1/*
   2 * Copyright (C) 2014 Red Hat
   3 * Copyright (C) 2014 Intel Corp.
   4 *
   5 * Permission is hereby granted, free of charge, to any person obtaining a
   6 * copy of this software and associated documentation files (the "Software"),
   7 * to deal in the Software without restriction, including without limitation
   8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9 * and/or sell copies of the Software, and to permit persons to whom the
  10 * Software is furnished to do so, subject to the following conditions:
  11 *
  12 * The above copyright notice and this permission notice shall be included in
  13 * all copies or substantial portions of the Software.
  14 *
  15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  21 * OTHER DEALINGS IN THE SOFTWARE.
  22 *
  23 * Authors:
  24 * Rob Clark <robdclark@gmail.com>
  25 * Daniel Vetter <daniel.vetter@ffwll.ch>
  26 */
  27
  28#include <linux/dma-fence.h>
  29#include <linux/ktime.h>
  30
  31#include <drm/drm_atomic.h>
  32#include <drm/drm_atomic_helper.h>
  33#include <drm/drm_atomic_uapi.h>
  34#include <drm/drm_blend.h>
  35#include <drm/drm_bridge.h>
  36#include <drm/drm_damage_helper.h>
  37#include <drm/drm_device.h>
  38#include <drm/drm_drv.h>
  39#include <drm/drm_framebuffer.h>
  40#include <drm/drm_gem_atomic_helper.h>
  41#include <drm/drm_panic.h>
  42#include <drm/drm_print.h>
  43#include <drm/drm_self_refresh_helper.h>
  44#include <drm/drm_vblank.h>
  45#include <drm/drm_writeback.h>
  46
  47#include "drm_crtc_helper_internal.h"
  48#include "drm_crtc_internal.h"
  49
  50/**
  51 * DOC: overview
  52 *
  53 * This helper library provides implementations of check and commit functions on
  54 * top of the CRTC modeset helper callbacks and the plane helper callbacks. It
  55 * also provides convenience implementations for the atomic state handling
  56 * callbacks for drivers which don't need to subclass the drm core structures to
  57 * add their own additional internal state.
  58 *
  59 * This library also provides default implementations for the check callback in
  60 * drm_atomic_helper_check() and for the commit callback with
  61 * drm_atomic_helper_commit(). But the individual stages and callbacks are
  62 * exposed to allow drivers to mix and match and e.g. use the plane helpers only
  63 * together with a driver private modeset implementation.
  64 *
  65 * This library also provides implementations for all the legacy driver
  66 * interfaces on top of the atomic interface. See drm_atomic_helper_set_config(),
  67 * drm_atomic_helper_disable_plane(), and the various functions to implement
  68 * set_property callbacks. New drivers must not implement these functions
  69 * themselves but must use the provided helpers.
  70 *
  71 * The atomic helper uses the same function table structures as all other
  72 * modesetting helpers. See the documentation for &struct drm_crtc_helper_funcs,
  73 * struct &drm_encoder_helper_funcs and &struct drm_connector_helper_funcs. It
  74 * also shares the &struct drm_plane_helper_funcs function table with the plane
  75 * helpers.
  76 */
  77static void
  78drm_atomic_helper_plane_changed(struct drm_atomic_state *state,
  79				struct drm_plane_state *old_plane_state,
  80				struct drm_plane_state *plane_state,
  81				struct drm_plane *plane)
  82{
  83	struct drm_crtc_state *crtc_state;
  84
  85	if (old_plane_state->crtc) {
  86		crtc_state = drm_atomic_get_new_crtc_state(state,
  87							   old_plane_state->crtc);
  88
  89		if (WARN_ON(!crtc_state))
  90			return;
  91
  92		crtc_state->planes_changed = true;
  93	}
  94
  95	if (plane_state->crtc) {
  96		crtc_state = drm_atomic_get_new_crtc_state(state, plane_state->crtc);
  97
  98		if (WARN_ON(!crtc_state))
  99			return;
 100
 101		crtc_state->planes_changed = true;
 102	}
 103}
 104
 105static int handle_conflicting_encoders(struct drm_atomic_state *state,
 106				       bool disable_conflicting_encoders)
 107{
 108	struct drm_connector_state *new_conn_state;
 109	struct drm_connector *connector;
 110	struct drm_connector_list_iter conn_iter;
 111	struct drm_encoder *encoder;
 112	unsigned int encoder_mask = 0;
 113	int i, ret = 0;
 114
 115	/*
 116	 * First loop, find all newly assigned encoders from the connectors
 117	 * part of the state. If the same encoder is assigned to multiple
 118	 * connectors bail out.
 119	 */
 120	for_each_new_connector_in_state(state, connector, new_conn_state, i) {
 121		const struct drm_connector_helper_funcs *funcs = connector->helper_private;
 122		struct drm_encoder *new_encoder;
 123
 124		if (!new_conn_state->crtc)
 125			continue;
 126
 127		if (funcs->atomic_best_encoder)
 128			new_encoder = funcs->atomic_best_encoder(connector,
 129								 state);
 130		else if (funcs->best_encoder)
 131			new_encoder = funcs->best_encoder(connector);
 132		else
 133			new_encoder = drm_connector_get_single_encoder(connector);
 134
 135		if (new_encoder) {
 136			if (encoder_mask & drm_encoder_mask(new_encoder)) {
 137				drm_dbg_atomic(connector->dev,
 138					       "[ENCODER:%d:%s] on [CONNECTOR:%d:%s] already assigned\n",
 139					       new_encoder->base.id, new_encoder->name,
 140					       connector->base.id, connector->name);
 141
 142				return -EINVAL;
 143			}
 144
 145			encoder_mask |= drm_encoder_mask(new_encoder);
 146		}
 147	}
 148
 149	if (!encoder_mask)
 150		return 0;
 151
 152	/*
 153	 * Second loop, iterate over all connectors not part of the state.
 154	 *
 155	 * If a conflicting encoder is found and disable_conflicting_encoders
 156	 * is not set, an error is returned. Userspace can provide a solution
 157	 * through the atomic ioctl.
 158	 *
 159	 * If the flag is set conflicting connectors are removed from the CRTC
 160	 * and the CRTC is disabled if no encoder is left. This preserves
 161	 * compatibility with the legacy set_config behavior.
 162	 */
 163	drm_connector_list_iter_begin(state->dev, &conn_iter);
 164	drm_for_each_connector_iter(connector, &conn_iter) {
 165		struct drm_crtc_state *crtc_state;
 166
 167		if (drm_atomic_get_new_connector_state(state, connector))
 168			continue;
 169
 170		encoder = connector->state->best_encoder;
 171		if (!encoder || !(encoder_mask & drm_encoder_mask(encoder)))
 172			continue;
 173
 174		if (!disable_conflicting_encoders) {
 175			drm_dbg_atomic(connector->dev,
 176				       "[ENCODER:%d:%s] in use on [CRTC:%d:%s] by [CONNECTOR:%d:%s]\n",
 177				       encoder->base.id, encoder->name,
 178				       connector->state->crtc->base.id,
 179				       connector->state->crtc->name,
 180				       connector->base.id, connector->name);
 181			ret = -EINVAL;
 182			goto out;
 183		}
 184
 185		new_conn_state = drm_atomic_get_connector_state(state, connector);
 186		if (IS_ERR(new_conn_state)) {
 187			ret = PTR_ERR(new_conn_state);
 188			goto out;
 189		}
 190
 191		drm_dbg_atomic(connector->dev,
 192			       "[ENCODER:%d:%s] in use on [CRTC:%d:%s], disabling [CONNECTOR:%d:%s]\n",
 193			       encoder->base.id, encoder->name,
 194			       new_conn_state->crtc->base.id, new_conn_state->crtc->name,
 195			       connector->base.id, connector->name);
 196
 197		crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc);
 198
 199		ret = drm_atomic_set_crtc_for_connector(new_conn_state, NULL);
 200		if (ret)
 201			goto out;
 202
 203		if (!crtc_state->connector_mask) {
 204			ret = drm_atomic_set_mode_prop_for_crtc(crtc_state,
 205								NULL);
 206			if (ret < 0)
 207				goto out;
 208
 209			crtc_state->active = false;
 210		}
 211	}
 212out:
 213	drm_connector_list_iter_end(&conn_iter);
 214
 215	return ret;
 216}
 217
 218static void
 219set_best_encoder(struct drm_atomic_state *state,
 220		 struct drm_connector_state *conn_state,
 221		 struct drm_encoder *encoder)
 222{
 223	struct drm_crtc_state *crtc_state;
 224	struct drm_crtc *crtc;
 225
 226	if (conn_state->best_encoder) {
 227		/* Unset the encoder_mask in the old crtc state. */
 228		crtc = conn_state->connector->state->crtc;
 229
 230		/* A NULL crtc is an error here because we should have
 231		 * duplicated a NULL best_encoder when crtc was NULL.
 232		 * As an exception restoring duplicated atomic state
 233		 * during resume is allowed, so don't warn when
 234		 * best_encoder is equal to encoder we intend to set.
