[PATCH] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

[PATCH] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

[Alexandru Ardelean]

The iio_triggered_buffer_{predisable,postenable} functions attach/detach
the poll functions.

For the predisable hook, the disable code should occur before detaching
the poll func, and for the postenable hook, the poll func should be
attached before the enable code.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
 drivers/iio/accel/st_accel_buffer.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/accel/st_accel_buffer.c b/drivers/iio/accel/st_accel_buffer.c
index 7fddc137e91e..58cc6305f66e 100644
--- a/drivers/iio/accel/st_accel_buffer.c
+++ b/drivers/iio/accel/st_accel_buffer.c
@@ -40,6 +40,10 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
 	int err;
 	struct st_sensor_data *adata = iio_priv(indio_dev);
 
+	err = iio_triggered_buffer_postenable(indio_dev);
+	if (err < 0)
+		return err;
+
 	adata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
 	if (adata->buffer_data == NULL) {
 		err = -ENOMEM;
@@ -51,15 +55,12 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
 	if (err < 0)
 		goto st_accel_buffer_postenable_error;
 
-	err = iio_triggered_buffer_postenable(indio_dev);
-	if (err < 0)
-		goto st_accel_buffer_postenable_error;
-
 	return err;
 
 st_accel_buffer_postenable_error:
 	kfree(adata->buffer_data);
 allocate_memory_error:
+	iio_triggered_buffer_predisable(indio_dev);
 	return err;
 }
 
@@ -68,19 +69,17 @@ static int st_accel_buffer_predisable(struct iio_dev *indio_dev)
 	int err;
 	struct st_sensor_data *adata = iio_priv(indio_dev);
 
-	err = iio_triggered_buffer_predisable(indio_dev);
-	if (err < 0)
-		goto st_accel_buffer_predisable_error;
-
 	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
 	if (err < 0)
 		goto st_accel_buffer_predisable_error;
 
 	err = st_sensors_set_enable(indio_dev, false);
+	if (err < 0)
+		goto st_accel_buffer_predisable_error;
 
 st_accel_buffer_predisable_error:
 	kfree(adata->buffer_data);
-	return err;
+	return iio_triggered_buffer_predisable(indio_dev);
 }
 
 static const struct iio_buffer_setup_ops st_accel_buffer_setup_ops = {
-- 
2.20.1

[PATCH][V2] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

[Alexandru Ardelean]

The iio_triggered_buffer_{predisable,postenable} functions attach/detach
the poll functions.

For the predisable hook, the disable code should occur before detaching
the poll func, and for the postenable hook, the poll func should be
attached before the enable code.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
Changelog v1 -> v2:
* record the first error in st_accel_buffer_predisable() and return that 

 drivers/iio/accel/st_accel_buffer.c | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/accel/st_accel_buffer.c b/drivers/iio/accel/st_accel_buffer.c
index 7fddc137e91e..711ecd9bc898 100644
--- a/drivers/iio/accel/st_accel_buffer.c
+++ b/drivers/iio/accel/st_accel_buffer.c
@@ -40,6 +40,10 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
 	int err;
 	struct st_sensor_data *adata = iio_priv(indio_dev);
 
+	err = iio_triggered_buffer_postenable(indio_dev);
+	if (err < 0)
+		return err;
+
 	adata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
 	if (adata->buffer_data == NULL) {
 		err = -ENOMEM;
@@ -51,34 +55,33 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
 	if (err < 0)
 		goto st_accel_buffer_postenable_error;
 
-	err = iio_triggered_buffer_postenable(indio_dev);
-	if (err < 0)
-		goto st_accel_buffer_postenable_error;
-
 	return err;
 
 st_accel_buffer_postenable_error:
 	kfree(adata->buffer_data);
 allocate_memory_error:
+	iio_triggered_buffer_predisable(indio_dev);
 	return err;
 }
 
 static int st_accel_buffer_predisable(struct iio_dev *indio_dev)
 {
-	int err;
+	int err, err2;
 	struct st_sensor_data *adata = iio_priv(indio_dev);
 
