ACPI: thermal: Check whether cooling device exists before unregistering

OS should check whether the cooling device exists before it is unregistered.
If it doesn't exists, it is unnecessary to remove the sysfs link
and call the function of thermal_cooling_device_unregister.

http://bugzilla.kernel.org/show_bug.cgi?id=9982

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Tested-by    : Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 75ccf5d18bf4..697335c8423e 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -809,10 +809,12 @@ static int acpi_processor_remove(struct acpi_device *device, int type)
 
         acpi_processor_remove_fs(device);
 
-        sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
-        sysfs_remove_link(&pr->cdev->device.kobj, "device");
-        thermal_cooling_device_unregister(pr->cdev);
-        pr->cdev = NULL;
+        if (pr->cdev) {
+                sysfs_remove_link(&device->dev.kobj, "thermal_cooling");
+                sysfs_remove_link(&pr->cdev->device.kobj, "device");
+                thermal_cooling_device_unregister(pr->cdev);
+                pr->cdev = NULL;
+        }
 
         processors[pr->id] = NULL;