Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 4008 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
new file mode 100644
index 000000000..6060b69fa
--- /dev/null
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -0,0 +1,4008 @@
+/*
+ * Copyright (C) 2014 Red Hat
+ * Copyright (C) 2014 Intel Corp.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ * Rob Clark <robdclark@gmail.com>
+ * Daniel Vetter <daniel.vetter@ffwll.ch>
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_plane_helper.h>
+#include <drm/drm_crtc_helper.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_writeback.h>
+#include <linux/dma-fence.h>
+
+#include "drm_crtc_helper_internal.h"
+#include "drm_crtc_internal.h"
+
+/**
+ * DOC: overview
+ *
+ * This helper library provides implementations of check and commit functions on
+ * top of the CRTC modeset helper callbacks and the plane helper callbacks. It
+ * also provides convenience implementations for the atomic state handling
+ * callbacks for drivers which don't need to subclass the drm core structures to
+ * add their own additional internal state.
+ *
+ * This library also provides default implementations for the check callback in
+ * drm_atomic_helper_check() and for the commit callback with
+ * drm_atomic_helper_commit(). But the individual stages and callbacks are
+ * exposed to allow drivers to mix and match and e.g. use the plane helpers only
+ * together with a driver private modeset implementation.
+ *
+ * This library also provides implementations for all the legacy driver
+ * interfaces on top of the atomic interface. See drm_atomic_helper_set_config(),
+ * drm_atomic_helper_disable_plane(), drm_atomic_helper_disable_plane() and the
+ * various functions to implement set_property callbacks. New drivers must not
+ * implement these functions themselves but must use the provided helpers.
+ *
+ * The atomic helper uses the same function table structures as all other
+ * modesetting helpers. See the documentation for &struct drm_crtc_helper_funcs,
+ * struct &drm_encoder_helper_funcs and &struct drm_connector_helper_funcs. It
+ * also shares the &struct drm_plane_helper_funcs function table with the plane
+ * helpers.
+ */
+static void
+drm_atomic_helper_plane_changed(struct drm_atomic_state *state,
+				struct drm_plane_state *old_plane_state,
+				struct drm_plane_state *plane_state,
+				struct drm_plane *plane)
+{
+	struct drm_crtc_state *crtc_state;
+
+	if (old_plane_state->crtc) {
+		crtc_state = drm_atomic_get_new_crtc_state(state,
+							   old_plane_state->crtc);
+
+		if (WARN_ON(!crtc_state))
+			return;
+
+		crtc_state->planes_changed = true;
+	}
+
+	if (plane_state->crtc) {
+		crtc_state = drm_atomic_get_new_crtc_state(state, plane_state->crtc);
+
+		if (WARN_ON(!crtc_state))
+			return;
+
+		crtc_state->planes_changed = true;
+	}
+}
+
+static int handle_conflicting_encoders(struct drm_atomic_state *state,
+				       bool disable_conflicting_encoders)
+{
+	struct drm_connector_state *new_conn_state;
+	struct drm_connector *connector;
+	struct drm_connector_list_iter conn_iter;
+	struct drm_encoder *encoder;
+	unsigned encoder_mask = 0;
+	int i, ret = 0;
+
+	/*
+	 * First loop, find all newly assigned encoders from the connectors
+	 * part of the state. If the same encoder is assigned to multiple
+	 * connectors bail out.
+	 */
+	for_each_new_connector_in_state(state, connector, new_conn_state, i) {
+		const struct drm_connector_helper_funcs *funcs = connector->helper_private;
+		struct drm_encoder *new_encoder;
+
+		if (!new_conn_state->crtc)
+			continue;
+
+		if (funcs->atomic_best_encoder)
+			new_encoder = funcs->atomic_best_encoder(connector, new_conn_state);
+		else if (funcs->best_encoder)
+			new_encoder = funcs->best_encoder(connector);
+		else
+			new_encoder = drm_atomic_helper_best_encoder(connector);
+
+		if (new_encoder) {
+			if (encoder_mask & drm_encoder_mask(new_encoder)) {
+				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] on [CONNECTOR:%d:%s] already assigned\n",
+					new_encoder->base.id, new_encoder->name,
+					connector->base.id, connector->name);
+
+				return -EINVAL;
+			}
+
+			encoder_mask |= drm_encoder_mask(new_encoder);
+		}
+	}
+
+	if (!encoder_mask)
+		return 0;
+
+	/*
+	 * Second loop, iterate over all connectors not part of the state.
+	 *
+	 * If a conflicting encoder is found and disable_conflicting_encoders
+	 * is not set, an error is returned. Userspace can provide a solution
+	 * through the atomic ioctl.
+	 *
+	 * If the flag is set conflicting connectors are removed from the crtc
+	 * and the crtc is disabled if no encoder is left. This preserves
+	 * compatibility with the legacy set_config behavior.
+	 */
+	drm_connector_list_iter_begin(state->dev, &conn_iter);
+	drm_for_each_connector_iter(connector, &conn_iter) {
+		struct drm_crtc_state *crtc_state;
+
+		if (drm_atomic_get_new_connector_state(state, connector))
+			continue;
+
+		encoder = connector->state->best_encoder;
+		if (!encoder || !(encoder_mask & drm_encoder_mask(encoder)))
+			continue;
+
+		if (!disable_conflicting_encoders) {
+			DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s] by [CONNECTOR:%d:%s]\n",
+					 encoder->base.id, encoder->name,
+					 connector->state->crtc->base.id,
+					 connector->state->crtc->name,
+					 connector->base.id, connector->name);
+			ret = -EINVAL;
+			goto out;
+		}
+
+		new_conn_state = drm_atomic_get_connector_state(state, connector);
+		if (IS_ERR(new_conn_state)) {
+			ret = PTR_ERR(new_conn_state);
+			goto out;
+		}
+
+		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s], disabling [CONNECTOR:%d:%s]\n",
+				 encoder->base.id, encoder->name,
+				 new_conn_state->crtc->base.id, new_conn_state->crtc->name,
+				 connector->base.id, connector->name);
+
+		crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc);
+
+		ret = drm_atomic_set_crtc_for_connector(new_conn_state, NULL);
+		if (ret)
+			goto out;
+
+		if (!crtc_state->connector_mask) {
+			ret = drm_atomic_set_mode_prop_for_crtc(crtc_state,
+								NULL);
+			if (ret < 0)
+				goto out;
+
+			crtc_state->active = false;
+		}
+	}
+out:
+	drm_connector_list_iter_end(&conn_iter);
+
+	return ret;
+}
+
+static void
+set_best_encoder(struct drm_atomic_state *state,
+		 struct drm_connector_state *conn_state,
+		 struct drm_encoder *encoder)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_crtc *crtc;
+
+	if (conn_state->best_encoder) {
+		/* Unset the encoder_mask in the old crtc state. */
+		crtc = conn_state->connector->state->crtc;
+
+		/* A NULL crtc is an error here because we should have
+		 *  duplicated a NULL best_encoder when crtc was NULL.
+		 * As an exception restoring duplicated atomic state
+		 * during resume is allowed, so don't warn when
+		 * best_encoder is equal to encoder we intend to set.
+		 */
+		WARN_ON(!crtc && encoder != conn_state->best_encoder);
+		if (crtc) {
+			crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+
+			crtc_state->encoder_mask &=
+				~drm_encoder_mask(conn_state->best_encoder);
+		}
+	}
+
+	if (encoder) {
+		crtc = conn_state->crtc;
+		WARN_ON(!crtc);
+		if (crtc) {
+			crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+
+			crtc_state->encoder_mask |=
+				drm_encoder_mask(encoder);
+		}
+	}
+
+	conn_state->best_encoder = encoder;
+}
+
+static void
+steal_encoder(struct drm_atomic_state *state,
+	      struct drm_encoder *encoder)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *old_connector_state, *new_connector_state;
+	int i;
+
+	for_each_oldnew_connector_in_state(state, connector, old_connector_state, new_connector_state, i) {
+		struct drm_crtc *encoder_crtc;
+
+		if (new_connector_state->best_encoder != encoder)
+			continue;
+
+		encoder_crtc = old_connector_state->crtc;
+
+		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] in use on [CRTC:%d:%s], stealing it\n",
+				 encoder->base.id, encoder->name,
+				 encoder_crtc->base.id, encoder_crtc->name);
+
+		set_best_encoder(state, new_connector_state, NULL);
+
+		crtc_state = drm_atomic_get_new_crtc_state(state, encoder_crtc);
+		crtc_state->connectors_changed = true;
+
+		return;
+	}
+}
+
+static int
+update_connector_routing(struct drm_atomic_state *state,
+			 struct drm_connector *connector,
+			 struct drm_connector_state *old_connector_state,
+			 struct drm_connector_state *new_connector_state)
+{
+	const struct drm_connector_helper_funcs *funcs;
+	struct drm_encoder *new_encoder;
+	struct drm_crtc_state *crtc_state;
+
+	DRM_DEBUG_ATOMIC("Updating routing for [CONNECTOR:%d:%s]\n",
+			 connector->base.id,
+			 connector->name);
+
+	if (old_connector_state->crtc != new_connector_state->crtc) {
+		if (old_connector_state->crtc) {
+			crtc_state = drm_atomic_get_new_crtc_state(state, old_connector_state->crtc);
+			crtc_state->connectors_changed = true;
+		}
+
+		if (new_connector_state->crtc) {
+			crtc_state = drm_atomic_get_new_crtc_state(state, new_connector_state->crtc);
+			crtc_state->connectors_changed = true;
+		}
+	}
+
+	if (!new_connector_state->crtc) {
+		DRM_DEBUG_ATOMIC("Disabling [CONNECTOR:%d:%s]\n",
+				connector->base.id,
+				connector->name);
+
+		set_best_encoder(state, new_connector_state, NULL);
+
+		return 0;
+	}
+
+	crtc_state = drm_atomic_get_new_crtc_state(state,
+						   new_connector_state->crtc);
+	/*
+	 * For compatibility with legacy users, we want to make sure that
+	 * we allow DPMS On->Off modesets on unregistered connectors. Modesets
+	 * which would result in anything else must be considered invalid, to
+	 * avoid turning on new displays on dead connectors.
+	 *
+	 * Since the connector can be unregistered at any point during an
+	 * atomic check or commit, this is racy. But that's OK: all we care
+	 * about is ensuring that userspace can't do anything but shut off the
+	 * display on a connector that was destroyed after its been notified,
+	 * not before.
+	 */
+	if (drm_connector_is_unregistered(connector) && crtc_state->active) {
+		DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] is not registered\n",
+				 connector->base.id, connector->name);
+		return -EINVAL;
+	}
+
+	funcs = connector->helper_private;
+
+	if (funcs->atomic_best_encoder)
+		new_encoder = funcs->atomic_best_encoder(connector,
+							 new_connector_state);
+	else if (funcs->best_encoder)
+		new_encoder = funcs->best_encoder(connector);
+	else
+		new_encoder = drm_atomic_helper_best_encoder(connector);
+
+	if (!new_encoder) {
+		DRM_DEBUG_ATOMIC("No suitable encoder found for [CONNECTOR:%d:%s]\n",
+				 connector->base.id,
+				 connector->name);
+		return -EINVAL;
+	}
+
+	if (!drm_encoder_crtc_ok(new_encoder, new_connector_state->crtc)) {
+		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] incompatible with [CRTC:%d:%s]\n",
+				 new_encoder->base.id,
+				 new_encoder->name,
+				 new_connector_state->crtc->base.id,
+				 new_connector_state->crtc->name);
+		return -EINVAL;
+	}
+
+	if (new_encoder == new_connector_state->best_encoder) {
+		set_best_encoder(state, new_connector_state, new_encoder);
+
+		DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] keeps [ENCODER:%d:%s], now on [CRTC:%d:%s]\n",
+				 connector->base.id,
+				 connector->name,
+				 new_encoder->base.id,
+				 new_encoder->name,
+				 new_connector_state->crtc->base.id,
+				 new_connector_state->crtc->name);
+
+		return 0;
+	}
+
+	steal_encoder(state, new_encoder);
+
+	set_best_encoder(state, new_connector_state, new_encoder);
+
+	crtc_state->connectors_changed = true;
+
+	DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d:%s]\n",
+			 connector->base.id,
+			 connector->name,
+			 new_encoder->base.id,
+			 new_encoder->name,
+			 new_connector_state->crtc->base.id,
+			 new_connector_state->crtc->name);
+
+	return 0;
+}
+
+static int
+mode_fixup(struct drm_atomic_state *state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *new_conn_state;
+	int i;
+	int ret;
+
+	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
+		if (!new_crtc_state->mode_changed &&
+		    !new_crtc_state->connectors_changed)
+			continue;
+
+		drm_mode_copy(&new_crtc_state->adjusted_mode, &new_crtc_state->mode);
+	}
+
+	for_each_new_connector_in_state(state, connector, new_conn_state, i) {
+		const struct drm_encoder_helper_funcs *funcs;
+		struct drm_encoder *encoder;
+
+		WARN_ON(!!new_conn_state->best_encoder != !!new_conn_state->crtc);
+
+		if (!new_conn_state->crtc || !new_conn_state->best_encoder)
+			continue;
+
+		new_crtc_state =
+			drm_atomic_get_new_crtc_state(state, new_conn_state->crtc);
+
+		/*
+		 * Each encoder has at most one connector (since we always steal
+		 * it away), so we won't call ->mode_fixup twice.
+		 */
+		encoder = new_conn_state->best_encoder;
+		funcs = encoder->helper_private;
+
+		ret = drm_bridge_mode_fixup(encoder->bridge, &new_crtc_state->mode,
+				&new_crtc_state->adjusted_mode);
+		if (!ret) {
+			DRM_DEBUG_ATOMIC("Bridge fixup failed\n");
+			return -EINVAL;
+		}
+
+		if (funcs && funcs->atomic_check) {
+			ret = funcs->atomic_check(encoder, new_crtc_state,
+						  new_conn_state);
+			if (ret) {
+				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] check failed\n",
+						 encoder->base.id, encoder->name);
+				return ret;
+			}
+		} else if (funcs && funcs->mode_fixup) {
+			ret = funcs->mode_fixup(encoder, &new_crtc_state->mode,
+						&new_crtc_state->adjusted_mode);
+			if (!ret) {
+				DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] fixup failed\n",
+						 encoder->base.id, encoder->name);
+				return -EINVAL;
+			}
+		}
+	}
+
+	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		if (!new_crtc_state->enable)
+			continue;
+
+		if (!new_crtc_state->mode_changed &&
+		    !new_crtc_state->connectors_changed)
+			continue;
+
+		funcs = crtc->helper_private;
+		if (!funcs->mode_fixup)
+			continue;
+
+		ret = funcs->mode_fixup(crtc, &new_crtc_state->mode,
+					&new_crtc_state->adjusted_mode);
+		if (!ret) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] fixup failed\n",
+					 crtc->base.id, crtc->name);
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static enum drm_mode_status mode_valid_path(struct drm_connector *connector,
+					    struct drm_encoder *encoder,
+					    struct drm_crtc *crtc,
+					    struct drm_display_mode *mode)
+{
+	enum drm_mode_status ret;
+
+	ret = drm_encoder_mode_valid(encoder, mode);
+	if (ret != MODE_OK) {
+		DRM_DEBUG_ATOMIC("[ENCODER:%d:%s] mode_valid() failed\n",
+				encoder->base.id, encoder->name);
+		return ret;
+	}
+
+	ret = drm_bridge_mode_valid(encoder->bridge, mode);
+	if (ret != MODE_OK) {
+		DRM_DEBUG_ATOMIC("[BRIDGE] mode_valid() failed\n");
+		return ret;
+	}
+
+	ret = drm_crtc_mode_valid(crtc, mode);
+	if (ret != MODE_OK) {
+		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode_valid() failed\n",
+				crtc->base.id, crtc->name);
+		return ret;
+	}
+
+	return ret;
+}
+
+static int
+mode_valid(struct drm_atomic_state *state)
+{
+	struct drm_connector_state *conn_state;
+	struct drm_connector *connector;
+	int i;
+
+	for_each_new_connector_in_state(state, connector, conn_state, i) {
+		struct drm_encoder *encoder = conn_state->best_encoder;
+		struct drm_crtc *crtc = conn_state->crtc;
+		struct drm_crtc_state *crtc_state;
+		enum drm_mode_status mode_status;
+		struct drm_display_mode *mode;
+
+		if (!crtc || !encoder)
+			continue;
+
+		crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+		if (!crtc_state)
+			continue;
+		if (!crtc_state->mode_changed && !crtc_state->connectors_changed)
+			continue;
+
+		mode = &crtc_state->mode;
+
+		mode_status = mode_valid_path(connector, encoder, crtc, mode);
+		if (mode_status != MODE_OK)
+			return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * drm_atomic_helper_check_modeset - validate state object for modeset changes
+ * @dev: DRM device
+ * @state: the driver state object
+ *
+ * Check the state object to see if the requested state is physically possible.