-	err = iio_triggered_buffer_predisable(indio_dev);
-	if (err < 0)
-		goto st_accel_buffer_predisable_error;
-
 	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
 	if (err < 0)
 		goto st_accel_buffer_predisable_error;
 
 	err = st_sensors_set_enable(indio_dev, false);
+	if (err < 0)
+		goto st_accel_buffer_predisable_error;
 
 st_accel_buffer_predisable_error:
+	err2 = iio_triggered_buffer_predisable(indio_dev);
+	if (!err)
+		err = err2;
+
 	kfree(adata->buffer_data);
 	return err;
 }
-- 
2.20.1

Re: [PATCH][V2] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

[Jonathan Cameron]

On Wed, 29 May 2019 16:58:48 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:

> The iio_triggered_buffer_{predisable,postenable} functions attach/detach
> the poll functions.
> 
> For the predisable hook, the disable code should occur before detaching
> the poll func, and for the postenable hook, the poll func should be
> attached before the enable code.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
I think this is fine, but I'd like an ack from Lorenzo / Denis.

Note to those who have missed the background on this, the aim is
to both tidy up drivers, but long term to allow for simpler reworking
of the core by ensuring consistency of ordering and what is done
in each of these hooks.

Thanks,

Jonathan

> ---
> Changelog v1 -> v2:
> * record the first error in st_accel_buffer_predisable() and return that 
> 
>  drivers/iio/accel/st_accel_buffer.c | 21 ++++++++++++---------
>  1 file changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/iio/accel/st_accel_buffer.c b/drivers/iio/accel/st_accel_buffer.c
> index 7fddc137e91e..711ecd9bc898 100644
> --- a/drivers/iio/accel/st_accel_buffer.c
> +++ b/drivers/iio/accel/st_accel_buffer.c
> @@ -40,6 +40,10 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
>  	int err;
>  	struct st_sensor_data *adata = iio_priv(indio_dev);
>  
> +	err = iio_triggered_buffer_postenable(indio_dev);
> +	if (err < 0)
> +		return err;
> +
>  	adata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
>  	if (adata->buffer_data == NULL) {
>  		err = -ENOMEM;
> @@ -51,34 +55,33 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
>  	if (err < 0)
>  		goto st_accel_buffer_postenable_error;
>  
> -	err = iio_triggered_buffer_postenable(indio_dev);
> -	if (err < 0)
> -		goto st_accel_buffer_postenable_error;
> -
>  	return err;
>  
>  st_accel_buffer_postenable_error:
>  	kfree(adata->buffer_data);
>  allocate_memory_error:
> +	iio_triggered_buffer_predisable(indio_dev);
>  	return err;
>  }
>  
>  static int st_accel_buffer_predisable(struct iio_dev *indio_dev)
>  {
> -	int err;
> +	int err, err2;
>  	struct st_sensor_data *adata = iio_priv(indio_dev);
>  
> -	err = iio_triggered_buffer_predisable(indio_dev);
> -	if (err < 0)
> -		goto st_accel_buffer_predisable_error;
> -
>  	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
>  	if (err < 0)
>  		goto st_accel_buffer_predisable_error;
>  
>  	err = st_sensors_set_enable(indio_dev, false);
> +	if (err < 0)
> +		goto st_accel_buffer_predisable_error;
>  
>  st_accel_buffer_predisable_error:
> +	err2 = iio_triggered_buffer_predisable(indio_dev);
> +	if (!err)
> +		err = err2;
> +
>  	kfree(adata->buffer_data);
>  	return err;
>  }

RE: [PATCH][V2] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

[Denis CIOCCA]

Hi Jonathan, Alexandru,

I agree with you about the predisable but I am not convinced regarding the postenable.
Few modifications have been made on magn driver and never replicated on accel. I think should be done in the same way magn is implemented.
During postenable kmalloc should be called first because iio_triggered_buffer_postenable function it enables irq and if an interrupt arrives before the memory is allocated (wrong interrupt or failure of switching sensor off from previous disable) it could generate a null pointer exception. Make sense to you?

Thanks & Br,
Denis



-----Original Message-----
From: Jonathan Cameron <jic23@jic23.retrosnub.co.uk> 
Sent: Saturday, June 8, 2019 7:10 AM
To: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: linux-iio@vger.kernel.org; Denis CIOCCA <denis.ciocca@st.com>; Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Subject: Re: [PATCH][V2] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

On Wed, 29 May 2019 16:58:48 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:

> The iio_triggered_buffer_{predisable,postenable} functions 
> attach/detach the poll functions.
> 
> For the predisable hook, the disable code should occur before 
> detaching the poll func, and for the postenable hook, the poll func 
> should be attached before the enable code.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
I think this is fine, but I'd like an ack from Lorenzo / Denis.