 235		 */
 236		WARN_ON(!crtc && encoder != conn_state->best_encoder);
 237		if (crtc) {
 238			crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 239
 240			crtc_state->encoder_mask &=
 241				~drm_encoder_mask(conn_state->best_encoder);
 242		}
 243	}
 244
 245	if (encoder) {
 246		crtc = conn_state->crtc;
 247		WARN_ON(!crtc);
 248		if (crtc) {
 249			crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 250
 251			crtc_state->encoder_mask |=
 252				drm_encoder_mask(encoder);
 253		}
 254	}
 255
 256	conn_state->best_encoder = encoder;
 257}
 258
 259static void
 260steal_encoder(struct drm_atomic_state *state,
 261	      struct drm_encoder *encoder)
 262{
 263	struct drm_crtc_state *crtc_state;
 264	struct drm_connector *connector;
 265	struct drm_connector_state *old_connector_state, *new_connector_state;
 266	int i;
 267
 268	for_each_oldnew_connector_in_state(state, connector, old_connector_state, new_connector_state, i) {
 269		struct drm_crtc *encoder_crtc;
 270
 271		if (new_connector_state->best_encoder != encoder)
 272			continue;
 273
 274		encoder_crtc = old_connector_state->crtc;
 275
 276		drm_dbg_atomic(encoder->dev,
 277			       "[ENCODER:%d:%s] in use on [CRTC:%d:%s], stealing it\n",
 278			       encoder->base.id, encoder->name,
 279			       encoder_crtc->base.id, encoder_crtc->name);
 280
 281		set_best_encoder(state, new_connector_state, NULL);
 282
 283		crtc_state = drm_atomic_get_new_crtc_state(state, encoder_crtc);
 284		crtc_state->connectors_changed = true;
 285
 286		return;
 287	}
 288}
 289
 290static int
 291update_connector_routing(struct drm_atomic_state *state,
 292			 struct drm_connector *connector,
 293			 struct drm_connector_state *old_connector_state,
 294			 struct drm_connector_state *new_connector_state,
 295			 bool added_by_user)
 296{
 297	const struct drm_connector_helper_funcs *funcs;
 298	struct drm_encoder *new_encoder;
 299	struct drm_crtc_state *crtc_state;
 300
 301	drm_dbg_atomic(connector->dev, "Updating routing for [CONNECTOR:%d:%s]\n",
 302		       connector->base.id, connector->name);
 303
 304	if (old_connector_state->crtc != new_connector_state->crtc) {
 305		if (old_connector_state->crtc) {
 306			crtc_state = drm_atomic_get_new_crtc_state(state, old_connector_state->crtc);
 307			crtc_state->connectors_changed = true;
 308		}
 309
 310		if (new_connector_state->crtc) {
 311			crtc_state = drm_atomic_get_new_crtc_state(state, new_connector_state->crtc);
 312			crtc_state->connectors_changed = true;
 313		}
 314	}
 315
 316	if (!new_connector_state->crtc) {
 317		drm_dbg_atomic(connector->dev, "Disabling [CONNECTOR:%d:%s]\n",
 318				connector->base.id, connector->name);
 319
 320		set_best_encoder(state, new_connector_state, NULL);
 321
 322		return 0;
 323	}
 324
 325	crtc_state = drm_atomic_get_new_crtc_state(state,
 326						   new_connector_state->crtc);
 327	/*
 328	 * For compatibility with legacy users, we want to make sure that
 329	 * we allow DPMS On->Off modesets on unregistered connectors. Modesets
 330	 * which would result in anything else must be considered invalid, to
 331	 * avoid turning on new displays on dead connectors.
 332	 *
 333	 * Since the connector can be unregistered at any point during an
 334	 * atomic check or commit, this is racy. But that's OK: all we care
 335	 * about is ensuring that userspace can't do anything but shut off the
 336	 * display on a connector that was destroyed after it's been notified,
 337	 * not before.
 338	 *
 339	 * Additionally, we also want to ignore connector registration when
 340	 * we're trying to restore an atomic state during system resume since
 341	 * there's a chance the connector may have been destroyed during the
 342	 * process, but it's better to ignore that then cause
 343	 * drm_atomic_helper_resume() to fail.
 344	 *
 345	 * Last, we want to ignore connector registration when the connector
 346	 * was not pulled in the atomic state by user-space (ie, was pulled
 347	 * in by the driver, e.g. when updating a DP-MST stream).
 348	 */
 349	if (!state->duplicated && drm_connector_is_unregistered(connector) &&
 350	    added_by_user && crtc_state->active) {
 351		drm_dbg_atomic(connector->dev,
 352			       "[CONNECTOR:%d:%s] is not registered\n",
 353			       connector->base.id, connector->name);
 354		return -EINVAL;
 355	}
 356
 357	funcs = connector->helper_private;
 358
 359	if (funcs->atomic_best_encoder)
 360		new_encoder = funcs->atomic_best_encoder(connector, state);
 361	else if (funcs->best_encoder)
 362		new_encoder = funcs->best_encoder(connector);
 363	else
 364		new_encoder = drm_connector_get_single_encoder(connector);
 365
 366	if (!new_encoder) {
 367		drm_dbg_atomic(connector->dev,
 368			       "No suitable encoder found for [CONNECTOR:%d:%s]\n",
 369			       connector->base.id, connector->name);
 370		return -EINVAL;
 371	}
 372
 373	if (!drm_encoder_crtc_ok(new_encoder, new_connector_state->crtc)) {
 374		drm_dbg_atomic(connector->dev,
 375			       "[ENCODER:%d:%s] incompatible with [CRTC:%d:%s]\n",
 376			       new_encoder->base.id,
 377			       new_encoder->name,
 378			       new_connector_state->crtc->base.id,
 379			       new_connector_state->crtc->name);
 380		return -EINVAL;
 381	}
 382
 383	if (new_encoder == new_connector_state->best_encoder) {
 384		set_best_encoder(state, new_connector_state, new_encoder);
 385
 386		drm_dbg_atomic(connector->dev,
 387			       "[CONNECTOR:%d:%s] keeps [ENCODER:%d:%s], now on [CRTC:%d:%s]\n",
 388			       connector->base.id,
 389			       connector->name,
 390			       new_encoder->base.id,
 391			       new_encoder->name,
 392			       new_connector_state->crtc->base.id,
 393			       new_connector_state->crtc->name);
 394
 395		return 0;
 396	}
 397
 398	steal_encoder(state, new_encoder);
 399
 400	set_best_encoder(state, new_connector_state, new_encoder);
 401
 402	crtc_state->connectors_changed = true;
 403
 404	drm_dbg_atomic(connector->dev,
 405		       "[CONNECTOR:%d:%s] using [ENCODER:%d:%s] on [CRTC:%d:%s]\n",
 406		       connector->base.id,
 407		       connector->name,
 408		       new_encoder->base.id,
 409		       new_encoder->name,
 410		       new_connector_state->crtc->base.id,
 411		       new_connector_state->crtc->name);
 412
 413	return 0;
 414}
 415
 416static int
 417mode_fixup(struct drm_atomic_state *state)
 418{
 419	struct drm_crtc *crtc;
 420	struct drm_crtc_state *new_crtc_state;
 421	struct drm_connector *connector;
 422	struct drm_connector_state *new_conn_state;
 423	int i;
 424	int ret;
 425
 426	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
 427		if (!new_crtc_state->mode_changed &&
 428		    !new_crtc_state->connectors_changed)
 429			continue;
 430
 431		drm_mode_copy(&new_crtc_state->adjusted_mode, &new_crtc_state->mode);
 432	}
 433
 434	for_each_new_connector_in_state(state, connector, new_conn_state, i) {
 435		const struct drm_encoder_helper_funcs *funcs;
 436		struct drm_encoder *encoder;
 437		struct drm_bridge *bridge;
 438
 439		WARN_ON(!!new_conn_state->best_encoder != !!new_conn_state->crtc);
 440
 441		if (!new_conn_state->crtc || !new_conn_state->best_encoder)
 442			continue;
 443
 444		new_crtc_state =
 445			drm_atomic_get_new_crtc_state(state, new_conn_state->crtc);
 446
 447		/*
 448		 * Each encoder has at most one connector (since we always steal
 449		 * it away), so we won't call ->mode_fixup twice.
 450		 */
 451		encoder = new_conn_state->best_encoder;
 452		funcs = encoder->helper_private;
 453
 454		bridge = drm_bridge_chain_get_first_bridge(encoder);
 455		ret = drm_atomic_bridge_chain_check(bridge,
 456						    new_crtc_state,
 457						    new_conn_state);
 458		if (ret) {
 459			drm_dbg_atomic(encoder->dev, "Bridge atomic check failed\n");
 460			return ret;
 461		}
 462
 463		if (funcs && funcs->atomic_check) {
 464			ret = funcs->atomic_check(encoder, new_crtc_state,
 465						  new_conn_state);
 466			if (ret) {
 467				drm_dbg_atomic(encoder->dev,
 468					       "[ENCODER:%d:%s] check failed\n",
 469					       encoder->base.id, encoder->name);
 470				return ret;
 471			}
 472		} else if (funcs && funcs->mode_fixup) {
 473			ret = funcs->mode_fixup(encoder, &new_crtc_state->mode,
 474						&new_crtc_state->adjusted_mode);
 475			if (!ret) {
 476				drm_dbg_atomic(encoder->dev,
 477					       "[ENCODER:%d:%s] fixup failed\n",
 478					       encoder->base.id, encoder->name);
 479				return -EINVAL;
 480			}
 481		}
 482	}
 483
 484	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
 485		const struct drm_crtc_helper_funcs *funcs;
 486
 487		if (!new_crtc_state->enable)
 488			continue;
 489
 490		if (!new_crtc_state->mode_changed &&
 491		    !new_crtc_state->connectors_changed)
 492			continue;
 493
 494		funcs = crtc->helper_private;
 495		if (!funcs || !funcs->mode_fixup)
 496			continue;
 497
 498		ret = funcs->mode_fixup(crtc, &new_crtc_state->mode,
 499					&new_crtc_state->adjusted_mode);
 500		if (!ret) {
 501			drm_dbg_atomic(crtc->dev, "[CRTC:%d:%s] fixup failed\n",
 502				       crtc->base.id, crtc->name);
 503			return -EINVAL;
 504		}
 505	}
 506
 507	return 0;
 508}
 509
 510static enum drm_mode_status mode_valid_path(struct drm_connector *connector,
 511					    struct drm_encoder *encoder,
 512					    struct drm_crtc *crtc,
 513					    const struct drm_display_mode *mode)
 514{
 515	struct drm_bridge *bridge;
 516	enum drm_mode_status ret;
 517
 518	ret = drm_encoder_mode_valid(encoder, mode);
 519	if (ret != MODE_OK) {
 520		drm_dbg_atomic(encoder->dev,
 521			       "[ENCODER:%d:%s] mode_valid() failed\n",
 522			       encoder->base.id, encoder->name);
 523		return ret;
 524	}
 525
 526	bridge = drm_bridge_chain_get_first_bridge(encoder);
 527	ret = drm_bridge_chain_mode_valid(bridge, &connector->display_info,
 528					  mode);
 529	if (ret != MODE_OK) {
 530		drm_dbg_atomic(encoder->dev, "[BRIDGE] mode_valid() failed\n");
 531		return ret;
 532	}
 533
 534	ret = drm_crtc_mode_valid(crtc, mode);
 535	if (ret != MODE_OK) {
 536		drm_dbg_atomic(encoder->dev, "[CRTC:%d:%s] mode_valid() failed\n",
 537			       crtc->base.id, crtc->name);
 538		return ret;
 539	}
 540
 541	return ret;
 542}
 543
 544static int
 545mode_valid(struct drm_atomic_state *state)
 546{
 547	struct drm_connector_state *conn_state;
 548	struct drm_connector *connector;
 549	int i;
 550
 551	for_each_new_connector_in_state(state, connector, conn_state, i) {
 552		struct drm_encoder *encoder = conn_state->best_encoder;
 553		struct drm_crtc *crtc = conn_state->crtc;
 554		struct drm_crtc_state *crtc_state;
 555		enum drm_mode_status mode_status;
 556		const struct drm_display_mode *mode;
 557
 558		if (!crtc || !encoder)
 559			continue;
 560
 561		crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 562		if (!crtc_state)
 563			continue;
 564		if (!crtc_state->mode_changed && !crtc_state->connectors_changed)
 565			continue;
 566
 567		mode = &crtc_state->mode;
 568
 569		mode_status = mode_valid_path(connector, encoder, crtc, mode);
 570		if (mode_status != MODE_OK)
 571			return -EINVAL;
 572	}
 573
 574	return 0;
 575}
 576
 577/**
 578 * drm_atomic_helper_check_modeset - validate state object for modeset changes
 579 * @dev: DRM device
 580 * @state: the driver state object
 581 *
 582 * Check the state object to see if the requested state is physically possible.
