[PATCH] drm/ttm: check the return value of register_shrinker

[Christian König]

Am 11.01.2018 um 06:16 schrieb Roger He:
> This fixes the build warning:
> "ignoring return value of 'register_shrinker', declared with
> attribute warn_unused_result [-Wunused-result]"
>
> Signed-off-by: Roger He <Hongbo.He at amd.com>

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

> ---
>   drivers/gpu/drm/ttm/ttm_page_alloc.c     | 21 ++++++++++++---------
>   drivers/gpu/drm/ttm/ttm_page_alloc_dma.c | 24 ++++++++++++++----------
>   2 files changed, 26 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> index 79854ab..0eab24e 100644
> --- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
> @@ -477,12 +477,12 @@ ttm_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
>   	return count;
>   }
>   
> -static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
> +static int ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
>   {
>   	manager->mm_shrink.count_objects = ttm_pool_shrink_count;
>   	manager->mm_shrink.scan_objects = ttm_pool_shrink_scan;
>   	manager->mm_shrink.seeks = 1;
> -	register_shrinker(&manager->mm_shrink);
> +	return register_shrinker(&manager->mm_shrink);
>   }
>   
>   static void ttm_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
> @@ -1034,15 +1034,18 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
>   
>   	ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
>   				   &glob->kobj, "pool");
> -	if (unlikely(ret != 0)) {
> -		kobject_put(&_manager->kobj);
> -		_manager = NULL;
> -		return ret;
> -	}
> -
> -	ttm_pool_mm_shrink_init(_manager);
> +	if (unlikely(ret != 0))
> +		goto error;
>   
> +	ret = ttm_pool_mm_shrink_init(_manager);
> +	if (unlikely(ret != 0))
> +		goto error;
>   	return 0;
> +
> +error:
> +	kobject_put(&_manager->kobj);
> +	_manager = NULL;
> +	return ret;
>   }
>   
>   void ttm_page_alloc_fini(void)
> diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> index 4c65940..c7f01a4 100644
> --- a/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> +++ b/drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
> @@ -1182,12 +1182,12 @@ ttm_dma_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
>   	return count;
>   }
>   
> -static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
> +static int ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
>   {
>   	manager->mm_shrink.count_objects = ttm_dma_pool_shrink_count;
>   	manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
>   	manager->mm_shrink.seeks = 1;
> -	register_shrinker(&manager->mm_shrink);
> +	return register_shrinker(&manager->mm_shrink);
>   }
>   
>   static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
> @@ -1197,7 +1197,7 @@ static void ttm_dma_pool_mm_shrink_fini(struct ttm_pool_manager *manager)
>   
>   int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
>   {
> -	int ret = -ENOMEM;
> +	int ret;
>   
>   	WARN_ON(_manager);
>   
> @@ -1205,7 +1205,7 @@ int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
>   
>   	_manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
>   	if (!_manager)
> -		goto err;
> +		return -ENOMEM;
>   
>   	mutex_init(&_manager->lock);
>   	INIT_LIST_HEAD(&_manager->pools);
> @@ -1217,13 +1217,17 @@ int ttm_dma_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
>   	/* This takes care of auto-freeing the _manager */
>   	ret = kobject_init_and_add(&_manager->kobj, &ttm_pool_kobj_type,
>   				   &glob->kobj, "dma_pool");
> -	if (unlikely(ret != 0)) {
> -		kobject_put(&_manager->kobj);
> -		goto err;
> -	}
> -	ttm_dma_pool_mm_shrink_init(_manager);
> +	if (unlikely(ret != 0))
> +		goto error;
> +
> +	ret = ttm_dma_pool_mm_shrink_init(_manager);
> +	if (unlikely(ret != 0))
> +		goto error;
>   	return 0;
> -err:
> +
> +error:
> +	kobject_put(&_manager->kobj);
> +	_manager = NULL;
>   	return ret;
>   }
>