From patchwork Mon Jun 4 05:16:58 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiang Liu X-Patchwork-Id: 162620 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id ACBDAB6FF5 for ; Mon, 4 Jun 2012 15:17:52 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756395Ab2FDFR0 (ORCPT ); Mon, 4 Jun 2012 01:17:26 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:40905 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755913Ab2FDFRZ (ORCPT ); Mon, 4 Jun 2012 01:17:25 -0400 Received: from huawei.com (szxga05-in [172.24.2.49]) by szxga05-in.huawei.com (iPlanet Messaging Server 5.2 HotFix 2.14 (built Aug 8 2006)) with ESMTP id <0M5200M81UQBDA@szxga05-in.huawei.com>; Mon, 04 Jun 2012 13:18:11 +0800 (CST) Received: from szxrg01-dlp.huawei.com ([172.24.2.119]) by szxga05-in.huawei.com (iPlanet Messaging Server 5.2 HotFix 2.14 (built Aug 8 2006)) with ESMTP id <0M5200FPVUQBSR@szxga05-in.huawei.com>; Mon, 04 Jun 2012 13:18:11 +0800 (CST) Received: from 172.24.2.119 (EHLO szxeml212-edg.china.huawei.com) ([172.24.2.119]) by szxrg01-dlp.huawei.com (MOS 4.1.9-GA FastPath queued) with ESMTP id AJP93111; Mon, 04 Jun 2012 13:17:19 +0800 (CST) Received: from SZXEML405-HUB.china.huawei.com (10.82.67.60) by szxeml212-edg.china.huawei.com (172.24.2.181) with Microsoft SMTP Server (TLS) id 14.1.323.3; Mon, 04 Jun 2012 13:17:22 +0800 Received: from localhost (10.107.208.49) by szxeml405-hub.china.huawei.com (10.82.67.60) with Microsoft SMTP Server id 14.1.323.3; Mon, 04 Jun 2012 13:17:10 +0800 Date: Mon, 04 Jun 2012 13:16:58 +0800 From: Jiang Liu Subject: [RFC PATCH v1 2/6] PCI: split PCI bus device registration into two stages In-reply-to: <1338787022-400-1-git-send-email-jiang.liu@huawei.com> X-Originating-IP: [10.107.208.49] To: Bjorn Helgaas , Yinghai Lu , Kenji Kaneshige Cc: Jiang Liu , Taku Izumi , Don Dutile , Greg KH , Yijing Wang , Keping Chen , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Message-id: <1338787022-400-2-git-send-email-jiang.liu@huawei.com> MIME-version: 1.0 X-Mailer: git-send-email 1.7.8.msysgit.0 Content-type: text/plain Content-transfer-encoding: 7BIT X-CFilter-Loop: Reflected References: <1338787022-400-1-git-send-email-jiang.liu@huawei.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Jiang Liu When handling BUS_NOTIFY_ADD_DEVICE event for a new 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 PCI bus device registration into two stages as below, so that the event handler could hold reference counts 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 --- drivers/pci/bus.c | 2 +- drivers/pci/probe.c | 1 + drivers/pci/remove.c | 10 +++++----- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 4ce5ef2..e2a0c52 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -187,7 +187,7 @@ 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 dacca26..47ffa6c 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -667,6 +667,7 @@ struct pci_bus *__ref pci_add_new_bus(struct pci_bus *parent, struct pci_dev *de down_write(&pci_bus_sem); list_add_tail(&child->node, &parent->children); up_write(&pci_bus_sem); + device_initialize(&child->dev); } return child; } diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index 6c07bc5..edbd117 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -70,11 +70,11 @@ void pci_remove_bus(struct pci_bus *pci_bus) list_del(&pci_bus->node); pci_bus_release_busn_res(pci_bus); up_write(&pci_bus_sem); - if (!pci_bus->is_added) - return; - - pci_remove_legacy_files(pci_bus); - device_unregister(&pci_bus->dev); + if (pci_bus->is_added) { + pci_remove_legacy_files(pci_bus); + device_del(&pci_bus->dev); + } + put_device(&pci_bus->dev); } EXPORT_SYMBOL(pci_remove_bus);