On Fri, 2026-08-14 at 16:57 +0200, Maxime Ripard wrote:
> The plane reset implementation creates a custom state
> subclass, but only initializes a pristine state without resetting any
> hardware. This 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]>
> ---
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> ---
> drivers/gpu/drm/nouveau/dispnv50/wndw.c | 15 +++++++--------
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
> b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
> index 15a322422f4e..378095138d12 100644
> --- a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
> +++ b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
> @@ -750,22 +750,21 @@ nv50_wndw_zpos_default(struct drm_plane *plane)
> {
> return (plane->type == DRM_PLANE_TYPE_PRIMARY) ? 0 :
> (plane->type == DRM_PLANE_TYPE_OVERLAY) ? 1 : 255;
> }
>
> -static void
> -nv50_wndw_reset(struct drm_plane *plane)
> +static struct drm_plane_state *nv50_wndw_create_state(struct
> drm_plane *plane)
> {
> struct nv50_wndw_atom *asyw;
>
> - if (WARN_ON(!(asyw = kzalloc_obj(*asyw))))
> - return;
> + asyw = kzalloc_obj(*asyw);
> + if (WARN_ON(!asyw))
> + return ERR_PTR(-ENOMEM);
Should this be drm_WARN_ON() while we're at it?
Otherwise, this looks good to me:
Reviewed-by: Lyude Paul <[email protected]>
>
> - if (plane->state)
> - plane->funcs->atomic_destroy_state(plane, plane-
> >state);
> + __drm_atomic_helper_plane_state_init(&asyw->state, plane);
>
> - __drm_atomic_helper_plane_reset(plane, &asyw->state);
> + return &asyw->state;
> }
>
> static void
> nv50_wndw_destroy(struct drm_plane *plane)
> {
> @@ -835,11 +834,11 @@ static bool
> nv50_plane_format_mod_supported(struct drm_plane *plane,
> const struct drm_plane_funcs
> nv50_wndw = {
> .update_plane = drm_atomic_helper_update_plane,
> .disable_plane = drm_atomic_helper_disable_plane,
> .destroy = nv50_wndw_destroy,
> - .reset = nv50_wndw_reset,
> + .atomic_create_state = nv50_wndw_create_state,
> .atomic_duplicate_state = nv50_wndw_atomic_duplicate_state,
> .atomic_destroy_state = nv50_wndw_atomic_destroy_state,
> .format_mod_supported = nv50_plane_format_mod_supported,
> };
>