 583 * This does all the CRTC and connector related computations for an atomic
 584 * update and adds any additional connectors needed for full modesets. It calls
 585 * the various per-object callbacks in the follow order:
 586 *
 587 * 1. &drm_connector_helper_funcs.atomic_best_encoder for determining the new encoder.
 588 * 2. &drm_connector_helper_funcs.atomic_check to validate the connector state.
 589 * 3. If it's determined a modeset is needed then all connectors on the affected
 590 *    CRTC are added and &drm_connector_helper_funcs.atomic_check is run on them.
 591 * 4. &drm_encoder_helper_funcs.mode_valid, &drm_bridge_funcs.mode_valid and
 592 *    &drm_crtc_helper_funcs.mode_valid are called on the affected components.
 593 * 5. &drm_bridge_funcs.mode_fixup is called on all encoder bridges.
 594 * 6. &drm_encoder_helper_funcs.atomic_check is called to validate any encoder state.
 595 *    This function is only called when the encoder will be part of a configured CRTC,
 596 *    it must not be used for implementing connector property validation.
 597 *    If this function is NULL, &drm_atomic_encoder_helper_funcs.mode_fixup is called
 598 *    instead.
 599 * 7. &drm_crtc_helper_funcs.mode_fixup is called last, to fix up the mode with CRTC constraints.
 600 *
 601 * &drm_crtc_state.mode_changed is set when the input mode is changed.
 602 * &drm_crtc_state.connectors_changed is set when a connector is added or
 603 * removed from the CRTC.  &drm_crtc_state.active_changed is set when
 604 * &drm_crtc_state.active changes, which is used for DPMS.
 605 * &drm_crtc_state.no_vblank is set from the result of drm_dev_has_vblank().
 606 * See also: drm_atomic_crtc_needs_modeset()
 607 *
 608 * IMPORTANT:
 609 *
 610 * Drivers which set &drm_crtc_state.mode_changed (e.g. in their
 611 * &drm_plane_helper_funcs.atomic_check hooks if a plane update can't be done
 612 * without a full modeset) _must_ call this function after that change. It is
 613 * permitted to call this function multiple times for the same update, e.g.
 614 * when the &drm_crtc_helper_funcs.atomic_check functions depend upon the
 615 * adjusted dotclock for fifo space allocation and watermark computation.
 616 *
 617 * RETURNS:
 618 * Zero for success or -errno
 619 */
 620int
 621drm_atomic_helper_check_modeset(struct drm_device *dev,
 622				struct drm_atomic_state *state)
 623{
 624	struct drm_crtc *crtc;
 625	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
 626	struct drm_connector *connector;
 627	struct drm_connector_state *old_connector_state, *new_connector_state;
 628	int i, ret;
 629	unsigned int connectors_mask = 0, user_connectors_mask = 0;
 630
 631	for_each_oldnew_connector_in_state(state, connector, old_connector_state, new_connector_state, i)
 632		user_connectors_mask |= BIT(i);
 633
 634	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
 635		bool has_connectors =
 636			!!new_crtc_state->connector_mask;
 637
 638		WARN_ON(!drm_modeset_is_locked(&crtc->mutex));
 639
 640		if (!drm_mode_equal(&old_crtc_state->mode, &new_crtc_state->mode)) {
 641			drm_dbg_atomic(dev, "[CRTC:%d:%s] mode changed\n",
 642				       crtc->base.id, crtc->name);
 643			new_crtc_state->mode_changed = true;
 644		}
 645
 646		if (old_crtc_state->enable != new_crtc_state->enable) {
 647			drm_dbg_atomic(dev, "[CRTC:%d:%s] enable changed\n",
 648				       crtc->base.id, crtc->name);
 649
 650			/*
 651			 * For clarity this assignment is done here, but
 652			 * enable == 0 is only true when there are no
 653			 * connectors and a NULL mode.
 654			 *
 655			 * The other way around is true as well. enable != 0
 656			 * implies that connectors are attached and a mode is set.
 657			 */
 658			new_crtc_state->mode_changed = true;
 659			new_crtc_state->connectors_changed = true;
 660		}
 661
 662		if (old_crtc_state->active != new_crtc_state->active) {
 663			drm_dbg_atomic(dev, "[CRTC:%d:%s] active changed\n",
 664				       crtc->base.id, crtc->name);
 665			new_crtc_state->active_changed = true;
 666		}
 667
 668		if (new_crtc_state->enable != has_connectors) {
 669			drm_dbg_atomic(dev, "[CRTC:%d:%s] enabled/connectors mismatch\n",
 670				       crtc->base.id, crtc->name);
 671
 672			return -EINVAL;
 673		}
 674
 675		if (drm_dev_has_vblank(dev))
 676			new_crtc_state->no_vblank = false;
 677		else
 678			new_crtc_state->no_vblank = true;
 679	}
 680
 681	ret = handle_conflicting_encoders(state, false);
 682	if (ret)
 683		return ret;
 684
 685	for_each_oldnew_connector_in_state(state, connector, old_connector_state, new_connector_state, i) {
 686		const struct drm_connector_helper_funcs *funcs = connector->helper_private;
 687
 688		WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 689
 690		/*
 691		 * This only sets crtc->connectors_changed for routing changes,
 692		 * drivers must set crtc->connectors_changed themselves when
 693		 * connector properties need to be updated.
 694		 */
 695		ret = update_connector_routing(state, connector,
 696					       old_connector_state,
 697					       new_connector_state,
 698					       BIT(i) & user_connectors_mask);
 699		if (ret)
 700			return ret;
 701		if (old_connector_state->crtc) {
 702			new_crtc_state = drm_atomic_get_new_crtc_state(state,
 703								       old_connector_state->crtc);
 704			if (old_connector_state->link_status !=
 705			    new_connector_state->link_status)
 706				new_crtc_state->connectors_changed = true;
 707
 708			if (old_connector_state->max_requested_bpc !=
 709			    new_connector_state->max_requested_bpc)
 710				new_crtc_state->connectors_changed = true;
 711		}
 712
 713		if (funcs->atomic_check)
 714			ret = funcs->atomic_check(connector, state);
 715		if (ret) {
 716			drm_dbg_atomic(dev,
 717				       "[CONNECTOR:%d:%s] driver check failed\n",
 718				       connector->base.id, connector->name);
 719			return ret;
 720		}
 721
 722		connectors_mask |= BIT(i);
 723	}
 724
 725	/*
 726	 * After all the routing has been prepared we need to add in any
 727	 * connector which is itself unchanged, but whose CRTC changes its
 728	 * configuration. This must be done before calling mode_fixup in case a
 729	 * crtc only changed its mode but has the same set of connectors.
 730	 */
 731	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
 732		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
 733			continue;
 734
 735		drm_dbg_atomic(dev,
 736			       "[CRTC:%d:%s] needs all connectors, enable: %c, active: %c\n",
 737			       crtc->base.id, crtc->name,
 738			       new_crtc_state->enable ? 'y' : 'n',
 739			       new_crtc_state->active ? 'y' : 'n');
 740
 741		ret = drm_atomic_add_affected_connectors(state, crtc);
 742		if (ret != 0)
 743			return ret;
 744
 745		ret = drm_atomic_add_affected_planes(state, crtc);
 746		if (ret != 0)
 747			return ret;
 748	}
 749
 750	/*
 751	 * Iterate over all connectors again, to make sure atomic_check()
 752	 * has been called on them when a modeset is forced.
 753	 */
 754	for_each_oldnew_connector_in_state(state, connector, old_connector_state, new_connector_state, i) {
 755		const struct drm_connector_helper_funcs *funcs = connector->helper_private;
 756
 757		if (connectors_mask & BIT(i))
 758			continue;
 759
 760		if (funcs->atomic_check)
 761			ret = funcs->atomic_check(connector, state);
 762		if (ret) {
 763			drm_dbg_atomic(dev,
 764				       "[CONNECTOR:%d:%s] driver check failed\n",
 765				       connector->base.id, connector->name);
 766			return ret;
 767		}
 768	}
 769
 770	/*
 771	 * Iterate over all connectors again, and add all affected bridges to
 772	 * the state.
 773	 */
 774	for_each_oldnew_connector_in_state(state, connector,
 775					   old_connector_state,
 776					   new_connector_state, i) {
 777		struct drm_encoder *encoder;
 778
 779		encoder = old_connector_state->best_encoder;
 780		ret = drm_atomic_add_encoder_bridges(state, encoder);
 781		if (ret)
 782			return ret;
 783
 784		encoder = new_connector_state->best_encoder;
 785		ret = drm_atomic_add_encoder_bridges(state, encoder);
 786		if (ret)
 787			return ret;
 788	}
 789
 790	ret = mode_valid(state);
 791	if (ret)
 792		return ret;
 793
 794	return mode_fixup(state);
 795}
 796EXPORT_SYMBOL(drm_atomic_helper_check_modeset);
 797
 798/**
 799 * drm_atomic_helper_check_wb_connector_state() - Check writeback connector state
 800 * @connector: corresponding connector
 801 * @state: the driver state object
 802 *
 803 * Checks if the writeback connector state is valid, and returns an error if it
 804 * isn't.
