[PATCH] drm: Drop unused drm_device_class_(un)register API

[PATCH] drm: Drop unused drm_device_class_(un)register API

[Tvrtko Ursulin]

The API has been unused since commit
ed89fff97382 ("drm/ttm: drop sysfs directory")
so lets remove it.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@gmail.com>
Cc: Simona Vetter <simona@ffwll.ch>
---
 drivers/gpu/drm/drm_sysfs.c | 32 --------------------------------
 include/drm/drm_sysfs.h     |  4 ----
 2 files changed, 36 deletions(-)

diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index 43b2c3eaa7e4..7433bf8136cc 100644
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -645,35 +645,3 @@ struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 	put_device(kdev);
 	return ERR_PTR(r);
 }
-
-/**
- * drm_class_device_register - register new device with the DRM sysfs class
- * @dev: device to register
- *
- * Registers a new &struct device within the DRM sysfs class. Essentially only
- * used by ttm to have a place for its global settings. Drivers should never use
- * this.
- */
-int drm_class_device_register(struct device *dev)
-{
-	if (!drm_class || IS_ERR(drm_class))
-		return -ENOENT;
-
-	dev->class = drm_class;
-	return device_register(dev);
-}
-EXPORT_SYMBOL_GPL(drm_class_device_register);
-
-/**
- * drm_class_device_unregister - unregister device with the DRM sysfs class
- * @dev: device to unregister
- *
- * Unregisters a &struct device from the DRM sysfs class. Essentially only used
- * by ttm to have a place for its global settings. Drivers should never use
- * this.
- */
-void drm_class_device_unregister(struct device *dev)
-{
-	return device_unregister(dev);
-}
-EXPORT_SYMBOL_GPL(drm_class_device_unregister);
diff --git a/include/drm/drm_sysfs.h b/include/drm/drm_sysfs.h
index 96a5d858404b..7695873a9456 100644
--- a/include/drm/drm_sysfs.h
+++ b/include/drm/drm_sysfs.h
@@ -3,13 +3,9 @@
 #define _DRM_SYSFS_H_
 
 struct drm_device;
-struct device;
 struct drm_connector;
 struct drm_property;
 
-int drm_class_device_register(struct device *dev);
-void drm_class_device_unregister(struct device *dev);
-
 void drm_sysfs_hotplug_event(struct drm_device *dev);
 void drm_sysfs_connector_hotplug_event(struct drm_connector *connector);
 void drm_sysfs_connector_property_event(struct drm_connector *connector,
-- 
2.52.0

Re: [PATCH] drm: Drop unused drm_device_class_(un)register API

[Thomas Zimmermann]

Hi

Am 29.04.26 um 10:57 schrieb Tvrtko Ursulin:
> The API has been unused since commit
> ed89fff97382 ("drm/ttm: drop sysfs directory")
> so lets remove it.

drm_privacy_screen_register() uses the same pattern. [1] If that helper 
is being converted over to drm_class_device_register(), the global 
drm_class could be internalized into drm_sysfb.c. Personally, I think 
this is the better solution, but either seems fine. [1] 
https://elixir.bootlin.com/linux/v7.0.1/source/drivers/gpu/drm/drm_privacy_screen.c#L405

