[PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Andy Shevchenko]

Use devm_add_action_or_reset() instead of devres_alloc() and
devres_add(), which works the same. This will simplify the
code. There is no functional changes.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/iio/buffer/kfifo_buf.c     | 29 +++++++++++++----------------
 drivers/iio/industrialio-trigger.c | 24 ++++++++++--------------
 2 files changed, 23 insertions(+), 30 deletions(-)

diff --git a/drivers/iio/buffer/kfifo_buf.c b/drivers/iio/buffer/kfifo_buf.c
index 38034c8bcc04..a126cc05fb38 100644
--- a/drivers/iio/buffer/kfifo_buf.c
+++ b/drivers/iio/buffer/kfifo_buf.c
@@ -224,9 +224,9 @@ void iio_kfifo_free(struct iio_buffer *r)
 }
 EXPORT_SYMBOL(iio_kfifo_free);
 
-static void devm_iio_kfifo_release(struct device *dev, void *res)
+static void devm_iio_kfifo_release(void *r)
 {
-	iio_kfifo_free(*(struct iio_buffer **)res);
+	iio_kfifo_free(r);
 }
 
 /**
@@ -234,23 +234,20 @@ static void devm_iio_kfifo_release(struct device *dev, void *res)
  * @dev:		Device to allocate kfifo buffer for
  *
  * RETURNS:
- * Pointer to allocated iio_buffer on success, NULL on failure.
+ * Pointer to allocated iio_buffer on success, error pointer on failure.
  */
 static struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
 {
-	struct iio_buffer **ptr, *r;
-
-	ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL);
-	if (!ptr)
-		return NULL;
+	struct iio_buffer *r;
+	int ret;
 
 	r = iio_kfifo_allocate();
-	if (r) {
-		*ptr = r;
-		devres_add(dev, ptr);
-	} else {
-		devres_free(ptr);
-	}
+	if (!r)
+		return ERR_PTR(-ENOMEM);
+
+	ret = devm_add_action_or_reset(dev, devm_iio_kfifo_release, r);
+	if (ret)
+		return ERR_PTR(ret);
 
 	return r;
 }
@@ -275,8 +272,8 @@ int devm_iio_kfifo_buffer_setup_ext(struct device *dev,
 	struct iio_buffer *buffer;
 
 	buffer = devm_iio_kfifo_allocate(dev);
-	if (!buffer)
-		return -ENOMEM;
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
 
 	indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
 	indio_dev->setup_ops = setup_ops;
diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c
index 54416a384232..00c8b7e5c8b9 100644
--- a/drivers/iio/industrialio-trigger.c
+++ b/drivers/iio/industrialio-trigger.c
@@ -634,9 +634,9 @@ void iio_trigger_free(struct iio_trigger *trig)
 }
 EXPORT_SYMBOL(iio_trigger_free);
 
-static void devm_iio_trigger_release(struct device *dev, void *res)
+static void devm_iio_trigger_release(void *trig)
 {
-	iio_trigger_free(*(struct iio_trigger **)res);
+	iio_trigger_free(trig);
 }
 
 /**
@@ -658,24 +658,20 @@ struct iio_trigger *__devm_iio_trigger_alloc(struct device *parent,
 					     struct module *this_mod,
 					     const char *fmt, ...)
 {
-	struct iio_trigger **ptr, *trig;
+	struct iio_trigger *trig;
 	va_list vargs;
-
-	ptr = devres_alloc(devm_iio_trigger_release, sizeof(*ptr),
-			   GFP_KERNEL);
-	if (!ptr)
-		return NULL;
+	int ret;
 
 	/* use raw alloc_dr for kmalloc caller tracing */
 	va_start(vargs, fmt);
 	trig = viio_trigger_alloc(parent, this_mod, fmt, vargs);
 	va_end(vargs);
-	if (trig) {
-		*ptr = trig;
-		devres_add(parent, ptr);
-	} else {
-		devres_free(ptr);
-	}
+	if (!trig)
+		return NULL;
+
+	ret = devm_add_action_or_reset(parent, devm_iio_trigger_release, trig);
+	if (ret)
+		return NULL;
 
 	return trig;
 }
-- 
2.50.1

Re: [PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Nuno Sá]

On Mon, 2026-02-16 at 09:14 +0100, Andy Shevchenko wrote:
> Use devm_add_action_or_reset() instead of devres_alloc() and
> devres_add(), which works the same. This will simplify the
> code. There is no functional changes.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---

LGTM. Just one minor "complain". Anyways:

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  drivers/iio/buffer/kfifo_buf.c     | 29 +++++++++++++----------------
>  drivers/iio/industrialio-trigger.c | 24 ++++++++++--------------
>  2 files changed, 23 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/iio/buffer/kfifo_buf.c b/drivers/iio/buffer/kfifo_buf.c
> index 38034c8bcc04..a126cc05fb38 100644
> --- a/drivers/iio/buffer/kfifo_buf.c
> +++ b/drivers/iio/buffer/kfifo_buf.c
> @@ -224,9 +224,9 @@ void iio_kfifo_free(struct iio_buffer *r)
>  }
>  EXPORT_SYMBOL(iio_kfifo_free);
>  
> -static void devm_iio_kfifo_release(struct device *dev, void *res)
> +static void devm_iio_kfifo_release(void *r)
>  {
> -	iio_kfifo_free(*(struct iio_buffer **)res);
> +	iio_kfifo_free(r);
>  }
>  
>  /**
> @@ -234,23 +234,20 @@ static void devm_iio_kfifo_release(struct device *dev, void *res)
>   * @dev:		Device to allocate kfifo buffer for
>   *
>   * RETURNS:
> - * Pointer to allocated iio_buffer on success, NULL on failure.
> + * Pointer to allocated iio_buffer on success, error pointer on failure.
>   */
>  static struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
>  {
> -	struct iio_buffer **ptr, *r;
> -
> -	ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL);
> -	if (!ptr)
> -		return NULL;
> +	struct iio_buffer *r;
> +	int ret;
>  
>  	r = iio_kfifo_allocate();
> -	if (r) {
> -		*ptr = r;
> -		devres_add(dev, ptr);
> -	} else {
> -		devres_free(ptr);
> -	}
> +	if (!r)
> +		return ERR_PTR(-ENOMEM);
> +
> +	ret = devm_add_action_or_reset(dev, devm_iio_kfifo_release, r);
> +	if (ret)
> +		return ERR_PTR(ret);
>  
>  	return r;
>  }
> @@ -275,8 +272,8 @@ int devm_iio_kfifo_buffer_setup_ext(struct device *dev,
>  	struct iio_buffer *buffer;
>  
>  	buffer = devm_iio_kfifo_allocate(dev);
> -	if (!buffer)
> -		return -ENOMEM;
> +	if (IS_ERR(buffer))
> +		return PTR_ERR(buffer);

Subtle change that could have been mentioned in the commit message. 


- Nuno Sá

Re: [PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Andy Shevchenko]

On Mon, Feb 16, 2026 at 02:31:57PM +0000, Nuno Sá wrote:
> On Mon, 2026-02-16 at 09:14 +0100, Andy Shevchenko wrote:
> > Use devm_add_action_or_reset() instead of devres_alloc() and
> > devres_add(), which works the same. This will simplify the
> > code. There is no functional changes.

> LGTM. Just one minor "complain". Anyways:

My answer below.

> Reviewed-by: Nuno Sá <nuno.sa@analog.com>

Thanks!

...

> > -	if (!buffer)
> > -		return -ENOMEM;
> > +	if (IS_ERR(buffer))
> > +		return PTR_ERR(buffer);
> 
> Subtle change that could have been mentioned in the commit message.

Actually not really a change. Currently the error code is shadowed to -ENOMEM,
but again currently the callee can't return anything else. So, it's just a use
of the regular pattern. TL;DR: there is no functional change currently. If
anything in the future comes returning different error codes here, that will
bring the difference.

Anyways, if Jonathan asks to elaborate and send a new version, I will do for
sure.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Nuno Sá]

On Tue, 2026-02-17 at 09:45 +0200, Andy Shevchenko wrote:
> On Mon, Feb 16, 2026 at 02:31:57PM +0000, Nuno Sá wrote:
> > On Mon, 2026-02-16 at 09:14 +0100, Andy Shevchenko wrote:
> > > Use devm_add_action_or_reset() instead of devres_alloc() and
> > > devres_add(), which works the same. This will simplify the
> > > code. There is no functional changes.
> 
> > LGTM. Just one minor "complain". Anyways:
> 
> My answer below.
> 
> > Reviewed-by: Nuno Sá <nuno.sa@analog.com>
> 
> Thanks!
> 
> ...
> 
> > > -	if (!buffer)
> > > -		return -ENOMEM;
> > > +	if (IS_ERR(buffer))
> > > +		return PTR_ERR(buffer);
> > 
> > Subtle change that could have been mentioned in the commit message.
> 
> Actually not really a change. Currently the error code is shadowed to -ENOMEM,

Well before that was explicit. Now it also depends on the internals of  __devm_add_action().
That is why I said it was subtle. But yes, no functional change.

