[Vivid][SRU][PATCH 1/2] device core: add BUS_NOTIFY_DRIVER_NOT_BOUND notification

[Phidias Chiang]

From: Andy Shevchenko <andriy.shevchenko at linux.intel.com>

BugLink: http://bugs.launchpad.net/bugs/1562778

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 at linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki at intel.com>
(cherry picked from commit 14b6257a5f3dca3817b0826cb32967e3c2b935c8)
Signed-off-by: Phidias Chiang <phidias.chiang at canonical.com>
Reviewed-by: Wen-chien Jesse Sung <jesse.sung at canonical.com>

---
 drivers/base/dd.c      | 10 ++++++++--
 include/linux/device.h |  1 +
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index f32ae2e..ae9181b 100644
--- a/drivers/base/dd.c
+++ b/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",
@@ -315,6 +318,10 @@ 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;
@@ -545,7 +552,6 @@ static void __device_release_driver(struct device *dev)
 			blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 						     BUS_NOTIFY_UNBOUND_DRIVER,
 						     dev);
-
 	}
 }
 
diff --git a/include/linux/device.h b/include/linux/device.h
index 7384efe..5f3a1b7 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -190,6 +190,7 @@ 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);
-- 
2.7.0