From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752971Ab2JLKzJ (ORCPT ); Fri, 12 Oct 2012 06:55:09 -0400 Received: from szxga01-in.huawei.com ([119.145.14.64]:4596 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751909Ab2JLKzF (ORCPT ); Fri, 12 Oct 2012 06:55:05 -0400 Message-ID: <5077F6E1.7090600@huawei.com> Date: Fri, 12 Oct 2012 18:54:25 +0800 From: Jiang Liu User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:9.0) Gecko/20111222 Thunderbird/9.0.1 MIME-Version: 1.0 To: Tang Chen CC: , , , , , , Subject: Re: [PATCH 2/3] Do not use acpi_device to find pci root bridge in _init code. References: <1350037890-5899-1-git-send-email-tangchen@cn.fujitsu.com> <1350037890-5899-3-git-send-email-tangchen@cn.fujitsu.com> <5077F2C2.1010300@huawei.com> <5077F407.3040205@cn.fujitsu.com> In-Reply-To: <5077F407.3040205@cn.fujitsu.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.108.108.229] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2012-10-12 18:42, Tang Chen wrote: > On 10/12/2012 06:36 PM, Jiang Liu wrote: >> On 2012-10-12 18:31, Tang Chen wrote: >>> When the kernel is being initialized, and some hardwares are not added >>> to system, there won't be acpi_device structs for these devices. But >>> acpi_is_root_bridge() depends on acpi_device struct. As a result, all >>> the not-added root bridge will not be judged as a root bridge in >>> find_root_bridges(). And further more, no handle_hotplug_event_root() >>> notifier will be installed for them. >>> >>> This patch introduces a new api to find all root bridges in system by >>> getting HID directly from ACPI namespace, not depending on acpi_device >>> struct. >>> >>> Signed-off-by: Tang Chen >>> --- >>> drivers/acpi/pci_root.c | 27 ++++++++++++++++++++++----- >>> 1 files changed, 22 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c >>> index 7d0fb03..3819bee 100644 >>> --- a/drivers/acpi/pci_root.c >>> +++ b/drivers/acpi/pci_root.c >>> @@ -128,9 +128,6 @@ EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle); >>> /** >>> * acpi_is_root_bridge - determine whether an ACPI CA node is a PCI root bridge >>> * @handle - the ACPI CA node in question. >>> - * >>> - * Note: we could make this API take a struct acpi_device * instead, but >>> - * for now, it's more convenient to operate on an acpi_handle. >>> */ >>> int acpi_is_root_bridge(acpi_handle handle) >>> { >>> @@ -138,8 +135,28 @@ int acpi_is_root_bridge(acpi_handle handle) >>> struct acpi_device *device; >>> >>> ret = acpi_bus_get_device(handle,&device); >>> - if (ret) >>> - return 0; >>> + if (ret) { >>> + /** >>> + * If a device is not added to the system yet, there won't be >>> + * an acpi_device struct for it. But it doesn't mean it is not >>> + * a PCI root bridge. In this case we need to get HID and CID >>> + * from ACPI namespace directly. >>> + */ >>> + struct acpi_device_info *info; >>> + acpi_status status; >>> + status = acpi_get_object_info(handle,&info); >>> + if (ACPI_FAILURE(status)) { >>> + printk(KERN_ERR PREFIX "%s: Error reading" >>> + "device info\n", __func__); >>> + return 0; >>> + } >>> + >>> + ret = acpi_match_object_info_ids(info, root_device_ids); >>> + if (ret) >>> + return 0; >>> + else >>> + return 1; >>> + } >> I have sent a similar patch to Yinghai before. For simplicity, we could >> use acpi_match_object_info_ids() instead of acpi_match_device_ids() >> directly. > > Hum, I must have missed it. :) > Using acpi_match_object_info_ids() directly seems good. I'm just worry > about if it could cause any other problem. :) > > So now, is this bug fixed ? And we don't need these patches, right ? > > Thanks. :) I think Yinghai has missed my patch too, so just suggest to use acpi_match_object_info_ids() directly. --Gerry > >> Thanks! >> Gerry >> >>> >>> ret = acpi_match_device_ids(device, root_device_ids); >>> if (ret) >> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-pci" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > > . >