[PATCH 00/12] notifier: add device-managed registration APIs and convert drivers

[PATCH 00/12] notifier: add device-managed registration APIs and convert drivers

[Eliav Farber]

Many drivers repeat the same boilerplate when registering notifiers with
device lifetime:

  1. Register the notifier with *_notifier_chain_register()
  2. Check for error
  3. Register a devm action to unregister on teardown
  4. Implement a per-driver static unregister callback

This series adds devm_atomic_notifier_chain_register(),
devm_blocking_notifier_chain_register(), and
devm_raw_notifier_chain_register() that automatically unregister the
notifier when the device is unbound, then converts 11 drivers to use
them.

Each conversion eliminates a per-driver unregister callback and the
associated devm_add_action_or_reset() call, reducing code by ~15 lines
per driver.

The implementation follows the established devres pattern used by other
device-managed kernel APIs.

Checkpatch reports 6 CHECKs (0 errors, 0 warnings) on patch 1:
- "extern prototypes should be avoided in .h files"
- "Alignment should match open parenthesis"

Both are intentional to match the existing coding style in notifier.h,
where all declarations use 'extern' and tab-indented continuation lines.

Eliav Farber (12):
  notifier: add device-managed registration APIs
  pwm: iqs620a: use devm_blocking_notifier_chain_register()
  iio: light: iqs621-als: use devm_blocking_notifier_chain_register()
  iio: position: iqs624: use devm_blocking_notifier_chain_register()
  gpio: adp5585: use devm_blocking_notifier_chain_register()
  platform/x86: bitland-mifs-wmi: use
    devm_blocking_notifier_chain_register()
  Input: adp5585: use devm_blocking_notifier_chain_register()
  ACPI: APEI: GHES: use devm_blocking_notifier_chain_register()
  platform/x86: uniwill-wmi: use devm_blocking_notifier_chain_register()
  gpio: eic-sprd: use devm_atomic_notifier_chain_register()
  gpio: gpiolib-kunit: use devm_blocking_notifier_chain_register()
  reboot: use devm_blocking_notifier_chain_register()

 drivers/acpi/apei/ghes.c                   |  15 +-
 drivers/gpio/gpio-adp5585.c                |  20 +--
 drivers/gpio/gpio-eic-sprd.c               |  17 +--
 drivers/gpio/gpiolib-kunit.c               |  14 +-
 drivers/iio/light/iqs621-als.c             |  24 +---
 drivers/iio/position/iqs624-pos.c          |  24 +---
 drivers/input/keyboard/adp5585-keys.c      |  18 +--
 drivers/platform/x86/bitland-mifs-wmi.c    |  17 +--
 drivers/platform/x86/uniwill/uniwill-wmi.c |  17 +--
 drivers/pwm/pwm-iqs620a.c                  |  21 +--
 include/linux/notifier.h                   |  10 ++
 kernel/notifier.c                          | 151 +++++++++++++++++++++
 kernel/reboot.c                            |  24 +---
 13 files changed, 191 insertions(+), 181 deletions(-)

-- 
2.47.3

[PATCH 01/12] notifier: add device-managed registration APIs

[Eliav Farber]

Add devm_atomic_notifier_chain_register(),
devm_blocking_notifier_chain_register(), and
devm_raw_notifier_chain_register() that automatically unregister the
notifier when the device is unbound.

Many drivers repeat the same boilerplate pattern:

  1. Register the notifier with *_notifier_chain_register()
  2. Check for error
  3. Register a devm action to unregister on teardown
  4. Implement a per-driver static unregister callback

With the new devm_*_notifier_chain_register() APIs, this reduces to a
single call with one error path, eliminating per-driver unregister
callbacks entirely.

The implementation follows the established devres pattern used by other
device-managed kernel APIs.