 805 *
 806 * RETURNS:
 807 * Zero for success or -errno
 808 */
 809int
 810drm_atomic_helper_check_wb_connector_state(struct drm_connector *connector,
 811					   struct drm_atomic_state *state)
 812{
 813	struct drm_connector_state *conn_state =
 814		drm_atomic_get_new_connector_state(state, connector);
 815	struct drm_writeback_job *wb_job = conn_state->writeback_job;
 816	struct drm_property_blob *pixel_format_blob;
 817	struct drm_framebuffer *fb;
 818	size_t i, nformats;
 819	u32 *formats;
 820
 821	if (!wb_job || !wb_job->fb)
 822		return 0;
 823
 824	pixel_format_blob = wb_job->connector->pixel_formats_blob_ptr;
 825	nformats = pixel_format_blob->length / sizeof(u32);
 826	formats = pixel_format_blob->data;
 827	fb = wb_job->fb;
 828
 829	for (i = 0; i < nformats; i++)
 830		if (fb->format->format == formats[i])
 831			return 0;
 832
 833	drm_dbg_kms(connector->dev, "Invalid pixel format %p4cc\n", &fb->format->format);
 834
 835	return -EINVAL;
 836}
 837EXPORT_SYMBOL(drm_atomic_helper_check_wb_connector_state);
 838
 839/**
 840 * drm_atomic_helper_check_plane_state() - Check plane state for validity
 841 * @plane_state: plane state to check
 842 * @crtc_state: CRTC state to check
 843 * @min_scale: minimum @src:@dest scaling factor in 16.16 fixed point
 844 * @max_scale: maximum @src:@dest scaling factor in 16.16 fixed point
 845 * @can_position: is it legal to position the plane such that it
 846 *                doesn't cover the entire CRTC?  This will generally
 847 *                only be false for primary planes.
 848 * @can_update_disabled: can the plane be updated while the CRTC
 849 *                       is disabled?
 850 *
 851 * Checks that a desired plane update is valid, and updates various
 852 * bits of derived state (clipped coordinates etc.). Drivers that provide
 853 * their own plane handling rather than helper-provided implementations may
 854 * still wish to call this function to avoid duplication of error checking
 855 * code.
 856 *
 857 * RETURNS:
 858 * Zero if update appears valid, error code on failure
 859 */
 860int drm_atomic_helper_check_plane_state(struct drm_plane_state *plane_state,
 861					const struct drm_crtc_state *crtc_state,
 862					int min_scale,
 863					int max_scale,
 864					bool can_position,
 865					bool can_update_disabled)
 866{
 867	struct drm_framebuffer *fb = plane_state->fb;
 868	struct drm_rect *src = &plane_state->src;
 869	struct drm_rect *dst = &plane_state->dst;
 870	unsigned int rotation = plane_state->rotation;
 871	struct drm_rect clip = {};
 872	int hscale, vscale;
 873
 874	WARN_ON(plane_state->crtc && plane_state->crtc != crtc_state->crtc);
 875
 876	*src = drm_plane_state_src(plane_state);
 877	*dst = drm_plane_state_dest(plane_state);
 878
 879	if (!fb) {
 880		plane_state->visible = false;
 881		return 0;
 882	}
 883
 884	/* crtc should only be NULL when disabling (i.e., !fb) */
 885	if (WARN_ON(!plane_state->crtc)) {
 886		plane_state->visible = false;
 887		return 0;
 888	}
 889
 890	if (!crtc_state->enable && !can_update_disabled) {
 891		drm_dbg_kms(plane_state->plane->dev,
 892			    "Cannot update plane of a disabled CRTC.\n");
 893		return -EINVAL;
 894	}
 895
 896	drm_rect_rotate(src, fb->width << 16, fb->height << 16, rotation);
 897
 898	/* Check scaling */
 899	hscale = drm_rect_calc_hscale(src, dst, min_scale, max_scale);
 900	vscale = drm_rect_calc_vscale(src, dst, min_scale, max_scale);
 901	if (hscale < 0 || vscale < 0) {
 902		drm_dbg_kms(plane_state->plane->dev,
 903			    "Invalid scaling of plane\n");
 904		drm_rect_debug_print("src: ", &plane_state->src, true);
 905		drm_rect_debug_print("dst: ", &plane_state->dst, false);
 906		return -ERANGE;
 907	}
 908
 909	if (crtc_state->enable)
 910		drm_mode_get_hv_timing(&crtc_state->mode, &clip.x2, &clip.y2);
 911
 912	plane_state->visible = drm_rect_clip_scaled(src, dst, &clip);
 913
 914	drm_rect_rotate_inv(src, fb->width << 16, fb->height << 16, rotation);
 915
 916	if (!plane_state->visible)
 917		/*
 918		 * Plane isn't visible; some drivers can handle this
 919		 * so we just return success here.  Drivers that can't
 920		 * (including those that use the primary plane helper's
 921		 * update function) will return an error from their
 922		 * update_plane handler.
 923		 */
 924		return 0;
 925
 926	if (!can_position && !drm_rect_equals(dst, &clip)) {
 927		drm_dbg_kms(plane_state->plane->dev,
 928			    "Plane must cover entire CRTC\n");
 929		drm_rect_debug_print("dst: ", dst, false);
 930		drm_rect_debug_print("clip: ", &clip, false);
 931		return -EINVAL;
 932	}
 933
 934	return 0;
 935}
 936EXPORT_SYMBOL(drm_atomic_helper_check_plane_state);
 937
 938/**
 939 * drm_atomic_helper_check_crtc_primary_plane() - Check CRTC state for primary plane
 940 * @crtc_state: CRTC state to check
 941 *
 942 * Checks that a CRTC has at least one primary plane attached to it, which is
 943 * a requirement on some hardware. Note that this only involves the CRTC side
 944 * of the test. To test if the primary plane is visible or if it can be updated
 945 * without the CRTC being enabled, use drm_atomic_helper_check_plane_state() in
 946 * the plane's atomic check.
 947 *
 948 * RETURNS:
 949 * 0 if a primary plane is attached to the CRTC, or an error code otherwise
 950 */
 951int drm_atomic_helper_check_crtc_primary_plane(struct drm_crtc_state *crtc_state)
 952{
 953	struct drm_crtc *crtc = crtc_state->crtc;
 954	struct drm_device *dev = crtc->dev;
 955	struct drm_plane *plane;
 956
 957	/* needs at least one primary plane to be enabled */
 958	drm_for_each_plane_mask(plane, dev, crtc_state->plane_mask) {
 959		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
 960			return 0;
 961	}
 962
 963	drm_dbg_atomic(dev, "[CRTC:%d:%s] primary plane missing\n", crtc->base.id, crtc->name);
 964
 965	return -EINVAL;
 966}
 967EXPORT_SYMBOL(drm_atomic_helper_check_crtc_primary_plane);
 968
 969/**
 970 * drm_atomic_helper_check_planes - validate state object for planes changes
 971 * @dev: DRM device
 972 * @state: the driver state object
 973 *
 974 * Check the state object to see if the requested state is physically possible.
 975 * This does all the plane update related checks using by calling into the
 976 * &drm_crtc_helper_funcs.atomic_check and &drm_plane_helper_funcs.atomic_check
 977 * hooks provided by the driver.
 978 *
 979 * It also sets &drm_crtc_state.planes_changed to indicate that a CRTC has
 980 * updated planes.
 981 *
 982 * RETURNS:
 983 * Zero for success or -errno
 984 */
 985int
 986drm_atomic_helper_check_planes(struct drm_device *dev,
 987			       struct drm_atomic_state *state)
 988{
 989	struct drm_crtc *crtc;
 990	struct drm_crtc_state *new_crtc_state;
 991	struct drm_plane *plane;
 992	struct drm_plane_state *new_plane_state, *old_plane_state;
 993	int i, ret = 0;
 994
 995	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
 996		const struct drm_plane_helper_funcs *funcs;
 997
 998		WARN_ON(!drm_modeset_is_locked(&plane->mutex));
 999
1000		funcs = plane->helper_private;
1001
1002		drm_atomic_helper_plane_changed(state, old_plane_state, new_plane_state, plane);
1003
1004		drm_atomic_helper_check_plane_damage(state, new_plane_state);
1005
1006		if (!funcs || !funcs->atomic_check)
1007			continue;
1008
1009		ret = funcs->atomic_check(plane, state);
1010		if (ret) {
1011			drm_dbg_atomic(plane->dev,
1012				       "[PLANE:%d:%s] atomic driver check failed\n",
1013				       plane->base.id, plane->name);
1014			return ret;
1015		}
1016	}
1017
1018	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
1019		const struct drm_crtc_helper_funcs *funcs;
1020
1021		funcs = crtc->helper_private;
1022
1023		if (!funcs || !funcs->atomic_check)
1024			continue;
1025
1026		ret = funcs->atomic_check(crtc, state);
1027		if (ret) {
1028			drm_dbg_atomic(crtc->dev,
1029				       "[CRTC:%d:%s] atomic driver check failed\n",
1030				       crtc->base.id, crtc->name);
1031			return ret;
1032		}
1033	}
1034
1035	return ret;
1036}
1037EXPORT_SYMBOL(drm_atomic_helper_check_planes);
1038
1039/**
1040 * drm_atomic_helper_check - validate state object
1041 * @dev: DRM device
1042 * @state: the driver state object
1043 *
1044 * Check the state object to see if the requested state is physically possible.
1045 * Only CRTCs and planes have check callbacks, so for any additional (global)
1046 * checking that a driver needs it can simply wrap that around this function.
1047 * Drivers without such needs can directly use this as their
1048 * &drm_mode_config_funcs.atomic_check callback.
1049 *
1050 * This just wraps the two parts of the state checking for planes and modeset
1051 * state in the default order: First it calls drm_atomic_helper_check_modeset()
1052 * and then drm_atomic_helper_check_planes(). The assumption is that the
1053 * @drm_plane_helper_funcs.atomic_check and @drm_crtc_helper_funcs.atomic_check
1054 * functions depend upon an updated adjusted_mode.clock to e.g. properly compute
1055 * watermarks.
1056 *
1057 * Note that zpos normalization will add all enable planes to the state which
1058 * might not desired for some drivers.
1059 * For example enable/disable of a cursor plane which have fixed zpos value
1060 * would trigger all other enabled planes to be forced to the state change.
1061 *
1062 * RETURNS:
1063 * Zero for success or -errno
1064 */
1065int drm_atomic_helper_check(struct drm_device *dev,
1066			    struct drm_atomic_state *state)
1067{
1068	int ret;
1069
1070	ret = drm_atomic_helper_check_modeset(dev, state);
1071	if (ret)
1072		return ret;
1073
1074	if (dev->mode_config.normalize_zpos) {
1075		ret = drm_atomic_normalize_zpos(dev, state);
1076		if (ret)
1077			return ret;
1078	}
1079
1080	ret = drm_atomic_helper_check_planes(dev, state);
1081	if (ret)
1082		return ret;
1083
1084	if (state->legacy_cursor_update)
1085		state->async_update = !drm_atomic_helper_async_check(dev, state);
1086
1087	drm_self_refresh_helper_alter_state(state);
1088
1089	return ret;
1090}
1091EXPORT_SYMBOL(drm_atomic_helper_check);
1092
1093static bool
1094crtc_needs_disable(struct drm_crtc_state *old_state,
1095		   struct drm_crtc_state *new_state)
1096{
1097	/*
1098	 * No new_state means the CRTC is off, so the only criteria is whether
1099	 * it's currently active or in self refresh mode.
