From 8c4baca915377987f3b5d266157c74925f6107f8 Mon Sep 17 00:00:00 2001
From: Toshi Kani <toshi.kani@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@hp.com>
[rjw: Changed the name of the new flag]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index d7e53ea..79de26e 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 3601738..d047771 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1812,7 +1812,7 @@ 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 d901982..2611577 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -100,6 +100,7 @@ enum acpi_hotplug_mode {
 struct acpi_hotplug_profile {
 	struct kobject kobj;
 	bool enabled:1;
+	bool ignore:1;
 	enum acpi_hotplug_mode mode;
 };
 
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