[PATCH] driver core: fix error handling in bus_add_device

The error handling in bus_add_device() and device_attach() is simply
non-existing. This patch propagates any error from device_attach to
the upper layers to allow for a proper recovery.

From: Hannes Reinecke <hare@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/base/bus.c

@@ -270,11 +270,14 @@ int bus_add_device(struct device * dev)
 
 	if (bus) {
 		pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id);
-		device_attach(dev);
+		error = device_attach(dev);
 		klist_add_tail(&bus->klist_devices, &dev->knode_bus);
-		device_add_attrs(bus, dev);
-		sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
-		sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
+		if (error >= 0)
+			error = device_add_attrs(bus, dev);
+		if (!error) {
+			sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
+			sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
+		}
 	}
 	return error;
 }
@@ -394,7 +397,7 @@ static int bus_rescan_devices_helper(struct device *dev, void *data)
 {
 	int *count = data;
 
-	if (!dev->driver && device_attach(dev))
+	if (!dev->driver && (device_attach(dev) > 0))
 		(*count)++;
 
 	return 0;

drivers/base/dd.c

@@ -119,7 +119,8 @@ static int __device_attach(struct device_driver * drv, void * data)
  *	driver_probe_device() for each pair. If a compatible
  *	pair is found, break out and return.
  *
- *	Returns 1 if the device was bound to a driver; 0 otherwise.
+ *	Returns 1 if the device was bound to a driver;
+ *	0 if no matching device was found; error code otherwise.
  */
 int device_attach(struct device * dev)
 {