From: Thierry Reding treding@nvidia.com
This function can be used to duplicate an atomic state object. This is useful for example to implement suspend/resume, where the state before suspend can be saved and restored upon resume.
v2: move locking to caller, be more explicit about prerequisites v3: explicitly pass lock acquisition context, improve kerneldoc
Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/drm_atomic_helper.c | 78 +++++++++++++++++++++++++++++++++++++ include/drm/drm_atomic_helper.h | 3 ++ 2 files changed, 81 insertions(+)
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index 634aa617811b..3232f4b838e4 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -2349,6 +2349,84 @@ drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector) EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
/** + * drm_atomic_helper_duplicate_state - duplicate an atomic state object + * @dev: DRM device + * @ctx: lock acquisition context + * + * Makes a copy of the current atomic state by looping over all objects and + * duplicating their respective states. + * + * Note that this treats atomic state as persistent between save and restore. + * Drivers must make sure that this is possible and won't result in confusion + * or erroneous behaviour. + * + * Note that if callers haven't already acquired all modeset locks this might + * return -EDEADLK, which must be handled by calling drm_modeset_backoff(). + * + * Returns: + * A pointer to the copy of the atomic state object on success or an + * ERR_PTR()-encoded error code on failure. + */ +struct drm_atomic_state * +drm_atomic_helper_duplicate_state(struct drm_device *dev, + struct drm_modeset_acquire_ctx *ctx) +{ + struct drm_atomic_state *state; + struct drm_connector *conn; + struct drm_plane *plane; + struct drm_crtc *crtc; + int err = 0; + + state = drm_atomic_state_alloc(dev); + if (!state) + return ERR_PTR(-ENOMEM); + + state->acquire_ctx = ctx; + + drm_for_each_crtc(crtc, dev) { + struct drm_crtc_state *crtc_state; + + crtc_state = drm_atomic_get_crtc_state(state, crtc); + if (IS_ERR(crtc_state)) { + err = PTR_ERR(crtc_state); + goto free; + } + } + + drm_for_each_plane(plane, dev) { + struct drm_plane_state *plane_state; + + plane_state = drm_atomic_get_plane_state(state, plane); + if (IS_ERR(plane_state)) { + err = PTR_ERR(plane_state); + goto free; + } + } + + drm_for_each_connector(conn, dev) { + struct drm_connector_state *conn_state; + + conn_state = drm_atomic_get_connector_state(state, conn); + if (IS_ERR(conn_state)) { + err = PTR_ERR(conn_state); + goto free; + } + } + + /* clear the acquire context so that it isn't accidentally reused */ + state->acquire_ctx = NULL; + +free: + if (err < 0) { + drm_atomic_state_free(state); + state = ERR_PTR(err); + } + + return state; +} +EXPORT_SYMBOL(drm_atomic_helper_duplicate_state); + +/** * __drm_atomic_helper_connector_destroy_state - release connector state * @connector: connector object * @state: connector state object to release diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h index 4ffe9dca07c4..1547eb43c14a 100644 --- a/include/drm/drm_atomic_helper.h +++ b/include/drm/drm_atomic_helper.h @@ -118,6 +118,9 @@ __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector, struct drm_connector_state *state); struct drm_connector_state * drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector); +struct drm_atomic_state * +drm_atomic_helper_duplicate_state(struct drm_device *dev, + struct drm_modeset_acquire_ctx *ctx); void __drm_atomic_helper_connector_destroy_state(struct drm_connector *connector, struct drm_connector_state *state);