From patchwork Tue Jan 8 16:52:21 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v3,2/6] PCI: split registration of PCI bus devices into two stages From: Jiang Liu X-Patchwork-Id: 210441 Message-Id: <1357663945-16054-3-git-send-email-jiang.liu@huawei.com> To: Bjorn Helgaas Cc: Jiang Liu , "Rafael J . Wysocki" , Yijing Wang , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Yinghai Lu Date: Wed, 9 Jan 2013 00:52:21 +0800 When handling BUS_NOTIFY_ADD_DEVICE event for a PCI bridge device, the notification handler can't hold reference count to the new PCI bus because the device object for the new bus (pci_dev->subordinate->dev) hasn't been initialized yet. Split the registration of PCI bus device into two stages as below, so that the event handler could hold reference count to the new PCI bus when handling BUS_NOTIFY_ADD_DEVICE event. 1) device_initialize(&pci_dev->dev) 2) device_initialize(&pci_dev->subordinate->dev) 3) notify BUS_NOTIFY_ADD_DEVICE event for pci_dev 4) device_add(&pci_dev->dev) 5) device_add(&pci_dev->subordinate->dev) Signed-off-by: Jiang Liu Signed-off-by: Yinghai Lu Acked-by: Rafael J. Wysocki --- drivers/pci/bus.c | 2 +- drivers/pci/probe.c | 4 +++- drivers/pci/remove.c | 10 +++++----- 3 files changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index ad6a8b6..2fea481 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -198,7 +198,7 @@ int pci_bus_add_child(struct pci_bus *bus) if (bus->bridge) bus->dev.parent = bus->bridge; - retval = device_register(&bus->dev); + retval = device_add(&bus->dev); if (retval) return retval; diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index e557d6f..a8315c2 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -642,6 +642,7 @@ static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent, */ child->dev.class = &pcibus_class; dev_set_name(&child->dev, "%04x:%02x", pci_domain_nr(child), busnr); + device_initialize(&child->dev); /* * Set up the primary, secondary and subordinate @@ -1678,7 +1679,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus, b->dev.class = &pcibus_class; b->dev.parent = b->bridge; dev_set_name(&b->dev, "%04x:%02x", pci_domain_nr(b), bus); - error = device_register(&b->dev); + device_initialize(&b->dev); + error = device_add(&b->dev); if (error) goto class_dev_reg_err; diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index fc38c48..a1fdd0f 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -48,11 +48,11 @@ void pci_remove_bus(struct pci_bus *bus) list_del(&bus->node); pci_bus_release_busn_res(bus); up_write(&pci_bus_sem); - if (!bus->is_added) - return; - - pci_remove_legacy_files(bus); - device_unregister(&bus->dev); + if (bus->is_added) { + pci_remove_legacy_files(bus); + device_del(&bus->dev); + } + put_device(&bus->dev); } EXPORT_SYMBOL(pci_remove_bus);