From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754617Ab3ALX2Y (ORCPT ); Sat, 12 Jan 2013 18:28:24 -0500 Received: from hydra.sisk.pl ([212.160.235.94]:39174 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754444Ab3ALX2X (ORCPT ); Sat, 12 Jan 2013 18:28:23 -0500 From: "Rafael J. Wysocki" To: Yinghai Lu Cc: Bjorn Helgaas , Len Brown , Taku Izumi , Jiang Liu , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Subject: Re: [PATCH v8 11/22] PCI: correctly detect ACPI PCI host bridge objects Date: Sun, 13 Jan 2013 00:34:10 +0100 Message-ID: <2669837.JomPNBOLKK@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.8.0-rc3+; KDE/4.9.5; x86_64; ; ) In-Reply-To: <1357944049-29620-12-git-send-email-yinghai@kernel.org> References: <1357944049-29620-1-git-send-email-yinghai@kernel.org> <1357944049-29620-12-git-send-email-yinghai@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, January 11, 2013 02:40:38 PM Yinghai Lu wrote: > From: Jiang Liu > > The code in pci_root_hp.c depends on function acpi_is_root_bridge() > to check whether an ACPI object is a PCI host bridge or not. > If an ACPI device hasn't been created for the ACPI object yet, > function acpi_is_root_bridge() will return false even if the object > is a PCI host bridge object. That behavior will cause two issues: > 1) No ACPI notification handler installed for PCI host bridges absent > at startup, so hotplug events for those bridges won't be handled. > 2) rescan_root_bridge() can't reenumerate offlined PCI host bridges > because the ACPI devices have been already destroyed. > > So use acpi_match_object_info_ids() to correctly detect PCI host bridges. > > -v2: update to use acpi_match_object_info_ids() from Tang Chen - Yinghai > -v3: drop the PNP0A008, according to Bjorn. > > Signed-off-by: Jiang Liu > Signed-off-by: Yinghai Lu > Cc: Len Brown > Cc: linux-acpi@vger.kernel.org > --- > drivers/acpi/pci_root.c | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c > index 5ae36d8..d30fb94 100644 > --- a/drivers/acpi/pci_root.c > +++ b/drivers/acpi/pci_root.c > @@ -923,6 +923,23 @@ static void handle_hotplug_event_root(acpi_handle handle, u32 type, > _handle_hotplug_event_root); > } > > +static bool acpi_is_root_bridge_object(acpi_handle handle) > +{ > + struct acpi_device_info *info = NULL; > + acpi_status status; > + bool ret; > + > + status = acpi_get_object_info(handle, &info); > + if (ACPI_FAILURE(status)) > + return false; > + > + ret = !acpi_match_object_info_ids(info, root_device_ids); > + Well, I kind of don't understand why don't we check info->flags against ACPI_PCI_ROOT_BRIDGE that acpi_get_object_info() sets for us if it finds a PCI root bridge? > + kfree(info); > + > + return ret; > +} > + > static acpi_status __init > find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv) > { > @@ -931,7 +948,7 @@ find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv) > .pointer = objname }; > int *count = (int *)context; > > - if (!acpi_is_root_bridge(handle)) > + if (!acpi_is_root_bridge_object(handle)) > return AE_OK; > > (*count)++; > Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.