Best regards
Thomas

>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Maxime Ripard <mripard@kernel.org>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Simona Vetter <simona@ffwll.ch>
> ---
>   drivers/gpu/drm/drm_sysfs.c | 32 --------------------------------
>   include/drm/drm_sysfs.h     |  4 ----
>   2 files changed, 36 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
> index 43b2c3eaa7e4..7433bf8136cc 100644
> --- a/drivers/gpu/drm/drm_sysfs.c
> +++ b/drivers/gpu/drm/drm_sysfs.c
> @@ -645,35 +645,3 @@ struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
>   	put_device(kdev);
>   	return ERR_PTR(r);
>   }
> -
> -/**
> - * drm_class_device_register - register new device with the DRM sysfs class
> - * @dev: device to register
> - *
> - * Registers a new &struct device within the DRM sysfs class. Essentially only
> - * used by ttm to have a place for its global settings. Drivers should never use
> - * this.
> - */
> -int drm_class_device_register(struct device *dev)
> -{
> -	if (!drm_class || IS_ERR(drm_class))
> -		return -ENOENT;
> -
> -	dev->class = drm_class;
> -	return device_register(dev);
> -}
> -EXPORT_SYMBOL_GPL(drm_class_device_register);
> -
> -/**
> - * drm_class_device_unregister - unregister device with the DRM sysfs class
> - * @dev: device to unregister
> - *
> - * Unregisters a &struct device from the DRM sysfs class. Essentially only used
> - * by ttm to have a place for its global settings. Drivers should never use
> - * this.
> - */
> -void drm_class_device_unregister(struct device *dev)
> -{
> -	return device_unregister(dev);
> -}
> -EXPORT_SYMBOL_GPL(drm_class_device_unregister);
> diff --git a/include/drm/drm_sysfs.h b/include/drm/drm_sysfs.h
> index 96a5d858404b..7695873a9456 100644
> --- a/include/drm/drm_sysfs.h
> +++ b/include/drm/drm_sysfs.h
> @@ -3,13 +3,9 @@
>   #define _DRM_SYSFS_H_
>   
>   struct drm_device;
> -struct device;
>   struct drm_connector;
>   struct drm_property;
>   
> -int drm_class_device_register(struct device *dev);
> -void drm_class_device_unregister(struct device *dev);
> -
>   void drm_sysfs_hotplug_event(struct drm_device *dev);
>   void drm_sysfs_connector_hotplug_event(struct drm_connector *connector);
>   void drm_sysfs_connector_property_event(struct drm_connector *connector,

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)

Re: [PATCH] drm: Drop unused drm_device_class_(un)register API

[Tvrtko Ursulin]

On 29/04/2026 10:35, Thomas Zimmermann wrote:
> Hi
> 
> Am 29.04.26 um 10:57 schrieb Tvrtko Ursulin:
>> The API has been unused since commit
>> ed89fff97382 ("drm/ttm: drop sysfs directory")
>> so lets remove it.
> 
> drm_privacy_screen_register() uses the same pattern. [1] If that helper 
> is being converted over to drm_class_device_register(), the global 
> drm_class could be internalized into drm_sysfb.c. Personally, I think 
> this is the better solution, but either seems fine. [1] https:// 
> elixir.bootlin.com/linux/v7.0.1/source/drivers/gpu/drm/ 
> drm_privacy_screen.c#L405

I did not spot that one. The alternative sounds reasonable to me. Adding 
Hans to check if he wants to take over converting this driver.

Regards,

Tvrtko
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
>> Cc: Christian König <christian.koenig@amd.com>
>> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>> Cc: Maxime Ripard <mripard@kernel.org>
>> Cc: Thomas Zimmermann <tzimmermann@suse.de>
>> Cc: David Airlie <airlied@gmail.com>
>> Cc: Simona Vetter <simona@ffwll.ch>
>> ---
>>   drivers/gpu/drm/drm_sysfs.c | 32 --------------------------------
>>   include/drm/drm_sysfs.h     |  4 ----
>>   2 files changed, 36 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
>> index 43b2c3eaa7e4..7433bf8136cc 100644
>> --- a/drivers/gpu/drm/drm_sysfs.c
>> +++ b/drivers/gpu/drm/drm_sysfs.c
>> @@ -645,35 +645,3 @@ struct device *drm_sysfs_minor_alloc(struct 
>> drm_minor *minor)
>>       put_device(kdev);
>>       return ERR_PTR(r);
>>   }
>> -
>> -/**
>> - * drm_class_device_register - register new device with the DRM sysfs 
>> class
>> - * @dev: device to register
>> - *
>> - * Registers a new &struct device within the DRM sysfs class. 
>> Essentially only
>> - * used by ttm to have a place for its global settings. Drivers 
>> should never use
>> - * this.
>> - */
>> -int drm_class_device_register(struct device *dev)
>> -{
>> -    if (!drm_class || IS_ERR(drm_class))
>> -        return -ENOENT;
>> -
>> -    dev->class = drm_class;
>> -    return device_register(dev);
>> -}
>> -EXPORT_SYMBOL_GPL(drm_class_device_register);
>> -
>> -/**
>> - * drm_class_device_unregister - unregister device with the DRM sysfs 
>> class
>> - * @dev: device to unregister
>> - *
>> - * Unregisters a &struct device from the DRM sysfs class. Essentially 
>> only used
>> - * by ttm to have a place for its global settings. Drivers should 
>> never use
>> - * this.
>> - */
>> -void drm_class_device_unregister(struct device *dev)
>> -{
>> -    return device_unregister(dev);
>> -}
>> -EXPORT_SYMBOL_GPL(drm_class_device_unregister);
>> diff --git a/include/drm/drm_sysfs.h b/include/drm/drm_sysfs.h
>> index 96a5d858404b..7695873a9456 100644
>> --- a/include/drm/drm_sysfs.h
>> +++ b/include/drm/drm_sysfs.h
>> @@ -3,13 +3,9 @@
>>   #define _DRM_SYSFS_H_
>>   struct drm_device;
>> -struct device;
>>   struct drm_connector;
>>   struct drm_property;
>> -int drm_class_device_register(struct device *dev);
>> -void drm_class_device_unregister(struct device *dev);
>> -
>>   void drm_sysfs_hotplug_event(struct drm_device *dev);
>>   void drm_sysfs_connector_hotplug_event(struct drm_connector 
>> *connector);
>>   void drm_sysfs_connector_property_event(struct drm_connector 
>> *connector,
> 

