[PATCH v2] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[PATCH v2] 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>
---
v2:
 - added returns mistakenly removed
 - remove unnecessary ret in adxrs290_get_rate_data(),
   adxrs290_get_temp_data() and adxrs290_get_3db_freq()
 - invert condition in adxrs290_trigger_handler() to eliminate goto

 drivers/iio/gyro/adxrs290.c | 65 ++++++++++++-------------------------
 1 file changed, 20 insertions(+), 45 deletions(-)

diff --git a/drivers/iio/gyro/adxrs290.c b/drivers/iio/gyro/adxrs290.c
index 3efe385ebedc..25b6dd6e986d 100644
--- a/drivers/iio/gyro/adxrs290.c
+++ b/drivers/iio/gyro/adxrs290.c
@@ -115,65 +115,47 @@ 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 +202,11 @@ 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;
 
@@ -237,20 +219,17 @@ static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)
 		break;
 	default:
 		ret = -EINVAL;
-		goto out_unlock;
+		return ret;
 	}
 
 	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;
 }
 
@@ -506,21 +485,17 @@ static irqreturn_t adxrs290_trigger_handler(int irq, void *p)
 	u8 tx = ADXRS290_READ_REG(ADXRS290_REG_DATAX0);
 	int ret;
 
-	mutex_lock(&st->lock);
+	scoped_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;
-
-	iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
+	if (ret >= 0)
+		iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
 					   pf->timestamp);
+	}
 
-out_unlock_notify:
-	mutex_unlock(&st->lock);
 	iio_trigger_notify_done(indio_dev->trig);
-
 	return IRQ_HANDLED;
 }
 
-- 
2.43.0

Re: [PATCH v2] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[Andy Shevchenko]

On Thu, Apr 23, 2026 at 07:37:51PM -0300, 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.

...

>  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);

+ blank line.

We usually consider guard()() as not semantically linked to any code above
or below

>  	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;
>  }

Ditto for the similar cases below.

...

> static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)

>  	default:
>  		ret = -EINVAL;
> -		goto out_unlock;
> +		return ret;

Just return directly the given error code.

...

> static irqreturn_t adxrs290_trigger_handler(int irq, void *p)

> -	mutex_lock(&st->lock);
> +	scoped_guard(mutex, &st->lock){

No. Besides wrong style of this line, this has a very broken indentation now.

>  	/* 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;
> -
> -	iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
> +	if (ret >= 0)
> +		iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
>  					   pf->timestamp);
> +	}
>  
> -out_unlock_notify:
> -	mutex_unlock(&st->lock);

>  	iio_trigger_notify_done(indio_dev->trig);
> -
>  	return IRQ_HANDLED;

Stray change.

>  }

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[Jonathan Cameron]

On Fri, 24 Apr 2026 12:24:07 +0300
Andy Shevchenko <andriy.shevchenko@intel.com> wrote:

> On Thu, Apr 23, 2026 at 07:37:51PM -0300, 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.  
> 
> ...
> 
> >  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);  
> 
> + blank line.
> 
> We usually consider guard()() as not semantically linked to any code above
> or below
> 
> >  	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;
> >  }  
> 
> Ditto for the similar cases below.
> 
> ...
> 
> > static int adxrs290_set_mode(struct iio_dev *indio_dev, enum adxrs290_mode mode)  
> 
> >  	default:
> >  		ret = -EINVAL;
> > -		goto out_unlock;
> > +		return ret;  
> 
> Just return directly the given error code.
> 
> ...
> 
> > static irqreturn_t adxrs290_trigger_handler(int irq, void *p)  
> 
> > -	mutex_lock(&st->lock);
> > +	scoped_guard(mutex, &st->lock){  
> 
> No. Besides wrong style of this line, this has a very broken indentation now.
> 
> >  	/* 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;
> > -
> > -	iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
> > +	if (ret >= 0)
No to this as well. Keep the error out of line.  Which makes the use
of guard() here tricky.  You could do a do { guard(); } while(0) loop so that
you can use break with out it being odd looking.

(I don't like breaks out of scoped_guard() because it's non obvious scoped
guard is actually a loop.

> > +		iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
> >  					   pf->timestamp);
> > +	}

> >  
> > -out_unlock_notify:
> > -	mutex_unlock(&st->lock);  
> 
> >  	iio_trigger_notify_done(indio_dev->trig);
> > -
> >  	return IRQ_HANDLED;  
> 
> Stray change.
> 
> >  }  
> 

Re: [PATCH v2] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[Guilherme Dias]

Em sex., 24 de abr. de 2026 às 07:39, Jonathan Cameron
<jic23@kernel.org> escreveu:
>
> On Fri, 24 Apr 2026 12:24:07 +0300
> Andy Shevchenko <andriy.shevchenko@intel.com> wrote:
>
> > On Thu, Apr 23, 2026 at 07:37:51PM -0300, 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.
...
> > >     /* 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;
> > > -
> > > -   iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
> > > +   if (ret >= 0)
> No to this as well. Keep the error out of line.  Which makes the use
> of guard() here tricky.  You could do a do { guard(); } while(0) loop so that
> you can use break with out it being odd looking.
>
> (I don't like breaks out of scoped_guard() because it's non obvious scoped
> guard is actually a loop.

Thanks for the suggestion — just to confirm I understood correctly, do
you mean something like this?

...
 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)
            break;

 iio_push_to_buffers_with_timestamp(indio_dev, &st->buffer,
                         pf->timestamp);
 } while (0);

 iio_trigger_notify_done(indio_dev->trig);
 return IRQ_HANDLED;
}

Keeping the error out of line again.

--
Kind regards,
Guilherme Dias

Re: [PATCH v2] iio: gyro: adxrs290: Use guard(mutex) in lieu of manual lock+unlock

[Andy Shevchenko]

On Mon, Apr 27, 2026 at 07:04:23PM -0300, Guilherme Dias wrote:
> Em sex., 24 de abr. de 2026 às 07:39, Jonathan Cameron
> <jic23@kernel.org> escreveu:
> > On Fri, 24 Apr 2026 12:24:07 +0300
> > Andy Shevchenko <andriy.shevchenko@intel.com> wrote:
> > > On Thu, Apr 23, 2026 at 07:37:51PM -0300, Guilherme Dias wrote:

...

> > > >     /* 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;

> > > > +   if (ret >= 0)
> > No to this as well. Keep the error out of line.  Which makes the use
> > of guard() here tricky.  You could do a do { guard(); } while(0) loop so that
> > you can use break with out it being odd looking.
> >
> > (I don't like breaks out of scoped_guard() because it's non obvious scoped
> > guard is actually a loop.
> 
> Thanks for the suggestion — just to confirm I understood correctly, do
> you mean something like this?

Yes, with proper indentation made.

-- 
With Best Regards,
Andy Shevchenko