driver core: don't fail attaching the device if it cannot be bound

Don't fail bus_attach_device() if the device cannot be bound.

If dev->driver has been specified, reset it to NULL if device_bind_driver()
failed and add the device as an unbound device.  As a result,
bus_attach_device() now cannot fail, and we can remove some checking from
device_add().

Also remove an unneeded check in bus_rescan_devices_helper().

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 11 insertions, 13 deletions

diff --git a/drivers/base/base.h b/drivers/base/base.h
index de7e1442ce60..d597f2659b23 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -16,7 +16,7 @@ extern int cpu_dev_init(void);
 extern int attribute_container_init(void);
 
 extern int bus_add_device(struct device * dev);
-extern int bus_attach_device(struct device * dev);
+extern void bus_attach_device(struct device * dev);
 extern void bus_remove_device(struct device * dev);
 extern struct bus_type *get_bus(struct bus_type * bus);
 extern void put_bus(struct bus_type * bus);
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 9df2e6dff519..20b6dc8706fa 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -447,7 +447,7 @@ out_put:
  *      - Add device to bus's list of devices.
  *      - Try to attach to driver.
  */
-int bus_attach_device(struct device * dev)
+void bus_attach_device(struct device * dev)
 {
         struct bus_type *bus = dev->bus;
         int ret = 0;
@@ -456,13 +456,12 @@ int bus_attach_device(struct device * dev)
                 dev->is_registered = 1;
                 if (bus->drivers_autoprobe)
                         ret = device_attach(dev);
-                if (ret >= 0) {
+                WARN_ON(ret < 0);
+                if (ret >= 0)
                         klist_add_tail(&dev->knode_bus, &bus->klist_devices);
-                        ret = 0;
-                } else
+                else
                         dev->is_registered = 0;
         }
-        return ret;
 }
 
 /**
@@ -669,8 +668,6 @@ static int __must_check bus_rescan_devices_helper(struct device *dev,
                 ret = device_attach(dev);
                 if (dev->parent)
                         up(&dev->parent->sem);
-                if (ret > 0)
-                        ret = 0;
         }
         return ret < 0 ? ret : 0;
 }
diff --git a/drivers/base/core.c b/drivers/base/core.c
index bffb69e4bde2..be6aeb430798 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -677,8 +677,7 @@ int device_add(struct device *dev)
                 goto BusError;
         if (!dev->uevent_suppress)
                 kobject_uevent(&dev->kobj, KOBJ_ADD);
-        if ((error = bus_attach_device(dev)))
-                goto AttachError;
+        bus_attach_device(dev);
         if (parent)
                 klist_add_tail(&dev->knode_parent, &parent->klist_children);
 
@@ -697,8 +696,6 @@ int device_add(struct device *dev)
         kfree(class_name);
         put_device(dev);
         return error;
- AttachError:
-        bus_remove_device(dev);
  BusError:
         device_pm_remove(dev);
  PMError:
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 616b4bbacf1b..18dba8e78da7 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -232,7 +232,7 @@ static int device_probe_drivers(void *data)
  *
  *      Returns 1 if the device was bound to a driver;
  *      0 if no matching device was found or multithreaded probing is done;
- *      error code otherwise.
+ *      -ENODEV if the device is not registered.
  *
  *      When called for a USB interface, @dev->parent->sem must be held.
  */
@@ -246,6 +246,10 @@ int device_attach(struct device * dev)
                 ret = device_bind_driver(dev);
                 if (ret == 0)
                         ret = 1;
+                else {
+                        dev->driver = NULL;
+                        ret = 0;
+                }
         } else {
                 if (dev->bus->multithread_probe)
                         probe_task = kthread_run(device_probe_drivers, dev,