PM / devfreq: Don't delete sysfs group twice

The 'userspace' governor adds a sysfs entry, which is removed when
the governor is changed, or the devfreq device is released. However,
when the latter occurs via device_unregister(), device_del() is
called first, which removes the sysfs entries recursively and deletes
the kobject.

This means we get an Oops when the governor calls
sysfs_remove_group() on the deleted kobject. Fix this by only doing
the call when kobj *hasn't* been kobject_del()'d.

Note that we can't just remove the call to sysfs_remove_group()
entirely - it's needed for when the governor is changed to one which
doesn't need a sysfs entry.

Signed-off-by: Chris Diamand <chris.diamand@arm.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/drivers/devfreq/governor_userspace.c b/drivers/devfreq/governor_userspace.c
index 35de6e8..9db4d6f 100644 (file)
--- a/drivers/devfreq/governor_userspace.c
+++ b/drivers/devfreq/governor_userspace.c
@@ -112,7 +112,13 @@ out:
 
 static void userspace_exit(struct devfreq *devfreq)
 {
-       sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group);
+       /*
+        * Remove the sysfs entry, unless this is being called after
+        * device_del(), which should have done this already via kobject_del().
+        */
+       if (devfreq->dev.kobj.sd)
+               sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group);
+
        kfree(devfreq->data);
        devfreq->data = NULL;
 }