1100	 */
1101	if (!new_state)
1102		return drm_atomic_crtc_effectively_active(old_state);
1103
1104	/*
1105	 * We need to disable bridge(s) and CRTC if we're transitioning out of
1106	 * self-refresh and changing CRTCs at the same time, because the
1107	 * bridge tracks self-refresh status via CRTC state.
1108	 */
1109	if (old_state->self_refresh_active &&
1110	    old_state->crtc != new_state->crtc)
1111		return true;
1112
1113	/*
1114	 * We also need to run through the crtc_funcs->disable() function if
1115	 * the CRTC is currently on, if it's transitioning to self refresh
1116	 * mode, or if it's in self refresh mode and needs to be fully
1117	 * disabled.
1118	 */
1119	return old_state->active ||
1120	       (old_state->self_refresh_active && !new_state->active) ||
1121	       new_state->self_refresh_active;
1122}
1123
1124static void
1125disable_outputs(struct drm_device *dev, struct drm_atomic_state *old_state)
1126{
1127	struct drm_connector *connector;
1128	struct drm_connector_state *old_conn_state, *new_conn_state;
1129	struct drm_crtc *crtc;
1130	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
1131	int i;
1132
1133	for_each_oldnew_connector_in_state(old_state, connector, old_conn_state, new_conn_state, i) {
1134		const struct drm_encoder_helper_funcs *funcs;
1135		struct drm_encoder *encoder;
1136		struct drm_bridge *bridge;
1137
1138		/*
1139		 * Shut down everything that's in the changeset and currently
1140		 * still on. So need to check the old, saved state.
1141		 */
1142		if (!old_conn_state->crtc)
1143			continue;
1144
1145		old_crtc_state = drm_atomic_get_old_crtc_state(old_state, old_conn_state->crtc);
1146
1147		if (new_conn_state->crtc)
1148			new_crtc_state = drm_atomic_get_new_crtc_state(
1149						old_state,
1150						new_conn_state->crtc);
1151		else
1152			new_crtc_state = NULL;
1153
1154		if (!crtc_needs_disable(old_crtc_state, new_crtc_state) ||
1155		    !drm_atomic_crtc_needs_modeset(old_conn_state->crtc->state))
1156			continue;
1157
1158		encoder = old_conn_state->best_encoder;
1159
1160		/* We shouldn't get this far if we didn't previously have
1161		 * an encoder.. but WARN_ON() rather than explode.
1162		 */
1163		if (WARN_ON(!encoder))
1164			continue;
1165
1166		funcs = encoder->helper_private;
1167
1168		drm_dbg_atomic(dev, "disabling [ENCODER:%d:%s]\n",
1169			       encoder->base.id, encoder->name);
1170
1171		/*
1172		 * Each encoder has at most one connector (since we always steal
1173		 * it away), so we won't call disable hooks twice.
1174		 */
1175		bridge = drm_bridge_chain_get_first_bridge(encoder);
1176		drm_atomic_bridge_chain_disable(bridge, old_state);
1177
1178		/* Right function depends upon target state. */
1179		if (funcs) {
1180			if (funcs->atomic_disable)
1181				funcs->atomic_disable(encoder, old_state);
1182			else if (new_conn_state->crtc && funcs->prepare)
1183				funcs->prepare(encoder);
1184			else if (funcs->disable)
1185				funcs->disable(encoder);
1186			else if (funcs->dpms)
1187				funcs->dpms(encoder, DRM_MODE_DPMS_OFF);
1188		}
1189
1190		drm_atomic_bridge_chain_post_disable(bridge, old_state);
1191	}
1192
1193	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
1194		const struct drm_crtc_helper_funcs *funcs;
1195		int ret;
1196
1197		/* Shut down everything that needs a full modeset. */
1198		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
1199			continue;
1200
1201		if (!crtc_needs_disable(old_crtc_state, new_crtc_state))
1202			continue;
1203
1204		funcs = crtc->helper_private;
1205
1206		drm_dbg_atomic(dev, "disabling [CRTC:%d:%s]\n",
1207			       crtc->base.id, crtc->name);
1208
1209
1210		/* Right function depends upon target state. */
1211		if (new_crtc_state->enable && funcs->prepare)
1212			funcs->prepare(crtc);
1213		else if (funcs->atomic_disable)
1214			funcs->atomic_disable(crtc, old_state);
1215		else if (funcs->disable)
1216			funcs->disable(crtc);
1217		else if (funcs->dpms)
1218			funcs->dpms(crtc, DRM_MODE_DPMS_OFF);
1219
1220		if (!drm_dev_has_vblank(dev))
1221			continue;
1222
1223		ret = drm_crtc_vblank_get(crtc);
1224		/*
1225		 * Self-refresh is not a true "disable"; ensure vblank remains
1226		 * enabled.
1227		 */
1228		if (new_crtc_state->self_refresh_active)
1229			WARN_ONCE(ret != 0,
1230				  "driver disabled vblank in self-refresh\n");
1231		else
1232			WARN_ONCE(ret != -EINVAL,
1233				  "driver forgot to call drm_crtc_vblank_off()\n");
1234		if (ret == 0)
1235			drm_crtc_vblank_put(crtc);
1236	}
1237}
1238
1239/**
1240 * drm_atomic_helper_update_legacy_modeset_state - update legacy modeset state
1241 * @dev: DRM device
1242 * @old_state: atomic state object with old state structures
1243 *
1244 * This function updates all the various legacy modeset state pointers in
1245 * connectors, encoders and CRTCs.
1246 *
1247 * Drivers can use this for building their own atomic commit if they don't have
1248 * a pure helper-based modeset implementation.
1249 *
1250 * Since these updates are not synchronized with lockings, only code paths
1251 * called from &drm_mode_config_helper_funcs.atomic_commit_tail can look at the
1252 * legacy state filled out by this helper. Defacto this means this helper and
1253 * the legacy state pointers are only really useful for transitioning an
1254 * existing driver to the atomic world.
1255 */
1256void
1257drm_atomic_helper_update_legacy_modeset_state(struct drm_device *dev,
1258					      struct drm_atomic_state *old_state)
1259{
1260	struct drm_connector *connector;
1261	struct drm_connector_state *old_conn_state, *new_conn_state;
1262	struct drm_crtc *crtc;
1263	struct drm_crtc_state *new_crtc_state;
1264	int i;
1265
1266	/* clear out existing links and update dpms */
1267	for_each_oldnew_connector_in_state(old_state, connector, old_conn_state, new_conn_state, i) {
1268		if (connector->encoder) {
1269			WARN_ON(!connector->encoder->crtc);
1270
1271			connector->encoder->crtc = NULL;
1272			connector->encoder = NULL;
1273		}
1274
1275		crtc = new_conn_state->crtc;
1276		if ((!crtc && old_conn_state->crtc) ||
1277		    (crtc && drm_atomic_crtc_needs_modeset(crtc->state))) {
1278			int mode = DRM_MODE_DPMS_OFF;
1279
1280			if (crtc && crtc->state->active)
1281				mode = DRM_MODE_DPMS_ON;
1282
1283			connector->dpms = mode;
1284		}
1285	}
1286
1287	/* set new links */
1288	for_each_new_connector_in_state(old_state, connector, new_conn_state, i) {
1289		if (!new_conn_state->crtc)
1290			continue;
1291
1292		if (WARN_ON(!new_conn_state->best_encoder))
1293			continue;
1294
1295		connector->encoder = new_conn_state->best_encoder;
1296		connector->encoder->crtc = new_conn_state->crtc;
1297	}
1298
1299	/* set legacy state in the crtc structure */
1300	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
1301		struct drm_plane *primary = crtc->primary;
1302		struct drm_plane_state *new_plane_state;
1303
1304		crtc->mode = new_crtc_state->mode;
1305		crtc->enabled = new_crtc_state->enable;
1306
1307		new_plane_state =
1308			drm_atomic_get_new_plane_state(old_state, primary);
1309
1310		if (new_plane_state && new_plane_state->crtc == crtc) {
1311			crtc->x = new_plane_state->src_x >> 16;
1312			crtc->y = new_plane_state->src_y >> 16;
1313		}
1314	}
1315}
1316EXPORT_SYMBOL(drm_atomic_helper_update_legacy_modeset_state);
1317
1318/**
1319 * drm_atomic_helper_calc_timestamping_constants - update vblank timestamping constants
1320 * @state: atomic state object
1321 *
1322 * Updates the timestamping constants used for precise vblank timestamps
1323 * by calling drm_calc_timestamping_constants() for all enabled crtcs in @state.
1324 */
1325void drm_atomic_helper_calc_timestamping_constants(struct drm_atomic_state *state)
1326{
1327	struct drm_crtc_state *new_crtc_state;
1328	struct drm_crtc *crtc;
1329	int i;
1330
1331	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
1332		if (new_crtc_state->enable)
1333			drm_calc_timestamping_constants(crtc,
1334							&new_crtc_state->adjusted_mode);
1335	}
1336}
1337EXPORT_SYMBOL(drm_atomic_helper_calc_timestamping_constants);
1338
1339static void
1340crtc_set_mode(struct drm_device *dev, struct drm_atomic_state *old_state)
1341{
1342	struct drm_crtc *crtc;
1343	struct drm_crtc_state *new_crtc_state;
1344	struct drm_connector *connector;
1345	struct drm_connector_state *new_conn_state;
1346	int i;
1347
1348	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
1349		const struct drm_crtc_helper_funcs *funcs;
1350
1351		if (!new_crtc_state->mode_changed)
1352			continue;
1353
1354		funcs = crtc->helper_private;
1355
1356		if (new_crtc_state->enable && funcs->mode_set_nofb) {
1357			drm_dbg_atomic(dev, "modeset on [CRTC:%d:%s]\n",
1358				       crtc->base.id, crtc->name);
1359
1360			funcs->mode_set_nofb(crtc);
1361		}
1362	}
1363
1364	for_each_new_connector_in_state(old_state, connector, new_conn_state, i) {
1365		const struct drm_encoder_helper_funcs *funcs;
1366		struct drm_encoder *encoder;
1367		struct drm_display_mode *mode, *adjusted_mode;
1368		struct drm_bridge *bridge;
1369
1370		if (!new_conn_state->best_encoder)
1371			continue;
1372
1373		encoder = new_conn_state->best_encoder;
1374		funcs = encoder->helper_private;
1375		new_crtc_state = new_conn_state->crtc->state;
1376		mode = &new_crtc_state->mode;
1377		adjusted_mode = &new_crtc_state->adjusted_mode;
1378
1379		if (!new_crtc_state->mode_changed)
1380			continue;
1381
1382		drm_dbg_atomic(dev, "modeset on [ENCODER:%d:%s]\n",
1383			       encoder->base.id, encoder->name);
1384
1385		/*
1386		 * Each encoder has at most one connector (since we always steal
1387		 * it away), so we won't call mode_set hooks twice.
