ACPI / hotplug: Fix conflicted PCI bridge notify handlers

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]
Cc: 3.9+ <stable@vger.kernel.org> # 3.9+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index b5cb729328a4dea5e001255f355a4fa41d92ebbb..a84ea1b51a8964cbea282a3d94983873bf6628b9 100644 (file)
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -65,6 +65,9 @@ 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 ce518867a18aaa49755d71a8d4a437cc565c8bf1..e76b5230f476ddfc8781e49eedd74c73ca3780a0 100644 (file)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1773,7 +1773,7 @@ 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 d64a3010332feaeb93f590d2a380637204af715d..5f4bb4501305d773b750bbf03a2fa6ea85335867 100644 (file)
--- 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;
 };