Note to those who have missed the background on this, the aim is to both tidy up drivers, but long term to allow for simpler reworking of the core by ensuring consistency of ordering and what is done in each of these hooks.

Thanks,

Jonathan

> ---
> Changelog v1 -> v2:
> * record the first error in st_accel_buffer_predisable() and return 
> that
> 
>  drivers/iio/accel/st_accel_buffer.c | 21 ++++++++++++---------
>  1 file changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/iio/accel/st_accel_buffer.c 
> b/drivers/iio/accel/st_accel_buffer.c
> index 7fddc137e91e..711ecd9bc898 100644
> --- a/drivers/iio/accel/st_accel_buffer.c
> +++ b/drivers/iio/accel/st_accel_buffer.c
> @@ -40,6 +40,10 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
>  	int err;
>  	struct st_sensor_data *adata = iio_priv(indio_dev);
>  
> +	err = iio_triggered_buffer_postenable(indio_dev);
> +	if (err < 0)
> +		return err;
> +
>  	adata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
>  	if (adata->buffer_data == NULL) {
>  		err = -ENOMEM;
> @@ -51,34 +55,33 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
>  	if (err < 0)
>  		goto st_accel_buffer_postenable_error;
>  
> -	err = iio_triggered_buffer_postenable(indio_dev);
> -	if (err < 0)
> -		goto st_accel_buffer_postenable_error;
> -
>  	return err;
>  
>  st_accel_buffer_postenable_error:
>  	kfree(adata->buffer_data);
>  allocate_memory_error:
> +	iio_triggered_buffer_predisable(indio_dev);
>  	return err;
>  }
>  
>  static int st_accel_buffer_predisable(struct iio_dev *indio_dev)  {
> -	int err;
> +	int err, err2;
>  	struct st_sensor_data *adata = iio_priv(indio_dev);
>  
> -	err = iio_triggered_buffer_predisable(indio_dev);
> -	if (err < 0)
> -		goto st_accel_buffer_predisable_error;
> -
>  	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
>  	if (err < 0)
>  		goto st_accel_buffer_predisable_error;
>  
>  	err = st_sensors_set_enable(indio_dev, false);
> +	if (err < 0)
> +		goto st_accel_buffer_predisable_error;
>  
>  st_accel_buffer_predisable_error:
> +	err2 = iio_triggered_buffer_predisable(indio_dev);
> +	if (!err)
> +		err = err2;
> +
>  	kfree(adata->buffer_data);
>  	return err;
>  }

Re: [PATCH][V2] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

[Ardelean, Alexandru]

On Mon, 2019-06-10 at 21:20 +0000, Denis CIOCCA wrote:
> [External]
> 
> 
> Hi Jonathan, Alexandru,
> 
> I agree with you about the predisable but I am not convinced regarding the postenable.
> Few modifications have been made on magn driver and never replicated on accel. I think should be done in the same way
> magn is implemented.
> During postenable kmalloc should be called first because iio_triggered_buffer_postenable function it enables irq and
> if an interrupt arrives before the memory is allocated (wrong interrupt or failure of switching sensor off from
> previous disable) it could generate a null pointer exception. Make sense to you?

I got the gist of it.
And it makes sense.
I'll update the patch.

[on a related topic]
One curious/question: would it make sense to move the allocation of `buffer_data` somewhere in
`drivers/iio/common/st_sensor/st_sensors_buffer.c` ?
I was looking for `buffer_data` [and how it's used], and notice this.

