[3.11.y.z extended stable] Patch "ACPI / hotplug: Fix conflicted PCI bridge notify handlers" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    ACPI / hotplug: Fix conflicted PCI bridge notify handlers

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 03809e2a9cab1a36cff90c3778c6d4e9de5484f1 Mon Sep 17 00:00:00 2001
From: Toshi Kani <toshi.kani at hp.com>
Date: Wed, 20 Nov 2013 14:25:34 +0100
Subject: ACPI / hotplug: Fix conflicted PCI bridge notify handlers

commit ca499fc87ed945094d952da0eb7eea7dbeb1feec upstream.

The PCI host bridge scan handler installs its own notify handler,
handle_hotplug_event_root(), by itself.  Nevertheless, the ACPI
hotplug framework also installs the common notify handler,
acpi_hotplug_notify_cb(), for PCI root bridges.  This causes
acpi_hotplug_notify_cb() to call _OST method with unsupported
error as hotplug.enabled is not set.

To address this issue, introduce hotplug.ignore flag, which
indicates that the scan handler installs its own notify handler by
itself.  The ACPI hotplug framework does not install the common
notify handler when this flag is set.

Signed-off-by: Toshi Kani <toshi.kani at hp.com>
[rjw: Changed the name of the new flag]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/acpi/pci_root.c | 3 +++
 drivers/acpi/scan.c     | 2 +-
 include/acpi/acpi_bus.h | 1 +
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 7dbe92c..fa2881b 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -63,6 +63,9 @@ static struct acpi_scan_handler pci_root_handler = {
 	.ids = root_device_ids,
 	.attach = acpi_pci_root_add,
 	.detach = acpi_pci_root_remove,
+	.hotplug = {
+		.ignore = true,
+	},
 };

 static DEFINE_MUTEX(osc_lock);
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 0ebb955..2487853 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1881,7 +1881,7 @@ static void acpi_scan_init_hotplug(acpi_handle handle, int type)
 	 */
 	list_for_each_entry(hwid, &pnp.ids, list) {
 		handler = acpi_scan_match_handler(hwid->id, NULL);
-		if (handler) {
+		if (handler && !handler->hotplug.ignore) {
 			acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
 					acpi_hotplug_notify_cb, handler);
 			break;
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 94383a7..fea538b 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -90,6 +90,7 @@ enum acpi_hotplug_mode {
 struct acpi_hotplug_profile {
 	struct kobject kobj;
 	bool enabled:1;
+	bool ignore:1;
 	enum acpi_hotplug_mode mode;
 };

--
1.8.3.2