Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932541Ab2JCXAk (ORCPT ); Wed, 3 Oct 2012 19:00:40 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:31232 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932453Ab2JCXAe (ORCPT ); Wed, 3 Oct 2012 19:00:34 -0400 From: Yinghai Lu To: Len Brown , Bjorn Helgaas , Greg Kroah-Hartman Cc: Andrew Morton , Linus Torvalds , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Yinghai Lu Subject: [PATCH 2/4] ACPI: use device drivers_autoprobe to delay loading acpi drivers Date: Wed, 3 Oct 2012 16:00:12 -0700 Message-Id: <1349305214-3241-3-git-send-email-yinghai@kernel.org> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1349305214-3241-1-git-send-email-yinghai@kernel.org> References: <1349305214-3241-1-git-send-email-yinghai@kernel.org> X-Source-IP: acsinet22.oracle.com [141.146.126.238] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3566 Lines: 117 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 | 46 +++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 45 insertions(+), 1 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index cbb3ed1..1bafa2d 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -1474,6 +1474,19 @@ 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; + + dev->drivers_autoprobe = true; + ret = device_attach(&dev->dev); + WARN_ON(ret < 0); + + list_for_each_entry(child, &dev->children, node) + acpi_bus_attach(child); +} + /* * acpi_bus_add and acpi_bus_start * @@ -1491,11 +1504,17 @@ 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); @@ -1636,3 +1655,28 @@ 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: + to_acpi_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); -- 1.7.7 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/