diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 23e4661a62feaa56423cc36538f513b61a24c60f..4f6e52961951741459c54e9ad53f090a99bd034b 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -795,6 +795,9 @@ int drm_atomic_helper_check(struct drm_device *dev,
if (ret)
return ret;
+ if (state->legacy_cursor_update)
+ state->async_update = !drm_atomic_helper_async_check(dev, state);
+
return ret;
}
EXPORT_SYMBOL(drm_atomic_helper_check);
@@ -1352,6 +1355,114 @@ static void commit_work(struct work_struct *work)
commit_tail(state);
}
+/**
+ * drm_atomic_helper_async_check - check if state can be commited asynchronously
+ * @dev: DRM device
+ * @state: the driver state object
+ *
+ * This helper will check if it is possible to commit the state asynchronously.
+ * Async commits are not supposed to swap the states like normal sync commits
+ * but just do in-place changes on the current state.
+ *
+ * It will return 0 if the commit can happen in an asynchronous fashion or error
+ * if not. Note that error just mean it can't be commited asynchronously, if it
+ * fails the commit should be treated like a normal synchronous commit.
+ */
+int drm_atomic_helper_async_check(struct drm_device *dev,
+ struct drm_atomic_state *state)
+{
+ struct drm_crtc *crtc;
+ struct drm_crtc_state *crtc_state;
+ struct drm_crtc_commit *commit;
+ struct drm_plane *__plane, *plane = NULL;
+ struct drm_plane_state *__plane_state, *plane_state = NULL;
+ const struct drm_plane_helper_funcs *funcs;
+ int i, j, n_planes = 0;
+
+ for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
+ if (drm_atomic_crtc_needs_modeset(crtc_state))
+ return -EINVAL;
+ }
+
+ for_each_new_plane_in_state(state, __plane, __plane_state, i) {
+ n_planes++;
+ plane = __plane;
+ plane_state = __plane_state;
+ }
+
+ /* FIXME: we support only single plane updates for now */
+ if (!plane || n_planes != 1)
+ return -EINVAL;
+
+ if (!plane_state->crtc)
+ return -EINVAL;
+
+ funcs = plane->helper_private;
+ if (!funcs->atomic_async_update)
+ return -EINVAL;
+
+ if (plane_state->fence)
+ return -EINVAL;
+
+ /*
+ * Don't do an async update if there is an outstanding commit modifying
+ * the plane. This prevents our async update's changes from getting
+ * overridden by a previous synchronous update's state.
+ */
+ for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
+ if (plane->crtc != crtc)
+ continue;
+
+ spin_lock(&crtc->commit_lock);
+ commit = list_first_entry_or_null(&crtc->commit_list,
+ struct drm_crtc_commit,
+ commit_entry);
+ if (!commit) {
+ spin_unlock(&crtc->commit_lock);
+ continue;
+ }
+ spin_unlock(&crtc->commit_lock);
+
+ if (!crtc->state->state)
+ continue;
+
+ for_each_plane_in_state(crtc->state->state, __plane,
+ __plane_state, j) {
+ if (__plane == plane)
+ return -EINVAL;
+ }
+ }
+
+ return funcs->atomic_async_check(plane, plane_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_async_check);
+
+/**
+ * drm_atomic_helper_async_commit - commit state asynchronously
+ * @dev: DRM device
+ * @state: the driver state object
+ *
+ * This function commits a state asynchronously, i.e., not vblank
+ * synchronized. It should be used on a state only when
+ * drm_atomic_async_check() succeeds. Async commits are not supposed to swap
+ * the states like normal sync commits, but just do in-place changes on the
+ * current state.
