[PATCH 4.15 008/105] iio: adc: meson-saradc: unlock on error in meson_sar_adc_lock()

[Greg Kroah-Hartman]

4.15-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 3c3e4b3a708a9d6451052e348981f37d2b3e92b0 upstream.

The meson_sar_adc_lock() function is not supposed to hold the
"indio_dev->mlock" on the error path.

Fixes: 3adbf3427330 ("iio: adc: add a driver for the SAR ADC found in Amlogic Meson SoCs")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: <Stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/iio/adc/meson_saradc.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/iio/adc/meson_saradc.c
+++ b/drivers/iio/adc/meson_saradc.c
@@ -462,8 +462,10 @@ static int meson_sar_adc_lock(struct iio
 			regmap_read(priv->regmap, MESON_SAR_ADC_DELAY, &val);
 		} while (val & MESON_SAR_ADC_DELAY_BL30_BUSY && timeout--);
 
-		if (timeout < 0)
+		if (timeout < 0) {
+			mutex_unlock(&indio_dev->mlock);
 			return -ETIMEDOUT;
+		}
 	}
 
 	return 0;