+ * This does all the crtc and connector related computations for an atomic
+ * update and adds any additional connectors needed for full modesets. It calls
+ * the various per-object callbacks in the follow order:
+ *
+ * 1. &drm_connector_helper_funcs.atomic_best_encoder for determining the new encoder.
+ * 2. &drm_connector_helper_funcs.atomic_check to validate the connector state.
+ * 3. If it's determined a modeset is needed then all connectors on the affected crtc
+ *    crtc are added and &drm_connector_helper_funcs.atomic_check is run on them.
+ * 4. &drm_encoder_helper_funcs.mode_valid, &drm_bridge_funcs.mode_valid and
+ *    &drm_crtc_helper_funcs.mode_valid are called on the affected components.
+ * 5. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
+ * 6. &drm_encoder_helper_funcs.atomic_check is called to validate any encoder state.
+ *    This function is only called when the encoder will be part of a configured crtc,
+ *    it must not be used for implementing connector property validation.
+ *    If this function is NULL, &drm_atomic_encoder_helper_funcs.mode_fixup is called
+ *    instead.
+ * 7. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the mode with crtc constraints.
+ *
+ * &drm_crtc_state.mode_changed is set when the input mode is changed.
+ * &drm_crtc_state.connectors_changed is set when a connector is added or
+ * removed from the crtc.  &drm_crtc_state.active_changed is set when
+ * &drm_crtc_state.active changes, which is used for DPMS.
+ * See also: drm_atomic_crtc_needs_modeset()
+ *
+ * IMPORTANT:
+ *
+ * Drivers which set &drm_crtc_state.mode_changed (e.g. in their
+ * &drm_plane_helper_funcs.atomic_check hooks if a plane update can't be done
+ * without a full modeset) _must_ call this function afterwards after that
+ * change. It is permitted to call this function multiple times for the same
+ * update, e.g. when the &drm_crtc_helper_funcs.atomic_check functions depend
+ * upon the adjusted dotclock for fifo space allocation and watermark
+ * computation.
+ *
+ * RETURNS:
+ * Zero for success or -errno
+ */
+int
+drm_atomic_helper_check_modeset(struct drm_device *dev,
+				struct drm_atomic_state *state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *old_connector_state, *new_connector_state;
+	int i, ret;
+	unsigned connectors_mask = 0;
+
+	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
+		bool has_connectors =
+			!!new_crtc_state->connector_mask;
+
+		WARN_ON(!drm_modeset_is_locked(&crtc->mutex));
+
+		if (!drm_mode_equal(&old_crtc_state->mode, &new_crtc_state->mode)) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] mode changed\n",
+					 crtc->base.id, crtc->name);
+			new_crtc_state->mode_changed = true;
+		}
+
+		if (old_crtc_state->enable != new_crtc_state->enable) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enable changed\n",
+					 crtc->base.id, crtc->name);
+
+			/*
+			 * For clarity this assignment is done here, but
+			 * enable == 0 is only true when there are no
+			 * connectors and a NULL mode.
+			 *
+			 * The other way around is true as well. enable != 0
+			 * iff connectors are attached and a mode is set.
+			 */
+			new_crtc_state->mode_changed = true;
+			new_crtc_state->connectors_changed = true;
+		}
+
+		if (old_crtc_state->active != new_crtc_state->active) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] active changed\n",
+					 crtc->base.id, crtc->name);
+			new_crtc_state->active_changed = true;
+		}
+
+		if (new_crtc_state->enable != has_connectors) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] enabled/connectors mismatch\n",
+					 crtc->base.id, crtc->name);
+
+			return -EINVAL;
+		}
+	}
+
+	ret = handle_conflicting_encoders(state, false);
+	if (ret)
+		return ret;
+
+	for_each_oldnew_connector_in_state(state, connector, old_connector_state, new_connector_state, i) {
+		const struct drm_connector_helper_funcs *funcs = connector->helper_private;
+
+		WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
+
+		/*
+		 * This only sets crtc->connectors_changed for routing changes,
+		 * drivers must set crtc->connectors_changed themselves when
+		 * connector properties need to be updated.
+		 */
+		ret = update_connector_routing(state, connector,
+					       old_connector_state,
+					       new_connector_state);
+		if (ret)
+			return ret;
+		if (old_connector_state->crtc) {
+			new_crtc_state = drm_atomic_get_new_crtc_state(state,
+								       old_connector_state->crtc);
+			if (old_connector_state->link_status !=
+			    new_connector_state->link_status)
+				new_crtc_state->connectors_changed = true;
+		}
+
+		if (funcs->atomic_check)
+			ret = funcs->atomic_check(connector, new_connector_state);
+		if (ret)
+			return ret;
+
+		connectors_mask |= BIT(i);
+	}
+
+	/*
+	 * After all the routing has been prepared we need to add in any
+	 * connector which is itself unchanged, but who's crtc changes it's
+	 * configuration. This must be done before calling mode_fixup in case a
+	 * crtc only changed its mode but has the same set of connectors.
+	 */
+	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
+		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
+			continue;
+
+		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] needs all connectors, enable: %c, active: %c\n",
+				 crtc->base.id, crtc->name,
+				 new_crtc_state->enable ? 'y' : 'n',
+				 new_crtc_state->active ? 'y' : 'n');
+
+		ret = drm_atomic_add_affected_connectors(state, crtc);
+		if (ret != 0)
+			return ret;
+
+		ret = drm_atomic_add_affected_planes(state, crtc);
+		if (ret != 0)
+			return ret;
+	}
+
+	/*
+	 * Iterate over all connectors again, to make sure atomic_check()
+	 * has been called on them when a modeset is forced.
+	 */
+	for_each_oldnew_connector_in_state(state, connector, old_connector_state, new_connector_state, i) {
+		const struct drm_connector_helper_funcs *funcs = connector->helper_private;
+
+		if (connectors_mask & BIT(i))
+			continue;
+
+		if (funcs->atomic_check)
+			ret = funcs->atomic_check(connector, new_connector_state);
+		if (ret)
+			return ret;
+	}
+
+	ret = mode_valid(state);
+	if (ret)
+		return ret;
+
+	return mode_fixup(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_check_modeset);
+
+/**
+ * drm_atomic_helper_check_plane_state() - Check plane state for validity
+ * @plane_state: plane state to check
+ * @crtc_state: crtc state to check
+ * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
+ * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
+ * @can_position: is it legal to position the plane such that it
+ *                doesn't cover the entire crtc?  This will generally
+ *                only be false for primary planes.
+ * @can_update_disabled: can the plane be updated while the crtc
+ *                       is disabled?
+ *
+ * Checks that a desired plane update is valid, and updates various
+ * bits of derived state (clipped coordinates etc.). Drivers that provide
+ * their own plane handling rather than helper-provided implementations may
+ * still wish to call this function to avoid duplication of error checking
+ * code.
+ *
+ * RETURNS:
+ * Zero if update appears valid, error code on failure
+ */
+int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
+					const struct drm_crtc_state *crtc_state,
+					int min_scale,
+					int max_scale,
+					bool can_position,
+					bool can_update_disabled)
+{
+	struct drm_framebuffer *fb = plane_state->fb;
+	struct drm_rect *src = &plane_state->src;
+	struct drm_rect *dst = &plane_state->dst;
+	unsigned int rotation = plane_state->rotation;
+	struct drm_rect clip = {};
+	int hscale, vscale;
+
+	WARN_ON(plane_state->crtc && plane_state->crtc != crtc_state->crtc);
+
+	*src = drm_plane_state_src(plane_state);
+	*dst = drm_plane_state_dest(plane_state);
+
+	if (!fb) {
+		plane_state->visible = false;
+		return 0;
+	}
+
+	/* crtc should only be NULL when disabling (i.e., !fb) */
+	if (WARN_ON(!plane_state->crtc)) {
+		plane_state->visible = false;
+		return 0;
+	}
+
+	if (!crtc_state->enable && !can_update_disabled) {
+		DRM_DEBUG_KMS("Cannot update plane of a disabled CRTC.\n");
+		return -EINVAL;
+	}
+
+	drm_rect_rotate(src, fb->width << 16, fb->height << 16, rotation);
+
+	/* Check scaling */
+	hscale = drm_rect_calc_hscale(src, dst, min_scale, max_scale);
+	vscale = drm_rect_calc_vscale(src, dst, min_scale, max_scale);
+	if (hscale < 0 || vscale < 0) {
+		DRM_DEBUG_KMS("Invalid scaling of plane\n");
+		drm_rect_debug_print("src: ", &plane_state->src, true);
+		drm_rect_debug_print("dst: ", &plane_state->dst, false);
+		return -ERANGE;
+	}
+
+	if (crtc_state->enable)
+		drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
+
+	plane_state->visible = drm_rect_clip_scaled(src, dst, &clip);
+
+	drm_rect_rotate_inv(src, fb->width << 16, fb->height << 16, rotation);
+
+	if (!plane_state->visible)
+		/*
+		 * Plane isn't visible; some drivers can handle this
+		 * so we just return success here.  Drivers that can't
+		 * (including those that use the primary plane helper's
+		 * update function) will return an error from their
+		 * update_plane handler.
+		 */
+		return 0;
+
+	if (!can_position && !drm_rect_equals(dst, &clip)) {
+		DRM_DEBUG_KMS("Plane must cover entire CRTC\n");
+		drm_rect_debug_print("dst: ", dst, false);
+		drm_rect_debug_print("clip: ", &clip, false);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_helper_check_plane_state);
+
+/**
+ * drm_atomic_helper_check_planes - validate state object for planes changes
+ * @dev: DRM device
+ * @state: the driver state object
+ *
+ * Check the state object to see if the requested state is physically possible.
+ * This does all the plane update related checks using by calling into the
+ * &drm_crtc_helper_funcs.atomic_check and &drm_plane_helper_funcs.atomic_check
+ * hooks provided by the driver.
+ *
+ * It also sets &drm_crtc_state.planes_changed to indicate that a crtc has
+ * updated planes.
+ *
+ * RETURNS:
+ * Zero for success or -errno
+ */
+int
+drm_atomic_helper_check_planes(struct drm_device *dev,
+			       struct drm_atomic_state *state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_plane *plane;
+	struct drm_plane_state *new_plane_state, *old_plane_state;
+	int i, ret = 0;
+
+	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
+		const struct drm_plane_helper_funcs *funcs;
+
+		WARN_ON(!drm_modeset_is_locked(&plane->mutex));
+
+		funcs = plane->helper_private;
+
+		drm_atomic_helper_plane_changed(state, old_plane_state, new_plane_state, plane);
+
+		if (!funcs || !funcs->atomic_check)
+			continue;
+
+		ret = funcs->atomic_check(plane, new_plane_state);
+		if (ret) {
+			DRM_DEBUG_ATOMIC("[PLANE:%d:%s] atomic driver check failed\n",
+					 plane->base.id, plane->name);
+			return ret;
+		}
+	}
+
+	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		funcs = crtc->helper_private;
+
+		if (!funcs || !funcs->atomic_check)
+			continue;
+
+		ret = funcs->atomic_check(crtc, new_crtc_state);
+		if (ret) {
+			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] atomic driver check failed\n",
+					 crtc->base.id, crtc->name);
+			return ret;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_check_planes);
+
+/**
+ * drm_atomic_helper_check - validate state object
+ * @dev: DRM device
+ * @state: the driver state object
+ *
+ * Check the state object to see if the requested state is physically possible.
+ * Only crtcs and planes have check callbacks, so for any additional (global)
+ * checking that a driver needs it can simply wrap that around this function.
+ * Drivers without such needs can directly use this as their
+ * &drm_mode_config_funcs.atomic_check callback.
+ *
+ * This just wraps the two parts of the state checking for planes and modeset
+ * state in the default order: First it calls drm_atomic_helper_check_modeset()
+ * and then drm_atomic_helper_check_planes(). The assumption is that the
+ * @drm_plane_helper_funcs.atomic_check and @drm_crtc_helper_funcs.atomic_check
+ * functions depend upon an updated adjusted_mode.clock to e.g. properly compute
+ * watermarks.
+ *
+ * Note that zpos normalization will add all enable planes to the state which
+ * might not desired for some drivers.
+ * For example enable/disable of a cursor plane which have fixed zpos value
+ * would trigger all other enabled planes to be forced to the state change.
+ *
+ * RETURNS:
+ * Zero for success or -errno
+ */
+int drm_atomic_helper_check(struct drm_device *dev,
+			    struct drm_atomic_state *state)
+{
+	int ret;
+
+	ret = drm_atomic_helper_check_modeset(dev, state);
+	if (ret)
+		return ret;
+
+	if (dev->mode_config.normalize_zpos) {
+		ret = drm_atomic_normalize_zpos(dev, state);
+		if (ret)
+			return ret;
+	}
+
+	ret = drm_atomic_helper_check_planes(dev, state);
+	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);
+
+static void
+disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
+{
+	struct drm_connector *connector;
+	struct drm_connector_state *old_conn_state, *new_conn_state;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	int i;
+
+	for_each_oldnew_connector_in_state(old_state, connector, old_conn_state, new_conn_state, i) {
+		const struct drm_encoder_helper_funcs *funcs;
+		struct drm_encoder *encoder;
+
+		/* Shut down everything that's in the changeset and currently
+		 * still on. So need to check the old, saved state. */
+		if (!old_conn_state->crtc)
+			continue;
+
+		old_crtc_state = drm_atomic_get_old_crtc_state(old_state, old_conn_state->crtc);
+
+		if (!old_crtc_state->active ||
+		    !drm_atomic_crtc_needs_modeset(old_conn_state->crtc->state))
+			continue;
+
+		encoder = old_conn_state->best_encoder;
+
+		/* We shouldn't get this far if we didn't previously have
+		 * an encoder.. but WARN_ON() rather than explode.
