[PATCH v5] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[PATCH v5] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[Guilherme Dias]

Use guard(mutex) to automatically release the lock on scope exit,
simplifying the error handling path and removing the need for
explicit unlock and goto-based cleanup.

Signed-off-by: Guilherme Dias <guilhermeabreu200105@usp.br>
Co-developed-by: João Paulo Menezes Linaris <jplinaris@usp.br>
Signed-off-by: João Paulo Menezes Linaris <jplinaris@usp.br>
---
v5:
 - add cleanup.h

v4:
 - fix indentation

 drivers/iio/gyro/adxrs290.c | 75 +++++++++++++++----------------------
 1 file changed, 31 insertions(+), 44 deletions(-)

diff --git a/drivers/iio/gyro/adxrs290.c b/drivers/iio/gyro/adxrs290.c
index 3efe385ebedc..35928383d4f2 100644
--- a/drivers/iio/gyro/adxrs290.c
+++ b/drivers/iio/gyro/adxrs290.c
@@ -8,6 +8,7 @@
 
 #include <linux/bitfield.h>
 #include <linux/bitops.h>
+#include <linux/cleanup.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
@@ -115,65 +116,53 @@ static const int adxrs290_hpf_3db_freq_hz_table[][2] = {
 static int adxrs290_get_rate_data(struct iio_dev *indio_dev, const u8 cmd, int *val)
 {
 	struct adxrs290_state *st = iio_priv(indio_dev);
-	int ret = 0;
 	int temp;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
+
 	temp = spi_w8r16(st->spi, cmd);
-	if (temp < 0) {
-		ret = temp;
-		goto err_unlock;
-	}
+	if (temp < 0)
+		return temp;
 
 	*val = sign_extend32(temp, 15);
 
-err_unlock:
-	mutex_unlock(&st->lock);
-	return ret;
+	return 0;
 }
 
 static int adxrs290_get_temp_data(struct iio_dev *indio_dev, int *val)
 {
 	const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_TEMP0);
 	struct adxrs290_state *st = iio_priv(indio_dev);
-	int ret = 0;
 	int temp;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
+
 	temp = spi_w8r16(st->spi, cmd);
-	if (temp < 0) {
-		ret = temp;
-		goto err_unlock;
-	}
+	if (temp < 0)
+		return temp;
 
 	/* extract lower 12 bits temperature reading */
 	*val = sign_extend32(temp, 11);
 
-err_unlock:
-	mutex_unlock(&st->lock);
-	return ret;
+	return 0;
 }
 
 static int adxrs290_get_3db_freq(struct iio_dev *indio_dev, u8 *val, u8 *val2)
 {
 	const u8 cmd = ADXRS290_READ_REG(ADXRS290_REG_FILTER);
 	struct adxrs290_state *st = iio_priv(indio_dev);
-	int ret = 0;
 	short temp;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
+
 	temp = spi_w8r8(st->spi, cmd);
-	if (temp < 0) {
-		ret = temp;
-		goto err_unlock;
-	}
+	if (temp < 0)
+		return temp;
 
 	*val = FIELD_GET(ADXRS290_LPF_MASK, temp);
 	*val2 = FIELD_GET(ADXRS290_HPF_MASK, temp);
 
-err_unlock:
-	mutex_unlock(&st->lock);
-	return ret;
+	return 0;
 }
 
 static int adxrs290_spi_write_reg(struct spi_device *spi, const u8 reg,
@@ -220,11 +209,11 @@ static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)
 	if (st->mode == mode)
 		return 0;
 
-	mutex_lock(&st->lock);
+	guard(mutex)(&st->lock);
 
 	ret = spi_w8r8(st->spi, ADXRS290_READ_REG(ADXRS290_REG_POWER_CTL));
 	if (ret < 0)
-		goto out_unlock;
+		return ret;
 
 	val = ret;
 
