[PATCH RESEND] regulator: Fix possible nullpointer dereference in regulator_enable()

["Heiko Stübner" <heiko@sntech.de>]

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>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

---
no changes, except adding the ack from Mark Brown from 2011-09-19
and including the relevant (and forgotten in the first try) LKML

 drivers/regulator/core.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 026f3d4..c9dd19c 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1425,7 +1425,7 @@ int regulator_enable(struct regulator *regulator)
 	ret = _regulator_enable(rdev);
 	mutex_unlock(&rdev->mutex);
 
-	if (ret != 0)
+	if (ret != 0 && rdev->supply)
 		regulator_disable(rdev->supply);
 
 	return ret;
-- 
1.7.2.3