Thanks
Alex

> 
> Thanks & Br,
> Denis
> 
> 
> 
> -----Original Message-----
> From: Jonathan Cameron <jic23@jic23.retrosnub.co.uk>
> Sent: Saturday, June 8, 2019 7:10 AM
> To: Alexandru Ardelean <alexandru.ardelean@analog.com>
> Cc: linux-iio@vger.kernel.org; Denis CIOCCA <denis.ciocca@st.com>; Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
> Subject: Re: [PATCH][V2] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions
> 
> On Wed, 29 May 2019 16:58:48 +0300
> Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:
> 
> > The iio_triggered_buffer_{predisable,postenable} functions
> > attach/detach the poll functions.
> > 
> > For the predisable hook, the disable code should occur before
> > detaching the poll func, and for the postenable hook, the poll func
> > should be attached before the enable code.
> > 
> > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> I think this is fine, but I'd like an ack from Lorenzo / Denis.
> 
> Note to those who have missed the background on this, the aim is to both tidy up drivers, but long term to allow for
> simpler reworking of the core by ensuring consistency of ordering and what is done in each of these hooks.
> 
> Thanks,
> 
> Jonathan
> 
> > ---
> > Changelog v1 -> v2:
> > * record the first error in st_accel_buffer_predisable() and return
> > that
> > 
> >  drivers/iio/accel/st_accel_buffer.c | 21 ++++++++++++---------
> >  1 file changed, 12 insertions(+), 9 deletions(-)
> > 
> > diff --git a/drivers/iio/accel/st_accel_buffer.c
> > b/drivers/iio/accel/st_accel_buffer.c
> > index 7fddc137e91e..711ecd9bc898 100644
> > --- a/drivers/iio/accel/st_accel_buffer.c
> > +++ b/drivers/iio/accel/st_accel_buffer.c
> > @@ -40,6 +40,10 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
> >       int err;
> >       struct st_sensor_data *adata = iio_priv(indio_dev);
> > 
> > +     err = iio_triggered_buffer_postenable(indio_dev);
> > +     if (err < 0)
> > +             return err;
> > +
> >       adata->buffer_data = kmalloc(indio_dev->scan_bytes, GFP_KERNEL);
> >       if (adata->buffer_data == NULL) {
> >               err = -ENOMEM;
> > @@ -51,34 +55,33 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
> >       if (err < 0)
> >               goto st_accel_buffer_postenable_error;
> > 
> > -     err = iio_triggered_buffer_postenable(indio_dev);
> > -     if (err < 0)
> > -             goto st_accel_buffer_postenable_error;
> > -
> >       return err;
> > 
> >  st_accel_buffer_postenable_error:
> >       kfree(adata->buffer_data);
> >  allocate_memory_error:
> > +     iio_triggered_buffer_predisable(indio_dev);
> >       return err;
> >  }
> > 
> >  static int st_accel_buffer_predisable(struct iio_dev *indio_dev)  {
> > -     int err;
> > +     int err, err2;
> >       struct st_sensor_data *adata = iio_priv(indio_dev);
> > 
> > -     err = iio_triggered_buffer_predisable(indio_dev);
> > -     if (err < 0)
> > -             goto st_accel_buffer_predisable_error;
> > -
> >       err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
> >       if (err < 0)
> >               goto st_accel_buffer_predisable_error;
> > 
> >       err = st_sensors_set_enable(indio_dev, false);
> > +     if (err < 0)
> > +             goto st_accel_buffer_predisable_error;
> > 
> >  st_accel_buffer_predisable_error:
> > +     err2 = iio_triggered_buffer_predisable(indio_dev);
> > +     if (!err)
> > +             err = err2;
> > +
> >       kfree(adata->buffer_data);
> >       return err;
> >  }

[PATCH][V3] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

[Alexandru Ardelean]

The iio_triggered_buffer_{predisable,postenable} functions attach/detach
the poll functions.

For the predisable hook, the disable code should occur before detaching
the poll func, and for the postenable hook, the poll func should be
attached before the enable code.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---

Changelog v1 -> v2:
* record the first error in st_accel_buffer_predisable() and return that 

Changelog v2 -> v3:
* move iio_triggered_buffer_postenable() after the allocation, but before
  `st_sensors_set_axis_enable()` based on comment from
  `Denis Ciocca <denis.ciocca@st.com>`

 drivers/iio/accel/st_accel_buffer.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/accel/st_accel_buffer.c b/drivers/iio/accel/st_accel_buffer.c
index 7fddc137e91e..802ab7d2d93f 100644
--- a/drivers/iio/accel/st_accel_buffer.c
+++ b/drivers/iio/accel/st_accel_buffer.c
@@ -46,17 +46,19 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
 		goto allocate_memory_error;
 	}
 
-	err = st_sensors_set_axis_enable(indio_dev,
-					(u8)indio_dev->active_scan_mask[0]);
+	err = iio_triggered_buffer_postenable(indio_dev);
 	if (err < 0)
 		goto st_accel_buffer_postenable_error;
 