Signed-off-by: Eliav Farber <farbere@amazon.com>
---
 include/linux/notifier.h |  10 +++
 kernel/notifier.c        | 151 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 161 insertions(+)

diff --git a/include/linux/notifier.h b/include/linux/notifier.h
index 01b6c9d9956f..aa3745d7459b 100644
--- a/include/linux/notifier.h
+++ b/include/linux/notifier.h
@@ -46,6 +46,7 @@
  * often but notifier_blocks will seldom be removed.
  */
 
+struct device;
 struct notifier_block;
 
 typedef	int (*notifier_fn_t)(struct notifier_block *nb,
@@ -145,10 +146,19 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
 
 extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
 		struct notifier_block *nb);
+extern int devm_atomic_notifier_chain_register(struct device *dev,
+		struct atomic_notifier_head *nh,
+		struct notifier_block *nb);
 extern int blocking_notifier_chain_register(struct blocking_notifier_head *nh,
 		struct notifier_block *nb);
+extern int devm_blocking_notifier_chain_register(struct device *dev,
+		struct blocking_notifier_head *nh,
+		struct notifier_block *nb);
 extern int raw_notifier_chain_register(struct raw_notifier_head *nh,
 		struct notifier_block *nb);
+extern int devm_raw_notifier_chain_register(struct device *dev,
+		struct raw_notifier_head *nh,
+		struct notifier_block *nb);
 extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh,
 		struct notifier_block *nb);
 
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 2f9fe7c30287..b811638aa878 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-only
+#include <linux/device.h>
 #include <linux/kdebug.h>
 #include <linux/kprobes.h>
 #include <linux/export.h>
@@ -197,6 +198,55 @@ int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh,
 }
 EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister);
 
+struct atomic_notifier_chain_devres {
+	struct atomic_notifier_head *nh;
+	struct notifier_block *nb;
+};
+
+static void devm_atomic_notifier_chain_unregister(struct device *dev, void *res)
+{
+	struct atomic_notifier_chain_devres *dr = res;
+
+	atomic_notifier_chain_unregister(dr->nh, dr->nb);
+}
+
+/**
+ *	devm_atomic_notifier_chain_register - Device-managed atomic notifier registration
+ *	@dev: Device to tie the notifier lifetime to
+ *	@nh: Pointer to head of the atomic notifier chain
+ *	@n: New entry in notifier chain
+ *
+ *	Adds a notifier to an atomic notifier chain and registers a cleanup
+ *	action to automatically unregister it when @dev is unbound.
+ *
+ *	Returns 0 on success, negative errno on error.
+ */
+int devm_atomic_notifier_chain_register(struct device *dev,
+					struct atomic_notifier_head *nh,
+					struct notifier_block *n)
+{
+	struct atomic_notifier_chain_devres *dr;
+	int ret;
+
+	dr = devres_alloc(devm_atomic_notifier_chain_unregister,
+			  sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	ret = atomic_notifier_chain_register(nh, n);
+	if (ret) {
+		devres_free(dr);
+		return ret;
+	}
+
+	dr->nh = nh;
+	dr->nb = n;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_atomic_notifier_chain_register);
+
 /**
  *	atomic_notifier_call_chain - Call functions in an atomic notifier chain
  *	@nh: Pointer to head of the atomic notifier chain
@@ -349,6 +399,57 @@ int blocking_notifier_call_chain_robust(struct blocking_notifier_head *nh,
 }
 EXPORT_SYMBOL_GPL(blocking_notifier_call_chain_robust);
 
+struct blocking_notifier_chain_devres {
+	struct blocking_notifier_head *nh;
+	struct notifier_block *nb;
+};
+
+static void devm_blocking_notifier_chain_unregister(struct device *dev,
+						    void *res)
+{
+	struct blocking_notifier_chain_devres *dr = res;
+
+	blocking_notifier_chain_unregister(dr->nh, dr->nb);
+}
+
+/**
+ *	devm_blocking_notifier_chain_register - Device-managed blocking notifier registration
+ *	@dev: Device to tie the notifier lifetime to
+ *	@nh: Pointer to head of the blocking notifier chain
+ *	@n: New entry in notifier chain
+ *
+ *	Adds a notifier to a blocking notifier chain and registers a cleanup
+ *	action to automatically unregister it when @dev is unbound.
+ *	Must be called in process context.
+ *
+ *	Returns 0 on success, negative errno on error.
+ */
+int devm_blocking_notifier_chain_register(struct device *dev,
+					  struct blocking_notifier_head *nh,
+					  struct notifier_block *n)
+{
+	struct blocking_notifier_chain_devres *dr;
+	int ret;
+
+	dr = devres_alloc(devm_blocking_notifier_chain_unregister,
+			  sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	ret = blocking_notifier_chain_register(nh, n);
+	if (ret) {
+		devres_free(dr);
+		return ret;
+	}
+
+	dr->nh = nh;
+	dr->nb = n;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_blocking_notifier_chain_register);
+
 /**
  *	blocking_notifier_call_chain - Call functions in a blocking notifier chain
  *	@nh: Pointer to head of the blocking notifier chain
@@ -430,6 +531,56 @@ int raw_notifier_call_chain_robust(struct raw_notifier_head *nh,
 }
 EXPORT_SYMBOL_GPL(raw_notifier_call_chain_robust);
 
