[PATCH v4 1/3] iio:pressure:ms5611: fix oops when probing regulator

[Gregor Boirie <gregor.boirie-ITF29qwbsa/QT0dZR+AlfA@public.gmane.org>]

When not compiled-in, regulator layer will return a NULL pointer when
trying to get a reference to any regulator using devm_regulator_get().  As
IS_ERR() does not consider this an error, the ms5611 probing operation will
try to enable a NULL regulator, which will invariably cause a kernel
crash.
This patch fixes this situation by using devm_regulator_get_optional()
instead of devm_regulator_get().

Signed-off-by: Gregor Boirie <gregor.boirie-ITF29qwbsa/QT0dZR+AlfA@public.gmane.org>
---
 drivers/iio/pressure/ms5611_core.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/pressure/ms5611_core.c b/drivers/iio/pressure/ms5611_core.c
index 992ad8d..a9c4d49 100644
--- a/drivers/iio/pressure/ms5611_core.c
+++ b/drivers/iio/pressure/ms5611_core.c
@@ -291,8 +291,8 @@ static const struct iio_info ms5611_info = {
 static int ms5611_init(struct iio_dev *indio_dev)
 {
 	int ret;
-	struct regulator *vdd = devm_regulator_get(indio_dev->dev.parent,
-	                                           "vdd");
+	struct regulator *vdd =
+		devm_regulator_get_optional(indio_dev->dev.parent, "vdd");
 
 	/* Enable attached regulator if any. */
 	if (!IS_ERR(vdd)) {
@@ -302,6 +302,10 @@ static int ms5611_init(struct iio_dev *indio_dev)
 			        "failed to enable Vdd supply: %d\n", ret);
 			return ret;
 		}
+	} else {
+		ret = PTR_ERR(vdd);
+		if (ret != -ENODEV)
+			return ret;
 	}
 
 	ret = ms5611_reset(indio_dev);
-- 
2.1.4

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html