From: Sonny Rao <sonny@burdell.org>

We need to serialize access to the global rtc_idr even in this error path.

Signed-off-by: Sonny Rao <sonny@burdell.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 drivers/rtc/class.c |    2 ++
 1 file changed, 2 insertions(+)

diff -puN drivers/rtc/class.c~rtc-fix-idr-locking drivers/rtc/class.c
--- a/drivers/rtc/class.c~rtc-fix-idr-locking
+++ a/drivers/rtc/class.c
@@ -93,7 +93,9 @@ exit_kfree:
 	kfree(rtc);
 
 exit_idr:
+	mutex_lock(&idr_lock);
 	idr_remove(&rtc_idr, id);
+	mutex_unlock(&idr_lock);
 
 exit:
 	dev_err(dev, "rtc core: unable to register %s, err = %d\n",
_