Re: [PATCH v3 07/20] drm/colorop: Create drm_atomic_helper_colorop_create_state()

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Fri, Apr 24, 2026 at 12:18:47PM +0200, Maxime Ripard wrote:
> Commit 47b5ac7daa46 ("drm/atomic: Add new atomic_create_state callback
> to drm_private_obj") introduced a new pattern for allocating drm object
> states.
> 
> Instead of relying on the reset() callback, it created a new
> atomic_create_state hook. This is helpful because reset is a bit
> overloaded: it's used to create the initial software state, reset it,
> but also reset the hardware.
> 
> It can also be used either at probe time, to create the initial state
> and possibly reset the hardware to an expected default, but also during
> suspend/resume.
> 
> Both these cases come with different expectations too: during the
> initialization, we want to initialize all states, but during
> suspend/resume, drm_private_states for example are expected to be kept
> around.
> 
> reset() also isn't fallible, which makes it harder to handle
> initialization errors properly. This is only really relevant for some
> drivers though, since all the helpers for reset only create a new
> state, and don't touch the hardware at all.
> 
> It was thus decided to create a new hook that would allocate and
> initialize a pristine state without any side effect:
> atomic_create_state to untangle a bit some of it, and to separate the
> initialization with the actual reset one might need during a
> suspend/resume.
> 
> Continue the transition to the new pattern with drm_colorop.
> 
> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
> Signed-off-by: Maxime Ripard <mripard@kernel.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

> ---
>  drivers/gpu/drm/drm_colorop.c | 23 +++++++++++++++++++++++
>  include/drm/drm_colorop.h     |  2 ++
>  2 files changed, 25 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_colorop.c b/drivers/gpu/drm/drm_colorop.c
> index 4c4d0a953e35..c0eecde8c176 100644
> --- a/drivers/gpu/drm/drm_colorop.c
> +++ b/drivers/gpu/drm/drm_colorop.c
> @@ -521,10 +521,33 @@ static void __drm_colorop_state_init(struct drm_colorop_state *colorop_state,
>  							   &val))
>  			colorop_state->curve_1d_type = val;
>  	}
>  }
>  
> +/**
> + * drm_atomic_helper_colorop_create_state - Allocates and initializes colorop atomic state
> + * @colorop: drm colorop
> + *
> + * Initializes a pristine @drm_colorop_state.
> + *
> + * RETURNS:
> + * Pointer to new colorop state, or ERR_PTR on failure.
> + */
> +struct drm_colorop_state *
> +drm_atomic_helper_colorop_create_state(struct drm_colorop *colorop)
> +{
> +	struct drm_colorop_state *state;
> +
> +	state = kzalloc_obj(*state);
> +	if (!state)
> +		return ERR_PTR(-ENOMEM);
> +
> +	__drm_colorop_state_init(state, colorop);
> +
> +	return state;
> +}
> +
>  /**
>   * __drm_colorop_reset - reset state on colorop
>   * @colorop: drm colorop
>   * @colorop_state: colorop state to assign
>   *
> diff --git a/include/drm/drm_colorop.h b/include/drm/drm_colorop.h
> index bd082854ca74..874ed693329c 100644
> --- a/include/drm/drm_colorop.h
> +++ b/include/drm/drm_colorop.h
> @@ -423,10 +423,12 @@ int drm_plane_colorop_3dlut_init(struct drm_device *dev, struct drm_colorop *col
>  				 struct drm_plane *plane, const struct drm_colorop_funcs *funcs,
>  				 uint32_t lut_size,
>  				 enum drm_colorop_lut3d_interpolation_type interpolation,
>  				 uint32_t flags);
>  
> +struct drm_colorop_state *
> +drm_atomic_helper_colorop_create_state(struct drm_colorop *colorop);
>  struct drm_colorop_state *
>  drm_atomic_helper_colorop_duplicate_state(struct drm_colorop *colorop);
>  
>  void drm_colorop_atomic_destroy_state(struct drm_colorop *colorop,
>  				      struct drm_colorop_state *state);
> 

-- 
Regards,

Laurent Pinchart