[PATCH] iio: magnetometer: ak8974: Fix runtime PM imbalance on error

[Dinghao Liu]

When devm_regmap_init_i2c() returns an error code, a pairing
runtime PM usage counter decrement is needed to keep the
counter balanced. For error paths after ak8974_set_power(),
ak8974_detect() and ak8974_reset(), things are the same.

However, When iio_triggered_buffer_setup() returns an error
code, we don't need such a decrement because there is already
one before this call. Things are the same for other error paths
after it.

Signed-off-by: Dinghao Liu <dinghao....@zju.edu.cn>
---
 drivers/iio/magnetometer/ak8974.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/magnetometer/ak8974.c 
b/drivers/iio/magnetometer/ak8974.c
index d32996702110..c1bdb304eb9e 100644
--- a/drivers/iio/magnetometer/ak8974.c
+++ b/drivers/iio/magnetometer/ak8974.c
@@ -764,18 +764,24 @@ static int ak8974_probe(struct i2c_client *i2c,
        ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
        if (IS_ERR(ak8974->map)) {
                dev_err(&i2c->dev, "failed to allocate register map\n");
+               pm_runtime_put_noidle(&i2c->dev);
+               pm_runtime_disable(&i2c->dev);
                return PTR_ERR(ak8974->map);
        }
 
        ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
        if (ret) {
                dev_err(&i2c->dev, "could not power on\n");
+               pm_runtime_put_noidle(&i2c->dev);
+               pm_runtime_disable(&i2c->dev);
                goto power_off;
        }
 
        ret = ak8974_detect(ak8974);
        if (ret) {
                dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n");
+               pm_runtime_put_noidle(&i2c->dev);
+               pm_runtime_disable(&i2c->dev);
                goto power_off;
        }
 
@@ -786,6 +792,8 @@ static int ak8974_probe(struct i2c_client *i2c,
        ret = ak8974_reset(ak8974);
        if (ret) {
                dev_err(&i2c->dev, "AK8974 reset failed\n");
+               pm_runtime_put_noidle(&i2c->dev);
+               pm_runtime_disable(&i2c->dev);
                goto power_off;
        }
 
@@ -851,7 +859,6 @@ static int ak8974_probe(struct i2c_client *i2c,
 cleanup_buffer:
        iio_triggered_buffer_cleanup(indio_dev);
 disable_pm:
-       pm_runtime_put_noidle(&i2c->dev);
        pm_runtime_disable(&i2c->dev);
        ak8974_set_power(ak8974, AK8974_PWR_OFF);
 power_off:
-- 
2.17.1