+		 */
+		if (WARN_ON(!encoder))
+			continue;
+
+		funcs = encoder->helper_private;
+
+		DRM_DEBUG_ATOMIC("disabling [ENCODER:%d:%s]\n",
+				 encoder->base.id, encoder->name);
+
+		/*
+		 * Each encoder has at most one connector (since we always steal
+		 * it away), so we won't call disable hooks twice.
+		 */
+		drm_bridge_disable(encoder->bridge);
+
+		/* Right function depends upon target state. */
+		if (funcs) {
+			if (new_conn_state->crtc && funcs->prepare)
+				funcs->prepare(encoder);
+			else if (funcs->disable)
+				funcs->disable(encoder);
+			else if (funcs->dpms)
+				funcs->dpms(encoder, DRM_MODE_DPMS_OFF);
+		}
+
+		drm_bridge_post_disable(encoder->bridge);
+	}
+
+	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+		int ret;
+
+		/* Shut down everything that needs a full modeset. */
+		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
+			continue;
+
+		if (!old_crtc_state->active)
+			continue;
+
+		funcs = crtc->helper_private;
+
+		DRM_DEBUG_ATOMIC("disabling [CRTC:%d:%s]\n",
+				 crtc->base.id, crtc->name);
+
+
+		/* Right function depends upon target state. */
+		if (new_crtc_state->enable && funcs->prepare)
+			funcs->prepare(crtc);
+		else if (funcs->atomic_disable)
+			funcs->atomic_disable(crtc, old_crtc_state);
+		else if (funcs->disable)
+			funcs->disable(crtc);
+		else
+			funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
+
+		if (!(dev->irq_enabled && dev->num_crtcs))
+			continue;
+
+		ret = drm_crtc_vblank_get(crtc);
+		WARN_ONCE(ret != -EINVAL, "driver forgot to call drm_crtc_vblank_off()\n");
+		if (ret == 0)
+			drm_crtc_vblank_put(crtc);
+	}
+}
+
+/**
+ * drm_atomic_helper_update_legacy_modeset_state - update legacy modeset state
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * This function updates all the various legacy modeset state pointers in
+ * connectors, encoders and crtcs. It also updates the timestamping constants
+ * used for precise vblank timestamps by calling
+ * drm_calc_timestamping_constants().
+ *
+ * Drivers can use this for building their own atomic commit if they don't have
+ * a pure helper-based modeset implementation.
+ *
+ * Since these updates are not synchronized with lockings, only code paths
+ * called from &drm_mode_config_helper_funcs.atomic_commit_tail can look at the
+ * legacy state filled out by this helper. Defacto this means this helper and
+ * the legacy state pointers are only really useful for transitioning an
+ * existing driver to the atomic world.
+ */
+void
+drm_atomic_helper_update_legacy_modeset_state(struct drm_device *dev,
+					      struct drm_atomic_state *old_state)
+{
+	struct drm_connector *connector;
+	struct drm_connector_state *old_conn_state, *new_conn_state;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state;
+	int i;
+
+	/* clear out existing links and update dpms */
+	for_each_oldnew_connector_in_state(old_state, connector, old_conn_state, new_conn_state, i) {
+		if (connector->encoder) {
+			WARN_ON(!connector->encoder->crtc);
+
+			connector->encoder->crtc = NULL;
+			connector->encoder = NULL;
+		}
+
+		crtc = new_conn_state->crtc;
+		if ((!crtc && old_conn_state->crtc) ||
+		    (crtc && drm_atomic_crtc_needs_modeset(crtc->state))) {
+			int mode = DRM_MODE_DPMS_OFF;
+
+			if (crtc && crtc->state->active)
+				mode = DRM_MODE_DPMS_ON;
+
+			connector->dpms = mode;
+		}
+	}
+
+	/* set new links */
+	for_each_new_connector_in_state(old_state, connector, new_conn_state, i) {
+		if (!new_conn_state->crtc)
+			continue;
+
+		if (WARN_ON(!new_conn_state->best_encoder))
+			continue;
+
+		connector->encoder = new_conn_state->best_encoder;
+		connector->encoder->crtc = new_conn_state->crtc;
+	}
+
+	/* set legacy state in the crtc structure */
+	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
+		struct drm_plane *primary = crtc->primary;
+		struct drm_plane_state *new_plane_state;
+
+		crtc->mode = new_crtc_state->mode;
+		crtc->enabled = new_crtc_state->enable;
+
+		new_plane_state =
+			drm_atomic_get_new_plane_state(old_state, primary);
+
+		if (new_plane_state && new_plane_state->crtc == crtc) {
+			crtc->x = new_plane_state->src_x >> 16;
+			crtc->y = new_plane_state->src_y >> 16;
+		}
+
+		if (new_crtc_state->enable)
+			drm_calc_timestamping_constants(crtc,
+							&new_crtc_state->adjusted_mode);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_update_legacy_modeset_state);
+
+static void
+crtc_set_mode(struct drm_device *dev, struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *new_conn_state;
+	int i;
+
+	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		if (!new_crtc_state->mode_changed)
+			continue;
+
+		funcs = crtc->helper_private;
+
+		if (new_crtc_state->enable && funcs->mode_set_nofb) {
+			DRM_DEBUG_ATOMIC("modeset on [CRTC:%d:%s]\n",
+					 crtc->base.id, crtc->name);
+
+			funcs->mode_set_nofb(crtc);
+		}
+	}
+
+	for_each_new_connector_in_state(old_state, connector, new_conn_state, i) {
+		const struct drm_encoder_helper_funcs *funcs;
+		struct drm_encoder *encoder;
+		struct drm_display_mode *mode, *adjusted_mode;
+
+		if (!new_conn_state->best_encoder)
+			continue;
+
+		encoder = new_conn_state->best_encoder;
+		funcs = encoder->helper_private;
+		new_crtc_state = new_conn_state->crtc->state;
+		mode = &new_crtc_state->mode;
+		adjusted_mode = &new_crtc_state->adjusted_mode;
+
+		if (!new_crtc_state->mode_changed)
+			continue;
+
+		DRM_DEBUG_ATOMIC("modeset on [ENCODER:%d:%s]\n",
+				 encoder->base.id, encoder->name);
+
+		/*
+		 * Each encoder has at most one connector (since we always steal
+		 * it away), so we won't call mode_set hooks twice.
+		 */
+		if (funcs && funcs->atomic_mode_set) {
+			funcs->atomic_mode_set(encoder, new_crtc_state,
+					       new_conn_state);
+		} else if (funcs && funcs->mode_set) {
+			funcs->mode_set(encoder, mode, adjusted_mode);
+		}
+
+		drm_bridge_mode_set(encoder->bridge, mode, adjusted_mode);
+	}
+}
+
+/**
+ * drm_atomic_helper_commit_modeset_disables - modeset commit to disable outputs
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * This function shuts down all the outputs that need to be shut down and
+ * prepares them (if required) with the new mode.
+ *
+ * For compatibility with legacy crtc helpers this should be called before
+ * drm_atomic_helper_commit_planes(), which is what the default commit function
+ * does. But drivers with different needs can group the modeset commits together
+ * and do the plane commits at the end. This is useful for drivers doing runtime
+ * PM since planes updates then only happen when the CRTC is actually enabled.
+ */
+void drm_atomic_helper_commit_modeset_disables(struct drm_device *dev,
+					       struct drm_atomic_state *old_state)
+{
+	disable_outputs(dev, old_state);
+
+	drm_atomic_helper_update_legacy_modeset_state(dev, old_state);
+
+	crtc_set_mode(dev, old_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_disables);
+
+static void drm_atomic_helper_commit_writebacks(struct drm_device *dev,
+						struct drm_atomic_state *old_state)
+{
+	struct drm_connector *connector;
+	struct drm_connector_state *new_conn_state;
+	int i;
+
+	for_each_new_connector_in_state(old_state, connector, new_conn_state, i) {
+		const struct drm_connector_helper_funcs *funcs;
+
+		funcs = connector->helper_private;
+		if (!funcs->atomic_commit)
+			continue;
+
+		if (new_conn_state->writeback_job && new_conn_state->writeback_job->fb) {
+			WARN_ON(connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK);
+			funcs->atomic_commit(connector, new_conn_state);
+		}
+	}
+}
+
+/**
+ * drm_atomic_helper_commit_modeset_enables - modeset commit to enable outputs
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * This function enables all the outputs with the new configuration which had to
+ * be turned off for the update.
+ *
+ * For compatibility with legacy crtc helpers this should be called after
+ * drm_atomic_helper_commit_planes(), which is what the default commit function
+ * does. But drivers with different needs can group the modeset commits together
+ * and do the plane commits at the end. This is useful for drivers doing runtime
+ * PM since planes updates then only happen when the CRTC is actually enabled.
+ */
+void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
+					      struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *new_conn_state;
+	int i;
+
+	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		/* Need to filter out CRTCs where only planes change. */
+		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
+			continue;
+
+		if (!new_crtc_state->active)
+			continue;
+
+		funcs = crtc->helper_private;
+
+		if (new_crtc_state->enable) {
+			DRM_DEBUG_ATOMIC("enabling [CRTC:%d:%s]\n",
+					 crtc->base.id, crtc->name);
+
+			if (funcs->atomic_enable)
+				funcs->atomic_enable(crtc, old_crtc_state);
+			else
+				funcs->commit(crtc);
+		}
+	}
+
+	for_each_new_connector_in_state(old_state, connector, new_conn_state, i) {
+		const struct drm_encoder_helper_funcs *funcs;
+		struct drm_encoder *encoder;
+
+		if (!new_conn_state->best_encoder)
+			continue;
+
+		if (!new_conn_state->crtc->state->active ||
+		    !drm_atomic_crtc_needs_modeset(new_conn_state->crtc->state))
+			continue;
+
+		encoder = new_conn_state->best_encoder;
+		funcs = encoder->helper_private;
+
+		DRM_DEBUG_ATOMIC("enabling [ENCODER:%d:%s]\n",
+				 encoder->base.id, encoder->name);
+
+		/*
+		 * Each encoder has at most one connector (since we always steal
+		 * it away), so we won't call enable hooks twice.
+		 */
+		drm_bridge_pre_enable(encoder->bridge);
+
+		if (funcs) {
+			if (funcs->enable)
+				funcs->enable(encoder);
+			else if (funcs->commit)
+				funcs->commit(encoder);
+		}
+
+		drm_bridge_enable(encoder->bridge);
+	}
+
+	drm_atomic_helper_commit_writebacks(dev, old_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);
+
+/**
+ * drm_atomic_helper_wait_for_fences - wait for fences stashed in plane state
+ * @dev: DRM device
+ * @state: atomic state object with old state structures
+ * @pre_swap: If true, do an interruptible wait, and @state is the new state.
+ * 	Otherwise @state is the old state.
+ *
+ * For implicit sync, driver should fish the exclusive fence out from the
+ * incoming fb's and stash it in the drm_plane_state.  This is called after
+ * drm_atomic_helper_swap_state() so it uses the current plane state (and
+ * just uses the atomic state to find the changed planes)
+ *
+ * Note that @pre_swap is needed since the point where we block for fences moves
+ * around depending upon whether an atomic commit is blocking or
+ * non-blocking. For non-blocking commit all waiting needs to happen after
+ * drm_atomic_helper_swap_state() is called, but for blocking commits we want
+ * to wait **before** we do anything that can't be easily rolled back. That is
+ * before we call drm_atomic_helper_swap_state().
+ *
+ * Returns zero if success or < 0 if dma_fence_wait() fails.
+ */
+int drm_atomic_helper_wait_for_fences(struct drm_device *dev,
+				      struct drm_atomic_state *state,
+				      bool pre_swap)
+{
+	struct drm_plane *plane;
+	struct drm_plane_state *new_plane_state;
+	int i, ret;
+
+	for_each_new_plane_in_state(state, plane, new_plane_state, i) {
+		if (!new_plane_state->fence)
+			continue;
+
+		WARN_ON(!new_plane_state->fb);
+
+		/*
+		 * If waiting for fences pre-swap (ie: nonblock), userspace can
+		 * still interrupt the operation. Instead of blocking until the
+		 * timer expires, make the wait interruptible.
+		 */
+		ret = dma_fence_wait(new_plane_state->fence, pre_swap);
+		if (ret)
+			return ret;
+
+		dma_fence_put(new_plane_state->fence);
+		new_plane_state->fence = NULL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_helper_wait_for_fences);
+
+/**
+ * drm_atomic_helper_wait_for_vblanks - wait for vblank on crtcs
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * Helper to, after atomic commit, wait for vblanks on all effected
+ * crtcs (ie. before cleaning up old framebuffers using
+ * drm_atomic_helper_cleanup_planes()). It will only wait on CRTCs where the
+ * framebuffers have actually changed to optimize for the legacy cursor and
+ * plane update use-case.
+ *
+ * Drivers using the nonblocking commit tracking support initialized by calling
+ * drm_atomic_helper_setup_commit() should look at
+ * drm_atomic_helper_wait_for_flip_done() as an alternative.
+ */
+void
+drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
+		struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	int i, ret;
+	unsigned crtc_mask = 0;
+
+	 /*
+	  * Legacy cursor ioctls are completely unsynced, and userspace
+	  * relies on that (by doing tons of cursor updates).
+	  */
+	if (old_state->legacy_cursor_update)
+		return;
+
+	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
+		if (!new_crtc_state->active)
+			continue;
+
+		ret = drm_crtc_vblank_get(crtc);
+		if (ret != 0)
+			continue;
+
+		crtc_mask |= drm_crtc_mask(crtc);
+		old_state->crtcs[i].last_vblank_count = drm_crtc_vblank_count(crtc);
+	}
+
+	for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		if (!(crtc_mask & drm_crtc_mask(crtc)))
+			continue;
+
+		ret = wait_event_timeout(dev->vblank[i].queue,
+				old_state->crtcs[i].last_vblank_count !=
+					drm_crtc_vblank_count(crtc),
+				msecs_to_jiffies(50));
+
+		WARN(!ret, "[CRTC:%d:%s] vblank wait timed out\n",
+		     crtc->base.id, crtc->name);
+
+		drm_crtc_vblank_put(crtc);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_wait_for_vblanks);
+
+/**
+ * drm_atomic_helper_wait_for_flip_done - wait for all page flips to be done
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * Helper to, after atomic commit, wait for page flips on all effected
+ * crtcs (ie. before cleaning up old framebuffers using
+ * drm_atomic_helper_cleanup_planes()). Compared to
+ * drm_atomic_helper_wait_for_vblanks() this waits for the completion of on all
+ * CRTCs, assuming that cursors-only updates are signalling their completion
+ * immediately (or using a different path).
+ *
+ * This requires that drivers use the nonblocking commit tracking support
+ * initialized using drm_atomic_helper_setup_commit().
+ */
+void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev,
+					  struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	int i;
+
+	for (i = 0; i < dev->mode_config.num_crtc; i++) {
+		struct drm_crtc_commit *commit = old_state->crtcs[i].commit;
+		int ret;
+
+		crtc = old_state->crtcs[i].ptr;
+
+		if (!crtc || !commit)
+			continue;
+
+		ret = wait_for_completion_timeout(&commit->flip_done, 10 * HZ);
+		if (ret == 0)
+			DRM_ERROR("[CRTC:%d:%s] flip_done timed out\n",
+				  crtc->base.id, crtc->name);
+	}
+
+	if (old_state->fake_commit)
+		complete_all(&old_state->fake_commit->flip_done);
+}
+EXPORT_SYMBOL(drm_atomic_helper_wait_for_flip_done);
+
+/**
+ * drm_atomic_helper_commit_tail - commit atomic update to hardware
+ * @old_state: atomic state object with old state structures
+ *
+ * This is the default implementation for the
+ * &drm_mode_config_helper_funcs.atomic_commit_tail hook, for drivers
+ * that do not support runtime_pm or do not need the CRTC to be
+ * enabled to perform a commit. Otherwise, see
+ * drm_atomic_helper_commit_tail_rpm().
