Re: [PATCH v2 3/7] drm/panfrost: Move shrinker initialization and unplug one level down

[Boris Brezillon]

On Thu, 04 Jun 2026 18:35:22 +0100
Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx> wrote:

> Since the moment we call drm_dev_register() the device should be in a
> position to accept jobs, so it's best if the shrinker is already
> initialized by then.
> 
> On top of that, make shrinker functions take an panfrost_device pointer
> like other functions in the same sequence and rename them accordingly.
> 
> Essentially mimic the init/fini behaviour in Panthor.
> 
> Signed-off-by: Adrián Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/panfrost/panfrost_device.c       | 7 +++++++
>  drivers/gpu/drm/panfrost/panfrost_drv.c          | 6 ------
>  drivers/gpu/drm/panfrost/panfrost_gem.h          | 4 ++--
>  drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c | 8 ++------
>  4 files changed, 11 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c
> index 7fed22d555a5..87b372c9e675 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.c
> @@ -282,9 +282,15 @@ int panfrost_device_init(struct panfrost_device *pfdev)
>  	if (err)
>  		goto out_job;
>  
> +	err = panfrost_gem_shrinker_init(pfdev);
> +	if (err)
> +		goto out_perfcnt;
> +
>  	panfrost_gem_init(pfdev);

It feels weird to have the GEM shrinker initialized before the GEM
component. Also, I'd consider the shrinker part of the GEM logic, so
maybe call panfrost_gem_shrinker_init() from panfrost_gem_init() and
change the prototype of panfrost_gem_init() to return an int.

>  
>  	return 0;
> +out_perfcnt:
> +	panfrost_perfcnt_fini(pfdev);
>  out_job:
>  	panfrost_jm_fini(pfdev);
>  out_mmu:
> @@ -306,6 +312,7 @@ int panfrost_device_init(struct panfrost_device *pfdev)
>  
>  void panfrost_device_fini(struct panfrost_device *pfdev)
>  {
> +	panfrost_gem_shrinker_fini(pfdev);
>  	panfrost_perfcnt_fini(pfdev);
>  	panfrost_jm_fini(pfdev);
>  	panfrost_mmu_fini(pfdev);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> index cb8e5015847f..2d4b6aa95c66 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> @@ -1000,14 +1000,9 @@ static int panfrost_probe(struct platform_device *pdev)
>  	if (err < 0)
>  		goto err_out1;
>  
> -	err = panfrost_gem_shrinker_init(&pfdev->base);
> -	if (err)
> -		goto err_out2;
>  
>  	return 0;
>  
> -err_out2:
> -	drm_dev_unregister(&pfdev->base);
>  err_out1:
>  	pm_runtime_disable(pfdev->base.dev);
>  	panfrost_device_fini(pfdev);
> @@ -1021,7 +1016,6 @@ static void panfrost_remove(struct platform_device *pdev)
>  	struct panfrost_device *pfdev = platform_get_drvdata(pdev);
>  
>  	drm_dev_unregister(&pfdev->base);
> -	panfrost_gem_shrinker_cleanup(&pfdev->base);
>  
>  	pm_runtime_get_sync(pfdev->base.dev);
>  	pm_runtime_disable(pfdev->base.dev);
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
> index 79d4377019e9..323a1aee255e 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
> @@ -154,8 +154,8 @@ panfrost_gem_mapping_get(struct panfrost_gem_object *bo,
>  void panfrost_gem_mapping_put(struct panfrost_gem_mapping *mapping);
>  void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
>  
> -int panfrost_gem_shrinker_init(struct drm_device *dev);
> -void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
> +int panfrost_gem_shrinker_init(struct panfrost_device *pfdev);
> +void panfrost_gem_shrinker_fini(struct panfrost_device *pfdev);
>  
>  void panfrost_gem_set_label(struct drm_gem_object *obj, const char *label);
>  int panfrost_gem_sync(struct drm_gem_object *obj, u32 type,
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> index 2fe967a90bcb..fefae87535d6 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
> @@ -95,10 +95,8 @@ panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
>   *
>   * This function registers and sets up the panfrost shrinker.
>   */
> -int panfrost_gem_shrinker_init(struct drm_device *dev)
> +int panfrost_gem_shrinker_init(struct panfrost_device *pfdev)
>  {
> -	struct panfrost_device *pfdev = to_panfrost_device(dev);
> -
>  	pfdev->shrinker = shrinker_alloc(0, "drm-panfrost");
>  	if (!pfdev->shrinker)
>  		return -ENOMEM;
> @@ -118,10 +116,8 @@ int panfrost_gem_shrinker_init(struct drm_device *dev)
>   *
>   * This function unregisters the panfrost shrinker.
>   */
> -void panfrost_gem_shrinker_cleanup(struct drm_device *dev)
> +void panfrost_gem_shrinker_fini(struct panfrost_device *pfdev)
>  {
> -	struct panfrost_device *pfdev = to_panfrost_device(dev);
> -
>  	if (pfdev->shrinker)
>  		shrinker_free(pfdev->shrinker);
>  }
>