-	err = iio_triggered_buffer_postenable(indio_dev);
+	err = st_sensors_set_axis_enable(indio_dev,
+					(u8)indio_dev->active_scan_mask[0]);
 	if (err < 0)
-		goto st_accel_buffer_postenable_error;
+		goto st_sensors_set_axis_enable_error;
 
 	return err;
 
+st_sensors_set_axis_enable_error:
+	iio_triggered_buffer_predisable(indio_dev);
 st_accel_buffer_postenable_error:
 	kfree(adata->buffer_data);
 allocate_memory_error:
@@ -65,20 +67,22 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
 
 static int st_accel_buffer_predisable(struct iio_dev *indio_dev)
 {
-	int err;
+	int err, err2;
 	struct st_sensor_data *adata = iio_priv(indio_dev);
 
-	err = iio_triggered_buffer_predisable(indio_dev);
-	if (err < 0)
-		goto st_accel_buffer_predisable_error;
-
 	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
 	if (err < 0)
 		goto st_accel_buffer_predisable_error;
 
 	err = st_sensors_set_enable(indio_dev, false);
+	if (err < 0)
+		goto st_accel_buffer_predisable_error;
 
 st_accel_buffer_predisable_error:
+	err2 = iio_triggered_buffer_predisable(indio_dev);
+	if (!err)
+		err = err2;
+
 	kfree(adata->buffer_data);
 	return err;
 }
-- 
2.20.1

RE: [PATCH][V3] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

[Denis CIOCCA]

Hi Alexandru,

Looks good to me.

Acked-by: Denis Ciocca <denis.ciocca@st.com>

Thanks,
Denis


-----Original Message-----
From: linux-iio-owner@vger.kernel.org <linux-iio-owner@vger.kernel.org> On Behalf Of Alexandru Ardelean
Sent: Friday, June 14, 2019 3:47 AM
To: linux-iio@vger.kernel.org
Cc: Alexandru Ardelean <alexandru.ardelean@analog.com>
Subject: [PATCH][V3] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

The iio_triggered_buffer_{predisable,postenable} functions attach/detach the poll functions.

For the predisable hook, the disable code should occur before detaching the poll func, and for the postenable hook, the poll func should be attached before the enable code.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---

Changelog v1 -> v2:
* record the first error in st_accel_buffer_predisable() and return that 

Changelog v2 -> v3:
* move iio_triggered_buffer_postenable() after the allocation, but before
  `st_sensors_set_axis_enable()` based on comment from
  `Denis Ciocca <denis.ciocca@st.com>`

 drivers/iio/accel/st_accel_buffer.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/iio/accel/st_accel_buffer.c b/drivers/iio/accel/st_accel_buffer.c
index 7fddc137e91e..802ab7d2d93f 100644
--- a/drivers/iio/accel/st_accel_buffer.c
+++ b/drivers/iio/accel/st_accel_buffer.c
@@ -46,17 +46,19 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
 		goto allocate_memory_error;
 	}
 
-	err = st_sensors_set_axis_enable(indio_dev,
-					(u8)indio_dev->active_scan_mask[0]);
+	err = iio_triggered_buffer_postenable(indio_dev);
 	if (err < 0)
 		goto st_accel_buffer_postenable_error;
 
-	err = iio_triggered_buffer_postenable(indio_dev);
+	err = st_sensors_set_axis_enable(indio_dev,
+					(u8)indio_dev->active_scan_mask[0]);
 	if (err < 0)
-		goto st_accel_buffer_postenable_error;
+		goto st_sensors_set_axis_enable_error;
 
 	return err;
 
+st_sensors_set_axis_enable_error:
+	iio_triggered_buffer_predisable(indio_dev);
 st_accel_buffer_postenable_error:
 	kfree(adata->buffer_data);
 allocate_memory_error:
@@ -65,20 +67,22 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
 
 static int st_accel_buffer_predisable(struct iio_dev *indio_dev)  {
-	int err;
+	int err, err2;
 	struct st_sensor_data *adata = iio_priv(indio_dev);
 
