From nobody Wed Apr 8 04:24:13 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 406CE3BF69B; Tue, 10 Mar 2026 16:07:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773158844; cv=none; b=qe/Kd0noTyv7+EFQPzp66ABtSLNjCqcfyP4oaO0FjlV1V/X3LzIED5QYrQKu46dji8DSsc4LRoozYzfuR9qdMTB1t3AwDcfd32YfSH/qzwuTS9JdQK4S9ux44A7o+g9megTI8p1L7BQT2cU1NsX28MAnThqm/RT9gVHetCIzGHA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773158844; c=relaxed/simple; bh=vjC/BB4+6nV6lrTleZ0dvGqZuB+/+HLlfLrcv7dUBiQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Y5CVjYE0MQsNIdgWelPWeum4MpicG4XiFXc9bryBidq8yFwVHY60nLoVCCtJlXpKkVzcK+2duSqvg/0KzuYfg1ir3gB7wF8IL6xEKDYqMNA+E41Syk94VbDk+sdWP1K6q5A+JPmGTSa6TzsiktFdnL+5tC1SCcHnzSX06zFJ+U4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LhycQOGp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LhycQOGp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 792EBC19423; Tue, 10 Mar 2026 16:07:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773158843; bh=vjC/BB4+6nV6lrTleZ0dvGqZuB+/+HLlfLrcv7dUBiQ=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=LhycQOGpSsJG7C/UDjQuZfiU0jn7+7HADmoSEN0DPDxdxYl7/Zbr2a6Z1xgsxW/2w NTNlOYRwUFYV8Cx4G8uwu3vXjbTiAWvAobQN14Wt5nQf+09ET4UbMl1ON0U7tKYgvq rYbq4isL9To0mABPD9fCDZ+Uw5IIVfGqQ8HTkGz8mewvTjOfZpbGd7dzclMsGI9o6D JgPJdP/ce9mrNtTcoPwaF+kL9B/OBWnchjpItvTQvS9VxZEZCg85xzsBEu1EsNx1RQ EOO/2R0qpu7kjJBj3jbMxHED2DokpQuAdsYYbbuKGXKF1hqmR/97xRZvRvXtgNUWPp pwUq3UwoX+DxA== From: Maxime Ripard Date: Tue, 10 Mar 2026 17:06:57 +0100 Subject: [PATCH 05/14] drm/plane: Add new atomic_create_state callback Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260310-drm-mode-config-init-v1-5-de7397c8e1cf@kernel.org> References: <20260310-drm-mode-config-init-v1-0-de7397c8e1cf@kernel.org> In-Reply-To: <20260310-drm-mode-config-init-v1-0-de7397c8e1cf@kernel.org> To: Maarten Lankhorst , Thomas Zimmermann , David Airlie , Simona Vetter , Jonathan Corbet , Shuah Khan , Dmitry Baryshkov , Jyri Sarha , Tomi Valkeinen , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec Cc: dri-devel@lists.freedesktop.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Maxime Ripard X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=7412; i=mripard@kernel.org; h=from:subject:message-id; bh=vjC/BB4+6nV6lrTleZ0dvGqZuB+/+HLlfLrcv7dUBiQ=; b=owGbwMvMwCmsHn9OcpHtvjLG02pJDJkbHJdeFXjLeLCd+dKzDcftFjPxH9kdONWp+c5Ui998p erCUSfTO6awMAhzMsiKKbI8kQk7vbx9cZWD/cofMHNYmUCGMHBxCsBEON4xVhxYN/cJx/PaUMlV W7p/xd6ycH4nLp1b+PRI6bd/O9JuiayUip65bknRzTyVj5f3MKq/YWxY6GUyy+99WYPZcq+kS29 kFmytUnsn1Ne6/pm12HLZkJ3feRV+XD/0UlxR4Mkcn60yO1UB X-Developer-Key: i=mripard@kernel.org; a=openpgp; fpr=BE5675C37E818C8B5764241C254BCFC56BF6CE8D 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 tate, 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. And reset() isn't fallible, which makes it harder to handle initialization errors properly. And this is only really relevant for some drivers, 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. Let's continue the transition to the new pattern with planes. Signed-off-by: Maxime Ripard --- drivers/gpu/drm/drm_atomic_state_helper.c | 41 +++++++++++++++++++++++++++= ++++ drivers/gpu/drm/drm_mode_config.c | 18 ++++++++++++++ include/drm/drm_atomic_state_helper.h | 4 +++ include/drm/drm_plane.h | 13 ++++++++++ 4 files changed, 76 insertions(+) diff --git a/drivers/gpu/drm/drm_atomic_state_helper.c b/drivers/gpu/drm/dr= m_atomic_state_helper.c index a1abf4247c348eca21da348c3893dd843b9ed391..898e168eeae1c3899121ffd13c7= 9fae7803fcd2a 100644 --- a/drivers/gpu/drm/drm_atomic_state_helper.c +++ b/drivers/gpu/drm/drm_atomic_state_helper.c @@ -318,10 +318,29 @@ void __drm_atomic_helper_plane_reset(struct drm_plane= *plane, =20 plane->state =3D plane_state; } EXPORT_SYMBOL(__drm_atomic_helper_plane_reset); =20 +/** + * __drm_atomic_helper_plane_create_state - initializes plane state + * @plane: plane object + * @state: new state to initialize + * + * Initializes the newly allocated @state, usually required when + * initializing the drivers. + * + * @state is assumed to be zeroed. + * + * This is useful for drivers that subclass @drm_plane_state. + */ +void __drm_atomic_helper_plane_create_state(struct drm_plane *plane, + struct drm_plane_state *state) +{ + __drm_atomic_helper_plane_reset(plane, state); +} +EXPORT_SYMBOL(__drm_atomic_helper_plane_create_state); + /** * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for= planes * @plane: drm plane * * Resets the atomic state for @plane by freeing the state pointer (which = might @@ -337,10 +356,32 @@ void drm_atomic_helper_plane_reset(struct drm_plane *= plane) if (plane->state) __drm_atomic_helper_plane_reset(plane, plane->state); } EXPORT_SYMBOL(drm_atomic_helper_plane_reset); =20 +/** + * drm_atomic_helper_plane_create_state - default &drm_plane_funcs.atomic_= create_state hook for planes + * @plane: plane object + * + * Initializes a pristine @drm_plane_state. + * + * This is useful for drivers that don't subclass @drm_plane_state. + */ +struct drm_plane_state *drm_atomic_helper_plane_create_state(struct drm_pl= ane *plane) +{ + struct drm_plane_state *state; + + state =3D kzalloc_obj(*state); + if (!state) + return ERR_PTR(-ENOMEM); + + __drm_atomic_helper_plane_reset(plane, state); + + return state; +} +EXPORT_SYMBOL(drm_atomic_helper_plane_create_state); + /** * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state * @plane: plane object * @state: atomic plane state * diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_c= onfig.c index 54c27376f9894ef5eee378bb5b1e5fc7049de922..43fe64540b8ec4df4bb823d96db= 607e6bfe58824 100644 --- a/drivers/gpu/drm/drm_mode_config.c +++ b/drivers/gpu/drm/drm_mode_config.c @@ -180,10 +180,26 @@ int drm_mode_getresources(struct drm_device *dev, voi= d *data, drm_connector_list_iter_end(&conn_iter); =20 return ret; } =20 +static int drm_mode_config_plane_create_state(struct drm_plane *plane) +{ + struct drm_plane_state *plane_state; + + if (!plane->funcs->atomic_create_state) + return 0; + + plane_state =3D plane->funcs->atomic_create_state(plane); + if (IS_ERR(plane_state)) + return PTR_ERR(plane_state); + + plane->state =3D plane_state; + + return 0; +} + /** * drm_mode_config_reset - call ->reset callbacks * @dev: drm device * * This functions calls all the crtc's, encoder's and connector's ->reset @@ -207,10 +223,12 @@ void drm_mode_config_reset(struct drm_device *dev) drm_colorop_reset(colorop); =20 drm_for_each_plane(plane, dev) if (plane->funcs->reset) plane->funcs->reset(plane); + else if (plane->funcs->atomic_create_state) + drm_mode_config_plane_create_state(plane); =20 drm_for_each_crtc(crtc, dev) if (crtc->funcs->reset) crtc->funcs->reset(crtc); =20 diff --git a/include/drm/drm_atomic_state_helper.h b/include/drm/drm_atomic= _state_helper.h index 900672c6ea90ba9cb87e38a7c84225972aee43c5..f56a91fca20e778d8ccb1767301= dc00783bf40f3 100644 --- a/include/drm/drm_atomic_state_helper.h +++ b/include/drm/drm_atomic_state_helper.h @@ -51,12 +51,16 @@ struct drm_crtc_state * drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc); void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state); void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc, struct drm_crtc_state *state); =20 +void __drm_atomic_helper_plane_create_state(struct drm_plane *plane, + struct drm_plane_state *state); void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *state, struct drm_plane *plane); +struct drm_plane_state * +drm_atomic_helper_plane_create_state(struct drm_plane *plane); void __drm_atomic_helper_plane_reset(struct drm_plane *plane, struct drm_plane_state *state); void drm_atomic_helper_plane_reset(struct drm_plane *plane); void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane, struct drm_plane_state *state); diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h index 703ef4d1bbbcf084c43aa5e127d28691878061c4..4d4d511b681d50c17fbc593cce9= f706d63e04a52 100644 --- a/include/drm/drm_plane.h +++ b/include/drm/drm_plane.h @@ -386,10 +386,23 @@ struct drm_plane_funcs { * 0 on success or a negative error code on failure. */ int (*set_property)(struct drm_plane *plane, struct drm_property *property, uint64_t val); =20 + /** + * @atomic_create_state: + * + * Allocates a pristine, initialized, state for the plane object + * and returns it. + * + * RETURNS: + * + * A new, pristine, plane state instance or an error pointer + * on failure. + */ + struct drm_plane_state *(*atomic_create_state)(struct drm_plane *plane); + /** * @atomic_duplicate_state: * * Duplicate the current atomic state for this plane and return it. * The core and helpers guarantee that any atomic state duplicated with --=20 2.53.0