Commit 397fd77c authored by Thierry Reding's avatar Thierry Reding Committed by Daniel Vetter

drm/atomic-helper: Implement drm_atomic_helper_duplicate_state()

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: default avatarThierry Reding <treding@nvidia.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 6e48ae32
......@@ -2371,6 +2371,84 @@ 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
......
......@@ -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);
......
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