From 0187294d227dfc42889e1da8f8ce1e44fc25f147 Mon Sep 17 00:00:00 2001

From: Dinghao Liu <dinghao.liu@zju.edu.cn>

Date: Tue, 26 May 2020 18:47:17 +0800

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

Git-commit: 0187294d227dfc42889e1da8f8ce1e44fc25f147

Patch-mainline: v5.8-rc6

References: git-fixes

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>

Fixes: 7c94a8b2ee8c ("iio: magn: add a driver for AK8974")

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Cc: <Stable@vger.kernel.org>

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/iio/magnetometer/ak8974.c |   19 ++++++++++---------

 1 file changed, 10 insertions(+), 9 deletions(-)

--- a/drivers/iio/magnetometer/ak8974.c

+++ b/drivers/iio/magnetometer/ak8974.c

@@ -764,19 +764,21 @@ static int ak8974_probe(struct i2c_clien

 	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_clien

 	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 @@ no_irq:

 		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 @@ disable_pm:

 	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;