- Nuno Sá
> 

Re: [PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Andy Shevchenko]

On Tue, Feb 17, 2026 at 01:29:07PM +0000, Nuno Sá wrote:
> On Tue, 2026-02-17 at 09:45 +0200, Andy Shevchenko wrote:
> > On Mon, Feb 16, 2026 at 02:31:57PM +0000, Nuno Sá wrote:
> > > On Mon, 2026-02-16 at 09:14 +0100, Andy Shevchenko wrote:

...

> > > > -	if (!buffer)
> > > > -		return -ENOMEM;
> > > > +	if (IS_ERR(buffer))
> > > > +		return PTR_ERR(buffer);
> > > 
> > > Subtle change that could have been mentioned in the commit message.
> > 
> > Actually not really a change. Currently the error code is shadowed to -ENOMEM,
> 
> Well before that was explicit. Now it also depends on the internals of  __devm_add_action().

True, but if that ever changed, we will have a new error code coming from
->probe() and that's fine. ->probe() is not stricted to the certain error codes.

> That is why I said it was subtle. But yes, no functional change.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Nuno Sá]

On Tue, 2026-02-17 at 15:32 +0200, Andy Shevchenko wrote:
> On Tue, Feb 17, 2026 at 01:29:07PM +0000, Nuno Sá wrote:
> > On Tue, 2026-02-17 at 09:45 +0200, Andy Shevchenko wrote:
> > > On Mon, Feb 16, 2026 at 02:31:57PM +0000, Nuno Sá wrote:
> > > > On Mon, 2026-02-16 at 09:14 +0100, Andy Shevchenko wrote:
> 
> ...
> 
> > > > > -	if (!buffer)
> > > > > -		return -ENOMEM;
> > > > > +	if (IS_ERR(buffer))
> > > > > +		return PTR_ERR(buffer);
> > > > 
> > > > Subtle change that could have been mentioned in the commit message.
> > > 
> > > Actually not really a change. Currently the error code is shadowed to -ENOMEM,
> > 
> > Well before that was explicit. Now it also depends on the internals of  __devm_add_action().
> 
> True, but if that ever changed, we will have a new error code coming from
> ->probe() and that's fine. ->probe() is not stricted to the certain error codes.

Note that I'm not complaining about the change. Just that it could have been mentioned
in the commit :)

- Nuno Sá
> 

Re: [PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Jonathan Cameron]

On Mon, 16 Feb 2026 09:14:12 +0100
Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> Use devm_add_action_or_reset() instead of devres_alloc() and
> devres_add(), which works the same. This will simplify the
> code. There is no functional changes.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Nice.  There was a mass sweep up of these cases a few years
back but I guess these instances slipped through the scripting
that was used to find those.

> ---
>  drivers/iio/buffer/kfifo_buf.c     | 29 +++++++++++++----------------
>  drivers/iio/industrialio-trigger.c | 24 ++++++++++--------------
>  2 files changed, 23 insertions(+), 30 deletions(-)
> 
> diff --git a/drivers/iio/buffer/kfifo_buf.c b/drivers/iio/buffer/kfifo_buf.c
> index 38034c8bcc04..a126cc05fb38 100644
> --- a/drivers/iio/buffer/kfifo_buf.c
> +++ b/drivers/iio/buffer/kfifo_buf.c
> @@ -234,23 +234,20 @@ static void devm_iio_kfifo_release(struct device *dev, void *res)
>   * @dev:		Device to allocate kfifo buffer for
>   *
>   * RETURNS:
> - * Pointer to allocated iio_buffer on success, NULL on failure.
> + * Pointer to allocated iio_buffer on success, error pointer on failure.

This had me briefly confused as I failed to notice it was static
(no idea why I gave such a simple internal function kernel-doc!)