@@ -236,21 +225,18 @@ static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)
 		val |= ADXRS290_MEASUREMENT;
 		break;
 	default:
-		ret = -EINVAL;
-		goto out_unlock;
+		return -EINVAL;
 	}
 
 	ret = adxrs290_spi_write_reg(st->spi, ADXRS290_REG_POWER_CTL, val);
 	if (ret < 0) {
 		dev_err(&st->spi->dev, "unable to set mode: %d\n", ret);
-		goto out_unlock;
+		return ret;
 	}
 
 	/* update cached mode */
 	st->mode = mode;
 
-out_unlock:
-	mutex_unlock(&st->lock);
 	return ret;
 }
 
@@ -506,19 +492,20 @@ static irqreturn_t adxrs290_trigger_handler(int irq, void *p)
 	u8 tx = ADXRS290_READ_REG(ADXRS290_REG_DATAX0);
 	int ret;
 
-	mutex_lock(&st->lock);
+	do {
+		guard(mutex)(&st->lock);
 
-	/* exercise a bulk data capture starting from reg DATAX0... */
-	ret = spi_write_then_read(st->spi, &tx, sizeof(tx), st->buffer.channels,
-				  sizeof(st->buffer.channels));
-	if (ret < 0)
-		goto out_unlock_notify;
+		/* exercise a bulk data capture starting from reg DATAX0... */
+		ret = spi_write_then_read(st->spi, &tx, sizeof(tx),
+					  st->buffer.channels,
+					  sizeof(st->buffer.channels));
+		if (ret < 0)
+			break;
 
-	iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
-					   pf->timestamp);
+		iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
+						   pf->timestamp);
+	} while (0);
 
-out_unlock_notify:
-	mutex_unlock(&st->lock);
 	iio_trigger_notify_done(indio_dev->trig);
 
 	return IRQ_HANDLED;
-- 
2.43.0

Re: [PATCH v5] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[Maxwell Doose]

On Mon May 4, 2026 at 2:04 PM CDT, Guilherme Dias wrote:
> Use guard(mutex) to automatically release the lock on scope exit,
> simplifying the error handling path and removing the need for
> explicit unlock and goto-based cleanup.
>
> Signed-off-by: Guilherme Dias <guilhermeabreu200105@usp.br>
> Co-developed-by: João Paulo Menezes Linaris <jplinaris@usp.br>
> Signed-off-by: João Paulo Menezes Linaris <jplinaris@usp.br>
> ---
> v5:
>  - add cleanup.h
>
> v4:
>  - fix indentation
>
>  drivers/iio/gyro/adxrs290.c | 75 +++++++++++++++----------------------
>  1 file changed, 31 insertions(+), 44 deletions(-)
>

LGTM.

Reviewed-by: Maxwell Doose <m32285159@gmail.com>

best regards,
max

Re: [PATCH v5] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[Andy Shevchenko]

On Mon, May 04, 2026 at 04:04:25PM -0300, Guilherme Dias wrote:
> Use guard(mutex) to automatically release the lock on scope exit,

Better to point that guard is kinda "operator" and hence we refer to it as
guard()() [note double parentheses], but it's minor, just for the future.

> simplifying the error handling path and removing the need for
> explicit unlock and goto-based cleanup.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v5] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[Jonathan Cameron]

On Tue, 5 May 2026 11:49:19 +0300
Andy Shevchenko <andriy.shevchenko@intel.com> wrote:

> On Mon, May 04, 2026 at 04:04:25PM -0300, Guilherme Dias wrote:
> > Use guard(mutex) to automatically release the lock on scope exit,  
> 
> Better to point that guard is kinda "operator" and hence we refer to it as
> guard()() [note double parentheses], but it's minor, just for the future.
> 
> > simplifying the error handling path and removing the need for
> > explicit unlock and goto-based cleanup.  
> 
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
> 


Applied to the testing branch of iio.git

Thanks for the patch and thanks to all those involved in review!

Jonathan