Do not disable driver and bus shutdown hook when class shutdown hook is set.

As seen from the implementation of the single class shutdown hook this
is not very sound design.

Rename the class shutdown hook to shutdown_pre to make it clear it runs
before the driver shutdown hook.

Signed-off-by: Michal Suchanek <[e-mail]>
Reviewed-by: Jarkko Sakkinen <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/base/core.c

···
 		pm_runtime_get_noresume(dev);
 		pm_runtime_barrier(dev);
 
-		if (dev->class && dev->class->shutdown) {
+		if (dev->class && dev->class->shutdown_pre) {
 			if (initcall_debug)
-				dev_info(dev, "shutdown\n");
-			dev->class->shutdown(dev);
-		} else if (dev->bus && dev->bus->shutdown) {
+				dev_info(dev, "shutdown_pre\n");
+			dev->class->shutdown_pre(dev);
+		}
+		if (dev->bus && dev->bus->shutdown) {
 			if (initcall_debug)
 				dev_info(dev, "shutdown\n");
 			dev->bus->shutdown(dev);

drivers/char/tpm/tpm-chip.c

···
 		chip->ops = NULL;
 		up_write(&chip->ops_sem);
 	}
-	/* Allow bus- and device-specific code to run. Note: since chip->ops
-	 * is NULL, more-specific shutdown code will not be able to issue TPM
-	 * commands.
-	 */
-	if (dev->bus && dev->bus->shutdown)
-		dev->bus->shutdown(dev);
-	else if (dev->driver && dev->driver->shutdown)
-		dev->driver->shutdown(dev);
+
 	return 0;
 }
 
···
 	device_initialize(&chip->devs);
 
 	chip->dev.class = tpm_class;
-	chip->dev.class->shutdown = tpm_class_shutdown;
+	chip->dev.class->shutdown_pre = tpm_class_shutdown;
 	chip->dev.release = tpm_dev_release;
 	chip->dev.parent = pdev;
 	chip->dev.groups = chip->groups;

include/linux/device.h

···
  * @suspend:	Used to put the device to sleep mode, usually to a low power
  *		state.
  * @resume:	Used to bring the device from the sleep mode.
- * @shutdown:	Called at shut-down time to quiesce the device.
+ * @shutdown_pre: Called at shut-down time before driver shutdown.
  * @ns_type:	Callbacks so sysfs can detemine namespaces.
  * @namespace:	Namespace of the device belongs to this class.
  * @pm:		The default device power management operations of this class.
···
 
 	int (*suspend)(struct device *dev, pm_message_t state);
 	int (*resume)(struct device *dev);
-	int (*shutdown)(struct device *dev);
+	int (*shutdown_pre)(struct device *dev);
 
 	const struct kobj_ns_type_operations *ns_type;
 	const void *(*namespace)(struct device *dev);