+ */
+void drm_atomic_helper_async_commit(struct drm_device *dev,
+ struct drm_atomic_state *state)
+{
+ struct drm_plane *plane;
+ struct drm_plane_state *plane_state;
+ const struct drm_plane_helper_funcs *funcs;
+ int i;
+
+ for_each_new_plane_in_state(state, plane, plane_state, i) {
+ funcs = plane->helper_private;
+ funcs->atomic_async_update(plane, plane_state);
+ }
+}
+EXPORT_SYMBOL(drm_atomic_helper_async_commit);
+
/**
* drm_atomic_helper_commit - commit validated state object
* @dev: DRM device
@@ -1376,6 +1487,17 @@ int drm_atomic_helper_commit(struct drm_device *dev,
{
int ret;
+ if (state->async_update) {
+ ret = drm_atomic_helper_prepare_planes(dev, state);
+ if (ret)
+ return ret;
+
+ drm_atomic_helper_async_commit(dev, state);
+ drm_atomic_helper_cleanup_planes(dev, state);
+
+ return 0;
+ }
+
ret = drm_atomic_helper_setup_commit(state, nonblock);
if (ret)
return ret;
diff --git a/include/drm/drm_atomic.h b/include/drm/drm_atomic.h
index 0196f264a418a1d0885cd5cb4ebbf3ab56f3c91e..dcc8e0cdb7ff64f5cf406d2332a902ebc0d7fcbf 100644
--- a/include/drm/drm_atomic.h
+++ b/include/drm/drm_atomic.h
@@ -207,6 +207,7 @@ struct __drm_private_objs_state {
* @dev: parent DRM device
* @allow_modeset: allow full modeset
* @legacy_cursor_update: hint to enforce legacy cursor IOCTL semantics
+ * @async_update: hint for asynchronous plane update
* @planes: pointer to array of structures with per-plane data
* @crtcs: pointer to array of CRTC pointers
* @num_connector: size of the @connectors and @connector_states arrays
@@ -221,6 +222,7 @@ struct drm_atomic_state {
struct drm_device *dev;
bool allow_modeset : 1;
bool legacy_cursor_update : 1;
+ bool async_update : 1;
struct __drm_planes_state *planes;
struct __drm_crtcs_state *crtcs;
int num_connector;
diff --git a/include/drm/drm_atomic_helper.h b/include/drm/drm_atomic_helper.h
index 3bfeb2b2f746ff65aab15623747a5cc7caa4cb53..dd196cc0afd7b612ce8cd9852d7145303fda62c1 100644
--- a/include/drm/drm_atomic_helper.h
+++ b/include/drm/drm_atomic_helper.h
@@ -44,6 +44,10 @@ void drm_atomic_helper_commit_tail(struct drm_atomic_state *state);
int drm_atomic_helper_commit(struct drm_device *dev,
struct drm_atomic_state *state,
bool nonblock);
+int drm_atomic_helper_async_check(struct drm_device *dev,
+ struct drm_atomic_state *state);
+void drm_atomic_helper_async_commit(struct drm_device *dev,
+ struct drm_atomic_state *state);
int drm_atomic_helper_wait_for_fences(struct drm_device *dev,
struct drm_atomic_state *state,
diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h
index c85124f687baab4669518d6cc37caebc0fb732ce..06569845708c26ad90cf41869d23501dda613b65 100644
--- a/include/drm/drm_modeset_helper_vtables.h
+++ b/include/drm/drm_modeset_helper_vtables.h
@@ -1135,6 +1135,56 @@ struct drm_plane_helper_funcs {
*/
void (*atomic_disable)(struct drm_plane *plane,
struct drm_plane_state *old_state);
+
+ /**
+ * @atomic_async_check:
+ *
+ * Drivers should set this function pointer to check if the plane state
+ * can be updated in a async fashion. Here async means "not vblank
+ * synchronized".
+ *
+ * This hook is called by drm_atomic_async_check() to establish if a
+ * given update can be committed asynchronously, that is, if it can
+ * jump ahead of the state currently queued for update.
+ *
+ * RETURNS:
+ *
+ * Return 0 on success and any error returned indicates that the update
+ * can not be applied in asynchronous manner.
+ */
+ int (*atomic_async_check)(struct drm_plane *plane,
+ struct drm_plane_state *state);
+
+ /**
+ * @atomic_async_update:
+ *
+ * Drivers should set this function pointer to perform asynchronous
+ * updates of planes, that is, jump ahead of the currently queued
+ * state and update the plane. Here async means "not vblank
+ * synchronized".
+ *
+ * This hook is called by drm_atomic_helper_async_commit().
+ *
+ * An async update will happen on legacy cursor updates. An async
+ * update won't happen if there is an outstanding commit modifying
+ * the same plane.
+ *
+ * Note that unlike &drm_plane_helper_funcs.atomic_update this hook
+ * takes the new &drm_plane_state as parameter. When doing async_update
+ * drivers shouldn't replace the &drm_plane_state but update the
+ * current one with the new plane configurations in the new
+ * plane_state.
+ *
+ * FIXME:
+ * - It only works for single plane updates
+ * - Async Pageflips are not supported yet
+ * - Some hw might still scan out the old buffer until the next
+ * vblank, however we let go of the fb references as soon as
+ * we run this hook. For now drivers must implement their own workers
+ * for deferring if needed, until a common solution is created.
+ */
+ void (*atomic_async_update)(struct drm_plane *plane,
+ struct drm_plane_state *new_state);
};
/**