1388		 */
1389		if (funcs && funcs->atomic_mode_set) {
1390			funcs->atomic_mode_set(encoder, new_crtc_state,
1391					       new_conn_state);
1392		} else if (funcs && funcs->mode_set) {
1393			funcs->mode_set(encoder, mode, adjusted_mode);
1394		}
1395
1396		bridge = drm_bridge_chain_get_first_bridge(encoder);
1397		drm_bridge_chain_mode_set(bridge, mode, adjusted_mode);
1398	}
1399}
1400
1401/**
1402 * drm_atomic_helper_commit_modeset_disables - modeset commit to disable outputs
1403 * @dev: DRM device
1404 * @old_state: atomic state object with old state structures
1405 *
1406 * This function shuts down all the outputs that need to be shut down and
1407 * prepares them (if required) with the new mode.
1408 *
1409 * For compatibility with legacy CRTC helpers this should be called before
1410 * drm_atomic_helper_commit_planes(), which is what the default commit function
1411 * does. But drivers with different needs can group the modeset commits together
1412 * and do the plane commits at the end. This is useful for drivers doing runtime
1413 * PM since planes updates then only happen when the CRTC is actually enabled.
1414 */
1415void drm_atomic_helper_commit_modeset_disables(struct drm_device *dev,
1416					       struct drm_atomic_state *old_state)
1417{
1418	disable_outputs(dev, old_state);
1419
1420	drm_atomic_helper_update_legacy_modeset_state(dev, old_state);
1421	drm_atomic_helper_calc_timestamping_constants(old_state);
1422
1423	crtc_set_mode(dev, old_state);
1424}
1425EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_disables);
1426
1427static void drm_atomic_helper_commit_writebacks(struct drm_device *dev,
1428						struct drm_atomic_state *old_state)
1429{
1430	struct drm_connector *connector;
1431	struct drm_connector_state *new_conn_state;
1432	int i;
1433
1434	for_each_new_connector_in_state(old_state, connector, new_conn_state, i) {
1435		const struct drm_connector_helper_funcs *funcs;
1436
1437		funcs = connector->helper_private;
1438		if (!funcs->atomic_commit)
1439			continue;
1440
1441		if (new_conn_state->writeback_job && new_conn_state->writeback_job->fb) {
1442			WARN_ON(connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK);
1443			funcs->atomic_commit(connector, old_state);
1444		}
1445	}
1446}
1447
1448/**
1449 * drm_atomic_helper_commit_modeset_enables - modeset commit to enable outputs
1450 * @dev: DRM device
1451 * @old_state: atomic state object with old state structures
1452 *
1453 * This function enables all the outputs with the new configuration which had to
1454 * be turned off for the update.
1455 *
1456 * For compatibility with legacy CRTC helpers this should be called after
1457 * drm_atomic_helper_commit_planes(), which is what the default commit function
1458 * does. But drivers with different needs can group the modeset commits together
1459 * and do the plane commits at the end. This is useful for drivers doing runtime
1460 * PM since planes updates then only happen when the CRTC is actually enabled.
1461 */
1462void drm_atomic_helper_commit_modeset_enables(struct drm_device *dev,
1463					      struct drm_atomic_state *old_state)
1464{
1465	struct drm_crtc *crtc;
1466	struct drm_crtc_state *old_crtc_state;
1467	struct drm_crtc_state *new_crtc_state;
1468	struct drm_connector *connector;
1469	struct drm_connector_state *new_conn_state;
1470	int i;
1471
1472	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
1473		const struct drm_crtc_helper_funcs *funcs;
1474
1475		/* Need to filter out CRTCs where only planes change. */
1476		if (!drm_atomic_crtc_needs_modeset(new_crtc_state))
1477			continue;
1478
1479		if (!new_crtc_state->active)
1480			continue;
1481
1482		funcs = crtc->helper_private;
1483
1484		if (new_crtc_state->enable) {
1485			drm_dbg_atomic(dev, "enabling [CRTC:%d:%s]\n",
1486				       crtc->base.id, crtc->name);
1487			if (funcs->atomic_enable)
1488				funcs->atomic_enable(crtc, old_state);
1489			else if (funcs->commit)
1490				funcs->commit(crtc);
1491		}
1492	}
1493
1494	for_each_new_connector_in_state(old_state, connector, new_conn_state, i) {
1495		const struct drm_encoder_helper_funcs *funcs;
1496		struct drm_encoder *encoder;
1497		struct drm_bridge *bridge;
1498
1499		if (!new_conn_state->best_encoder)
1500			continue;
1501
1502		if (!new_conn_state->crtc->state->active ||
1503		    !drm_atomic_crtc_needs_modeset(new_conn_state->crtc->state))
1504			continue;
1505
1506		encoder = new_conn_state->best_encoder;
1507		funcs = encoder->helper_private;
1508
1509		drm_dbg_atomic(dev, "enabling [ENCODER:%d:%s]\n",
1510			       encoder->base.id, encoder->name);
1511
1512		/*
1513		 * Each encoder has at most one connector (since we always steal
1514		 * it away), so we won't call enable hooks twice.
1515		 */
1516		bridge = drm_bridge_chain_get_first_bridge(encoder);
1517		drm_atomic_bridge_chain_pre_enable(bridge, old_state);
1518
1519		if (funcs) {
1520			if (funcs->atomic_enable)
1521				funcs->atomic_enable(encoder, old_state);
1522			else if (funcs->enable)
1523				funcs->enable(encoder);
1524			else if (funcs->commit)
1525				funcs->commit(encoder);
1526		}
1527
1528		drm_atomic_bridge_chain_enable(bridge, old_state);
1529	}
1530
1531	drm_atomic_helper_commit_writebacks(dev, old_state);
1532}
1533EXPORT_SYMBOL(drm_atomic_helper_commit_modeset_enables);
1534
1535/*
1536 * For atomic updates which touch just a single CRTC, calculate the time of the
1537 * next vblank, and inform all the fences of the deadline.
1538 */
1539static void set_fence_deadline(struct drm_device *dev,
1540			       struct drm_atomic_state *state)
1541{
1542	struct drm_crtc *crtc;
1543	struct drm_crtc_state *new_crtc_state;
1544	struct drm_plane *plane;
1545	struct drm_plane_state *new_plane_state;
1546	ktime_t vbltime = 0;
1547	int i;
1548
1549	for_each_new_crtc_in_state (state, crtc, new_crtc_state, i) {
1550		ktime_t v;
1551
1552		if (drm_atomic_crtc_needs_modeset(new_crtc_state))
1553			continue;
1554
1555		if (!new_crtc_state->active)
1556			continue;
1557
1558		if (drm_crtc_next_vblank_start(crtc, &v))
1559			continue;
1560
1561		if (!vbltime || ktime_before(v, vbltime))
1562			vbltime = v;
1563	}
1564
1565	/* If no CRTCs updated, then nothing to do: */
1566	if (!vbltime)
1567		return;
1568
1569	for_each_new_plane_in_state (state, plane, new_plane_state, i) {
1570		if (!new_plane_state->fence)
1571			continue;
1572		dma_fence_set_deadline(new_plane_state->fence, vbltime);
1573	}
1574}
1575
1576/**
1577 * drm_atomic_helper_wait_for_fences - wait for fences stashed in plane state
1578 * @dev: DRM device
1579 * @state: atomic state object with old state structures
1580 * @pre_swap: If true, do an interruptible wait, and @state is the new state.
1581 *	Otherwise @state is the old state.
1582 *
1583 * For implicit sync, driver should fish the exclusive fence out from the
1584 * incoming fb's and stash it in the drm_plane_state.  This is called after
1585 * drm_atomic_helper_swap_state() so it uses the current plane state (and
1586 * just uses the atomic state to find the changed planes)
1587 *
1588 * Note that @pre_swap is needed since the point where we block for fences moves
1589 * around depending upon whether an atomic commit is blocking or
1590 * non-blocking. For non-blocking commit all waiting needs to happen after
1591 * drm_atomic_helper_swap_state() is called, but for blocking commits we want
1592 * to wait **before** we do anything that can't be easily rolled back. That is
1593 * before we call drm_atomic_helper_swap_state().
1594 *
1595 * Returns zero if success or < 0 if dma_fence_wait() fails.
1596 */
1597int drm_atomic_helper_wait_for_fences(struct drm_device *dev,
1598				      struct drm_atomic_state *state,
1599				      bool pre_swap)
1600{
1601	struct drm_plane *plane;
1602	struct drm_plane_state *new_plane_state;
1603	int i, ret;
1604
1605	set_fence_deadline(dev, state);
1606
1607	for_each_new_plane_in_state(state, plane, new_plane_state, i) {
1608		if (!new_plane_state->fence)
1609			continue;
1610
1611		WARN_ON(!new_plane_state->fb);
1612
1613		/*
1614		 * If waiting for fences pre-swap (ie: nonblock), userspace can
1615		 * still interrupt the operation. Instead of blocking until the
1616		 * timer expires, make the wait interruptible.
1617		 */
1618		ret = dma_fence_wait(new_plane_state->fence, pre_swap);
1619		if (ret)
1620			return ret;
1621
1622		dma_fence_put(new_plane_state->fence);
1623		new_plane_state->fence = NULL;
1624	}
1625
1626	return 0;
1627}
1628EXPORT_SYMBOL(drm_atomic_helper_wait_for_fences);
1629
1630/**
1631 * drm_atomic_helper_wait_for_vblanks - wait for vblank on CRTCs
1632 * @dev: DRM device
1633 * @old_state: atomic state object with old state structures
1634 *
1635 * Helper to, after atomic commit, wait for vblanks on all affected
1636 * CRTCs (ie. before cleaning up old framebuffers using
1637 * drm_atomic_helper_cleanup_planes()). It will only wait on CRTCs where the
1638 * framebuffers have actually changed to optimize for the legacy cursor and
1639 * plane update use-case.