Re: [PATCH] drm: Drop unused drm_device_class_(un)register API

[Christian König]

On 4/29/26 10:57, Tvrtko Ursulin wrote:
> The API has been unused since commit
> ed89fff97382 ("drm/ttm: drop sysfs directory")
> so lets remove it.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
> Cc: Christian König <christian.koenig@amd.com>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Maxime Ripard <mripard@kernel.org>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Simona Vetter <simona@ffwll.ch>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>  drivers/gpu/drm/drm_sysfs.c | 32 --------------------------------
>  include/drm/drm_sysfs.h     |  4 ----
>  2 files changed, 36 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
> index 43b2c3eaa7e4..7433bf8136cc 100644
> --- a/drivers/gpu/drm/drm_sysfs.c
> +++ b/drivers/gpu/drm/drm_sysfs.c
> @@ -645,35 +645,3 @@ struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
>  	put_device(kdev);
>  	return ERR_PTR(r);
>  }
> -
> -/**
> - * drm_class_device_register - register new device with the DRM sysfs class
> - * @dev: device to register
> - *
> - * Registers a new &struct device within the DRM sysfs class. Essentially only
> - * used by ttm to have a place for its global settings. Drivers should never use
> - * this.
> - */
> -int drm_class_device_register(struct device *dev)
> -{
> -	if (!drm_class || IS_ERR(drm_class))
> -		return -ENOENT;
> -
> -	dev->class = drm_class;
> -	return device_register(dev);
> -}
> -EXPORT_SYMBOL_GPL(drm_class_device_register);
> -
> -/**
> - * drm_class_device_unregister - unregister device with the DRM sysfs class
> - * @dev: device to unregister
> - *
> - * Unregisters a &struct device from the DRM sysfs class. Essentially only used
> - * by ttm to have a place for its global settings. Drivers should never use
> - * this.
> - */
> -void drm_class_device_unregister(struct device *dev)
> -{
> -	return device_unregister(dev);
> -}
> -EXPORT_SYMBOL_GPL(drm_class_device_unregister);
> diff --git a/include/drm/drm_sysfs.h b/include/drm/drm_sysfs.h
> index 96a5d858404b..7695873a9456 100644
> --- a/include/drm/drm_sysfs.h
> +++ b/include/drm/drm_sysfs.h
> @@ -3,13 +3,9 @@
>  #define _DRM_SYSFS_H_
>  
>  struct drm_device;
> -struct device;
>  struct drm_connector;
>  struct drm_property;
>  
> -int drm_class_device_register(struct device *dev);
> -void drm_class_device_unregister(struct device *dev);
> -
>  void drm_sysfs_hotplug_event(struct drm_device *dev);
>  void drm_sysfs_connector_hotplug_event(struct drm_connector *connector);
>  void drm_sysfs_connector_property_event(struct drm_connector *connector,