+struct raw_notifier_chain_devres {
+	struct raw_notifier_head *nh;
+	struct notifier_block *nb;
+};
+
+static void devm_raw_notifier_chain_unregister(struct device *dev, void *res)
+{
+	struct raw_notifier_chain_devres *dr = res;
+
+	raw_notifier_chain_unregister(dr->nh, dr->nb);
+}
+
+/**
+ *	devm_raw_notifier_chain_register - Device-managed raw notifier registration
+ *	@dev: Device to tie the notifier lifetime to
+ *	@nh: Pointer to head of the raw notifier chain
+ *	@n: New entry in notifier chain
+ *
+ *	Adds a notifier to a raw notifier chain and registers a cleanup
+ *	action to automatically unregister it when @dev is unbound.
+ *	All locking must be provided by the caller.
+ *
+ *	Returns 0 on success, negative errno on error.
+ */
+int devm_raw_notifier_chain_register(struct device *dev,
+				     struct raw_notifier_head *nh,
+				     struct notifier_block *n)
+{
+	struct raw_notifier_chain_devres *dr;
+	int ret;
+
+	dr = devres_alloc(devm_raw_notifier_chain_unregister,
+			  sizeof(*dr), GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	ret = raw_notifier_chain_register(nh, n);
+	if (ret) {
+		devres_free(dr);
+		return ret;
+	}
+
+	dr->nh = nh;
+	dr->nb = n;
+	devres_add(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_raw_notifier_chain_register);
+
 /**
  *	raw_notifier_call_chain - Call functions in a raw notifier chain
  *	@nh: Pointer to head of the raw notifier chain
-- 
2.47.3

Re: [PATCH 01/12] notifier: add device-managed registration APIs

[Bartosz Golaszewski]

On Thu, 23 Jul 2026 19:53:14 +0200, Eliav Farber <farbere@amazon.com> said:
> Add devm_atomic_notifier_chain_register(),
> devm_blocking_notifier_chain_register(), and
> devm_raw_notifier_chain_register() that automatically unregister the
> notifier when the device is unbound.
>
> Many drivers repeat the same boilerplate pattern:
>
>   1. Register the notifier with *_notifier_chain_register()
>   2. Check for error
>   3. Register a devm action to unregister on teardown
>   4. Implement a per-driver static unregister callback
>
> With the new devm_*_notifier_chain_register() APIs, this reduces to a
> single call with one error path, eliminating per-driver unregister
> callbacks entirely.
>
> The implementation follows the established devres pattern used by other
> device-managed kernel APIs.
>
> Signed-off-by: Eliav Farber <farbere@amazon.com>
> ---
>  include/linux/notifier.h |  10 +++
>  kernel/notifier.c        | 151 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 161 insertions(+)
>
> diff --git a/include/linux/notifier.h b/include/linux/notifier.h
> index 01b6c9d9956f..aa3745d7459b 100644
> --- a/include/linux/notifier.h
> +++ b/include/linux/notifier.h
> @@ -46,6 +46,7 @@
>   * often but notifier_blocks will seldom be removed.
>   */
>
> +struct device;
>  struct notifier_block;
>
>  typedef	int (*notifier_fn_t)(struct notifier_block *nb,
> @@ -145,10 +146,19 @@ extern void srcu_init_notifier_head(struct srcu_notifier_head *nh);
>
>  extern int atomic_notifier_chain_register(struct atomic_notifier_head *nh,
>  		struct notifier_block *nb);
> +extern int devm_atomic_notifier_chain_register(struct device *dev,
> +		struct atomic_notifier_head *nh,
> +		struct notifier_block *nb);

Please don't use extern with function prototypes in new code.