+ *
+ * Note that the default ordering of how the various stages are called is to
+ * match the legacy modeset helper library closest.
+ */
+void drm_atomic_helper_commit_tail(struct drm_atomic_state *old_state)
+{
+	struct drm_device *dev = old_state->dev;
+
+	drm_atomic_helper_commit_modeset_disables(dev, old_state);
+
+	drm_atomic_helper_commit_planes(dev, old_state, 0);
+
+	drm_atomic_helper_commit_modeset_enables(dev, old_state);
+
+	drm_atomic_helper_fake_vblank(old_state);
+
+	drm_atomic_helper_commit_hw_done(old_state);
+
+	drm_atomic_helper_wait_for_vblanks(dev, old_state);
+
+	drm_atomic_helper_cleanup_planes(dev, old_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_tail);
+
+/**
+ * drm_atomic_helper_commit_tail_rpm - commit atomic update to hardware
+ * @old_state: new modeset state to be committed
+ *
+ * This is an alternative implementation for the
+ * &drm_mode_config_helper_funcs.atomic_commit_tail hook, for drivers
+ * that support runtime_pm or need the CRTC to be enabled to perform a
+ * commit. Otherwise, one should use the default implementation
+ * drm_atomic_helper_commit_tail().
+ */
+void drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state)
+{
+	struct drm_device *dev = old_state->dev;
+
+	drm_atomic_helper_commit_modeset_disables(dev, old_state);
+
+	drm_atomic_helper_commit_modeset_enables(dev, old_state);
+
+	drm_atomic_helper_commit_planes(dev, old_state,
+					DRM_PLANE_COMMIT_ACTIVE_ONLY);
+
+	drm_atomic_helper_fake_vblank(old_state);
+
+	drm_atomic_helper_commit_hw_done(old_state);
+
+	drm_atomic_helper_wait_for_vblanks(dev, old_state);
+
+	drm_atomic_helper_cleanup_planes(dev, old_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_tail_rpm);
+
+static void commit_tail(struct drm_atomic_state *old_state)
+{
+	struct drm_device *dev = old_state->dev;
+	const struct drm_mode_config_helper_funcs *funcs;
+
+	funcs = dev->mode_config.helper_private;
+
+	drm_atomic_helper_wait_for_fences(dev, old_state, false);
+
+	drm_atomic_helper_wait_for_dependencies(old_state);
+
+	if (funcs && funcs->atomic_commit_tail)
+		funcs->atomic_commit_tail(old_state);
+	else
+		drm_atomic_helper_commit_tail(old_state);
+
+	drm_atomic_helper_commit_cleanup_done(old_state);
+
+	drm_atomic_state_put(old_state);
+}
+
+static void commit_work(struct work_struct *work)
+{
+	struct drm_atomic_state *state = container_of(work,
+						      struct drm_atomic_state,
+						      commit_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_plane *plane = NULL;
+	struct drm_plane_state *old_plane_state = NULL;
+	struct drm_plane_state *new_plane_state = NULL;
+	const struct drm_plane_helper_funcs *funcs;
+	int i, 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_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i)
+		n_planes++;
+
+	/* FIXME: we support only single plane updates for now */
+	if (n_planes != 1)
+		return -EINVAL;
+
+	if (!new_plane_state->crtc ||
+	    old_plane_state->crtc != new_plane_state->crtc)
+		return -EINVAL;
+
+	/*
+	 * FIXME: Since prepare_fb and cleanup_fb are always called on
+	 * the new_plane_state for async updates we need to block framebuffer
+	 * changes. This prevents use of a fb that's been cleaned up and
+	 * double cleanups from occuring.
+	 */
+	if (old_plane_state->fb != new_plane_state->fb)
+		return -EINVAL;
+
+	funcs = plane->helper_private;
+	if (!funcs->atomic_async_update)
+		return -EINVAL;
+
+	if (new_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.
+	 */
+	if (old_plane_state->commit &&
+	    !try_wait_for_completion(&old_plane_state->commit->hw_done))
+		return -EBUSY;
+
+	return funcs->atomic_async_check(plane, new_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.
+ *
+ * TODO: Implement full swap instead of doing in-place changes.
+ */
+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) {
+		struct drm_framebuffer *new_fb = plane_state->fb;
+		struct drm_framebuffer *old_fb = plane->state->fb;
+
+		funcs = plane->helper_private;
+		funcs->atomic_async_update(plane, plane_state);
+
+		/*
+		 * ->atomic_async_update() is supposed to update the
+		 * plane->state in-place, make sure at least common
+		 * properties have been properly updated.
+		 */
+		WARN_ON_ONCE(plane->state->fb != new_fb);
+		WARN_ON_ONCE(plane->state->crtc_x != plane_state->crtc_x);
+		WARN_ON_ONCE(plane->state->crtc_y != plane_state->crtc_y);
+		WARN_ON_ONCE(plane->state->src_x != plane_state->src_x);
+		WARN_ON_ONCE(plane->state->src_y != plane_state->src_y);
+
+		/*
+		 * Make sure the FBs have been swapped so that cleanups in the
+		 * new_state performs a cleanup in the old FB.
+		 */
+		WARN_ON_ONCE(plane_state->fb != old_fb);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_async_commit);
+
+/**
+ * drm_atomic_helper_commit - commit validated state object
+ * @dev: DRM device
+ * @state: the driver state object
+ * @nonblock: whether nonblocking behavior is requested.
+ *
+ * This function commits a with drm_atomic_helper_check() pre-validated state
+ * object. This can still fail when e.g. the framebuffer reservation fails. This
+ * function implements nonblocking commits, using
+ * drm_atomic_helper_setup_commit() and related functions.
+ *
+ * Committing the actual hardware state is done through the
+ * &drm_mode_config_helper_funcs.atomic_commit_tail callback, or it's default
+ * implementation drm_atomic_helper_commit_tail().
+ *
+ * RETURNS:
+ * Zero for success or -errno.
+ */
+int drm_atomic_helper_commit(struct drm_device *dev,
+			     struct drm_atomic_state *state,
+			     bool nonblock)
+{
+	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;
+
+	INIT_WORK(&state->commit_work, commit_work);
+
+	ret = drm_atomic_helper_prepare_planes(dev, state);
+	if (ret)
+		return ret;
+
+	if (!nonblock) {
+		ret = drm_atomic_helper_wait_for_fences(dev, state, true);
+		if (ret)
+			goto err;
+	}
+
+	/*
+	 * This is the point of no return - everything below never fails except
+	 * when the hw goes bonghits. Which means we can commit the new state on
+	 * the software side now.
+	 */
+
+	ret = drm_atomic_helper_swap_state(state, true);
+	if (ret)
+		goto err;
+
+	/*
+	 * Everything below can be run asynchronously without the need to grab
+	 * any modeset locks at all under one condition: It must be guaranteed
+	 * that the asynchronous work has either been cancelled (if the driver
+	 * supports it, which at least requires that the framebuffers get
+	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
+	 * before the new state gets committed on the software side with
+	 * drm_atomic_helper_swap_state().
+	 *
+	 * This scheme allows new atomic state updates to be prepared and
+	 * checked in parallel to the asynchronous completion of the previous
+	 * update. Which is important since compositors need to figure out the
+	 * composition of the next frame right after having submitted the
+	 * current layout.
+	 *
+	 * NOTE: Commit work has multiple phases, first hardware commit, then
+	 * cleanup. We want them to overlap, hence need system_unbound_wq to
+	 * make sure work items don't artifically stall on each another.
+	 */
+
+	drm_atomic_state_get(state);
+	if (nonblock)
+		queue_work(system_unbound_wq, &state->commit_work);
+	else
+		commit_tail(state);
+
+	return 0;
+
+err:
+	drm_atomic_helper_cleanup_planes(dev, state);
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit);
+
+/**
+ * DOC: implementing nonblocking commit
+ *
+ * Nonblocking atomic commits have to be implemented in the following sequence:
+ *
+ * 1. Run drm_atomic_helper_prepare_planes() first. This is the only function
+ * which commit needs to call which can fail, so we want to run it first and
+ * synchronously.
+ *
+ * 2. Synchronize with any outstanding nonblocking commit worker threads which
+ * might be affected the new state update. This can be done by either cancelling
+ * or flushing the work items, depending upon whether the driver can deal with
+ * cancelled updates. Note that it is important to ensure that the framebuffer
+ * cleanup is still done when cancelling.
+ *
+ * Asynchronous workers need to have sufficient parallelism to be able to run
+ * different atomic commits on different CRTCs in parallel. The simplest way to
+ * achive this is by running them on the &system_unbound_wq work queue. Note
+ * that drivers are not required to split up atomic commits and run an
+ * individual commit in parallel - userspace is supposed to do that if it cares.
+ * But it might be beneficial to do that for modesets, since those necessarily
+ * must be done as one global operation, and enabling or disabling a CRTC can
+ * take a long time. But even that is not required.
+ *
+ * 3. The software state is updated synchronously with
+ * drm_atomic_helper_swap_state(). Doing this under the protection of all modeset
+ * locks means concurrent callers never see inconsistent state. And doing this
+ * while it's guaranteed that no relevant nonblocking worker runs means that
+ * nonblocking workers do not need grab any locks. Actually they must not grab
+ * locks, for otherwise the work flushing will deadlock.
+ *
+ * 4. Schedule a work item to do all subsequent steps, using the split-out
+ * commit helpers: a) pre-plane commit b) plane commit c) post-plane commit and
+ * then cleaning up the framebuffers after the old framebuffer is no longer
+ * being displayed.
+ *
+ * The above scheme is implemented in the atomic helper libraries in
+ * drm_atomic_helper_commit() using a bunch of helper functions. See
+ * drm_atomic_helper_setup_commit() for a starting point.
+ */
+
+static int stall_checks(struct drm_crtc *crtc, bool nonblock)
+{
+	struct drm_crtc_commit *commit, *stall_commit = NULL;
+	bool completed = true;
+	int i;
+	long ret = 0;
+
+	spin_lock(&crtc->commit_lock);
+	i = 0;
+	list_for_each_entry(commit, &crtc->commit_list, commit_entry) {
+		if (i == 0) {
+			completed = try_wait_for_completion(&commit->flip_done);
+			/* Userspace is not allowed to get ahead of the previous
+			 * commit with nonblocking ones. */
+			if (!completed && nonblock) {
+				spin_unlock(&crtc->commit_lock);
+				return -EBUSY;
+			}
+		} else if (i == 1) {
+			stall_commit = drm_crtc_commit_get(commit);
+			break;
+		}
+
+		i++;
+	}
+	spin_unlock(&crtc->commit_lock);
+
+	if (!stall_commit)
+		return 0;
+
+	/* We don't want to let commits get ahead of cleanup work too much,
+	 * stalling on 2nd previous commit means triple-buffer won't ever stall.
+	 */
+	ret = wait_for_completion_interruptible_timeout(&stall_commit->cleanup_done,
+							10*HZ);
+	if (ret == 0)
+		DRM_ERROR("[CRTC:%d:%s] cleanup_done timed out\n",
+			  crtc->base.id, crtc->name);
+
+	drm_crtc_commit_put(stall_commit);
+
+	return ret < 0 ? ret : 0;
+}
+
+static void release_crtc_commit(struct completion *completion)
+{
+	struct drm_crtc_commit *commit = container_of(completion,
+						      typeof(*commit),
+						      flip_done);
+
+	drm_crtc_commit_put(commit);
+}
+
+static void init_commit(struct drm_crtc_commit *commit, struct drm_crtc *crtc)
+{
+	init_completion(&commit->flip_done);
+	init_completion(&commit->hw_done);
+	init_completion(&commit->cleanup_done);
+	INIT_LIST_HEAD(&commit->commit_entry);
+	kref_init(&commit->ref);
+	commit->crtc = crtc;
+}
+
+static struct drm_crtc_commit *
+crtc_or_fake_commit(struct drm_atomic_state *state, struct drm_crtc *crtc)
+{
+	if (crtc) {
+		struct drm_crtc_state *new_crtc_state;
+
+		new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+
+		return new_crtc_state->commit;
+	}
+
+	if (!state->fake_commit) {
+		state->fake_commit = kzalloc(sizeof(*state->fake_commit), GFP_KERNEL);
+		if (!state->fake_commit)
+			return NULL;
+
+		init_commit(state->fake_commit, NULL);
+	}
+
+	return state->fake_commit;
+}
+
+/**
+ * drm_atomic_helper_setup_commit - setup possibly nonblocking commit
+ * @state: new modeset state to be committed
+ * @nonblock: whether nonblocking behavior is requested.
+ *
+ * This function prepares @state to be used by the atomic helper's support for
+ * nonblocking commits. Drivers using the nonblocking commit infrastructure
+ * should always call this function from their
+ * &drm_mode_config_funcs.atomic_commit hook.
+ *
+ * To be able to use this support drivers need to use a few more helper
+ * functions. drm_atomic_helper_wait_for_dependencies() must be called before
+ * actually committing the hardware state, and for nonblocking commits this call
+ * must be placed in the async worker. See also drm_atomic_helper_swap_state()
+ * and it's stall parameter, for when a driver's commit hooks look at the
+ * &drm_crtc.state, &drm_plane.state or &drm_connector.state pointer directly.
+ *
+ * Completion of the hardware commit step must be signalled using
+ * drm_atomic_helper_commit_hw_done(). After this step the driver is not allowed
+ * to read or change any permanent software or hardware modeset state. The only
+ * exception is state protected by other means than &drm_modeset_lock locks.
+ * Only the free standing @state with pointers to the old state structures can
+ * be inspected, e.g. to clean up old buffers using
+ * drm_atomic_helper_cleanup_planes().
+ *
+ * At the very end, before cleaning up @state drivers must call
+ * drm_atomic_helper_commit_cleanup_done().
+ *
+ * This is all implemented by in drm_atomic_helper_commit(), giving drivers a
+ * complete and easy-to-use default implementation of the atomic_commit() hook.
+ *
+ * The tracking of asynchronously executed and still pending commits is done
+ * using the core structure &drm_crtc_commit.
+ *
+ * By default there's no need to clean up resources allocated by this function
+ * explicitly: drm_atomic_state_default_clear() will take care of that
+ * automatically.
+ *
+ * Returns:
+ *
+ * 0 on success. -EBUSY when userspace schedules nonblocking commits too fast,
+ * -ENOMEM on allocation failures and -EINTR when a signal is pending.
