Re: [PATCH v2 02/20] drm/atomic: Drop drm_private_state.obj assignment from create_state

Thomas Zimmermann
2026-04-21T13:03:53Z

Hi

Am 20.03.26 um 17:27 schrieb Maxime Ripard:
> The initial intent of the atomic_create_state helper was to simply
> allocate a proper drm_private_state and returning it, without any side
> effect.
>
> However, the __drm_atomic_helper_private_obj_create_state() introduces a
> side effect by setting the drm_private_obj.state to the newly allocated
> state.
>
> This assignment defeats the purpose, but is also redundant since
> the only caller, drm_atomic_private_obj_init(), will also set this
> pointer to the newly allocated state.

Is this paragraph no longer up to date? Grepping for
__drm_atomic_helper_private_obj_create_state returns plenty of callers.
Best regards Thomas
>
> Let's drop the assignment in __drm_atomic_helper_private_obj_create_state().
>
> Fixes: e7be39ed1716 ("drm/atomic-helper: Add private_obj atomic_create_state helper")
> Signed-off-by: Maxime Ripard <mripard@kernel.org>
> ---
> drivers/gpu/drm/drm_atomic_state_helper.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/drm_atomic_state_helper.c
> index 76746ad4a1bbb7142c067c93dd05fbec5d2f98eb..875149494b00e1eb7481e87d7d7038103b72b7e3 100644
> --- a/drivers/gpu/drm/drm_atomic_state_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_state_helper.c
> @@ -729,12 +729,10 @@ EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
> void __drm_atomic_helper_private_obj_create_state(struct drm_private_obj *obj,
> struct drm_private_state *state)
> {
> if (state)
> state->obj = obj;
> -
> - obj->state = state;
> }
> EXPORT_SYMBOL(__drm_atomic_helper_private_obj_create_state);
>
> /**
> * __drm_atomic_helper_private_obj_duplicate_state - copy atomic private state
>

--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)