>  extern int blocking_notifier_chain_register(struct blocking_notifier_head *nh,
>  		struct notifier_block *nb);
> +extern int devm_blocking_notifier_chain_register(struct device *dev,
> +		struct blocking_notifier_head *nh,
> +		struct notifier_block *nb);
>  extern int raw_notifier_chain_register(struct raw_notifier_head *nh,
>  		struct notifier_block *nb);
> +extern int devm_raw_notifier_chain_register(struct device *dev,
> +		struct raw_notifier_head *nh,
> +		struct notifier_block *nb);
>  extern int srcu_notifier_chain_register(struct srcu_notifier_head *nh,
>  		struct notifier_block *nb);
>
> diff --git a/kernel/notifier.c b/kernel/notifier.c
> index 2f9fe7c30287..b811638aa878 100644
> --- a/kernel/notifier.c
> +++ b/kernel/notifier.c
> @@ -1,4 +1,5 @@
>  // SPDX-License-Identifier: GPL-2.0-only
> +#include <linux/device.h>
>  #include <linux/kdebug.h>
>  #include <linux/kprobes.h>
>  #include <linux/export.h>
> @@ -197,6 +198,55 @@ int atomic_notifier_chain_unregister(struct atomic_notifier_head *nh,
>  }
>  EXPORT_SYMBOL_GPL(atomic_notifier_chain_unregister);
>
> +struct atomic_notifier_chain_devres {
> +	struct atomic_notifier_head *nh;
> +	struct notifier_block *nb;
> +};
> +
> +static void devm_atomic_notifier_chain_unregister(struct device *dev, void *res)
> +{
> +	struct atomic_notifier_chain_devres *dr = res;
> +
> +	atomic_notifier_chain_unregister(dr->nh, dr->nb);
> +}
> +
> +/**
> + *	devm_atomic_notifier_chain_register - Device-managed atomic notifier registration
> + *	@dev: Device to tie the notifier lifetime to
> + *	@nh: Pointer to head of the atomic notifier chain
> + *	@n: New entry in notifier chain
> + *
> + *	Adds a notifier to an atomic notifier chain and registers a cleanup
> + *	action to automatically unregister it when @dev is unbound.
> + *
> + *	Returns 0 on success, negative errno on error.

Should be:

Returns:
0 on success...

Bart

[PATCH 02/12] pwm: iqs620a: use devm_blocking_notifier_chain_register()

[Eliav Farber]

Replace the blocking_notifier_chain_register() +
devm_add_action_or_reset() pattern with a single call to
devm_blocking_notifier_chain_register(), removing the
iqs620_pwm_notifier_unregister() callback.

Signed-off-by: Eliav Farber <farbere@amazon.com>
---
 drivers/pwm/pwm-iqs620a.c | 21 +++------------------
 1 file changed, 3 insertions(+), 18 deletions(-)

diff --git a/drivers/pwm/pwm-iqs620a.c b/drivers/pwm/pwm-iqs620a.c
index 13e5e138c8e9..12f7b1415ed4 100644
--- a/drivers/pwm/pwm-iqs620a.c
+++ b/drivers/pwm/pwm-iqs620a.c
@@ -173,17 +173,7 @@ static const struct pwm_ops iqs620_pwm_ops = {
 	.get_state = iqs620_pwm_get_state,
 };
 
-static void iqs620_pwm_notifier_unregister(void *context)
-{
-	struct iqs620_pwm_private *iqs620_pwm = context;
-	int ret;
 
-	ret = blocking_notifier_chain_unregister(&iqs620_pwm->iqs62x->nh,
-						 &iqs620_pwm->notifier);
-	if (ret)
-		dev_err(iqs620_pwm->dev,
-			"Failed to unregister notifier: %d\n", ret);
-}
 
 static int iqs620_pwm_probe(struct platform_device *pdev)
 {
@@ -218,19 +208,14 @@ static int iqs620_pwm_probe(struct platform_device *pdev)
 	mutex_init(&iqs620_pwm->lock);
 
 	iqs620_pwm->notifier.notifier_call = iqs620_pwm_notifier;
-	ret = blocking_notifier_chain_register(&iqs620_pwm->iqs62x->nh,
-					       &iqs620_pwm->notifier);
+	ret = devm_blocking_notifier_chain_register(&pdev->dev,
+						    &iqs620_pwm->iqs62x->nh,
+						    &iqs620_pwm->notifier);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
 		return ret;
 	}
 
