Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757975Ab3D2QUH (ORCPT ); Mon, 29 Apr 2013 12:20:07 -0400 Received: from mail-pd0-f172.google.com ([209.85.192.172]:65356 "EHLO mail-pd0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757559Ab3D2QUF (ORCPT ); Mon, 29 Apr 2013 12:20:05 -0400 Message-ID: <517E9DAC.7030709@gmail.com> Date: Tue, 30 Apr 2013 00:19:56 +0800 From: Jiang Liu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130308 Thunderbird/17.0.4 MIME-Version: 1.0 To: Yinghai Lu CC: Bjorn Helgaas , "Rafael J. Wysocki" , Jiang Liu , Gavin Guo , linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH -v3] PCI, ACPI, hotplug: Fix BUS_CHECK event handle on root bridge References: <1366940798-15268-1-git-send-email-yinghai@kernel.org> In-Reply-To: <1366940798-15268-1-git-send-email-yinghai@kernel.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5181 Lines: 130 Hi Yinghai, Reviewed-by: Jiang Liu Thanks! On 04/26/2013 09:46 AM, Yinghai Lu wrote: > Gavin found that acpiphp does not handle hotplug anymore even after > now we have acpiphp built-in preparing for v3.10. > > Bjorn analyzed bootlog, he found that > acpiphp: ACPI Hot Plug PCI Controller Driver version: 0.5 > ACPI: PCI Root Bridge [PCI0] (domain 0000 [bus 00-3e]) > \_SB_.PCI0:_OSC invalid UUID > acpiphp: Slot [1] registered > acpiphp: Slot [1-1] registered > acpi root: \_SB_.PCI0 notify handler is installed > _handle_hotplug_event_root: Bus check notify on \_SB_.PCI0 > _handle_hotplug_event_root: Bus check notify on \_SB_.PCI0 > And that means: > So we should be using acpiphp, which you do have built in statically, > and it found a couple slots. And we did get two bus check notifies on > \_SB_.PCI0, so we *should* be re-enumerating PCI bus 0000:00. But it > looks like we're handling this as a host bridge hotplug event instead > of a PCI device hotplug. My guess is that > handle_root_bridge_insertion() does nothing because the PCI0 ACPI > device already exists, though I would expect to see the "acpi device > exists..." in your dmesg log if this were the case. > > Also according to Rafael and Bjorn, it is perfect fine that we > should enumerate bus by sending event to root bridge after hotadd > device to slots under that root bridge or children bridges. > > It turns out that it is regression caused by > | commit 668192b678201d2fff27c6cc76bb003c1ec4a52a > | Author: Yinghai Lu > | Date: Mon Jan 21 13:20:48 2013 -0800 > | > | PCI: acpiphp: Move host bridge hotplug to pci_root.c > > We should check slots when BUS_CHECK is sent to root bridge acpi handle. > > Restore the old behavoir by calling acpi_check_bridge and check_sub_bridge > in acpiphp. > > Jiang Liu acctually have simimar patch but it forgets calling > acpi_check_bridge() for system that have slots on root bus directly. > That is still valid, as in QEMU we still have that slots on bus 0 at > least. But my first version patch wrongly check if root bridge exists > before check_sub_bridge for children bridges. > > -v2: Don't check bridge for acpi_walk_namespace with check_sub_bridges. > also put back bridge reference. > -v3: More changelog and etc. > > Reported-by: Gavin Guo > Tested-by: Gavin Guo > Signed-off-by: Yinghai Lu > > --- > drivers/acpi/pci_root.c | 2 ++ > drivers/pci/hotplug/acpiphp_glue.c | 14 ++++++++++++++ > include/linux/pci-acpi.h | 2 ++ > 3 files changed, 18 insertions(+) > > Index: linux-2.6/drivers/acpi/pci_root.c > =================================================================== > --- linux-2.6.orig/drivers/acpi/pci_root.c > +++ linux-2.6/drivers/acpi/pci_root.c > @@ -643,6 +643,8 @@ static void _handle_hotplug_event_root(s > (char *)buffer.pointer); > if (!root) > handle_root_bridge_insertion(handle); > + else > + acpiphp_check_host_bridge(handle); > > break; > > Index: linux-2.6/drivers/pci/hotplug/acpiphp_glue.c > =================================================================== > --- linux-2.6.orig/drivers/pci/hotplug/acpiphp_glue.c > +++ linux-2.6/drivers/pci/hotplug/acpiphp_glue.c > @@ -950,6 +950,20 @@ check_sub_bridges(acpi_handle handle, u3 > return AE_OK ; > } > > +void acpiphp_check_host_bridge(acpi_handle handle) > +{ > + struct acpiphp_bridge *bridge; > + > + bridge = acpiphp_handle_to_bridge(handle); > + if (bridge) { > + acpiphp_check_bridge(bridge); > + put_bridge(bridge); > + } > + > + acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, > + ACPI_UINT32_MAX, check_sub_bridges, NULL, NULL, NULL); > +} > + > static void _handle_hotplug_event_bridge(struct work_struct *work) > { > struct acpiphp_bridge *bridge; > Index: linux-2.6/include/linux/pci-acpi.h > =================================================================== > --- linux-2.6.orig/include/linux/pci-acpi.h > +++ linux-2.6/include/linux/pci-acpi.h > @@ -60,11 +60,13 @@ static inline void acpi_pci_slot_remove( > void acpiphp_init(void); > void acpiphp_enumerate_slots(struct pci_bus *bus, acpi_handle handle); > void acpiphp_remove_slots(struct pci_bus *bus); > +void acpiphp_check_host_bridge(acpi_handle handle); > #else > static inline void acpiphp_init(void) { } > static inline void acpiphp_enumerate_slots(struct pci_bus *bus, > acpi_handle handle) { } > static inline void acpiphp_remove_slots(struct pci_bus *bus) { } > +static inline void acpiphp_check_host_bridge(acpi_handle handle) { } > #endif > > #else /* CONFIG_ACPI */ > -- > 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 > -- 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/