1640 *
1641 * Drivers using the nonblocking commit tracking support initialized by calling
1642 * drm_atomic_helper_setup_commit() should look at
1643 * drm_atomic_helper_wait_for_flip_done() as an alternative.
1644 */
1645void
1646drm_atomic_helper_wait_for_vblanks(struct drm_device *dev,
1647		struct drm_atomic_state *old_state)
1648{
1649	struct drm_crtc *crtc;
1650	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
1651	int i, ret;
1652	unsigned int crtc_mask = 0;
1653
1654	 /*
1655	  * Legacy cursor ioctls are completely unsynced, and userspace
1656	  * relies on that (by doing tons of cursor updates).
1657	  */
1658	if (old_state->legacy_cursor_update)
1659		return;
1660
1661	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
1662		if (!new_crtc_state->active)
1663			continue;
1664
1665		ret = drm_crtc_vblank_get(crtc);
1666		if (ret != 0)
1667			continue;
1668
1669		crtc_mask |= drm_crtc_mask(crtc);
1670		old_state->crtcs[i].last_vblank_count = drm_crtc_vblank_count(crtc);
1671	}
1672
1673	for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
1674		if (!(crtc_mask & drm_crtc_mask(crtc)))
1675			continue;
1676
1677		ret = wait_event_timeout(dev->vblank[i].queue,
1678				old_state->crtcs[i].last_vblank_count !=
1679					drm_crtc_vblank_count(crtc),
1680				msecs_to_jiffies(100));
1681
1682		WARN(!ret, "[CRTC:%d:%s] vblank wait timed out\n",
1683		     crtc->base.id, crtc->name);
1684
1685		drm_crtc_vblank_put(crtc);
1686	}
1687}
1688EXPORT_SYMBOL(drm_atomic_helper_wait_for_vblanks);
1689
1690/**
1691 * drm_atomic_helper_wait_for_flip_done - wait for all page flips to be done
1692 * @dev: DRM device
1693 * @old_state: atomic state object with old state structures
1694 *
1695 * Helper to, after atomic commit, wait for page flips on all affected
1696 * crtcs (ie. before cleaning up old framebuffers using
1697 * drm_atomic_helper_cleanup_planes()). Compared to
1698 * drm_atomic_helper_wait_for_vblanks() this waits for the completion on all
1699 * CRTCs, assuming that cursors-only updates are signalling their completion
1700 * immediately (or using a different path).
1701 *
1702 * This requires that drivers use the nonblocking commit tracking support
1703 * initialized using drm_atomic_helper_setup_commit().
1704 */
1705void drm_atomic_helper_wait_for_flip_done(struct drm_device *dev,
1706					  struct drm_atomic_state *old_state)
1707{
1708	struct drm_crtc *crtc;
1709	int i;
1710
1711	for (i = 0; i < dev->mode_config.num_crtc; i++) {
1712		struct drm_crtc_commit *commit = old_state->crtcs[i].commit;
1713		int ret;
1714
1715		crtc = old_state->crtcs[i].ptr;
1716
1717		if (!crtc || !commit)
1718			continue;
1719
1720		ret = wait_for_completion_timeout(&commit->flip_done, 10 * HZ);
1721		if (ret == 0)
1722			drm_err(dev, "[CRTC:%d:%s] flip_done timed out\n",
1723				crtc->base.id, crtc->name);
1724	}
1725
1726	if (old_state->fake_commit)
1727		complete_all(&old_state->fake_commit->flip_done);
1728}
1729EXPORT_SYMBOL(drm_atomic_helper_wait_for_flip_done);
1730
1731/**
1732 * drm_atomic_helper_commit_tail - commit atomic update to hardware
1733 * @old_state: atomic state object with old state structures
1734 *
1735 * This is the default implementation for the
1736 * &drm_mode_config_helper_funcs.atomic_commit_tail hook, for drivers
1737 * that do not support runtime_pm or do not need the CRTC to be
1738 * enabled to perform a commit. Otherwise, see
1739 * drm_atomic_helper_commit_tail_rpm().
1740 *
1741 * Note that the default ordering of how the various stages are called is to
1742 * match the legacy modeset helper library closest.
1743 */
1744void drm_atomic_helper_commit_tail(struct drm_atomic_state *old_state)
1745{
1746	struct drm_device *dev = old_state->dev;
1747
1748	drm_atomic_helper_commit_modeset_disables(dev, old_state);
1749
1750	drm_atomic_helper_commit_planes(dev, old_state, 0);
1751
1752	drm_atomic_helper_commit_modeset_enables(dev, old_state);
1753
1754	drm_atomic_helper_fake_vblank(old_state);
1755
1756	drm_atomic_helper_commit_hw_done(old_state);
1757
1758	drm_atomic_helper_wait_for_vblanks(dev, old_state);
1759
1760	drm_atomic_helper_cleanup_planes(dev, old_state);
1761}
1762EXPORT_SYMBOL(drm_atomic_helper_commit_tail);
1763
1764/**
1765 * drm_atomic_helper_commit_tail_rpm - commit atomic update to hardware
1766 * @old_state: new modeset state to be committed
1767 *
1768 * This is an alternative implementation for the
1769 * &drm_mode_config_helper_funcs.atomic_commit_tail hook, for drivers
1770 * that support runtime_pm or need the CRTC to be enabled to perform a
1771 * commit. Otherwise, one should use the default implementation
1772 * drm_atomic_helper_commit_tail().
1773 */
1774void drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state)
1775{
1776	struct drm_device *dev = old_state->dev;
1777
1778	drm_atomic_helper_commit_modeset_disables(dev, old_state);
1779
1780	drm_atomic_helper_commit_modeset_enables(dev, old_state);
1781
1782	drm_atomic_helper_commit_planes(dev, old_state,
1783					DRM_PLANE_COMMIT_ACTIVE_ONLY);
1784
1785	drm_atomic_helper_fake_vblank(old_state);
1786
1787	drm_atomic_helper_commit_hw_done(old_state);
1788
1789	drm_atomic_helper_wait_for_vblanks(dev, old_state);
1790
1791	drm_atomic_helper_cleanup_planes(dev, old_state);
1792}
1793EXPORT_SYMBOL(drm_atomic_helper_commit_tail_rpm);
1794
1795static void commit_tail(struct drm_atomic_state *old_state)
1796{
1797	struct drm_device *dev = old_state->dev;
1798	const struct drm_mode_config_helper_funcs *funcs;
1799	struct drm_crtc_state *new_crtc_state;
1800	struct drm_crtc *crtc;
1801	ktime_t start;
1802	s64 commit_time_ms;
1803	unsigned int i, new_self_refresh_mask = 0;
1804
1805	funcs = dev->mode_config.helper_private;
1806
1807	/*
1808	 * We're measuring the _entire_ commit, so the time will vary depending
1809	 * on how many fences and objects are involved. For the purposes of self
1810	 * refresh, this is desirable since it'll give us an idea of how
1811	 * congested things are. This will inform our decision on how often we
1812	 * should enter self refresh after idle.
1813	 *
1814	 * These times will be averaged out in the self refresh helpers to avoid
1815	 * overreacting over one outlier frame
1816	 */
1817	start = ktime_get();
1818
1819	drm_atomic_helper_wait_for_fences(dev, old_state, false);
1820
1821	drm_atomic_helper_wait_for_dependencies(old_state);
1822
1823	/*
1824	 * We cannot safely access new_crtc_state after
1825	 * drm_atomic_helper_commit_hw_done() so figure out which crtc's have
1826	 * self-refresh active beforehand:
1827	 */
1828	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i)
1829		if (new_crtc_state->self_refresh_active)
1830			new_self_refresh_mask |= BIT(i);
1831
1832	if (funcs && funcs->atomic_commit_tail)
1833		funcs->atomic_commit_tail(old_state);
1834	else
1835		drm_atomic_helper_commit_tail(old_state);
1836
1837	commit_time_ms = ktime_ms_delta(ktime_get(), start);
1838	if (commit_time_ms > 0)
1839		drm_self_refresh_helper_update_avg_times(old_state,
1840						 (unsigned long)commit_time_ms,
1841						 new_self_refresh_mask);
1842
1843	drm_atomic_helper_commit_cleanup_done(old_state);
1844
1845	drm_atomic_state_put(old_state);
1846}
1847
1848static void commit_work(struct work_struct *work)
1849{
1850	struct drm_atomic_state *state = container_of(work,
1851						      struct drm_atomic_state,
1852						      commit_work);
1853	commit_tail(state);
1854}
1855
1856/**
1857 * drm_atomic_helper_async_check - check if state can be committed asynchronously
1858 * @dev: DRM device
1859 * @state: the driver state object
1860 *
1861 * This helper will check if it is possible to commit the state asynchronously.
1862 * Async commits are not supposed to swap the states like normal sync commits
1863 * but just do in-place changes on the current state.
1864 *
1865 * It will return 0 if the commit can happen in an asynchronous fashion or error
1866 * if not. Note that error just mean it can't be committed asynchronously, if it
1867 * fails the commit should be treated like a normal synchronous commit.
1868 */
1869int drm_atomic_helper_async_check(struct drm_device *dev,
1870				   struct drm_atomic_state *state)
1871{
1872	struct drm_crtc *crtc;
1873	struct drm_crtc_state *crtc_state;
1874	struct drm_plane *plane = NULL;
1875	struct drm_plane_state *old_plane_state = NULL;
1876	struct drm_plane_state *new_plane_state = NULL;
1877	const struct drm_plane_helper_funcs *funcs;
1878	int i, ret, n_planes = 0;
1879
1880	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
1881		if (drm_atomic_crtc_needs_modeset(crtc_state))
1882			return -EINVAL;
1883	}
1884
1885	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i)
1886		n_planes++;
1887
1888	/* FIXME: we support only single plane updates for now */
1889	if (n_planes != 1) {
1890		drm_dbg_atomic(dev,
1891			       "only single plane async updates are supported\n");
1892		return -EINVAL;
1893	}
1894
1895	if (!new_plane_state->crtc ||
1896	    old_plane_state->crtc != new_plane_state->crtc) {
1897		drm_dbg_atomic(dev,
1898			       "[PLANE:%d:%s] async update cannot change CRTC\n",
1899			       plane->base.id, plane->name);
1900		return -EINVAL;
1901	}
1902
1903	funcs = plane->helper_private;
1904	if (!funcs->atomic_async_update) {
1905		drm_dbg_atomic(dev,
1906			       "[PLANE:%d:%s] driver does not support async updates\n",
1907			       plane->base.id, plane->name);
1908		return -EINVAL;
1909	}
1910
1911	if (new_plane_state->fence) {
1912		drm_dbg_atomic(dev,
1913			       "[PLANE:%d:%s] missing fence for async update\n",
1914			       plane->base.id, plane->name);
1915		return -EINVAL;
1916	}
1917
1918	/*
1919	 * Don't do an async update if there is an outstanding commit modifying
1920	 * the plane.  This prevents our async update's changes from getting
1921	 * overridden by a previous synchronous update's state.