-	ret = devm_add_action_or_reset(&pdev->dev,
-				       iqs620_pwm_notifier_unregister,
-				       iqs620_pwm);
-	if (ret)
-		return ret;
-
 	ret = devm_pwmchip_add(&pdev->dev, chip);
 	if (ret)
 		dev_err(&pdev->dev, "Failed to add device: %d\n", ret);
-- 
2.47.3

[PATCH 03/12] iio: light: iqs621-als: use devm_blocking_notifier_chain_register()

[Eliav Farber]

Replace the blocking_notifier_chain_register() +
devm_add_action_or_reset() pattern with a single call to
devm_blocking_notifier_chain_register(), removing the
iqs621_als_notifier_unregister() callback.

Signed-off-by: Eliav Farber <farbere@amazon.com>
---
 drivers/iio/light/iqs621-als.c | 24 +++---------------------
 1 file changed, 3 insertions(+), 21 deletions(-)

diff --git a/drivers/iio/light/iqs621-als.c b/drivers/iio/light/iqs621-als.c
index cd5843e3e2c3..f9d215ef1970 100644
--- a/drivers/iio/light/iqs621-als.c
+++ b/drivers/iio/light/iqs621-als.c
@@ -179,19 +179,6 @@ static int iqs621_als_notifier(struct notifier_block *notifier,
 	return NOTIFY_OK;
 }
 
-static void iqs621_als_notifier_unregister(void *context)
-{
-	struct iqs621_als_private *iqs621_als = context;
-	struct iio_dev *indio_dev = iqs621_als->indio_dev;
-	int ret;
-
-	ret = blocking_notifier_chain_unregister(&iqs621_als->iqs62x->nh,
-						 &iqs621_als->notifier);
-	if (ret)
-		dev_err(indio_dev->dev.parent,
-			"Failed to unregister notifier: %d\n", ret);
-}
-
 static int iqs621_als_read_raw(struct iio_dev *indio_dev,
 			       struct iio_chan_spec const *chan,
 			       int *val, int *val2, long mask)
@@ -563,19 +550,14 @@ static int iqs621_als_probe(struct platform_device *pdev)
 	mutex_init(&iqs621_als->lock);
 
 	iqs621_als->notifier.notifier_call = iqs621_als_notifier;
-	ret = blocking_notifier_chain_register(&iqs621_als->iqs62x->nh,
-					       &iqs621_als->notifier);
+	ret = devm_blocking_notifier_chain_register(&pdev->dev,
+						    &iqs621_als->iqs62x->nh,
+						    &iqs621_als->notifier);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
 		return ret;
 	}
 
-	ret = devm_add_action_or_reset(&pdev->dev,
-				       iqs621_als_notifier_unregister,
-				       iqs621_als);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(&pdev->dev, indio_dev);
 }
 
-- 
2.47.3

Re: [PATCH 03/12] iio: light: iqs621-als: use devm_blocking_notifier_chain_register()

[Jonathan Cameron]

On Thu, 23 Jul 2026 17:53:16 +0000
Eliav Farber <farbere@amazon.com> wrote:

> Replace the blocking_notifier_chain_register() +
> devm_add_action_or_reset() pattern with a single call to
> devm_blocking_notifier_chain_register(), removing the
> iqs621_als_notifier_unregister() callback.
> 
> Signed-off-by: Eliav Farber <farbere@amazon.com>
Acked-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

Seems relatively unlikely to cause a merge conflict if these changes
go through non subsystem trees - hence the Ack rather than asking
for an immutable branch with patch 1 on it.

Thanks,

Jonathan

[PATCH 04/12] iio: position: iqs624: use devm_blocking_notifier_chain_register()

[Eliav Farber]

Replace the blocking_notifier_chain_register() +
devm_add_action_or_reset() pattern with a single call to
devm_blocking_notifier_chain_register(), removing the
iqs624_pos_notifier_unregister() callback.

