commit d1685e4e2c3854782272f32b71f2f3eff5c6e0d0
Author: Heiko Stübner <heiko@sntech.de>
Date:   Fri Oct 14 18:00:29 2011 +0200

    regulator: Fix possible nullpointer dereference in regulator_enable()

    In the case where _regulator_enable returns an error it was not checked
    if a supplying regulator exists before trying to disable it, leading
    to a null pointer-dereference if no supplying regulator existed.

    Signed-off-by: Heiko Stuebner <heiko@sntech.de>
    Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

Index: source/drivers/regulator/core.c
===================================================================
--- source.orig/drivers/regulator/core.c	2011-11-28 22:48:14.000000000 +0000
+++ source/drivers/regulator/core.c	2011-12-03 23:01:59.000000000 +0000
@@ -1425,7 +1425,7 @@
 	ret = _regulator_enable(rdev);
 	mutex_unlock(&rdev->mutex);
 
-	if (ret != 0)
+	if (ret != 0 && rdev->supply)
 		regulator_disable(rdev->supply);
 
 	return ret;