ACPI / scan: Annotate physical_node_lock in acpi_scan_is_offline()

acpi_scan_is_offline() may be called under the physical_node_lock
lock of the given device object's parent, so prevent lockdep from
complaining about that by annotating that instance with
SINGLE_DEPTH_NESTING.

Fixes: caa73ea158de (ACPI / hotplug / driver core: Handle containers in a special way)
Reported-and-tested-by: Xie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 69bc0d888c012523d03f15267c3ca75a1d4a10e3..8d40467d37f9ab93ba7477d0b441e7b5962a7702 100644 (file)
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -375,7 +375,11 @@ bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent)
        struct acpi_device_physical_node *pn;
        bool offline = true;
 
-       mutex_lock(&adev->physical_node_lock);
+       /*
+        * acpi_container_offline() calls this for all of the container's
+        * children under the container's physical_node_lock lock.
+        */
+       mutex_lock_nested(&adev->physical_node_lock, SINGLE_DEPTH_NESTING);
 
        list_for_each_entry(pn, &adev->physical_node_list, node)
                if (device_supports_offline(pn->dev) && !pn->dev->offline) {