From patchwork Sun Sep 16 13:16:01 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiang Liu X-Patchwork-Id: 184129 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 52DE62C0080 for ; Sun, 16 Sep 2012 23:19:57 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750980Ab2IPNSh (ORCPT ); Sun, 16 Sep 2012 09:18:37 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:37761 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750930Ab2IPNSg (ORCPT ); Sun, 16 Sep 2012 09:18:36 -0400 Received: by pbbrr13 with SMTP id rr13so7791089pbb.19 for ; Sun, 16 Sep 2012 06:18:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=x+d4vvJ83XJxshpOhxbHvGOWnnztsI5H4jaoZPh3NPQ=; b=bX+Kj/Ag2MM408b0MgbqodHPr58ioddj5xt/v4c8zZBC6trZLmzC/MqQ8k1goWE6B0 v+7eC/CJF81hwWHfcD+oD1ftle8IJEa7X/LSGYfFAKO2FPm451tUSCynrOTVSm3h2FrD fBBDMLiC+PbePZSFMYcC12S5hHdYRU8ZDAPhYe4VciYurKb7K5zaNhOmhu4QBIBHD14x 6Vk+XKAsO8Pf1s6Z9baWpYkXqpgwu/FCR1eNQt6Yl0788433yZwLrIiTqqSqb4QiVwzE bBnOEy24pw8GzZlLoFpmnApqAGMKRUJTNqDfmmdssXXeSGyDYXas+baT8Ldy7l///+6v eKkg== Received: by 10.68.241.226 with SMTP id wl2mr15979278pbc.62.1347801516343; Sun, 16 Sep 2012 06:18:36 -0700 (PDT) Received: from localhost.localdomain ([221.221.18.122]) by mx.google.com with ESMTPS id pw9sm4998226pbb.42.2012.09.16.06.18.27 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 16 Sep 2012 06:18:35 -0700 (PDT) From: Jiang Liu To: Bjorn Helgaas Cc: Jiang Liu , Yinghai Lu , Kenji Kaneshige , Yijing Wang , Jiang Liu , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: [PATCH v3] PCI: split registration of PCI bus devices into two stages Date: Sun, 16 Sep 2012 21:16:01 +0800 Message-Id: <1347801361-18565-1-git-send-email-jiang.liu@huawei.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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 --- V2->V3 Fix a failing in error recover path according to Yinghai's suggestion. --- 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 4b0970b..11a5c28 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -189,7 +189,7 @@ 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 5dbad03..7ef8c1b 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -639,6 +639,7 @@ 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 @@ -1672,7 +1673,8 @@ 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 37b9407..86a4636 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);