3b439e1d315aff59c1b4f0fc43c5cd2d82b4138 > > pci_stop_root_bus() is just a walk over devices on the root bus stopping > them and pci_remove_root_bus() starts with the removal of those devices. > > Surely, those two list walks can be combined into one? maybe ok, but we have to problem to make sure stop pci drivers before "driver" for ioapic/dmar. also stop all first and remove all make it much cleaner. and add path is two steps too. Add them all, and then attach driver for all. Thanks Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tuesday, December 31, 2013 10:45:46 AM Yinghai Lu wrote: > On Mon, Dec 30, 2013 at 5:15 AM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > On Monday, December 30, 2013 01:51:28 PM Rafael J. Wysocki wrote: > >> > We have patches that need to stop ioapic and iommu between > >> > pci_stop_root_bus and pci_remove_root_bus. > > > > BTW, what *exactly* do they need to be stopped between? After these two patches: > > need to stop regular pci drivers before stop "driver" for ioapic/dmar. > > > > >> > Please check if the problem still happen after > >> > > >> > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=c4a0a5d964e90b93eb4101c3927b788e083e530f > >> > > >> > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=e3b439e1d315aff59c1b4f0fc43c5cd2d82b4138 > > > > pci_stop_root_bus() is just a walk over devices on the root bus stopping > > them and pci_remove_root_bus() starts with the removal of those devices. > > > > Surely, those two list walks can be combined into one? > > maybe ok, but we have to problem to make sure stop pci drivers before > "driver" for ioapic/dmar. That's fine, but ioapic/dmar stopping need not happen between the stopping of drivers and removing of devices on the root bus I suppose? Actually, I think that the ioapic/dmar stopping should be carried out after removing all of the root bus devices, or it can be racy with respect to a driver reload. Isn't that the case? > also stop all first and remove all make it much cleaner. Well, I don't think that's worth special casing, though, because device removal may be triggered via sysfs anyway for any PCI device. In my opinion it would be cleaner to use pci_stop_and_remove_bus_device() everywhere for PCI device removal. > and add path is two steps too. Add them all, and then attach driver for all. The removal need not mirror the probing ... Thanks, Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Dec 31, 2013 at 1:03 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > On Tuesday, December 31, 2013 10:45:46 AM Yinghai Lu wrote: >> On Mon, Dec 30, 2013 at 5:15 AM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: >> > On Monday, December 30, 2013 01:51:28 PM Rafael J. Wysocki wrote: >> >> > We have patches that need to stop ioapic and iommu between >> >> > pci_stop_root_bus and pci_remove_root_bus. >> > >> > BTW, what *exactly* do they need to be stopped between? After these two patches: >> >> need to stop regular pci drivers before stop "driver" for ioapic/dmar. >> >> > >> >> > Please check if the problem still happen after >> >> > >> >> > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=c4a0a5d964e90b93eb4101c3927b788e083e530f >> >> > >> >> > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=e3b439e1d315aff59c1b4f0fc43c5cd2d82b4138 >> > >> > pci_stop_root_bus() is just a walk over devices on the root bus stopping >> > them and pci_remove_root_bus() starts with the removal of those devices. >> > >> > Surely, those two list walks can be combined into one? >> >> maybe ok, but we have to problem to make sure stop pci drivers before >> "driver" for ioapic/dmar. > > That's fine, but ioapic/dmar stopping need not happen between the stopping of > drivers and removing of devices on the root bus I suppose? > > Actually, I think that the ioapic/dmar stopping should be carried out after > removing all of the root bus devices, or it can be racy with respect to a > driver reload. Isn't that the case? No. It should be before removing all root bus devices. as they need to access the pci devices during stop ioapic and dmar. Also ioapic itself could one one pci device. Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thursday, January 02, 2014 02:47:04 PM Yinghai Lu wrote: > On Tue, Dec 31, 2013 at 1:03 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > On Tuesday, December 31, 2013 10:45:46 AM Yinghai Lu wrote: > >> On Mon, Dec 30, 2013 at 5:15 AM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > >> > On Monday, December 30, 2013 01:51:28 PM Rafael J. Wysocki wrote: > >> >> > We have patches that need to stop ioapic and iommu between > >> >> > pci_stop_root_bus and pci_remove_root_bus. > >> > > >> > BTW, what *exactly* do they need to be stopped between? After these two patches: > >> > >> need to stop regular pci drivers before stop "driver" for ioapic/dmar. > >> > >> > > >> >> > Please check if the problem still happen after > >> >> > > >> >> > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=c4a0a5d964e90b93eb4101c3927b788e083e530f > >> >> > > >> >> > http://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/patch/?id=e3b439e1d315aff59c1b4f0fc43c5cd2d82b4138 > >> > > >> > pci_stop_root_bus() is just a walk over devices on the root bus stopping > >> > them and