[PATCH 5.12 079/296] iio: adc: ad7124: Fix missbalanced regulator enable / disable on error.

Greg Kroah-Hartman
2021-05-31T16:11:00Z

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

commit 4573472315f0fa461330545ff2aa2f6da0b1ae76 upstream.

If the devm_regulator_get() call succeeded but not the regulator_enable()
then regulator_disable() would be called on a regulator that was not
enabled.

Fix this by moving regulator enabling / disabling over to
devm_ management via devm_add_action_or_reset.

Alexandru's sign-off here because he pulled Jonathan's patch into
a larger set which Jonathan then applied.

Fixes: b3af341bbd96 ("iio: adc: Add ad7124 support")
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/iio/adc/ad7124.c | 29 +++++++++++++----------------
1 file changed, 13 insertions(+), 16 deletions(-)

--- a/drivers/iio/adc/ad7124.c
+++ b/drivers/iio/adc/ad7124.c
@@ -707,6 +707,11 @@ static int ad7124_setup(struct ad7124_st
return ret;
}

+static void ad7124_reg_disable(void *r)
+{
+ regulator_disable(r);
+}
+
static int ad7124_probe(struct spi_device *spi)
{
const struct ad7124_chip_info *info;
@@ -752,17 +757,20 @@ static int ad7124_probe(struct spi_devic
ret = regulator_enable(st->vref[i]);
if (ret)
return ret;
+
+ ret = devm_add_action_or_reset(&spi->dev, ad7124_reg_disable,
+ st->vref[i]);
+ if (ret)
+ return ret;
}

st->mclk = devm_clk_get(&spi->dev, "mclk");
- if (IS_ERR(st->mclk)) {
- ret = PTR_ERR(st->mclk);
- goto error_regulator_disable;
- }
+ if (IS_ERR(st->mclk))
+ return PTR_ERR(st->mclk);

ret = clk_prepare_enable(st->mclk);
if (ret < 0)
- goto error_regulator_disable;
+ return ret;

ret = ad7124_soft_reset(st);
if (ret < 0)
@@ -792,11 +800,6 @@ error_remove_trigger:
ad_sd_cleanup_buffer_and_trigger(indio_dev);
error_clk_disable_unprepare:
clk_disable_unprepare(st->mclk);
-error_regulator_disable:
- for (i = ARRAY_SIZE(st->vref) - 1; i >= 0; i--) {
- if (!IS_ERR_OR_NULL(st->vref[i]))
- regulator_disable(st->vref[i]);
- }

return ret;
}
@@ -805,17 +808,11 @@ static int ad7124_remove(struct spi_devi
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad7124_state *st = iio_priv(indio_dev);
- int i;

iio_device_unregister(indio_dev);
ad_sd_cleanup_buffer_and_trigger(indio_dev);
clk_disable_unprepare(st->mclk);

- for (i = ARRAY_SIZE(st->vref) - 1; i >= 0; i--) {
- if (!IS_ERR_OR_NULL(st->vref[i]))
- regulator_disable(st->vref[i]);
- }
-
return 0;
}