Re: [PATCH v2 56/61] drm/sun4i: layer: Convert to atomic_create_state

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The `.atomic_create_state` hook (`sun4i_backend_layer_create_state`) illegally retains state destruction logic, violating the factory function API contract.
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--- Patch [56]: [PATCH v2 56/61] drm/sun4i: layer: Convert to atomic_create_state ---
commit ff1555af002cdd0794b6aa7ae72c66565fbe6fdd
Author: Maxime Ripard <mripard@kernel.org>

drm/sun4i: layer: Convert to atomic_create_state

This commit converts the plane reset implementation to use
atomic_create_state. The existing implementation creates a custom state
subclass but only initializes a pristine state without resetting any
hardware, which matches the expected behavior of atomic_create_state.

> diff --git a/drivers/gpu/drm/sun4i/sun4i_layer.c b/drivers/gpu/drm/sun4i/sun4i_layer.c
> index d65587d96d9ee..b165960ca8e5d 100644
> --- a/drivers/gpu/drm/sun4i/sun4i_layer.c
> +++ b/drivers/gpu/drm/sun4i/sun4i_layer.c
> @@ -16,7 +16,7 @@
>  #include "sun4i_layer.h"
>  #include "sunxi_engine.h"
>  
> -static void sun4i_backend_layer_reset(struct drm_plane *plane)
> +static struct drm_plane_state *sun4i_backend_layer_create_state(struct drm_plane *plane)
>  {
>  	struct sun4i_layer_state *state;
>  
>  	if (plane->state) {
>  		state = state_to_sun4i_layer_state(plane->state);
>  
>  		__drm_atomic_helper_plane_destroy_state(&state->state);
>  
>  		kfree(state);
>  		plane->state = NULL;
>  	}

[Severity: Medium]
Should this state destruction logic be removed since this function is now
an atomic_create_state hook?

The atomic_create_state factory function API contract expects only
allocation and initialization of a new state object. Although the DRM core
guarantees plane->state is NULL before invoking this hook (making this
block functionally dead code), it appears the Coccinelle semantic patch
may have missed removing this destruction block during the conversion.

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260814-drm-no-more-plane-reset-v2-0-82d2963dd134@kernel.org?part=56