Re: [PATCH 1/2] drm/ttm: Check ttm_debugfs_root before creating files under it

[Christian König <christian.koenig@xxxxxxx>]

Am 13.01.23 um 06:34 schrieb Ma Jun:
> Check the ttm_debugfs_root before creating files under it.
> If the ttm_debugfs_root is NULL, all the files created for
> ttm/ will be placed in the /sys/kerne/debug/ but not
> /sys/kernel/debug/ttm/

Well NAK for upstreaming. Why should ttm_debugfs_root be NULL here?

Regards,
Christian.

> Signed-off-by: Ma Jun <Jun.Ma2@xxxxxxx>
> ---
>   drivers/gpu/drm/ttm/ttm_device.c |  3 ++-
>   drivers/gpu/drm/ttm/ttm_pool.c   | 10 ++++++----
>   drivers/gpu/drm/ttm/ttm_tt.c     |  5 +++--
>   3 files changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c
> index e7147e304637..967bc2244df3 100644
> --- a/drivers/gpu/drm/ttm/ttm_device.c
> +++ b/drivers/gpu/drm/ttm/ttm_device.c
> @@ -105,7 +105,8 @@ static int ttm_global_init(void)
>   	INIT_LIST_HEAD(&glob->device_list);
>   	atomic_set(&glob->bo_count, 0);
>   
> -	debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
> +	if(ttm_debugfs_root)
> +		debugfs_create_atomic_t("buffer_objects", 0444, ttm_debugfs_root,
>   				&glob->bo_count);
>   out:
>   	if (ret && ttm_debugfs_root)
> diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
> index 21b61631f73a..d95a65f759df 100644
> --- a/drivers/gpu/drm/ttm/ttm_pool.c
> +++ b/drivers/gpu/drm/ttm/ttm_pool.c
> @@ -713,10 +713,12 @@ int ttm_pool_mgr_init(unsigned long num_pages)
>   	}
>   
>   #ifdef CONFIG_DEBUG_FS
> -	debugfs_create_file("page_pool", 0444, ttm_debugfs_root, NULL,
> -			    &ttm_pool_debugfs_globals_fops);
> -	debugfs_create_file("page_pool_shrink", 0400, ttm_debugfs_root, NULL,
> -			    &ttm_pool_debugfs_shrink_fops);
> +	if(ttm_debugfs_root) {
> +		debugfs_create_file("page_pool", 0444, ttm_debugfs_root, NULL,
> +				    &ttm_pool_debugfs_globals_fops);
> +		debugfs_create_file("page_pool_shrink", 0400, ttm_debugfs_root, NULL,
> +				    &ttm_pool_debugfs_shrink_fops);
> +	}
>   #endif
>   
>   	mm_shrinker.count_objects = ttm_pool_shrinker_count;
> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> index d505603930a7..fec443494ef0 100644
> --- a/drivers/gpu/drm/ttm/ttm_tt.c
> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> @@ -394,8 +394,9 @@ DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink);
>   void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages)
>   {
>   #ifdef CONFIG_DEBUG_FS
> -	debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
> -			    &ttm_tt_debugfs_shrink_fops);
> +	if(ttm_debugfs_root)
> +		debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL,
> +				    &ttm_tt_debugfs_shrink_fops);
>   #endif
>   
>   	if (!ttm_pages_limit)