+ */
+int drm_atomic_helper_setup_commit(struct drm_atomic_state *state,
+				   bool nonblock)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	struct drm_connector *conn;
+	struct drm_connector_state *old_conn_state, *new_conn_state;
+	struct drm_plane *plane;
+	struct drm_plane_state *old_plane_state, *new_plane_state;
+	struct drm_crtc_commit *commit;
+	int i, ret;
+
+	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
+		commit = kzalloc(sizeof(*commit), GFP_KERNEL);
+		if (!commit)
+			return -ENOMEM;
+
+		init_commit(commit, crtc);
+
+		new_crtc_state->commit = commit;
+
+		ret = stall_checks(crtc, nonblock);
+		if (ret)
+			return ret;
+
+		/* Drivers only send out events when at least either current or
+		 * new CRTC state is active. Complete right away if everything
+		 * stays off. */
+		if (!old_crtc_state->active && !new_crtc_state->active) {
+			complete_all(&commit->flip_done);
+			continue;
+		}
+
+		/* Legacy cursor updates are fully unsynced. */
+		if (state->legacy_cursor_update) {
+			complete_all(&commit->flip_done);
+			continue;
+		}
+
+		if (!new_crtc_state->event) {
+			commit->event = kzalloc(sizeof(*commit->event),
+						GFP_KERNEL);
+			if (!commit->event)
+				return -ENOMEM;
+
+			new_crtc_state->event = commit->event;
+		}
+
+		new_crtc_state->event->base.completion = &commit->flip_done;
+		new_crtc_state->event->base.completion_release = release_crtc_commit;
+		drm_crtc_commit_get(commit);
+
+		commit->abort_completion = true;
+
+		state->crtcs[i].commit = commit;
+		drm_crtc_commit_get(commit);
+	}
+
+	for_each_oldnew_connector_in_state(state, conn, old_conn_state, new_conn_state, i) {
+		/* Userspace is not allowed to get ahead of the previous
+		 * commit with nonblocking ones. */
+		if (nonblock && old_conn_state->commit &&
+		    !try_wait_for_completion(&old_conn_state->commit->flip_done))
+			return -EBUSY;
+
+		/* Always track connectors explicitly for e.g. link retraining. */
+		commit = crtc_or_fake_commit(state, new_conn_state->crtc ?: old_conn_state->crtc);
+		if (!commit)
+			return -ENOMEM;
+
+		new_conn_state->commit = drm_crtc_commit_get(commit);
+	}
+
+	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
+		/* Userspace is not allowed to get ahead of the previous
+		 * commit with nonblocking ones. */
+		if (nonblock && old_plane_state->commit &&
+		    !try_wait_for_completion(&old_plane_state->commit->flip_done))
+			return -EBUSY;
+
+		/* Always track planes explicitly for async pageflip support. */
+		commit = crtc_or_fake_commit(state, new_plane_state->crtc ?: old_plane_state->crtc);
+		if (!commit)
+			return -ENOMEM;
+
+		new_plane_state->commit = drm_crtc_commit_get(commit);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_helper_setup_commit);
+
+/**
+ * drm_atomic_helper_wait_for_dependencies - wait for required preceeding commits
+ * @old_state: atomic state object with old state structures
+ *
+ * This function waits for all preceeding commits that touch the same CRTC as
+ * @old_state to both be committed to the hardware (as signalled by
+ * drm_atomic_helper_commit_hw_done) and executed by the hardware (as signalled
+ * by calling drm_crtc_send_vblank_event() on the &drm_crtc_state.event).
+ *
+ * This is part of the atomic helper support for nonblocking commits, see
+ * drm_atomic_helper_setup_commit() for an overview.
+ */
+void drm_atomic_helper_wait_for_dependencies(struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	struct drm_plane *plane;
+	struct drm_plane_state *old_plane_state;
+	struct drm_connector *conn;
+	struct drm_connector_state *old_conn_state;
+	struct drm_crtc_commit *commit;
+	int i;
+	long ret;
+
+	for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		commit = old_crtc_state->commit;
+
+		if (!commit)
+			continue;
+
+		ret = wait_for_completion_timeout(&commit->hw_done,
+						  10*HZ);
+		if (ret == 0)
+			DRM_ERROR("[CRTC:%d:%s] hw_done timed out\n",
+				  crtc->base.id, crtc->name);
+
+		/* Currently no support for overwriting flips, hence
+		 * stall for previous one to execute completely. */
+		ret = wait_for_completion_timeout(&commit->flip_done,
+						  10*HZ);
+		if (ret == 0)
+			DRM_ERROR("[CRTC:%d:%s] flip_done timed out\n",
+				  crtc->base.id, crtc->name);
+	}
+
+	for_each_old_connector_in_state(old_state, conn, old_conn_state, i) {
+		commit = old_conn_state->commit;
+
+		if (!commit)
+			continue;
+
+		ret = wait_for_completion_timeout(&commit->hw_done,
+						  10*HZ);
+		if (ret == 0)
+			DRM_ERROR("[CONNECTOR:%d:%s] hw_done timed out\n",
+				  conn->base.id, conn->name);
+
+		/* Currently no support for overwriting flips, hence
+		 * stall for previous one to execute completely. */
+		ret = wait_for_completion_timeout(&commit->flip_done,
+						  10*HZ);
+		if (ret == 0)
+			DRM_ERROR("[CONNECTOR:%d:%s] flip_done timed out\n",
+				  conn->base.id, conn->name);
+	}
+
+	for_each_old_plane_in_state(old_state, plane, old_plane_state, i) {
+		commit = old_plane_state->commit;
+
+		if (!commit)
+			continue;
+
+		ret = wait_for_completion_timeout(&commit->hw_done,
+						  10*HZ);
+		if (ret == 0)
+			DRM_ERROR("[PLANE:%d:%s] hw_done timed out\n",
+				  plane->base.id, plane->name);
+
+		/* Currently no support for overwriting flips, hence
+		 * stall for previous one to execute completely. */
+		ret = wait_for_completion_timeout(&commit->flip_done,
+						  10*HZ);
+		if (ret == 0)
+			DRM_ERROR("[PLANE:%d:%s] flip_done timed out\n",
+				  plane->base.id, plane->name);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_wait_for_dependencies);
+
+/**
+ * drm_atomic_helper_fake_vblank - fake VBLANK events if needed
+ * @old_state: atomic state object with old state structures
+ *
+ * This function walks all CRTCs and fake VBLANK events on those with
+ * &drm_crtc_state.no_vblank set to true and &drm_crtc_state.event != NULL.
+ * The primary use of this function is writeback connectors working in oneshot
+ * mode and faking VBLANK events. In this case they only fake the VBLANK event
+ * when a job is queued, and any change to the pipeline that does not touch the
+ * connector is leading to timeouts when calling
+ * drm_atomic_helper_wait_for_vblanks() or
+ * drm_atomic_helper_wait_for_flip_done().
+ *
+ * This is part of the atomic helper support for nonblocking commits, see
+ * drm_atomic_helper_setup_commit() for an overview.
+ */
+void drm_atomic_helper_fake_vblank(struct drm_atomic_state *old_state)
+{
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_crtc *crtc;
+	int i;
+
+	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
+		unsigned long flags;
+
+		if (!new_crtc_state->no_vblank)
+			continue;
+
+		spin_lock_irqsave(&old_state->dev->event_lock, flags);
+		if (new_crtc_state->event) {
+			drm_crtc_send_vblank_event(crtc,
+						   new_crtc_state->event);
+			new_crtc_state->event = NULL;
+		}
+		spin_unlock_irqrestore(&old_state->dev->event_lock, flags);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_fake_vblank);
+
+/**
+ * drm_atomic_helper_commit_hw_done - setup possible nonblocking commit
+ * @old_state: atomic state object with old state structures
+ *
+ * This function is used to signal completion of the hardware commit step. After
+ * this step the driver is not allowed to read or change any permanent software
+ * or hardware modeset state. The only exception is state protected by other
+ * means than &drm_modeset_lock locks.
+ *
+ * Drivers should try to postpone any expensive or delayed cleanup work after
+ * this function is called.
+ *
+ * This is part of the atomic helper support for nonblocking commits, see
+ * drm_atomic_helper_setup_commit() for an overview.
+ */
+void drm_atomic_helper_commit_hw_done(struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	struct drm_crtc_commit *commit;
+	int i;
+
+	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
+		commit = new_crtc_state->commit;
+		if (!commit)
+			continue;
+
+		/*
+		 * copy new_crtc_state->commit to old_crtc_state->commit,
+		 * it's unsafe to touch new_crtc_state after hw_done,
+		 * but we still need to do so in cleanup_done().
+		 */
+		if (old_crtc_state->commit)
+			drm_crtc_commit_put(old_crtc_state->commit);
+
+		old_crtc_state->commit = drm_crtc_commit_get(commit);
+
+		/* backend must have consumed any event by now */
+		WARN_ON(new_crtc_state->event);
+		complete_all(&commit->hw_done);
+	}
+
+	if (old_state->fake_commit) {
+		complete_all(&old_state->fake_commit->hw_done);
+		complete_all(&old_state->fake_commit->flip_done);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_hw_done);
+
+/**
+ * drm_atomic_helper_commit_cleanup_done - signal completion of commit
+ * @old_state: atomic state object with old state structures
+ *
+ * This signals completion of the atomic update @old_state, including any
+ * cleanup work. If used, it must be called right before calling
+ * drm_atomic_state_put().
+ *
+ * This is part of the atomic helper support for nonblocking commits, see
+ * drm_atomic_helper_setup_commit() for an overview.
+ */
+void drm_atomic_helper_commit_cleanup_done(struct drm_atomic_state *old_state)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state;
+	struct drm_crtc_commit *commit;
+	int i;
+
+	for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
+		commit = old_crtc_state->commit;
+		if (WARN_ON(!commit))
+			continue;
+
+		complete_all(&commit->cleanup_done);
+		WARN_ON(!try_wait_for_completion(&commit->hw_done));
+
+		spin_lock(&crtc->commit_lock);
+		list_del(&commit->commit_entry);
+		spin_unlock(&crtc->commit_lock);
+	}
+
+	if (old_state->fake_commit)
+		complete_all(&old_state->fake_commit->cleanup_done);
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_cleanup_done);
+
+/**
+ * drm_atomic_helper_prepare_planes - prepare plane resources before commit
+ * @dev: DRM device
+ * @state: atomic state object with new state structures
+ *
+ * This function prepares plane state, specifically framebuffers, for the new
+ * configuration, by calling &drm_plane_helper_funcs.prepare_fb. If any failure
+ * is encountered this function will call &drm_plane_helper_funcs.cleanup_fb on
+ * any already successfully prepared framebuffer.
+ *
+ * Returns:
+ * 0 on success, negative error code on failure.
+ */
+int drm_atomic_helper_prepare_planes(struct drm_device *dev,
+				     struct drm_atomic_state *state)
+{
+	struct drm_plane *plane;
+	struct drm_plane_state *new_plane_state;
+	int ret, i, j;
+
+	for_each_new_plane_in_state(state, plane, new_plane_state, i) {
+		const struct drm_plane_helper_funcs *funcs;
+
+		funcs = plane->helper_private;
+
+		if (funcs->prepare_fb) {
+			ret = funcs->prepare_fb(plane, new_plane_state);
+			if (ret)
+				goto fail;
+		}
+	}
+
+	return 0;
+
+fail:
+	for_each_new_plane_in_state(state, plane, new_plane_state, j) {
+		const struct drm_plane_helper_funcs *funcs;
+
+		if (j >= i)
+			continue;
+
+		funcs = plane->helper_private;
+
+		if (funcs->cleanup_fb)
+			funcs->cleanup_fb(plane, new_plane_state);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_prepare_planes);
+
+static bool plane_crtc_active(const struct drm_plane_state *state)
+{
+	return state->crtc && state->crtc->state->active;
+}
+
+/**
+ * drm_atomic_helper_commit_planes - commit plane state
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ * @flags: flags for committing plane state
+ *
+ * This function commits the new plane state using the plane and atomic helper
+ * functions for planes and crtcs. It assumes that the atomic state has already
+ * been pushed into the relevant object state pointers, since this step can no
+ * longer fail.
+ *
+ * It still requires the global state object @old_state to know which planes and
+ * crtcs need to be updated though.
+ *
+ * Note that this function does all plane updates across all CRTCs in one step.
+ * If the hardware can't support this approach look at
+ * drm_atomic_helper_commit_planes_on_crtc() instead.
+ *
+ * Plane parameters can be updated by applications while the associated CRTC is
+ * disabled. The DRM/KMS core will store the parameters in the plane state,
+ * which will be available to the driver when the CRTC is turned on. As a result
+ * most drivers don't need to be immediately notified of plane updates for a
+ * disabled CRTC.
+ *
+ * Unless otherwise needed, drivers are advised to set the ACTIVE_ONLY flag in
+ * @flags in order not to receive plane update notifications related to a
+ * disabled CRTC. This avoids the need to manually ignore plane updates in
+ * driver code when the driver and/or hardware can't or just don't need to deal
+ * with updates on disabled CRTCs, for example when supporting runtime PM.
+ *
+ * Drivers may set the NO_DISABLE_AFTER_MODESET flag in @flags if the relevant
+ * display controllers require to disable a CRTC's planes when the CRTC is
+ * disabled. This function would skip the &drm_plane_helper_funcs.atomic_disable
+ * call for a plane if the CRTC of the old plane state needs a modesetting
+ * operation. Of course, the drivers need to disable the planes in their CRTC
+ * disable callbacks since no one else would do that.
+ *
+ * The drm_atomic_helper_commit() default implementation doesn't set the
+ * ACTIVE_ONLY flag to most closely match the behaviour of the legacy helpers.
+ * This should not be copied blindly by drivers.
+ */
+void drm_atomic_helper_commit_planes(struct drm_device *dev,
+				     struct drm_atomic_state *old_state,
+				     uint32_t flags)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	struct drm_plane *plane;
+	struct drm_plane_state *old_plane_state, *new_plane_state;
+	int i;
+	bool active_only = flags & DRM_PLANE_COMMIT_ACTIVE_ONLY;
+	bool no_disable = flags & DRM_PLANE_COMMIT_NO_DISABLE_AFTER_MODESET;
+
+	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		funcs = crtc->helper_private;
+
+		if (!funcs || !funcs->atomic_begin)
+			continue;
+
+		if (active_only && !new_crtc_state->active)
+			continue;
+
+		funcs->atomic_begin(crtc, old_crtc_state);
+	}
+
+	for_each_oldnew_plane_in_state(old_state, plane, old_plane_state, new_plane_state, i) {
+		const struct drm_plane_helper_funcs *funcs;
+		bool disabling;
+
+		funcs = plane->helper_private;
+
+		if (!funcs)
+			continue;
+
+		disabling = drm_atomic_plane_disabling(old_plane_state,
+						       new_plane_state);
+
+		if (active_only) {
+			/*
+			 * Skip planes related to inactive CRTCs. If the plane
+			 * is enabled use the state of the current CRTC. If the
+			 * plane is being disabled use the state of the old
+			 * CRTC to avoid skipping planes being disabled on an
+			 * active CRTC.
+			 */
+			if (!disabling && !plane_crtc_active(new_plane_state))
+				continue;
+			if (disabling && !plane_crtc_active(old_plane_state))
+				continue;
+		}
+
+		/*
+		 * Special-case disabling the plane if drivers support it.