pci_remove_root_bus() starts with the removal of those devices. > >> > > >> > Surely, those two list walks can be combined into one? > >> > >> maybe ok, but we have to problem to make sure stop pci drivers before > >> "driver" for ioapic/dmar. > > > > That's fine, but ioapic/dmar stopping need not happen between the stopping of > > drivers and removing of devices on the root bus I suppose? > > > > Actually, I think that the ioapic/dmar stopping should be carried out after > > removing all of the root bus devices, or it can be racy with respect to a > > driver reload. Isn't that the case? > > No. It should be before removing all root bus devices. > as they need to access the pci devices during stop ioapic and dmar. > > Also ioapic itself could one one pci device. Well, if we stop drivers first, then stop ioapic/dmar and *then* remove devices, it is possible to rebind a driver to a device after ioapic/dmar has been stopped, which I guess will not lead to anything nice? Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Jan 2, 2014 at 4:45 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > On Thursday, January 02, 2014 02:47:04 PM Yinghai Lu wrote: >> >> No. It should be before removing all root bus devices. >> as they need to access the pci devices during stop ioapic and dmar. >> >> Also ioapic itself could one one pci device. > > Well, if we stop drivers first, then stop ioapic/dmar and *then* remove > devices, it is possible to rebind a driver to a device after ioapic/dmar has > been stopped, which I guess will not lead to anything nice? Not sure how that could happen. If it would really happen, we could set dev->match_driver to 0 in pci_stop_dev. Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Monday, January 06, 2014 11:28:43 AM Yinghai Lu wrote: > On Thu, Jan 2, 2014 at 4:45 PM, Rafael J. Wysocki <rjw@rjwysocki.net> wrote: > > On Thursday, January 02, 2014 02:47:04 PM Yinghai Lu wrote: > >> > >> No. It should be before removing all root bus devices. > >> as they need to access the pci devices during stop ioapic and dmar. > >> > >> Also ioapic itself could one one pci device. > > > > Well, if we stop drivers first, then stop ioapic/dmar and *then* remove > > devices, it is possible to rebind a driver to a device after ioapic/dmar has > > been stopped, which I guess will not lead to anything nice? > > Not sure how that could happen. > > If it would really happen, we could set dev->match_driver to 0 in pci_stop_dev. Simply, run "modprobe -r driver && modprobe driver" in a loop and remove the PCI host bridge the given device is on in parallel to that. Chances are, you'll see some nice breakage. Also what happens if somebody uses the "remove" sysfs attribute on a device needed by ioapic/dmar? Rafael -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: linux-pm/drivers/acpi/pci_root.c =================================================================== --- linux-pm.orig/drivers/acpi/pci_root.c +++ linux-pm/drivers/acpi/pci_root.c @@ -611,12 +611,10 @@ static void acpi_pci_root_remove(struct { struct acpi_pci_root *root = acpi_driver_data(device); - pci_stop_root_bus(root->bus); - device_set_run_wake(root->bus->bridge, false); pci_acpi_remove_bus_pm_notifier(device); - pci_remove_root_bus(root->bus); + pci_stop_and_remove_root_bus(root->bus); kfree(root); } Index: linux-pm/drivers/pci/remove.c =================================================================== --- linux-pm.orig/drivers/pci/remove.c +++ linux-pm/drivers/pci/remove.c @@ -114,7 +114,7 @@ void pci_stop_and_remove_bus_device(stru } EXPORT_SYMBOL(pci_stop_and_remove_bus_device); -void pci_stop_root_bus(struct pci_bus *bus) +void pci_stop_and_remove_root_bus(struct pci_bus *bus) { struct pci_dev *child, *tmp; struct pci_host_bridge *host_bridge; @@ -123,29 +123,14 @@ void pci_stop_root_bus(struct pci_bus *b return; host_bridge = to_pci_host_bridge(bus->bridge); - list_for_each_entry_safe_reverse(child, tmp, - &bus->devices, bus_list) - pci_stop_bus_device(child); + list_for_each_entry_safe_reverse(child, tmp, &bus->devices, bus_list) + pci_stop_and_remove_bus_device(child); /* stop the host bridge */ device_del(&host_bridge->dev); -} - -void pci_remove_root_bus(struct pci_bus *bus) -{ - struct pci_dev *child, *tmp; - struct pci_host_bridge *host_bridge; - - if (!pci_is_root_bus(bus)) - return; - - host_bridge = to_pci_host_bridge(bus->bridge); - list_for_each_entry_safe(child, tmp, - &bus->devices, bus_list) - pci_remove_bus_device(child); + /* remove the root bus */ pci_remove_bus(bus); host_bridge->bus = NULL; - /* remove the host bridge */ put_device(&host_bridge->dev); } Index: linux-pm/include/linux/pci.h =================================================================== --- linux-pm.orig/include/linux/pci.h +++ linux-pm/include/linux/pci.h @@ -779,8 +779,7 @@ struct pci_dev *pci_dev_get(struct pci_d void pci_dev_put(struct pci_dev *dev); void pci_remove_bus(struct pci_bus *b); void pci_stop_and_remove_bus_device(struct pci_dev *dev); -void pci_stop_root_bus(struct pci_bus *bus); -void pci_remove_root_bus(struct pci_bus *bus); +void pci_stop_and_remove_root_bus(struct pci_bus *bus); void pci_setup_cardbus(struct pci_bus *bus); void pci_sort_breadthfirst(void); #define dev_is_pci(d) ((d)->bus == &pci_bus_type)