The atomic reset path will need to create pristine default states from scratch for every plane, CRTC, and connector. This requires all of them to implement the atomic_create_state hook.
Introduce a drm_atomic_can_create_state() helper that iterates over all planes, CRTCs, and connectors and returns whether they all provide the hook. Color operations are excluded since they always use drm_atomic_helper_colorop_create_state() directly. This will be used both as a precondition before filling a commit with default states, and to report the device capability to userspace. Signed-off-by: Maxime Ripard <[email protected]> --- drivers/gpu/drm/drm_atomic.c | 49 ++++++++++++++++++++++++++++++++++++++++++++ include/drm/drm_atomic.h | 2 ++ 2 files changed, 51 insertions(+) diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c index e78f7eb6bfd1..d8251447e44a 100644 --- a/drivers/gpu/drm/drm_atomic.c +++ b/drivers/gpu/drm/drm_atomic.c @@ -1608,10 +1608,59 @@ drm_atomic_get_new_bridge_state(const struct drm_atomic_commit *state, return drm_priv_to_bridge_state(obj_state); } EXPORT_SYMBOL(drm_atomic_get_new_bridge_state); +/** + * drm_atomic_can_create_state - check if a device supports creating pristine states + * @dev: DRM device + * + * Check whether every plane, CRTC, and connector in @dev implements the + * &drm_plane_funcs.atomic_create_state, &drm_crtc_funcs.atomic_create_state, + * and &drm_connector_funcs.atomic_create_state hooks respectively. These hooks + * are required to create default states from scratch rather than duplicating + * the current state. + * + * Color operations are not checked because they always use + * drm_atomic_helper_colorop_create_state() and do not have a per-driver hook. + * + * Returns: + * True if all objects implement atomic_create_state, false otherwise. + */ +bool drm_atomic_can_create_state(struct drm_device *dev) +{ + struct drm_connector_list_iter conn_iter; + struct drm_connector *connector; + struct drm_plane *plane; + struct drm_crtc *crtc; + + /* + * colorops don't have an atomic_create_state hook but + * drm_atomic_helper_colorop_create_state() + */ + + drm_for_each_plane(plane, dev) + if (!plane->funcs->atomic_create_state) + return false; + + drm_for_each_crtc(crtc, dev) + if (!crtc->funcs->atomic_create_state) + return false; + + drm_connector_list_iter_begin(dev, &conn_iter); + drm_for_each_connector_iter(connector, &conn_iter) { + if (!connector->funcs->atomic_create_state) { + drm_connector_list_iter_end(&conn_iter); + return false; + } + } + drm_connector_list_iter_end(&conn_iter); + + return true; +} +EXPORT_SYMBOL(drm_atomic_can_create_state); + /** * drm_atomic_add_encoder_bridges - add bridges attached to an encoder * @state: atomic state * @encoder: DRM encoder * diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h index 00b3e9fc429a..7dc26e3da65c 100644 --- a/include/drm/drm_atomic.h +++ b/include/drm/drm_atomic.h @@ -700,10 +700,12 @@ int drm_crtc_commit_wait(struct drm_crtc_commit *commit); struct drm_atomic_commit * __must_check drm_atomic_commit_alloc(struct drm_device *dev); void drm_atomic_commit_clear(struct drm_atomic_commit *state); +bool drm_atomic_can_create_state(struct drm_device *dev); + /** * drm_atomic_commit_get - acquire a reference to the atomic state * @state: The atomic state * * Returns a new reference to the @state -- 2.55.0
