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From: Dinghao Liu <dinghao.liu@zju.edu.cn>
To: dinghao.liu@zju.edu.cn, kjlu@umn.edu
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Jonathan Cameron <jic23@kernel.org>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
	linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] [v2] iio: magnetometer: ak8974: Fix runtime PM imbalance on error
Date: Tue, 26 May 2020 18:47:17 +0800	[thread overview]
Message-ID: <20200526104717.3181-1-dinghao.liu@zju.edu.cn> (raw)

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, there will be two PM usgae counter decrements.

Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
---

Changelog:

v2: - Change 3 goto targets from "power_off" to
      "disabel_pm". Remove unused lable "power_off".
      Move 3 PM runtime related calls to the end of
      the function.
---
 drivers/iio/magnetometer/ak8974.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c
index d32996702110..c48c67d4b371 100644
--- a/drivers/iio/magnetometer/ak8974.c
+++ b/drivers/iio/magnetometer/ak8974.c
@@ -764,19 +764,21 @@ 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");
-		goto power_off;
+		goto disable_pm;
 	}
 
 	ret = ak8974_detect(ak8974);
 	if (ret) {
 		dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n");
-		goto power_off;
+		goto disable_pm;
 	}
 
 	ret = ak8974_selftest(ak8974);
@@ -786,14 +788,9 @@ static int ak8974_probe(struct i2c_client *i2c,
 	ret = ak8974_reset(ak8974);
 	if (ret) {
 		dev_err(&i2c->dev, "AK8974 reset failed\n");
-		goto power_off;
+		goto disable_pm;
 	}
 
-	pm_runtime_set_autosuspend_delay(&i2c->dev,
-					 AK8974_AUTOSUSPEND_DELAY);
-	pm_runtime_use_autosuspend(&i2c->dev);
-	pm_runtime_put(&i2c->dev);
-
 	indio_dev->dev.parent = &i2c->dev;
 	indio_dev->channels = ak8974_channels;
 	indio_dev->num_channels = ARRAY_SIZE(ak8974_channels);
@@ -846,6 +843,11 @@ static int ak8974_probe(struct i2c_client *i2c,
 		goto cleanup_buffer;
 	}
 
+	pm_runtime_set_autosuspend_delay(&i2c->dev,
+					 AK8974_AUTOSUSPEND_DELAY);
+	pm_runtime_use_autosuspend(&i2c->dev);
+	pm_runtime_put(&i2c->dev);
+
 	return 0;
 
 cleanup_buffer:
@@ -854,7 +856,6 @@ static int ak8974_probe(struct i2c_client *i2c,
 	pm_runtime_put_noidle(&i2c->dev);
 	pm_runtime_disable(&i2c->dev);
 	ak8974_set_power(ak8974, AK8974_PWR_OFF);
-power_off:
 	regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
 
 	return ret;
-- 
2.17.1


             reply	other threads:[~2020-05-26 10:48 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-26 10:47 Dinghao Liu [this message]
2020-05-26 11:13 ` [PATCH] [v2] iio: magnetometer: ak8974: Fix runtime PM imbalance on error Linus Walleij
2020-05-31 14:00   ` Jonathan Cameron
2020-06-08 12:12     ` Linus Walleij
2020-06-14 12:11       ` Jonathan Cameron

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