However that brings the obvious follow up question.  Given your
simplification does having a helper make sense given only a single caller?

Let's just squash it and have the two calls inline + some resulting docs
updates to get rid of the references to this function.

Thanks,

Jonathan


>   */
>  static struct iio_buffer *devm_iio_kfifo_allocate(struct device *dev)
>  {
> -	struct iio_buffer **ptr, *r;
> -
> -	ptr = devres_alloc(devm_iio_kfifo_release, sizeof(*ptr), GFP_KERNEL);
> -	if (!ptr)
> -		return NULL;
> +	struct iio_buffer *r;
> +	int ret;
>  
>  	r = iio_kfifo_allocate();
> -	if (r) {
> -		*ptr = r;
> -		devres_add(dev, ptr);
> -	} else {
> -		devres_free(ptr);
> -	}
> +	if (!r)
> +		return ERR_PTR(-ENOMEM);
> +
> +	ret = devm_add_action_or_reset(dev, devm_iio_kfifo_release, r);
> +	if (ret)
> +		return ERR_PTR(ret);
>  
>  	return r;
>  }
> @@ -275,8 +272,8 @@ int devm_iio_kfifo_buffer_setup_ext(struct device *dev,
>  	struct iio_buffer *buffer;
>  
>  	buffer = devm_iio_kfifo_allocate(dev);
> -	if (!buffer)
> -		return -ENOMEM;
> +	if (IS_ERR(buffer))
> +		return PTR_ERR(buffer);
>  
>  	indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
>  	indio_dev->setup_ops = setup_ops;

Re: [PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Andy Shevchenko]

On Fri, Feb 20, 2026 at 12:18 PM Jonathan Cameron <jic23@kernel.org> wrote:
> On Mon, 16 Feb 2026 09:14:12 +0100
> Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

...

> This had me briefly confused as I failed to notice it was static
> (no idea why I gave such a simple internal function kernel-doc!)
>
> However that brings the obvious follow up question.  Given your
> simplification does having a helper make sense given only a single caller?
>
> Let's just squash it and have the two calls inline + some resulting docs
> updates to get rid of the references to this function.

Do you want to have this change inside the proposed patch? Or in a
separate (pre/post) one?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Jonathan Cameron]

On Fri, 20 Feb 2026 12:27:40 +0200
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

> On Fri, Feb 20, 2026 at 12:18 PM Jonathan Cameron <jic23@kernel.org> wrote:
> > On Mon, 16 Feb 2026 09:14:12 +0100
> > Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:  
> 
> ...
> 
> > This had me briefly confused as I failed to notice it was static
> > (no idea why I gave such a simple internal function kernel-doc!)
> >
> > However that brings the obvious follow up question.  Given your
> > simplification does having a helper make sense given only a single caller?
> >
> > Let's just squash it and have the two calls inline + some resulting docs
> > updates to get rid of the references to this function.  
> 
> Do you want to have this change inside the proposed patch? Or in a
> separate (pre/post) one?
Same patch would be fine I think.  It's small and coupled to the code
getting simpler because of the main change here.  Seems like a pointless
dance to refactor same code twice.

Jonathan

> 

Re: [PATCH v1 1/1] iio: core: Simplify IIO core managed APIs

[Andy Shevchenko]

On Fri, Feb 20, 2026 at 12:14:50PM +0000, Jonathan Cameron wrote:
> On Fri, 20 Feb 2026 12:27:40 +0200
> Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> > On Fri, Feb 20, 2026 at 12:18 PM Jonathan Cameron <jic23@kernel.org> wrote:
> > > On Mon, 16 Feb 2026 09:14:12 +0100
> > > Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:  

...

> > > This had me briefly confused as I failed to notice it was static
> > > (no idea why I gave such a simple internal function kernel-doc!)
> > >
> > > However that brings the obvious follow up question.  Given your
> > > simplification does having a helper make sense given only a single caller?
> > >
> > > Let's just squash it and have the two calls inline + some resulting docs
> > > updates to get rid of the references to this function.  
> > 
> > Do you want to have this change inside the proposed patch? Or in a
> > separate (pre/post) one?
> Same patch would be fine I think.  It's small and coupled to the code
> getting simpler because of the main change here.  Seems like a pointless
> dance to refactor same code twice.

v2 has just been sent.

-- 
With Best Regards,
Andy Shevchenko