Re: [PATCH v2 18/61] drm/imx/dcss: Convert to atomic_create_state

On Fri, Aug 14, 2026 at 04:57:07PM +0200, Maxime Ripard wrote:
> The plane only initializes a pristine state in its reset hook
> using drm_atomic_helper_plane_reset(), which is equivalent to what
> atomic_create_state expects. Convert to it.
> 
> The conversion was done using the following Coccinelle semantic patch:
> 
> @@
> identifier funcs;
> symbol drm_atomic_helper_plane_reset;
> symbol drm_atomic_helper_plane_create_state;
> @@
> 
> struct drm_plane_funcs funcs = {
>   ...,
> - .reset = drm_atomic_helper_plane_reset,
> + .atomic_create_state = drm_atomic_helper_plane_create_state,
>   ...,
> };
> 
> @match_struct_reset@
> identifier funcs, reset_func;
> @@
> struct drm_plane_funcs funcs = {
>     ...,
>     .reset = reset_func,
>     ...,
> };
> 
> @reset_uses_helpers depends on match_struct_reset@
> identifier match_struct_reset.reset_func;
> @@
> 
>  void reset_func(...)
>  {
>  	<+...
> (
>  	__drm_atomic_helper_plane_reset(...);
> |
> 	__drm_gem_reset_shadow_plane(...);
> )
>  	...+>
>  }
> 
> @match_struct_destroy@
> identifier funcs, destroy_func;
> @@
> struct drm_plane_funcs funcs = {
>     ...,
>     .atomic_destroy_state = destroy_func,
>     ...,
> };
> 
> @script:python renamed_func@
> old_name << match_struct_reset.reset_func;
> new_name;
> @@
> if old_name.endswith("_reset"):
>     coccinelle.new_name = old_name.replace("_reset", "_create_state")
> else:
>     coccinelle.new_name = old_name
> 
> @update_struct depends on match_struct_reset && reset_uses_helpers@
> identifier match_struct_reset.funcs, match_struct_reset.reset_func;
> identifier renamed_func.new_name;
> @@
> struct drm_plane_funcs funcs = {
>     ...,
> -   .reset = reset_func,
> +   .atomic_create_state = new_name,
>     ...,
> };
> 
> @drop_destroy depends on update_struct && match_struct_destroy@
> identifier match_struct_reset.reset_func;
> identifier match_struct_destroy.destroy_func;
> identifier container_func;
> identifier P;
> symbol drm_atomic_helper_plane_destroy_state;
> symbol __drm_atomic_helper_plane_destroy_state;
> @@
> 
>  void reset_func(struct drm_plane *P)
>  {
>  	...
> (
> -	if (P->state) {
> - 		<+...
> (
> -		drm_atomic_helper_plane_destroy_state(P, P->state);
> |
> -		__drm_atomic_helper_plane_destroy_state(P->state);
> |
> -		P->funcs->atomic_destroy_state(P, P->state);
> |
> -		destroy_func(P, P->state);
> )
> - 		...+>
> - 	}
> |
> -	drm_WARN_ON_ONCE(P->dev, P->state);
> |
> -	WARN_ON(P->state);
> )
>  	...
> (
> -	kfree(P->state);
> |
> -	kfree(container_func(P->state));
> |
>  	// kfree is optional
> )
> (
> -	P->state = NULL;
> |
>  	// plane->state clearing is optional
> )
>  	...
>  }
> 
> @drop_destroy_mtk depends on update_struct@
> identifier P;
> symbol __drm_atomic_helper_plane_destroy_state;
> symbol to_mtk_plane_state;
> @@
> 
>  void mtk_plane_reset(struct drm_plane *P)
>  {
>  	...
> -	if (P->state) {
> -		__drm_atomic_helper_plane_destroy_state(P->state);
> -		...
> -	} else {
>  		...
> -	}
>  	...
>  }
> 
> @transform_nv50_wndw depends on update_struct@
> identifier S;
> @@
> 
>  void nv50_wndw_reset(...)
>  {
>  	...
> -	if (WARN_ON(!(S = kzalloc_obj(*S))))
> +	S = kzalloc_obj(*S);
> +	if (WARN_ON(!S))
>  		return;
>  	...
>  }
> 
> @transform_kzalloc depends on update_struct@
> identifier match_struct_reset.reset_func;
> identifier P, S;
> statement ST;
> statement list STL;
> @@
> 
>  void reset_func(struct drm_plane *P)
>  {
>  	<...
>  	S = kzalloc_obj(*S);
> (
> -	if (S)
> -	{
> -		STL
> -	}
> +	if (!S) return;
> +
> +	STL
> |
> -	if (S) ST
> +	if (!S) return;
> +
> +	ST
> )
> 	...>
>  }
> 
> @transform_body depends on update_struct@
> identifier match_struct_reset.reset_func;
> identifier renamed_func.new_name;
> identifier S, P;
> expression PS;
> @@
> - void reset_func(struct drm_plane *P)
> + struct drm_plane_state *new_name(struct drm_plane *P)
> {
> 	...
>  	S = kzalloc_obj(*S);
> 	...
> (
>  	if (!S) {
> 		...
> -		return;
> +		return ERR_PTR(-ENOMEM);
>  	}
> |
>  	if (WARN_ON(!S)) {
> 		...
> -		return;
> +		return ERR_PTR(-ENOMEM);
>  	}
> |
>  	if (S == NULL) {
>  		...
> -		return;
> +		return ERR_PTR(-ENOMEM);
>  	}
> )
> 	...
> (
> -	__drm_atomic_helper_plane_reset(P, PS);
> +	__drm_atomic_helper_plane_state_init(PS, P);
> |
> -	__drm_gem_reset_shadow_plane(P, PS);
> +	__drm_gem_shadow_plane_state_init(P, PS);
> )
> 	...
> }
> 
> @update_early_return depends on update_struct@
> identifier match_struct_reset.reset_func;
> identifier renamed_func.new_name;
> identifier P;
> expression PS;
> @@
>  struct drm_plane_state *new_name(struct drm_plane *P)
> {
> 	<+...
> -	return;
> +	return ERR_PTR(-EINVAL);
> 	...+>
> }
> 
> @update_return_plane depends on update_struct@
> identifier match_struct_reset.reset_func;
> identifier renamed_func.new_name;
> identifier P;
> expression PS;
> @@
>  struct drm_plane_state *new_name(struct drm_plane *P)
> {
> 	...
>  	__drm_atomic_helper_plane_state_init(PS, P);
> 	...
> +
> +	return PS;
> }
> 
> @update_return_shadow depends on update_struct@
> identifier renamed_func.new_name;
> identifier P;
> expression PS;
> @@
>  struct drm_plane_state *new_name(struct drm_plane *P)
> {
> 	...
>  	__drm_gem_shadow_plane_state_init(P, PS);
> 	...
> +
> +	return &PS->base;
> }
> 
> Signed-off-by: Maxime Ripard <[email protected]>

Reviewed-by: Laurentiu Palcu <[email protected]>

-- 
Thanks,
Laurentiu