+		 */
+		if (disabling && funcs->atomic_disable) {
+			struct drm_crtc_state *crtc_state;
+
+			crtc_state = old_plane_state->crtc->state;
+
+			if (drm_atomic_crtc_needs_modeset(crtc_state) &&
+			    no_disable)
+				continue;
+
+			funcs->atomic_disable(plane, old_plane_state);
+		} else if (new_plane_state->crtc || disabling) {
+			funcs->atomic_update(plane, old_plane_state);
+		}
+	}
+
+	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
+		const struct drm_crtc_helper_funcs *funcs;
+
+		funcs = crtc->helper_private;
+
+		if (!funcs || !funcs->atomic_flush)
+			continue;
+
+		if (active_only && !new_crtc_state->active)
+			continue;
+
+		funcs->atomic_flush(crtc, old_crtc_state);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_planes);
+
+/**
+ * drm_atomic_helper_commit_planes_on_crtc - commit plane state for a crtc
+ * @old_crtc_state: atomic state object with the old crtc state
+ *
+ * This function commits the new plane state using the plane and atomic helper
+ * functions for planes on the specific crtc. It assumes that the atomic state
+ * has already been pushed into the relevant object state pointers, since this
+ * step can no longer fail.
+ *
+ * This function is useful when plane updates should be done crtc-by-crtc
+ * instead of one global step like drm_atomic_helper_commit_planes() does.
+ *
+ * This function can only be savely used when planes are not allowed to move
+ * between different CRTCs because this function doesn't handle inter-CRTC
+ * depencies. Callers need to ensure that either no such depencies exist,
+ * resolve them through ordering of commit calls or through some other means.
+ */
+void
+drm_atomic_helper_commit_planes_on_crtc(struct drm_crtc_state *old_crtc_state)
+{
+	const struct drm_crtc_helper_funcs *crtc_funcs;
+	struct drm_crtc *crtc = old_crtc_state->crtc;
+	struct drm_atomic_state *old_state = old_crtc_state->state;
+	struct drm_crtc_state *new_crtc_state =
+		drm_atomic_get_new_crtc_state(old_state, crtc);
+	struct drm_plane *plane;
+	unsigned plane_mask;
+
+	plane_mask = old_crtc_state->plane_mask;
+	plane_mask |= new_crtc_state->plane_mask;
+
+	crtc_funcs = crtc->helper_private;
+	if (crtc_funcs && crtc_funcs->atomic_begin)
+		crtc_funcs->atomic_begin(crtc, old_crtc_state);
+
+	drm_for_each_plane_mask(plane, crtc->dev, plane_mask) {
+		struct drm_plane_state *old_plane_state =
+			drm_atomic_get_old_plane_state(old_state, plane);
+		struct drm_plane_state *new_plane_state =
+			drm_atomic_get_new_plane_state(old_state, plane);
+		const struct drm_plane_helper_funcs *plane_funcs;
+
+		plane_funcs = plane->helper_private;
+
+		if (!old_plane_state || !plane_funcs)
+			continue;
+
+		WARN_ON(new_plane_state->crtc &&
+			new_plane_state->crtc != crtc);
+
+		if (drm_atomic_plane_disabling(old_plane_state, new_plane_state) &&
+		    plane_funcs->atomic_disable)
+			plane_funcs->atomic_disable(plane, old_plane_state);
+		else if (new_plane_state->crtc ||
+			 drm_atomic_plane_disabling(old_plane_state, new_plane_state))
+			plane_funcs->atomic_update(plane, old_plane_state);
+	}
+
+	if (crtc_funcs && crtc_funcs->atomic_flush)
+		crtc_funcs->atomic_flush(crtc, old_crtc_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_planes_on_crtc);
+
+/**
+ * drm_atomic_helper_disable_planes_on_crtc - helper to disable CRTC's planes
+ * @old_crtc_state: atomic state object with the old CRTC state
+ * @atomic: if set, synchronize with CRTC's atomic_begin/flush hooks
+ *
+ * Disables all planes associated with the given CRTC. This can be
+ * used for instance in the CRTC helper atomic_disable callback to disable
+ * all planes.
+ *
+ * If the atomic-parameter is set the function calls the CRTC's
+ * atomic_begin hook before and atomic_flush hook after disabling the
+ * planes.
+ *
+ * It is a bug to call this function without having implemented the
+ * &drm_plane_helper_funcs.atomic_disable plane hook.
+ */
+void
+drm_atomic_helper_disable_planes_on_crtc(struct drm_crtc_state *old_crtc_state,
+					 bool atomic)
+{
+	struct drm_crtc *crtc = old_crtc_state->crtc;
+	const struct drm_crtc_helper_funcs *crtc_funcs =
+		crtc->helper_private;
+	struct drm_plane *plane;
+
+	if (atomic && crtc_funcs && crtc_funcs->atomic_begin)
+		crtc_funcs->atomic_begin(crtc, NULL);
+
+	drm_atomic_crtc_state_for_each_plane(plane, old_crtc_state) {
+		const struct drm_plane_helper_funcs *plane_funcs =
+			plane->helper_private;
+
+		if (!plane_funcs)
+			continue;
+
+		WARN_ON(!plane_funcs->atomic_disable);
+		if (plane_funcs->atomic_disable)
+			plane_funcs->atomic_disable(plane, NULL);
+	}
+
+	if (atomic && crtc_funcs && crtc_funcs->atomic_flush)
+		crtc_funcs->atomic_flush(crtc, NULL);
+}
+EXPORT_SYMBOL(drm_atomic_helper_disable_planes_on_crtc);
+
+/**
+ * drm_atomic_helper_cleanup_planes - cleanup plane resources after commit
+ * @dev: DRM device
+ * @old_state: atomic state object with old state structures
+ *
+ * This function cleans up plane state, specifically framebuffers, from the old
+ * configuration. Hence the old configuration must be perserved in @old_state to
+ * be able to call this function.
+ *
+ * This function must also be called on the new state when the atomic update
+ * fails at any point after calling drm_atomic_helper_prepare_planes().
+ */
+void drm_atomic_helper_cleanup_planes(struct drm_device *dev,
+				      struct drm_atomic_state *old_state)
+{
+	struct drm_plane *plane;
+	struct drm_plane_state *old_plane_state, *new_plane_state;
+	int i;
+
+	for_each_oldnew_plane_in_state(old_state, plane, old_plane_state, new_plane_state, i) {
+		const struct drm_plane_helper_funcs *funcs;
+		struct drm_plane_state *plane_state;
+
+		/*
+		 * This might be called before swapping when commit is aborted,
+		 * in which case we have to cleanup the new state.
+		 */
+		if (old_plane_state == plane->state)
+			plane_state = new_plane_state;
+		else
+			plane_state = old_plane_state;
+
+		funcs = plane->helper_private;
+
+		if (funcs->cleanup_fb)
+			funcs->cleanup_fb(plane, plane_state);
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_cleanup_planes);
+
+/**
+ * drm_atomic_helper_swap_state - store atomic state into current sw state
+ * @state: atomic state
+ * @stall: stall for preceeding commits
+ *
+ * This function stores the atomic state into the current state pointers in all
+ * driver objects. It should be called after all failing steps have been done
+ * and succeeded, but before the actual hardware state is committed.
+ *
+ * For cleanup and error recovery the current state for all changed objects will
+ * be swapped into @state.
+ *
+ * With that sequence it fits perfectly into the plane prepare/cleanup sequence:
+ *
+ * 1. Call drm_atomic_helper_prepare_planes() with the staged atomic state.
+ *
+ * 2. Do any other steps that might fail.
+ *
+ * 3. Put the staged state into the current state pointers with this function.
+ *
+ * 4. Actually commit the hardware state.
+ *
+ * 5. Call drm_atomic_helper_cleanup_planes() with @state, which since step 3
+ * contains the old state. Also do any other cleanup required with that state.
+ *
+ * @stall must be set when nonblocking commits for this driver directly access
+ * the &drm_plane.state, &drm_crtc.state or &drm_connector.state pointer. With
+ * the current atomic helpers this is almost always the case, since the helpers
+ * don't pass the right state structures to the callbacks.
+ *
+ * Returns:
+ *
+ * Returns 0 on success. Can return -ERESTARTSYS when @stall is true and the
+ * waiting for the previous commits has been interrupted.
+ */
+int drm_atomic_helper_swap_state(struct drm_atomic_state *state,
+				  bool stall)
+{
+	int i, ret;
+	struct drm_connector *connector;
+	struct drm_connector_state *old_conn_state, *new_conn_state;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	struct drm_plane *plane;
+	struct drm_plane_state *old_plane_state, *new_plane_state;
+	struct drm_crtc_commit *commit;
+	struct drm_private_obj *obj;
+	struct drm_private_state *old_obj_state, *new_obj_state;
+
+	if (stall) {
+		/*
+		 * We have to stall for hw_done here before
+		 * drm_atomic_helper_wait_for_dependencies() because flip
+		 * depth > 1 is not yet supported by all drivers. As long as
+		 * obj->state is directly dereferenced anywhere in the drivers
+		 * atomic_commit_tail function, then it's unsafe to swap state
+		 * before drm_atomic_helper_commit_hw_done() is called.
+		 */
+
+		for_each_old_crtc_in_state(state, crtc, old_crtc_state, i) {
+			commit = old_crtc_state->commit;
+
+			if (!commit)
+				continue;
+
+			ret = wait_for_completion_interruptible(&commit->hw_done);
+			if (ret)
+				return ret;
+		}
+
+		for_each_old_connector_in_state(state, connector, old_conn_state, i) {
+			commit = old_conn_state->commit;
+
+			if (!commit)
+				continue;
+
+			ret = wait_for_completion_interruptible(&commit->hw_done);
+			if (ret)
+				return ret;
+		}
+
+		for_each_old_plane_in_state(state, plane, old_plane_state, i) {
+			commit = old_plane_state->commit;
+
+			if (!commit)
+				continue;
+
+			ret = wait_for_completion_interruptible(&commit->hw_done);
+			if (ret)
+				return ret;
+		}
+	}
+
+	for_each_oldnew_connector_in_state(state, connector, old_conn_state, new_conn_state, i) {
+		WARN_ON(connector->state != old_conn_state);
+
+		old_conn_state->state = state;
+		new_conn_state->state = NULL;
+
+		state->connectors[i].state = old_conn_state;
+		connector->state = new_conn_state;
+	}
+
+	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
+		WARN_ON(crtc->state != old_crtc_state);
+
+		old_crtc_state->state = state;
+		new_crtc_state->state = NULL;
+
+		state->crtcs[i].state = old_crtc_state;
+		crtc->state = new_crtc_state;
+
+		if (new_crtc_state->commit) {
+			spin_lock(&crtc->commit_lock);
+			list_add(&new_crtc_state->commit->commit_entry,
+				 &crtc->commit_list);
+			spin_unlock(&crtc->commit_lock);
+
+			new_crtc_state->commit->event = NULL;
+		}
+	}
+
+	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
+		WARN_ON(plane->state != old_plane_state);
+
+		old_plane_state->state = state;
+		new_plane_state->state = NULL;
+
+		state->planes[i].state = old_plane_state;
+		plane->state = new_plane_state;
+	}
+
+	for_each_oldnew_private_obj_in_state(state, obj, old_obj_state, new_obj_state, i) {
+		WARN_ON(obj->state != old_obj_state);
+
+		old_obj_state->state = state;
+		new_obj_state->state = NULL;
+
+		state->private_objs[i].state = old_obj_state;
+		obj->state = new_obj_state;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_atomic_helper_swap_state);
+
+/**
+ * drm_atomic_helper_update_plane - Helper for primary plane update using atomic
+ * @plane: plane object to update
+ * @crtc: owning CRTC of owning plane
+ * @fb: framebuffer to flip onto plane
+ * @crtc_x: x offset of primary plane on crtc
+ * @crtc_y: y offset of primary plane on crtc
+ * @crtc_w: width of primary plane rectangle on crtc
+ * @crtc_h: height of primary plane rectangle on crtc
+ * @src_x: x offset of @fb for panning
+ * @src_y: y offset of @fb for panning
+ * @src_w: width of source rectangle in @fb
+ * @src_h: height of source rectangle in @fb
+ * @ctx: lock acquire context
+ *
+ * Provides a default plane update handler using the atomic driver interface.
+ *
+ * RETURNS:
+ * Zero on success, error code on failure
+ */
+int drm_atomic_helper_update_plane(struct drm_plane *plane,
+				   struct drm_crtc *crtc,
+				   struct drm_framebuffer *fb,
+				   int crtc_x, int crtc_y,
+				   unsigned int crtc_w, unsigned int crtc_h,
+				   uint32_t src_x, uint32_t src_y,
+				   uint32_t src_w, uint32_t src_h,
+				   struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_atomic_state *state;
+	struct drm_plane_state *plane_state;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(plane->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = ctx;
+	plane_state = drm_atomic_get_plane_state(state, plane);
+	if (IS_ERR(plane_state)) {
+		ret = PTR_ERR(plane_state);
+		goto fail;
+	}
+
+	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
+	if (ret != 0)
+		goto fail;
+	drm_atomic_set_fb_for_plane(plane_state, fb);
+	plane_state->crtc_x = crtc_x;
+	plane_state->crtc_y = crtc_y;
+	plane_state->crtc_w = crtc_w;
+	plane_state->crtc_h = crtc_h;
+	plane_state->src_x = src_x;
+	plane_state->src_y = src_y;
+	plane_state->src_w = src_w;
+	plane_state->src_h = src_h;
+
+	if (plane == crtc->cursor)
+		state->legacy_cursor_update = true;
+
+	ret = drm_atomic_commit(state);
+fail:
+	drm_atomic_state_put(state);
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_update_plane);
+
+/**
+ * drm_atomic_helper_disable_plane - Helper for primary plane disable using * atomic
+ * @plane: plane to disable
+ * @ctx: lock acquire context
+ *
+ * Provides a default plane disable handler using the atomic driver interface.
+ *
+ * RETURNS:
+ * Zero on success, error code on failure
+ */
+int drm_atomic_helper_disable_plane(struct drm_plane *plane,
+				    struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_atomic_state *state;
+	struct drm_plane_state *plane_state;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(plane->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = ctx;
+	plane_state = drm_atomic_get_plane_state(state, plane);
+	if (IS_ERR(plane_state)) {
+		ret = PTR_ERR(plane_state);
+		goto fail;
+	}
+
+	if (plane_state->crtc && plane_state->crtc->cursor == plane)
+		plane_state->state->legacy_cursor_update = true;
+
+	ret = __drm_atomic_helper_disable_plane(plane, plane_state);
+	if (ret != 0)
+		goto fail;
+
+	ret = drm_atomic_commit(state);
+fail:
+	drm_atomic_state_put(state);
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_disable_plane);
+
+/* just used from fb-helper and atomic-helper: */
+int __drm_atomic_helper_disable_plane(struct drm_plane *plane,
+		struct drm_plane_state *plane_state)
+{
+	int ret;
+
+	ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+	if (ret != 0)
+		return ret;
+
+	drm_atomic_set_fb_for_plane(plane_state, NULL);
+	plane_state->crtc_x = 0;
+	plane_state->crtc_y = 0;
+	plane_state->crtc_w = 0;
+	plane_state->crtc_h = 0;
+	plane_state->src_x = 0;
+	plane_state->src_y = 0;
+	plane_state->src_w = 0;
+	plane_state->src_h = 0;
+
+	return 0;
+}
+
+static int update_output_state(struct drm_atomic_state *state,
+			       struct drm_mode_set *set)
+{
+	struct drm_device *dev = set->crtc->dev;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *new_conn_state;
+	int ret, i;
+
+	ret = drm_modeset_lock(&dev->mode_config.connection_mutex,
+			       state->acquire_ctx);
+	if (ret)
+		return ret;
+
+	/* First disable all connectors on the target crtc. */
+	ret = drm_atomic_add_affected_connectors(state, set->crtc);
+	if (ret)
+		return ret;
+
+	for_each_new_connector_in_state(state, connector, new_conn_state, i) {
+		if (new_conn_state->crtc == set->crtc) {
+			ret = drm_atomic_set_crtc_for_connector(new_conn_state,
+								NULL);
+			if (ret)
+				return ret;
+
+			/* Make sure legacy setCrtc always re-trains */
+			new_conn_state->link_status = DRM_LINK_STATUS_GOOD;
+		}
+	}
+
+	/* Then set all connectors from set->connectors on the target crtc */
+	for (i = 0; i < set->num_connectors; i++) {
+		new_conn_state = drm_atomic_get_connector_state(state,
+							    set->connectors[i]);
+		if (IS_ERR(new_conn_state))
+			return PTR_ERR(new_conn_state);
+
+		ret = drm_atomic_set_crtc_for_connector(new_conn_state,
+							set->crtc);
+		if (ret)
+			return ret;
+	}
+
+	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
+		/* Don't update ->enable for the CRTC in the set_config request,
+		 * since a mismatch would indicate a bug in the upper layers.
