Re: [PATCH 01/10] drm/i915: Introduce sanity to the plane_config pointer vs. array thing

[Jani Nikula <jani.nikula@linux.intel.com>]

On Fri, 10 Apr 2026, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> The "plane_config" vs. "plane_configs" naming difference is very
> subtle, making it far too easy to use the wrong thing by accident.
> Introduce a separate type for the array, making it impossible to
> pass in the wrong thing. And while at it name the variable
> "all_plane_configs" to help the poor reader make sense of things.
>
> The .config_fini() prototype also mistakenly used the plural
> form despite only taking in a singular plane_config. So fix that
> one up as well.
>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Nice!

Reviewed-by: Jani Nikula <jani.nikula@intel.com>


> ---
>  .../drm/i915/display/intel_initial_plane.c    | 21 ++++++++++++-------
>  include/drm/intel/display_parent_interface.h  |  2 +-
>  2 files changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_initial_plane.c b/drivers/gpu/drm/i915/display/intel_initial_plane.c
> index ee545c033da6..4f51083dbd11 100644
> --- a/drivers/gpu/drm/i915/display/intel_initial_plane.c
> +++ b/drivers/gpu/drm/i915/display/intel_initial_plane.c
> @@ -11,6 +11,10 @@
>  #include "intel_initial_plane.h"
>  #include "intel_plane.h"
>  
> +struct intel_initial_plane_configs {
> +	struct intel_initial_plane_config config[I915_MAX_PIPES];
> +};
> +
>  void intel_initial_plane_vblank_wait(struct intel_crtc *crtc)
>  {
>  	struct intel_display *display = to_intel_display(crtc);
> @@ -20,7 +24,7 @@ void intel_initial_plane_vblank_wait(struct intel_crtc *crtc)
>  
>  static const struct intel_plane_state *
>  intel_reuse_initial_plane_obj(struct intel_crtc *this,
> -			      const struct intel_initial_plane_config plane_configs[])
> +			      const struct intel_initial_plane_configs *all_plane_configs)
>  {
>  	struct intel_display *display = to_intel_display(this);
>  	struct intel_crtc *crtc;
> @@ -39,7 +43,8 @@ intel_reuse_initial_plane_obj(struct intel_crtc *this,
>  		if (!plane_state->ggtt_vma)
>  			continue;
>  
> -		if (plane_configs[this->pipe].base == plane_configs[crtc->pipe].base)
> +		if (all_plane_configs->config[this->pipe].base ==
> +		    all_plane_configs->config[crtc->pipe].base)
>  			return plane_state;
>  	}
>  
> @@ -69,10 +74,10 @@ intel_alloc_initial_plane_obj(struct intel_display *display,
>  
>  static void
>  intel_find_initial_plane_obj(struct intel_crtc *crtc,
> -			     struct intel_initial_plane_config plane_configs[])
> +			     struct intel_initial_plane_configs *all_plane_configs)
>  {
>  	struct intel_display *display = to_intel_display(crtc);
> -	struct intel_initial_plane_config *plane_config = &plane_configs[crtc->pipe];
> +	struct intel_initial_plane_config *plane_config = &all_plane_configs->config[crtc->pipe];
>  	struct intel_plane *plane = to_intel_plane(crtc->base.primary);
>  	struct intel_plane_state *plane_state = to_intel_plane_state(plane->base.state);
>  	struct drm_framebuffer *fb;
> @@ -93,7 +98,7 @@ intel_find_initial_plane_obj(struct intel_crtc *crtc,
>  	} else {
>  		const struct intel_plane_state *other_plane_state;
>  
> -		other_plane_state = intel_reuse_initial_plane_obj(crtc, plane_configs);
> +		other_plane_state = intel_reuse_initial_plane_obj(crtc, all_plane_configs);
>  		if (!other_plane_state)
>  			goto nofb;
>  
> @@ -158,14 +163,14 @@ static void plane_config_fini(struct intel_display *display,
>  
>  void intel_initial_plane_config(struct intel_display *display)
>  {
> -	struct intel_initial_plane_config plane_configs[I915_MAX_PIPES] = {};
> +	struct intel_initial_plane_configs all_plane_configs = {};
>  	struct intel_crtc *crtc;
>  
>  	for_each_intel_crtc(display->drm, crtc) {
>  		const struct intel_crtc_state *crtc_state =
>  			to_intel_crtc_state(crtc->base.state);
>  		struct intel_initial_plane_config *plane_config =
> -			&plane_configs[crtc->pipe];
> +			&all_plane_configs.config[crtc->pipe];
>  
>  		if (!crtc_state->hw.active)
>  			continue;
> @@ -183,7 +188,7 @@ void intel_initial_plane_config(struct intel_display *display)
>  		 * If the fb is shared between multiple heads, we'll
>  		 * just get the first one.
>  		 */
> -		intel_find_initial_plane_obj(crtc, plane_configs);
> +		intel_find_initial_plane_obj(crtc, &all_plane_configs);
>  
>  		if (display->funcs.display->fixup_initial_plane_config(crtc, plane_config))
>  			intel_initial_plane_vblank_wait(crtc);
> diff --git a/include/drm/intel/display_parent_interface.h b/include/drm/intel/display_parent_interface.h
> index 258e6388ef77..9041897c772e 100644
> --- a/include/drm/intel/display_parent_interface.h
> +++ b/include/drm/intel/display_parent_interface.h
> @@ -91,7 +91,7 @@ struct intel_display_initial_plane_interface {
>  	struct drm_gem_object *(*alloc_obj)(struct drm_device *drm, struct intel_initial_plane_config *plane_config);
>  	int (*setup)(struct drm_plane_state *plane_state, struct intel_initial_plane_config *plane_config,
>  		     struct drm_framebuffer *fb, struct i915_vma *vma);
> -	void (*config_fini)(struct intel_initial_plane_config *plane_configs);
> +	void (*config_fini)(struct intel_initial_plane_config *plane_config);
>  };
>  
>  struct intel_display_irq_interface {

-- 
Jani Nikula, Intel