From patchwork Tue Oct 2 06:33:00 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yinghai Lu X-Patchwork-Id: 188386 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 088EE2C0080 for ; Tue, 2 Oct 2012 16:33:14 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751912Ab2JBGdL (ORCPT ); Tue, 2 Oct 2012 02:33:11 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:31265 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753381Ab2JBGdK (ORCPT ); Tue, 2 Oct 2012 02:33:10 -0400 Received: from ucsinet21.oracle.com (ucsinet21.oracle.com [156.151.31.93]) by acsinet15.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id q926X49V012988 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 2 Oct 2012 06:33:05 GMT Received: from acsmt357.oracle.com (acsmt357.oracle.com [141.146.40.157]) by ucsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id q926X3kx000486 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 2 Oct 2012 06:33:04 GMT Received: from abhmt111.oracle.com (abhmt111.oracle.com [141.146.116.63]) by acsmt357.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id q926X3hj010987; Tue, 2 Oct 2012 01:33:03 -0500 Received: from linux-siqj.site (/75.36.244.44) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 01 Oct 2012 23:33:03 -0700 From: Yinghai Lu To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Yinghai Lu Subject: [PATCH 02/10] ACPI: use device drivers_autoprobe to delay loading acpi drivers Date: Mon, 1 Oct 2012 23:33:00 -0700 Message-Id: <1349159588-15029-3-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1349159588-15029-1-git-send-email-yinghai@kernel.org> References: <1349159588-15029-1-git-send-email-yinghai@kernel.org> X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Current acpi driver for pci_root is working like this way for hotplug: acpi try to enumberate acpi device and create acpi_device for pci_root and loading driver for it, and that drivers .add aka acpi_pci_root_add calls pci_acpi_scan_root to enumerate pci devices but not add those pci devices into device tree to prevent drivers for pci devices get probed. Later .start aka acpi_pci_root_start will call pci_bus_add_devices to add pci devices into the tree to make drivers for pci devices get attached or probed. The reason for that .add must get back for pci_root, so could create acpi_device for other pci_devices. otherwise adding the pci device tree early than acpi_device will cause binding for acpi/pci failing becuse pci_device can not find acpi_dev that is not created yet. booting path is working becasue driver for acpi driver is registered later, that means all acpi_device get created at first, and later when acpi_driver get registered, and .add get called, that probe pci devices, when pci devices is found, it could find acpi_device and binding will be ok, even pci_add_bus_devices in done in acpi_pci_root_add. That .start design is broken, and it will leave pci devices out of device tree for a while. We could use device drivers_autoprobe and acpi_bus_type notifier to control the process to make sure for hot adding path, will have all acpi_device get created, then attach acpi driver for acpi_device for pci_root. That will make the path more like booting path. After that we could remove the workaround .start in acpi driver ops. Signed-off-by: Yinghai Lu --- drivers/acpi/scan.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 47 insertions(+), 1 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 5dfec09..67785da 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1451,6 +1451,20 @@ static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops, return -ENODEV; } +static void acpi_bus_attach(struct acpi_device *dev) +{ + struct acpi_device *child; + int ret; + + ret = device_attach(&dev->dev); + /* make rescan working ? */ + dev->dev.drivers_autoprobe = true; + WARN_ON(ret < 0); + + list_for_each_entry(child, &dev->children, node) + acpi_bus_attach(child); +} + /* * acpi_bus_add and acpi_bus_start * @@ -1468,11 +1482,17 @@ acpi_bus_add(struct acpi_device **child, struct acpi_device *parent, acpi_handle handle, int type) { struct acpi_bus_ops ops; + int result; memset(&ops, 0, sizeof(ops)); ops.acpi_op_add = 1; - return acpi_bus_scan(handle, &ops, child); + result = acpi_bus_scan(handle, &ops, child); + + if (*child) + acpi_bus_attach(*child); + + return result; } EXPORT_SYMBOL(acpi_bus_add); @@ -1610,3 +1630,29 @@ int __init acpi_scan_init(void) return result; } + +static int acpi_hp_notifier(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct device *dev = data; + + switch (event) { + case BUS_NOTIFY_ADD_DEVICE: + dev->drivers_autoprobe = false; + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block acpi_hp_nb = { + .notifier_call = &acpi_hp_notifier, +}; + +static int __init acpi_hp_init(void) +{ + return bus_register_notifier(&acpi_bus_type, + &acpi_hp_nb); +} + +fs_initcall(acpi_hp_init);