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* [PATCH] iio: adc: ad7280a: replace mutex_lock() with guard(mutex)
@ 2026-03-19 18:46 Matheus Giarola
  2026-03-20 19:53 ` kernel test robot
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Matheus Giarola @ 2026-03-19 18:46 UTC (permalink / raw)
  To: lars, Michael.Hennerich, jic23
  Cc: dlechner, nuno.sa, andy, linux-iio, linux-kernel, matheusgiarola,
	arthurpilone, davidbtadokoro

Use guard(mutex) instead of mutex_lock()/mutex_unlock(),
ensuring the mutex is released automatically when leaving
the function scope. The change improves error handling and
avoids issues such as missing unlocks. It also simplifies the
code by removing 'err_unlock' label and several mutex_unlock()
calls.

Signed-off-by: Matheus Giarola <matheusgiarola@usp.br>
---
 drivers/iio/adc/ad7280a.c | 27 ++++++++-------------------
 1 file changed, 8 insertions(+), 19 deletions(-)

diff --git a/drivers/iio/adc/ad7280a.c b/drivers/iio/adc/ad7280a.c
index ba12a3796e2b..3a4f0dd37d78 100644
--- a/drivers/iio/adc/ad7280a.c
+++ b/drivers/iio/adc/ad7280a.c
@@ -496,7 +496,7 @@ static ssize_t ad7280_store_balance_sw(struct iio_dev *indio_dev,
 	devaddr = chan->address >> 8;
 	ch = chan->address & 0xFF;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
 	if (readin)
 		st->cb_mask[devaddr] |= BIT(ch);
 	else
@@ -505,7 +505,6 @@ static ssize_t ad7280_store_balance_sw(struct iio_dev *indio_dev,
 	ret = ad7280_write(st, devaddr, AD7280A_CELL_BALANCE_REG, 0,
 			   FIELD_PREP(AD7280A_CELL_BALANCE_CHAN_BITMAP_MSK,
 				      st->cb_mask[devaddr]));
-	mutex_unlock(&st->lock);
 
 	return ret ? ret : len;
 }
@@ -519,10 +518,9 @@ static ssize_t ad7280_show_balance_timer(struct iio_dev *indio_dev,
 	unsigned int msecs;
 	int ret;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
 	ret = ad7280_read_reg(st, chan->address >> 8,
 			      (chan->address & 0xFF) + AD7280A_CB1_TIMER_REG);
-	mutex_unlock(&st->lock);
 
 	if (ret < 0)
 		return ret;
@@ -551,11 +549,10 @@ static ssize_t ad7280_store_balance_timer(struct iio_dev *indio_dev,
 	if (val > 31)
 		return -EINVAL;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
 	ret = ad7280_write(st, chan->address >> 8,
 			   (chan->address & 0xFF) + AD7280A_CB1_TIMER_REG, 0,
 			   FIELD_PREP(AD7280A_CB_TIMER_VAL_MSK, val));
-	mutex_unlock(&st->lock);
 
 	return ret ? ret : len;
 }
@@ -737,7 +734,7 @@ static int ad7280a_write_thresh(struct iio_dev *indio_dev,
 	if (val2 != 0)
 		return -EINVAL;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
 	switch (chan->type) {
 	case IIO_VOLTAGE:
 		value = ((val - 1000) * 100) / 1568; /* LSB 15.68mV */
@@ -760,8 +757,7 @@ static int ad7280a_write_thresh(struct iio_dev *indio_dev,
 			st->cell_threshlow = value;
 			break;
 		default:
-			ret = -EINVAL;
-			goto err_unlock;
+			return -EINVAL;
 		}
 		break;
 	case IIO_TEMP:
@@ -785,18 +781,12 @@ static int ad7280a_write_thresh(struct iio_dev *indio_dev,
 			st->aux_threshlow = value;
 			break;
 		default:
-			ret = -EINVAL;
-			goto err_unlock;
+			return -EINVAL;
 		}
 		break;
 	default:
-		ret = -EINVAL;
-		goto err_unlock;
+		return -EINVAL;
 	}
-
-err_unlock:
-	mutex_unlock(&st->lock);
-
 	return ret;
 }
 
@@ -885,13 +875,12 @@ static int ad7280_read_raw(struct iio_dev *indio_dev,
 
 	switch (m) {
 	case IIO_CHAN_INFO_RAW:
-		mutex_lock(&st->lock);
+		guard(mutex)(&st->lock);
 		if (chan->address == AD7280A_ALL_CELLS)
 			ret = ad7280_read_all_channels(st, st->scan_cnt, NULL);
 		else
 			ret = ad7280_read_channel(st, chan->address >> 8,
 						  chan->address & 0xFF);
-		mutex_unlock(&st->lock);
 
 		if (ret < 0)
 			return ret;
-- 
2.47.3


^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-03-25 20:32 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-03-19 18:46 [PATCH] iio: adc: ad7280a: replace mutex_lock() with guard(mutex) Matheus Giarola
2026-03-20 19:53 ` kernel test robot
2026-03-20 20:16 ` kernel test robot
2026-03-21 15:55 ` Jonathan Cameron
2026-03-25 19:21   ` Matheus Giarola
2026-03-25 20:32     ` Jonathan Cameron

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