+		 * The actual modeset code later on will catch any
+		 * inconsistencies here. */
+		if (crtc == set->crtc)
+			continue;
+
+		if (!new_crtc_state->connector_mask) {
+			ret = drm_atomic_set_mode_prop_for_crtc(new_crtc_state,
+								NULL);
+			if (ret < 0)
+				return ret;
+
+			new_crtc_state->active = false;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * drm_atomic_helper_set_config - set a new config from userspace
+ * @set: mode set configuration
+ * @ctx: lock acquisition context
+ *
+ * Provides a default crtc set_config handler using the atomic driver interface.
+ *
+ * NOTE: For backwards compatibility with old userspace this automatically
+ * resets the "link-status" property to GOOD, to force any link
+ * re-training. The SETCRTC ioctl does not define whether an update does
+ * need a full modeset or just a plane update, hence we're allowed to do
+ * that. See also drm_connector_set_link_status_property().
+ *
+ * Returns:
+ * Returns 0 on success, negative errno numbers on failure.
+ */
+int drm_atomic_helper_set_config(struct drm_mode_set *set,
+				 struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_atomic_state *state;
+	struct drm_crtc *crtc = set->crtc;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(crtc->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = ctx;
+	ret = __drm_atomic_helper_set_config(set, state);
+	if (ret != 0)
+		goto fail;
+
+	ret = handle_conflicting_encoders(state, true);
+	if (ret)
+		goto fail;
+
+	ret = drm_atomic_commit(state);
+
+fail:
+	drm_atomic_state_put(state);
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_set_config);
+
+/* just used from fb-helper and atomic-helper: */
+int __drm_atomic_helper_set_config(struct drm_mode_set *set,
+		struct drm_atomic_state *state)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_plane_state *primary_state;
+	struct drm_crtc *crtc = set->crtc;
+	int hdisplay, vdisplay;
+	int ret;
+
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state))
+		return PTR_ERR(crtc_state);
+
+	primary_state = drm_atomic_get_plane_state(state, crtc->primary);
+	if (IS_ERR(primary_state))
+		return PTR_ERR(primary_state);
+
+	if (!set->mode) {
+		WARN_ON(set->fb);
+		WARN_ON(set->num_connectors);
+
+		ret = drm_atomic_set_mode_for_crtc(crtc_state, NULL);
+		if (ret != 0)
+			return ret;
+
+		crtc_state->active = false;
+
+		ret = drm_atomic_set_crtc_for_plane(primary_state, NULL);
+		if (ret != 0)
+			return ret;
+
+		drm_atomic_set_fb_for_plane(primary_state, NULL);
+
+		goto commit;
+	}
+
+	WARN_ON(!set->fb);
+	WARN_ON(!set->num_connectors);
+
+	ret = drm_atomic_set_mode_for_crtc(crtc_state, set->mode);
+	if (ret != 0)
+		return ret;
+
+	crtc_state->active = true;
+
+	ret = drm_atomic_set_crtc_for_plane(primary_state, crtc);
+	if (ret != 0)
+		return ret;
+
+	drm_mode_get_hv_timing(set->mode, &hdisplay, &vdisplay);
+
+	drm_atomic_set_fb_for_plane(primary_state, set->fb);
+	primary_state->crtc_x = 0;
+	primary_state->crtc_y = 0;
+	primary_state->crtc_w = hdisplay;
+	primary_state->crtc_h = vdisplay;
+	primary_state->src_x = set->x << 16;
+	primary_state->src_y = set->y << 16;
+	if (drm_rotation_90_or_270(primary_state->rotation)) {
+		primary_state->src_w = vdisplay << 16;
+		primary_state->src_h = hdisplay << 16;
+	} else {
+		primary_state->src_w = hdisplay << 16;
+		primary_state->src_h = vdisplay << 16;
+	}
+
+commit:
+	ret = update_output_state(state, set);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int __drm_atomic_helper_disable_all(struct drm_device *dev,
+					   struct drm_modeset_acquire_ctx *ctx,
+					   bool clean_old_fbs)
+{
+	struct drm_atomic_state *state;
+	struct drm_connector_state *conn_state;
+	struct drm_connector *conn;
+	struct drm_plane_state *plane_state;
+	struct drm_plane *plane;
+	struct drm_crtc_state *crtc_state;
+	struct drm_crtc *crtc;
+	int ret, i;
+
+	state = drm_atomic_state_alloc(dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = ctx;
+
+	drm_for_each_crtc(crtc, dev) {
+		crtc_state = drm_atomic_get_crtc_state(state, crtc);
+		if (IS_ERR(crtc_state)) {
+			ret = PTR_ERR(crtc_state);
+			goto free;
+		}
+
+		crtc_state->active = false;
+
+		ret = drm_atomic_set_mode_prop_for_crtc(crtc_state, NULL);
+		if (ret < 0)
+			goto free;
+
+		ret = drm_atomic_add_affected_planes(state, crtc);
+		if (ret < 0)
+			goto free;
+
+		ret = drm_atomic_add_affected_connectors(state, crtc);
+		if (ret < 0)
+			goto free;
+	}
+
+	for_each_new_connector_in_state(state, conn, conn_state, i) {
+		ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
+		if (ret < 0)
+			goto free;
+	}
+
+	for_each_new_plane_in_state(state, plane, plane_state, i) {
+		ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+		if (ret < 0)
+			goto free;
+
+		drm_atomic_set_fb_for_plane(plane_state, NULL);
+	}
+
+	ret = drm_atomic_commit(state);
+free:
+	drm_atomic_state_put(state);
+	return ret;
+}
+
+/**
+ * drm_atomic_helper_disable_all - disable all currently active outputs
+ * @dev: DRM device
+ * @ctx: lock acquisition context
+ *
+ * Loops through all connectors, finding those that aren't turned off and then
+ * turns them off by setting their DPMS mode to OFF and deactivating the CRTC
+ * that they are connected to.
+ *
+ * This is used for example in suspend/resume to disable all currently active
+ * functions when suspending. If you just want to shut down everything at e.g.
+ * driver unload, look at drm_atomic_helper_shutdown().
+ *
+ * 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:
+ * 0 on success or a negative error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend(), drm_atomic_helper_resume() and
+ * drm_atomic_helper_shutdown().
+ */
+int drm_atomic_helper_disable_all(struct drm_device *dev,
+				  struct drm_modeset_acquire_ctx *ctx)
+{
+	return __drm_atomic_helper_disable_all(dev, ctx, false);
+}
+EXPORT_SYMBOL(drm_atomic_helper_disable_all);
+
+/**
+ * drm_atomic_helper_shutdown - shutdown all CRTC
+ * @dev: DRM device
+ *
+ * This shuts down all CRTC, which is useful for driver unloading. Shutdown on
+ * suspend should instead be handled with drm_atomic_helper_suspend(), since
+ * that also takes a snapshot of the modeset state to be restored on resume.
+ *
+ * This is just a convenience wrapper around drm_atomic_helper_disable_all(),
+ * and it is the atomic version of drm_crtc_force_disable_all().
+ */
+void drm_atomic_helper_shutdown(struct drm_device *dev)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	int ret;
+
+	drm_modeset_acquire_init(&ctx, 0);
+	while (1) {
+		ret = drm_modeset_lock_all_ctx(dev, &ctx);
+		if (!ret)
+			ret = __drm_atomic_helper_disable_all(dev, &ctx, true);
+
+		if (ret != -EDEADLK)
+			break;
+
+		drm_modeset_backoff(&ctx);
+	}
+
+	if (ret)
+		DRM_ERROR("Disabling all crtc's during unload failed with %i\n", ret);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+EXPORT_SYMBOL(drm_atomic_helper_shutdown);
+
+/**
+ * drm_atomic_helper_suspend - subsystem-level suspend helper
+ * @dev: DRM device
+ *
+ * Duplicates the current atomic state, disables all active outputs and then
+ * returns a pointer to the original atomic state to the caller. Drivers can
+ * pass this pointer to the drm_atomic_helper_resume() helper upon resume to
+ * restore the output configuration that was active at the time the system
+ * entered suspend.
+ *
+ * Note that it is potentially unsafe to use this. The atomic state object
+ * returned by this function is assumed to be persistent. Drivers must ensure
+ * that this holds true. Before calling this function, drivers must make sure
+ * to suspend fbdev emulation so that nothing can be using the device.
+ *
+ * Returns:
+ * A pointer to a copy of the state before suspend on success or an ERR_PTR()-
+ * encoded error code on failure. Drivers should store the returned atomic
+ * state object and pass it to the drm_atomic_helper_resume() helper upon
+ * resume.
+ *
+ * See also:
+ * drm_atomic_helper_duplicate_state(), drm_atomic_helper_disable_all(),
+ * drm_atomic_helper_resume(), drm_atomic_helper_commit_duplicated_state()
+ */
+struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_state *state;
+	int err;
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+retry:
+	err = drm_modeset_lock_all_ctx(dev, &ctx);
+	if (err < 0) {
+		state = ERR_PTR(err);
+		goto unlock;
+	}
+
+	state = drm_atomic_helper_duplicate_state(dev, &ctx);
+	if (IS_ERR(state))
+		goto unlock;
+
+	err = drm_atomic_helper_disable_all(dev, &ctx);
+	if (err < 0) {
+		drm_atomic_state_put(state);
+		state = ERR_PTR(err);
+		goto unlock;
+	}
+
+unlock:
+	if (PTR_ERR(state) == -EDEADLK) {
+		drm_modeset_backoff(&ctx);
+		goto retry;
+	}
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_suspend);
+
+/**
+ * drm_atomic_helper_commit_duplicated_state - commit duplicated state
+ * @state: duplicated atomic state to commit
+ * @ctx: pointer to acquire_ctx to use for commit.
+ *
+ * The state returned by drm_atomic_helper_duplicate_state() and
+ * drm_atomic_helper_suspend() is partially invalid, and needs to
+ * be fixed up before commit.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend()
+ */
+int drm_atomic_helper_commit_duplicated_state(struct drm_atomic_state *state,
+					      struct drm_modeset_acquire_ctx *ctx)
+{
+	int i, ret;
+	struct drm_plane *plane;
+	struct drm_plane_state *new_plane_state;
+	struct drm_connector *connector;
+	struct drm_connector_state *new_conn_state;
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *new_crtc_state;
+
+	state->acquire_ctx = ctx;
+
+	for_each_new_plane_in_state(state, plane, new_plane_state, i)
+		state->planes[i].old_state = plane->state;
+
+	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i)
+		state->crtcs[i].old_state = crtc->state;
+
+	for_each_new_connector_in_state(state, connector, new_conn_state, i)
+		state->connectors[i].old_state = connector->state;
+
+	ret = drm_atomic_commit(state);
+
+	state->acquire_ctx = NULL;
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_commit_duplicated_state);
+
+/**
+ * drm_atomic_helper_resume - subsystem-level resume helper
+ * @dev: DRM device
+ * @state: atomic state to resume to
+ *
+ * Calls drm_mode_config_reset() to synchronize hardware and software states,
+ * grabs all modeset locks and commits the atomic state object. This can be
+ * used in conjunction with the drm_atomic_helper_suspend() helper to
+ * implement suspend/resume for drivers that support atomic mode-setting.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ *
+ * See also:
+ * drm_atomic_helper_suspend()
+ */
+int drm_atomic_helper_resume(struct drm_device *dev,
+			     struct drm_atomic_state *state)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	int err;
+
+	drm_mode_config_reset(dev);
+
+	drm_modeset_acquire_init(&ctx, 0);
+	while (1) {
+		err = drm_modeset_lock_all_ctx(dev, &ctx);
+		if (err)
+			goto out;
+
+		err = drm_atomic_helper_commit_duplicated_state(state, &ctx);
+out:
+		if (err != -EDEADLK)
+			break;
+
+		drm_modeset_backoff(&ctx);
+	}
+
+	drm_atomic_state_put(state);
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	return err;
+}
+EXPORT_SYMBOL(drm_atomic_helper_resume);
+
+static int page_flip_common(struct drm_atomic_state *state,
+			    struct drm_crtc *crtc,
+			    struct drm_framebuffer *fb,
+			    struct drm_pending_vblank_event *event,
+			    uint32_t flags)
+{
+	struct drm_plane *plane = crtc->primary;
+	struct drm_plane_state *plane_state;
+	struct drm_crtc_state *crtc_state;
+	int ret = 0;
+
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state))
+		return PTR_ERR(crtc_state);
+
+	crtc_state->event = event;
+	crtc_state->pageflip_flags = flags;
+
+	plane_state = drm_atomic_get_plane_state(state, plane);
+	if (IS_ERR(plane_state))
+		return PTR_ERR(plane_state);
+
+	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
+	if (ret != 0)
+		return ret;
+	drm_atomic_set_fb_for_plane(plane_state, fb);
+
+	/* Make sure we don't accidentally do a full modeset. */
+	state->allow_modeset = false;
+	if (!crtc_state->active) {
+		DRM_DEBUG_ATOMIC("[CRTC:%d:%s] disabled, rejecting legacy flip\n",
+				 crtc->base.id, crtc->name);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+/**
+ * drm_atomic_helper_page_flip - execute a legacy page flip
+ * @crtc: DRM crtc
+ * @fb: DRM framebuffer
+ * @event: optional DRM event to signal upon completion
+ * @flags: flip flags for non-vblank sync'ed updates
+ * @ctx: lock acquisition context
+ *
+ * Provides a default &drm_crtc_funcs.page_flip implementation
+ * using the atomic driver interface.
+ *
+ * Returns:
+ * Returns 0 on success, negative errno numbers on failure.
+ *
+ * See also:
+ * drm_atomic_helper_page_flip_target()
+ */
+int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
+				struct drm_framebuffer *fb,
+				struct drm_pending_vblank_event *event,
+				uint32_t flags,
+				struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_plane *plane = crtc->primary;
+	struct drm_atomic_state *state;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(plane->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = ctx;
+
+	ret = page_flip_common(state, crtc, fb, event, flags);
+	if (ret != 0)
+		goto fail;
+
+	ret = drm_atomic_nonblocking_commit(state);
+fail:
+	drm_atomic_state_put(state);
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_page_flip);
+
+/**
+ * drm_atomic_helper_page_flip_target - do page flip on target vblank period.
+ * @crtc: DRM crtc
+ * @fb: DRM framebuffer
+ * @event: optional DRM event to signal upon completion
+ * @flags: flip flags for non-vblank sync'ed updates
+ * @target: specifying the target vblank period when the flip to take effect
+ * @ctx: lock acquisition context
+ *
+ * Provides a default &drm_crtc_funcs.page_flip_target implementation.