-	err = iio_triggered_buffer_predisable(indio_dev);
-	if (err < 0)
-		goto st_accel_buffer_predisable_error;
-
 	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
 	if (err < 0)
 		goto st_accel_buffer_predisable_error;
 
 	err = st_sensors_set_enable(indio_dev, false);
+	if (err < 0)
+		goto st_accel_buffer_predisable_error;
 
 st_accel_buffer_predisable_error:
+	err2 = iio_triggered_buffer_predisable(indio_dev);
+	if (!err)
+		err = err2;
+
 	kfree(adata->buffer_data);
 	return err;
 }
--
2.20.1

Re: [PATCH][V3] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions

[Jonathan Cameron]

On Mon, 17 Jun 2019 22:12:02 +0000
Denis CIOCCA <denis.ciocca@st.com> wrote:

> Hi Alexandru,
> 
> Looks good to me.
> 
> Acked-by: Denis Ciocca <denis.ciocca@st.com>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Thanks,

Jonathan


> 
> Thanks,
> Denis
> 
> 
> -----Original Message-----
> From: linux-iio-owner@vger.kernel.org <linux-iio-owner@vger.kernel.org> On Behalf Of Alexandru Ardelean
> Sent: Friday, June 14, 2019 3:47 AM
> To: linux-iio@vger.kernel.org
> Cc: Alexandru Ardelean <alexandru.ardelean@analog.com>
> Subject: [PATCH][V3] iio: st_accel: fix iio_triggered_buffer_{pre,post}enable positions
> 
> The iio_triggered_buffer_{predisable,postenable} functions attach/detach the poll functions.
> 
> For the predisable hook, the disable code should occur before detaching the poll func, and for the postenable hook, the poll func should be attached before the enable code.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
> ---
> 
> Changelog v1 -> v2:
> * record the first error in st_accel_buffer_predisable() and return that 
> 
> Changelog v2 -> v3:
> * move iio_triggered_buffer_postenable() after the allocation, but before
>   `st_sensors_set_axis_enable()` based on comment from
>   `Denis Ciocca <denis.ciocca@st.com>`
> 
>  drivers/iio/accel/st_accel_buffer.c | 22 +++++++++++++---------
>  1 file changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/iio/accel/st_accel_buffer.c b/drivers/iio/accel/st_accel_buffer.c
> index 7fddc137e91e..802ab7d2d93f 100644
> --- a/drivers/iio/accel/st_accel_buffer.c
> +++ b/drivers/iio/accel/st_accel_buffer.c
> @@ -46,17 +46,19 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
>  		goto allocate_memory_error;
>  	}
>  
> -	err = st_sensors_set_axis_enable(indio_dev,
> -					(u8)indio_dev->active_scan_mask[0]);
> +	err = iio_triggered_buffer_postenable(indio_dev);
>  	if (err < 0)
>  		goto st_accel_buffer_postenable_error;
>  
> -	err = iio_triggered_buffer_postenable(indio_dev);
> +	err = st_sensors_set_axis_enable(indio_dev,
> +					(u8)indio_dev->active_scan_mask[0]);
>  	if (err < 0)
> -		goto st_accel_buffer_postenable_error;
> +		goto st_sensors_set_axis_enable_error;
>  
>  	return err;
>  
> +st_sensors_set_axis_enable_error:
> +	iio_triggered_buffer_predisable(indio_dev);
>  st_accel_buffer_postenable_error:
>  	kfree(adata->buffer_data);
>  allocate_memory_error:
> @@ -65,20 +67,22 @@ static int st_accel_buffer_postenable(struct iio_dev *indio_dev)
>  
>  static int st_accel_buffer_predisable(struct iio_dev *indio_dev)  {
> -	int err;
> +	int err, err2;
>  	struct st_sensor_data *adata = iio_priv(indio_dev);
>  
> -	err = iio_triggered_buffer_predisable(indio_dev);
> -	if (err < 0)
> -		goto st_accel_buffer_predisable_error;
> -
>  	err = st_sensors_set_axis_enable(indio_dev, ST_SENSORS_ENABLE_ALL_AXIS);
>  	if (err < 0)
>  		goto st_accel_buffer_predisable_error;
>  
>  	err = st_sensors_set_enable(indio_dev, false);
> +	if (err < 0)
> +		goto st_accel_buffer_predisable_error;
>  
>  st_accel_buffer_predisable_error:
> +	err2 = iio_triggered_buffer_predisable(indio_dev);
> +	if (!err)
> +		err = err2;
> +
>  	kfree(adata->buffer_data);
>  	return err;
>  }
> --
> 2.20.1
>