Driver core: make old versions of udev work properly

If CONFIG_SYSFS_DEPRECATED is enabled, old versions of udev will work
properly with devices that are associated with a class.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/base/core.c b/drivers/base/core.c
index dbcd40b987d22764317aec8f82aa34f2983c4df5..8f8347b9197f057c0cf8f927f116a13747603737 100644 (file)
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -384,6 +384,19 @@ void device_initialize(struct device *dev)
        device_init_wakeup(dev, 0);
 }
 
+#ifdef CONFIG_SYSFS_DEPRECATED
+int setup_parent(struct device *dev, struct device *parent)
+{
+       /* Set the parent to the class, not the parent device */
+       /* this keeps sysfs from having a symlink to make old udevs happy */
+       if (dev->class)
+               dev->kobj.parent = &dev->class->subsys.kset.kobj;
+       else if (parent)
+               dev->kobj.parent = &parent->kobj;
+
+       return 0;
+}
+#else
 static int virtual_device_parent(struct device *dev)
 {
        if (!dev->class)
@@ -401,6 +414,22 @@ static int virtual_device_parent(struct device *dev)
        return 0;
 }
 
+int setup_parent(struct device *dev, struct device *parent)
+{
+       int error;
+
+       /* if this is a class device, and has no parent, create one */
+       if ((dev->class) && (parent == NULL)) {
+               error = virtual_device_parent(dev);
+               if (error)
+                       return error;
+       } else if (parent)
+               dev->kobj.parent = &parent->kobj;
+
+       return 0;
+}
+#endif
+
 /**
  *     device_add - add device to device hierarchy.
  *     @dev:   device.
@@ -423,23 +452,18 @@ int device_add(struct device *dev)
        if (!dev || !strlen(dev->bus_id))
                goto Error;
 
-       /* if this is a class device, and has no parent, create one */
-       if ((dev->class) && (dev->parent == NULL)) {
-               error = virtual_device_parent(dev);
-               if (error)
-                       goto Error;
-       }
+       pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
 
        parent = get_device(dev->parent);
 
-       pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
+       error = setup_parent(dev, parent);
+       if (error)
+               goto Error;
 
        /* first, register with generic layer. */
        kobject_set_name(&dev->kobj, "%s", dev->bus_id);
-       if (parent)
-               dev->kobj.parent = &parent->kobj;
-
-       if ((error = kobject_add(&dev->kobj)))
+       error = kobject_add(&dev->kobj);
+       if (error)
                goto Error;
 
        /* notify platform of device entry */
@@ -484,8 +508,11 @@ int device_add(struct device *dev)
        if (dev->class) {
                sysfs_create_link(&dev->kobj, &dev->class->subsys.kset.kobj,
                                  "subsystem");
-               sysfs_create_link(&dev->class->subsys.kset.kobj, &dev->kobj,
-                                 dev->bus_id);
+               /* If this is not a "fake" compatible device, then create the
+                * symlink from the class to the device. */
+               if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
+                       sysfs_create_link(&dev->class->subsys.kset.kobj,
+                                         &dev->kobj, dev->bus_id);
                if (parent) {
                        sysfs_create_link(&dev->kobj, &dev->parent->kobj, "device");
                        class_name = make_class_name(dev->class->name, &dev->kobj);
@@ -623,7 +650,11 @@ void device_del(struct device * dev)
        }
        if (dev->class) {
                sysfs_remove_link(&dev->kobj, "subsystem");
-               sysfs_remove_link(&dev->class->subsys.kset.kobj, dev->bus_id);
+               /* If this is not a "fake" compatible device, remove the
+                * symlink from the class to the device. */
+               if (dev->kobj.parent != &dev->class->subsys.kset.kobj)
+                       sysfs_remove_link(&dev->class->subsys.kset.kobj,
+                                         dev->bus_id);
                class_name = make_class_name(dev->class->name, &dev->kobj);
                if (parent) {
                        sysfs_remove_link(&dev->kobj, "device");