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

Laurent Pinchart
2026-05-04T16:41:48Z

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