device core: add BUS_NOTIFY_DRIVER_NOT_BOUND notification

The users of BUS_NOTIFY_BIND_DRIVER have no chance to do any cleanup in case of
a probe failure. In the result there might be problems, such as some resources
that had been allocated will continue to be allocated and therefore lead to a
resource leak.

Introduce a new notification to inform the subscriber that ->probe() failed. Do
the same in case of failed device_bind_driver() call.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/dd.c

@@ -268,6 +268,9 @@ int device_bind_driver(struct device *dev)
 	ret = driver_sysfs_add(dev);
 	if (!ret)
 		driver_bound(dev);
+	else if (dev->bus)
+		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(device_bind_driver);
@@ -290,7 +293,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	/* If using pinctrl, bind pins now before probing */
 	ret = pinctrl_bind_pins(dev);
 	if (ret)
-		goto probe_failed;
+		goto pinctrl_bind_failed;
 
 	if (driver_sysfs_add(dev)) {
 		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
@@ -334,6 +337,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	goto done;
 
 probe_failed:
+	if (dev->bus)
+		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
+					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
+pinctrl_bind_failed:
 	devres_release_all(dev);
 	driver_sysfs_remove(dev);
 	dev->driver = NULL;
@@ -701,7 +708,6 @@ static void __device_release_driver(struct device *dev)
 			blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 						     BUS_NOTIFY_UNBOUND_DRIVER,
 						     dev);
-
 	}
 }
 

include/linux/device.h

@@ -191,6 +191,7 @@ extern int bus_unregister_notifier(struct bus_type *bus,
 						      unbound */
 #define BUS_NOTIFY_UNBOUND_DRIVER	0x00000007 /* driver is unbound
 						      from the device */
+#define BUS_NOTIFY_DRIVER_NOT_BOUND	0x00000008 /* driver fails to be bound */
 
 extern struct kset *bus_get_kset(struct bus_type *bus);
 extern struct klist *bus_get_device_klist(struct bus_type *bus);