+ * Similar to drm_atomic_helper_page_flip() with extra parameter to specify
+ * target vblank period to flip.
+ *
+ * Returns:
+ * Returns 0 on success, negative errno numbers on failure.
+ */
+int drm_atomic_helper_page_flip_target(struct drm_crtc *crtc,
+				       struct drm_framebuffer *fb,
+				       struct drm_pending_vblank_event *event,
+				       uint32_t flags,
+				       uint32_t target,
+				       struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_plane *plane = crtc->primary;
+	struct drm_atomic_state *state;
+	struct drm_crtc_state *crtc_state;
+	int ret = 0;
+
+	state = drm_atomic_state_alloc(plane->dev);
+	if (!state)
+		return -ENOMEM;
+
+	state->acquire_ctx = ctx;
+
+	ret = page_flip_common(state, crtc, fb, event, flags);
+	if (ret != 0)
+		goto fail;
+
+	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
+	if (WARN_ON(!crtc_state)) {
+		ret = -EINVAL;
+		goto fail;
+	}
+	crtc_state->target_vblank = target;
+
+	ret = drm_atomic_nonblocking_commit(state);
+fail:
+	drm_atomic_state_put(state);
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_page_flip_target);
+
+/**
+ * drm_atomic_helper_best_encoder - Helper for
+ * 	&drm_connector_helper_funcs.best_encoder callback
+ * @connector: Connector control structure
+ *
+ * This is a &drm_connector_helper_funcs.best_encoder callback helper for
+ * connectors that support exactly 1 encoder, statically determined at driver
+ * init time.
+ */
+struct drm_encoder *
+drm_atomic_helper_best_encoder(struct drm_connector *connector)
+{
+	WARN_ON(connector->encoder_ids[1]);
+	return drm_encoder_find(connector->dev, NULL, connector->encoder_ids[0]);
+}
+EXPORT_SYMBOL(drm_atomic_helper_best_encoder);
+
+/**
+ * DOC: atomic state reset and initialization
+ *
+ * Both the drm core and the atomic helpers assume that there is always the full
+ * and correct atomic software state for all connectors, CRTCs and planes
+ * available. Which is a bit a problem on driver load and also after system
+ * suspend. One way to solve this is to have a hardware state read-out
+ * infrastructure which reconstructs the full software state (e.g. the i915
+ * driver).
+ *
+ * The simpler solution is to just reset the software state to everything off,
+ * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
+ * the atomic helpers provide default reset implementations for all hooks.
+ *
+ * On the upside the precise state tracking of atomic simplifies system suspend
+ * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
+ * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
+ * For other drivers the building blocks are split out, see the documentation
+ * for these functions.
+ */
+
+/**
+ * drm_atomic_helper_crtc_reset - default &drm_crtc_funcs.reset hook for CRTCs
+ * @crtc: drm CRTC
+ *
+ * Resets the atomic state for @crtc by freeing the state pointer (which might
+ * be NULL, e.g. at driver load time) and allocating a new empty state object.
+ */
+void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
+{
+	if (crtc->state)
+		__drm_atomic_helper_crtc_destroy_state(crtc->state);
+
+	kfree(crtc->state);
+	crtc->state = kzalloc(sizeof(*crtc->state), GFP_KERNEL);
+
+	if (crtc->state)
+		crtc->state->crtc = crtc;
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);
+
+/**
+ * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
+ * @crtc: CRTC object
+ * @state: atomic CRTC state
+ *
+ * Copies atomic state from a CRTC's current state and resets inferred values.
+ * This is useful for drivers that subclass the CRTC state.
+ */
+void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
+					      struct drm_crtc_state *state)
+{
+	memcpy(state, crtc->state, sizeof(*state));
+
+	if (state->mode_blob)
+		drm_property_blob_get(state->mode_blob);
+	if (state->degamma_lut)
+		drm_property_blob_get(state->degamma_lut);
+	if (state->ctm)
+		drm_property_blob_get(state->ctm);
+	if (state->gamma_lut)
+		drm_property_blob_get(state->gamma_lut);
+	state->mode_changed = false;
+	state->active_changed = false;
+	state->planes_changed = false;
+	state->connectors_changed = false;
+	state->color_mgmt_changed = false;
+	state->zpos_changed = false;
+	state->commit = NULL;
+	state->event = NULL;
+	state->pageflip_flags = 0;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
+
+/**
+ * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
+ * @crtc: drm CRTC
+ *
+ * Default CRTC state duplicate hook for drivers which don't have their own
+ * subclassed CRTC state structure.
+ */
+struct drm_crtc_state *
+drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
+{
+	struct drm_crtc_state *state;
+
+	if (WARN_ON(!crtc->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_crtc_duplicate_state(crtc, state);
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
+
+/**
+ * __drm_atomic_helper_crtc_destroy_state - release CRTC state
+ * @state: CRTC state object to release
+ *
+ * Releases all resources stored in the CRTC state without actually freeing
+ * the memory of the CRTC state. This is useful for drivers that subclass the
+ * CRTC state.
+ */
+void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
+{
+	if (state->commit) {
+		/*
+		 * In the event that a non-blocking commit returns
+		 * -ERESTARTSYS before the commit_tail work is queued, we will
+		 * have an extra reference to the commit object. Release it, if
+		 * the event has not been consumed by the worker.
+		 *
+		 * state->event may be freed, so we can't directly look at
+		 * state->event->base.completion.
+		 */
+		if (state->event && state->commit->abort_completion)
+			drm_crtc_commit_put(state->commit);
+
+		kfree(state->commit->event);
+		state->commit->event = NULL;
+
+		drm_crtc_commit_put(state->commit);
+	}
+
+	drm_property_blob_put(state->mode_blob);
+	drm_property_blob_put(state->degamma_lut);
+	drm_property_blob_put(state->ctm);
+	drm_property_blob_put(state->gamma_lut);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
+
+/**
+ * drm_atomic_helper_crtc_destroy_state - default state destroy hook
+ * @crtc: drm CRTC
+ * @state: CRTC state object to release
+ *
+ * Default CRTC state destroy hook for drivers which don't have their own
+ * subclassed CRTC state structure.
+ */
+void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
+					  struct drm_crtc_state *state)
+{
+	__drm_atomic_helper_crtc_destroy_state(state);
+	kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_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
+ * be NULL, e.g. at driver load time) and allocating a new empty state object.
+ */
+void drm_atomic_helper_plane_reset(struct drm_plane *plane)
+{
+	if (plane->state)
+		__drm_atomic_helper_plane_destroy_state(plane->state);
+
+	kfree(plane->state);
+	plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
+
+	if (plane->state) {
+		plane->state->plane = plane;
+		plane->state->rotation = DRM_MODE_ROTATE_0;
+
+		/* Reset the alpha value to fully opaque if it matters */
+		if (plane->alpha_property)
+			plane->state->alpha = plane->alpha_property->values[1];
+	}
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
+
+/**
+ * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
+ * @plane: plane object
+ * @state: atomic plane state
+ *
+ * Copies atomic state from a plane's current state. This is useful for
+ * drivers that subclass the plane state.
+ */
+void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
+					       struct drm_plane_state *state)
+{
+	memcpy(state, plane->state, sizeof(*state));
+
+	if (state->fb)
+		drm_framebuffer_get(state->fb);
+
+	state->fence = NULL;
+	state->commit = NULL;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
+
+/**
+ * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
+ * @plane: drm plane
+ *
+ * Default plane state duplicate hook for drivers which don't have their own
+ * subclassed plane state structure.
+ */
+struct drm_plane_state *
+drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
+{
+	struct drm_plane_state *state;
+
+	if (WARN_ON(!plane->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_plane_duplicate_state(plane, state);
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);
+
+/**
+ * __drm_atomic_helper_plane_destroy_state - release plane state
+ * @state: plane state object to release
+ *
+ * Releases all resources stored in the plane state without actually freeing
+ * the memory of the plane state. This is useful for drivers that subclass the
+ * plane state.
+ */
+void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
+{
+	if (state->fb)
+		drm_framebuffer_put(state->fb);
+
+	if (state->fence)
+		dma_fence_put(state->fence);
+
+	if (state->commit)
+		drm_crtc_commit_put(state->commit);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
+
+/**
+ * drm_atomic_helper_plane_destroy_state - default state destroy hook
+ * @plane: drm plane
+ * @state: plane state object to release
+ *
+ * Default plane state destroy hook for drivers which don't have their own
+ * subclassed plane state structure.
+ */
+void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
+					   struct drm_plane_state *state)
+{
+	__drm_atomic_helper_plane_destroy_state(state);
+	kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);
+
+/**
+ * __drm_atomic_helper_connector_reset - reset state on connector
+ * @connector: drm connector
+ * @conn_state: connector state to assign
+ *
+ * Initializes the newly allocated @conn_state and assigns it to
+ * the &drm_conector->state pointer of @connector, usually required when
+ * initializing the drivers or when called from the &drm_connector_funcs.reset
+ * hook.
+ *
+ * This is useful for drivers that subclass the connector state.
+ */
+void
+__drm_atomic_helper_connector_reset(struct drm_connector *connector,
+				    struct drm_connector_state *conn_state)
+{
+	if (conn_state)
+		conn_state->connector = connector;
+
+	connector->state = conn_state;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);
+
+/**
+ * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors
+ * @connector: drm connector
+ *
+ * Resets the atomic state for @connector by freeing the state pointer (which
+ * might be NULL, e.g. at driver load time) and allocating a new empty state
+ * object.
+ */
+void drm_atomic_helper_connector_reset(struct drm_connector *connector)
+{
+	struct drm_connector_state *conn_state =
+		kzalloc(sizeof(*conn_state), GFP_KERNEL);
+
+	if (connector->state)
+		__drm_atomic_helper_connector_destroy_state(connector->state);
+
+	kfree(connector->state);
+	__drm_atomic_helper_connector_reset(connector, conn_state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
+
+/**
+ * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
+ * @connector: connector object
+ * @state: atomic connector state
+ *
+ * Copies atomic state from a connector's current state. This is useful for
+ * drivers that subclass the connector state.
+ */
+void
+__drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
+					    struct drm_connector_state *state)
+{
+	memcpy(state, connector->state, sizeof(*state));
+	if (state->crtc)
+		drm_connector_get(connector);
+	state->commit = NULL;
+
+	/* Don't copy over a writeback job, they are used only once */
+	state->writeback_job = NULL;
+}
+EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
+
+/**
+ * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
+ * @connector: drm connector
+ *
+ * Default connector state duplicate hook for drivers which don't have their own
+ * subclassed connector state structure.
+ */
+struct drm_connector_state *
+drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
+{
+	struct drm_connector_state *state;
+
+	if (WARN_ON(!connector->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (state)
+		__drm_atomic_helper_connector_duplicate_state(connector, state);
+
+	return state;
+}
+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. This is used for example by suspend/
+ * resume support code to save the state prior to suspend such that it can
+ * be restored upon resume.
+ *
+ * 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.
+ *
+ * See also:
+ * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
+ */
+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_connector_list_iter conn_iter;
+	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_connector_list_iter_begin(dev, &conn_iter);
+	drm_for_each_connector_iter(conn, &conn_iter) {
+		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);
+			drm_connector_list_iter_end(&conn_iter);
+			goto free;
+		}
+	}
+	drm_connector_list_iter_end(&conn_iter);
+
+	/* clear the acquire context so that it isn't accidentally reused */
+	state->acquire_ctx = NULL;
+
+free:
+	if (err < 0) {
+		drm_atomic_state_put(state);
+		state = ERR_PTR(err);
+	}
+
+	return state;
+}
+EXPORT_SYMBOL(drm_atomic_helper_duplicate_state);
+
+/**
+ * __drm_atomic_helper_connector_destroy_state - release connector state
+ * @state: connector state object to release
+ *
+ * Releases all resources stored in the connector state without actually
+ * freeing the memory of the connector state. This is useful for drivers that
+ * subclass the connector state.
+ */
+void
+__drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
+{
+	if (state->crtc)
+		drm_connector_put(state->connector);
+
+	if (state->commit)
+		drm_crtc_commit_put(state->commit);
+}
+EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
+
+/**
+ * drm_atomic_helper_connector_destroy_state - default state destroy hook
+ * @connector: drm connector
+ * @state: connector state object to release
+ *
+ * Default connector state destroy hook for drivers which don't have their own
+ * subclassed connector state structure.
+ */
+void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
+					  struct drm_connector_state *state)
+{
+	__drm_atomic_helper_connector_destroy_state(state);
+	kfree(state);
+}
+EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
+
+/**
+ * drm_atomic_helper_legacy_gamma_set - set the legacy gamma correction table
+ * @crtc: CRTC object
+ * @red: red correction table
+ * @green: green correction table
+ * @blue: green correction table
+ * @size: size of the tables
+ * @ctx: lock acquire context
+ *
+ * Implements support for legacy gamma correction table for drivers
+ * that support color management through the DEGAMMA_LUT/GAMMA_LUT
+ * properties. See drm_crtc_enable_color_mgmt() and the containing chapter for
+ * how the atomic color management and gamma tables work.
+ */
+int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
+				       u16 *red, u16 *green, u16 *blue,
+				       uint32_t size,
+				       struct drm_modeset_acquire_ctx *ctx)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_atomic_state *state;
+	struct drm_crtc_state *crtc_state;
+	struct drm_property_blob *blob = NULL;
+	struct drm_color_lut *blob_data;
+	int i, ret = 0;
+	bool replaced;
+
+	state = drm_atomic_state_alloc(crtc->dev);
+	if (!state)
+		return -ENOMEM;
+
+	blob = drm_property_create_blob(dev,
+					sizeof(struct drm_color_lut) * size,
+					NULL);
+	if (IS_ERR(blob)) {
+		ret = PTR_ERR(blob);
+		blob = NULL;
+		goto fail;
+	}
+
+	/* Prepare GAMMA_LUT with the legacy values. */
+	blob_data = blob->data;
+	for (i = 0; i < size; i++) {
+		blob_data[i].red = red[i];
+		blob_data[i].green = green[i];
+		blob_data[i].blue = blue[i];
+	}
+
+	state->acquire_ctx = ctx;
+	crtc_state = drm_atomic_get_crtc_state(state, crtc);
+	if (IS_ERR(crtc_state)) {
+		ret = PTR_ERR(crtc_state);
+		goto fail;
+	}
+
+	/* Reset DEGAMMA_LUT and CTM properties. */
+	replaced  = drm_property_replace_blob(&crtc_state->degamma_lut, NULL);
+	replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
+	replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob);
+	crtc_state->color_mgmt_changed |= replaced;
+
+	ret = drm_atomic_commit(state);
+
+fail:
+	drm_atomic_state_put(state);
+	drm_property_blob_put(blob);
+	return ret;
+}
+EXPORT_SYMBOL(drm_atomic_helper_legacy_gamma_set);
+
+/**
+ * __drm_atomic_helper_private_duplicate_state - copy atomic private state
+ * @obj: CRTC object
+ * @state: new private object state
+ *
+ * Copies atomic state from a private objects's current state and resets inferred values.
+ * This is useful for drivers that subclass the private state.
+ */
+void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
+						     struct drm_private_state *state)
+{
+	memcpy(state, obj->state, sizeof(*state));
+}
+EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);