Signed-off-by: Eliav Farber <farbere@amazon.com>
---
 drivers/iio/position/iqs624-pos.c | 24 +++---------------------
 1 file changed, 3 insertions(+), 21 deletions(-)

diff --git a/drivers/iio/position/iqs624-pos.c b/drivers/iio/position/iqs624-pos.c
index 8239239c6ee2..d2aa2df71457 100644
--- a/drivers/iio/position/iqs624-pos.c
+++ b/drivers/iio/position/iqs624-pos.c
@@ -96,19 +96,6 @@ static int iqs624_pos_notifier(struct notifier_block *notifier,
 	return ret;
 }
 
-static void iqs624_pos_notifier_unregister(void *context)
-{
-	struct iqs624_pos_private *iqs624_pos = context;
-	struct iio_dev *indio_dev = iqs624_pos->indio_dev;
-	int ret;
-
-	ret = blocking_notifier_chain_unregister(&iqs624_pos->iqs62x->nh,
-						 &iqs624_pos->notifier);
-	if (ret)
-		dev_err(indio_dev->dev.parent,
-			"Failed to unregister notifier: %d\n", ret);
-}
-
 static int iqs624_pos_angle_get(struct iqs62x_core *iqs62x, unsigned int *val)
 {
 	int ret;
@@ -255,19 +242,14 @@ static int iqs624_pos_probe(struct platform_device *pdev)
 	mutex_init(&iqs624_pos->lock);
 
 	iqs624_pos->notifier.notifier_call = iqs624_pos_notifier;
-	ret = blocking_notifier_chain_register(&iqs624_pos->iqs62x->nh,
-					       &iqs624_pos->notifier);
+	ret = devm_blocking_notifier_chain_register(&pdev->dev,
+						    &iqs624_pos->iqs62x->nh,
+						    &iqs624_pos->notifier);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to register notifier: %d\n", ret);
 		return ret;
 	}
 
-	ret = devm_add_action_or_reset(&pdev->dev,
-				       iqs624_pos_notifier_unregister,
-				       iqs624_pos);
-	if (ret)
-		return ret;
-
 	return devm_iio_device_register(&pdev->dev, indio_dev);
 }
 
-- 
2.47.3

Re: [PATCH 04/12] iio: position: iqs624: use devm_blocking_notifier_chain_register()

[Jonathan Cameron]

On Thu, 23 Jul 2026 17:53:17 +0000
Eliav Farber <farbere@amazon.com> wrote:

> Replace the blocking_notifier_chain_register() +
> devm_add_action_or_reset() pattern with a single call to
> devm_blocking_notifier_chain_register(), removing the
> iqs624_pos_notifier_unregister() callback.
> 
> Signed-off-by: Eliav Farber <farbere@amazon.com>
Acked-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

Re: [PATCH 00/12] notifier: add device-managed registration APIs and convert drivers

[Bartosz Golaszewski]

On Thu, 23 Jul 2026 19:53:13 +0200, Eliav Farber <farbere@amazon.com> said:
> Many drivers repeat the same boilerplate when registering notifiers with
> device lifetime:
>
>   1. Register the notifier with *_notifier_chain_register()
>   2. Check for error
>   3. Register a devm action to unregister on teardown
>   4. Implement a per-driver static unregister callback
>
> This series adds devm_atomic_notifier_chain_register(),
> devm_blocking_notifier_chain_register(), and
> devm_raw_notifier_chain_register() that automatically unregister the
> notifier when the device is unbound, then converts 11 drivers to use
> them.
>
> Each conversion eliminates a per-driver unregister callback and the
> associated devm_add_action_or_reset() call, reducing code by ~15 lines
> per driver.
>
> The implementation follows the established devres pattern used by other
> device-managed kernel APIs.
>
> Checkpatch reports 6 CHECKs (0 errors, 0 warnings) on patch 1:
> - "extern prototypes should be avoided in .h files"
> - "Alignment should match open parenthesis"
>
> Both are intentional to match the existing coding style in notifier.h,
> where all declarations use 'extern' and tab-indented continuation lines.
>

What is the merging strategy? Acks and all patches go through driver core?

Bartosz