[PATCH] iio: pressure: mpl115: Fix runtime PM cleanup on probe failure

[Can Peng]

mpl115_probe() enables runtime PM when a shutdown GPIO is present and
then returns the result of devm_iio_device_register(). If registration
fails, runtime PM remains enabled and autosuspend remains selected.

The same unmanaged runtime PM state is also left behind on driver
unbind, as the IIO device registration is managed but the runtime PM
setup is not.

Use devm_pm_runtime_enable() so runtime PM is disabled automatically
on probe failure and driver unbind. Also unwind the initial
pm_runtime_get_noresume() reference if setting up runtime PM fails
before the matching put.

Fixes: 0c3a333524a3 ("iio: pressure: mpl115: Implementing low power mode by shutdown gpio")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Can Peng <pengcan@xxxxxxxxxx>
---
 drivers/iio/pressure/mpl115.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/pressure/mpl115.c b/drivers/iio/pressure/mpl115.c
index 16e112b796ba..9e77b76bd1fa 100644
--- a/drivers/iio/pressure/mpl115.c
+++ b/drivers/iio/pressure/mpl115.c
@@ -204,8 +204,17 @@ int mpl115_probe(struct device *dev, const char *name,
 	if (data->shutdown) {
 		/* Enable runtime PM */
 		pm_runtime_get_noresume(dev);
-		pm_runtime_set_active(dev);
-		pm_runtime_enable(dev);
+		ret = pm_runtime_set_active(dev);
+		if (ret) {
+			pm_runtime_put_noidle(dev);
+			return ret;
+		}
+
+		ret = devm_pm_runtime_enable(dev);
+		if (ret) {
+			pm_runtime_put_noidle(dev);
+			return ret;
+		}
 
 		/*
 		 * As the device takes 3 ms to come up with a fresh
-- 
2.53.0