1922	 */
1923	if (old_plane_state->commit &&
1924	    !try_wait_for_completion(&old_plane_state->commit->hw_done)) {
1925		drm_dbg_atomic(dev,
1926			       "[PLANE:%d:%s] inflight previous commit preventing async commit\n",
1927			       plane->base.id, plane->name);
1928		return -EBUSY;
1929	}
1930
1931	ret = funcs->atomic_async_check(plane, state);
1932	if (ret != 0)
1933		drm_dbg_atomic(dev,
1934			       "[PLANE:%d:%s] driver async check failed\n",
1935			       plane->base.id, plane->name);
1936	return ret;
1937}
1938EXPORT_SYMBOL(drm_atomic_helper_async_check);
1939
1940/**
1941 * drm_atomic_helper_async_commit - commit state asynchronously
1942 * @dev: DRM device
1943 * @state: the driver state object
1944 *
1945 * This function commits a state asynchronously, i.e., not vblank
1946 * synchronized. It should be used on a state only when
1947 * drm_atomic_async_check() succeeds. Async commits are not supposed to swap
1948 * the states like normal sync commits, but just do in-place changes on the
1949 * current state.
1950 *
1951 * TODO: Implement full swap instead of doing in-place changes.
1952 */
1953void drm_atomic_helper_async_commit(struct drm_device *dev,
1954				    struct drm_atomic_state *state)
1955{
1956	struct drm_plane *plane;
1957	struct drm_plane_state *plane_state;
1958	const struct drm_plane_helper_funcs *funcs;
1959	int i;
1960
1961	for_each_new_plane_in_state(state, plane, plane_state, i) {
1962		struct drm_framebuffer *new_fb = plane_state->fb;
1963		struct drm_framebuffer *old_fb = plane->state->fb;
1964
1965		funcs = plane->helper_private;
1966		funcs->atomic_async_update(plane, state);
1967
1968		/*
1969		 * ->atomic_async_update() is supposed to update the
1970		 * plane->state in-place, make sure at least common
1971		 * properties have been properly updated.
1972		 */
1973		WARN_ON_ONCE(plane->state->fb != new_fb);
1974		WARN_ON_ONCE(plane->state->crtc_x != plane_state->crtc_x);
1975		WARN_ON_ONCE(plane->state->crtc_y != plane_state->crtc_y);
1976		WARN_ON_ONCE(plane->state->src_x != plane_state->src_x);
1977		WARN_ON_ONCE(plane->state->src_y != plane_state->src_y);
1978
1979		/*
1980		 * Make sure the FBs have been swapped so that cleanups in the
1981		 * new_state performs a cleanup in the old FB.
1982		 */
1983		WARN_ON_ONCE(plane_state->fb != old_fb);
1984	}
1985}
1986EXPORT_SYMBOL(drm_atomic_helper_async_commit);
1987
1988/**
1989 * drm_atomic_helper_commit - commit validated state object
1990 * @dev: DRM device
1991 * @state: the driver state object
1992 * @nonblock: whether nonblocking behavior is requested.
1993 *
1994 * This function commits a with drm_atomic_helper_check() pre-validated state
1995 * object. This can still fail when e.g. the framebuffer reservation fails. This
1996 * function implements nonblocking commits, using
1997 * drm_atomic_helper_setup_commit() and related functions.
1998 *
1999 * Committing the actual hardware state is done through the
2000 * &drm_mode_config_helper_funcs.atomic_commit_tail callback, or its default
2001 * implementation drm_atomic_helper_commit_tail().
2002 *
2003 * RETURNS:
2004 * Zero for success or -errno.
2005 */
2006int drm_atomic_helper_commit(struct drm_device *dev,
2007			     struct drm_atomic_state *state,
2008			     bool nonblock)
2009{
2010	int ret;
2011
2012	if (state->async_update) {
2013		ret = drm_atomic_helper_prepare_planes(dev, state);
2014		if (ret)
2015			return ret;
2016
2017		drm_atomic_helper_async_commit(dev, state);
2018		drm_atomic_helper_unprepare_planes(dev, state);
2019
2020		return 0;
2021	}
2022
2023	ret = drm_atomic_helper_setup_commit(state, nonblock);
2024	if (ret)
2025		return ret;
2026
2027	INIT_WORK(&state->commit_work, commit_work);
2028
2029	ret = drm_atomic_helper_prepare_planes(dev, state);
2030	if (ret)
2031		return ret;
2032
2033	if (!nonblock) {
2034		ret = drm_atomic_helper_wait_for_fences(dev, state, true);
2035		if (ret)
2036			goto err;
2037	}
2038
2039	/*
2040	 * This is the point of no return - everything below never fails except
2041	 * when the hw goes bonghits. Which means we can commit the new state on
2042	 * the software side now.
2043	 */
2044
2045	ret = drm_atomic_helper_swap_state(state, true);
2046	if (ret)
2047		goto err;
2048
2049	/*
2050	 * Everything below can be run asynchronously without the need to grab
2051	 * any modeset locks at all under one condition: It must be guaranteed
2052	 * that the asynchronous work has either been cancelled (if the driver
2053	 * supports it, which at least requires that the framebuffers get
2054	 * cleaned up with drm_atomic_helper_cleanup_planes()) or completed
2055	 * before the new state gets committed on the software side with
2056	 * drm_atomic_helper_swap_state().
2057	 *
2058	 * This scheme allows new atomic state updates to be prepared and
2059	 * checked in parallel to the asynchronous completion of the previous
2060	 * update. Which is important since compositors need to figure out the
2061	 * composition of the next frame right after having submitted the
2062	 * current layout.
2063	 *
2064	 * NOTE: Commit work has multiple phases, first hardware commit, then
2065	 * cleanup. We want them to overlap, hence need system_unbound_wq to
2066	 * make sure work items don't artificially stall on each another.
2067	 */
2068
2069	drm_atomic_state_get(state);
2070	if (nonblock)
2071		queue_work(system_unbound_wq, &state->commit_work);
2072	else
2073		commit_tail(state);
2074
2075	return 0;
2076
2077err:
2078	drm_atomic_helper_unprepare_planes(dev, state);
2079	return ret;
2080}
2081EXPORT_SYMBOL(drm_atomic_helper_commit);
2082
2083/**
2084 * DOC: implementing nonblocking commit
2085 *
2086 * Nonblocking atomic commits should use struct &drm_crtc_commit to sequence
2087 * different operations against each another. Locks, especially struct
2088 * &drm_modeset_lock, should not be held in worker threads or any other
2089 * asynchronous context used to commit the hardware state.
2090 *
2091 * drm_atomic_helper_commit() implements the recommended sequence for
2092 * nonblocking commits, using drm_atomic_helper_setup_commit() internally:
2093 *
2094 * 1. Run drm_atomic_helper_prepare_planes(). Since this can fail and we
2095 * need to propagate out of memory/VRAM errors to userspace, it must be called
2096 * synchronously.
2097 *
2098 * 2. Synchronize with any outstanding nonblocking commit worker threads which
2099 * might be affected by the new state update. This is handled by
2100 * drm_atomic_helper_setup_commit().
2101 *
2102 * Asynchronous workers need to have sufficient parallelism to be able to run
2103 * different atomic commits on different CRTCs in parallel. The simplest way to
2104 * achieve this is by running them on the &system_unbound_wq work queue. Note
2105 * that drivers are not required to split up atomic commits and run an
2106 * individual commit in parallel - userspace is supposed to do that if it cares.
2107 * But it might be beneficial to do that for modesets, since those necessarily
2108 * must be done as one global operation, and enabling or disabling a CRTC can
2109 * take a long time. But even that is not required.
2110 *
2111 * IMPORTANT: A &drm_atomic_state update for multiple CRTCs is sequenced
2112 * against all CRTCs therein. Therefore for atomic state updates which only flip
2113 * planes the driver must not get the struct &drm_crtc_state of unrelated CRTCs
2114 * in its atomic check code: This would prevent committing of atomic updates to
2115 * multiple CRTCs in parallel. In general, adding additional state structures
2116 * should be avoided as much as possible, because this reduces parallelism in
2117 * (nonblocking) commits, both due to locking and due to commit sequencing
2118 * requirements.
2119 *
2120 * 3. The software state is updated synchronously with
2121 * drm_atomic_helper_swap_state(). Doing this under the protection of all modeset
2122 * locks means concurrent callers never see inconsistent state. Note that commit
2123 * workers do not hold any locks; their access is only coordinated through
2124 * ordering. If workers would access state only through the pointers in the
2125 * free-standing state objects (currently not the case for any driver) then even
2126 * multiple pending commits could be in-flight at the same time.
2127 *
2128 * 4. Schedule a work item to do all subsequent steps, using the split-out
2129 * commit helpers: a) pre-plane commit b) plane commit c) post-plane commit and
2130 * then cleaning up the framebuffers after the old framebuffer is no longer
2131 * being displayed. The scheduled work should synchronize against other workers
2132 * using the &drm_crtc_commit infrastructure as needed. See
2133 * drm_atomic_helper_setup_commit() for more details.
2134 */
2135
2136static int stall_checks(struct drm_crtc *crtc, bool nonblock)
2137{
2138	struct drm_crtc_commit *commit, *stall_commit = NULL;
2139	bool completed = true;
2140	int i;
2141	long ret = 0;
2142
2143	spin_lock(&crtc->commit_lock);
2144	i = 0;
2145	list_for_each_entry(commit, &crtc->commit_list, commit_entry) {
2146		if (i == 0) {
2147			completed = try_wait_for_completion(&commit->flip_done);
2148			/*
2149			 * Userspace is not allowed to get ahead of the previous
2150			 * commit with nonblocking ones.
2151			 */
2152			if (!completed && nonblock) {
2153				spin_unlock(&crtc->commit_lock);
2154				drm_dbg_atomic(crtc->dev,
2155					       "[CRTC:%d:%s] busy with a previous commit\n",
2156					       crtc->base.id, crtc->name);
2157
2158				return -EBUSY;
2159			}
2160		} else if (i == 1) {
2161			stall_commit = drm_crtc_commit_get(commit);
2162			break;
2163		}
2164
2165		i++;
2166	}
2167	spin_unlock(&crtc->commit_lock);
2168
2169	if (!stall_commit)
2170		return 0;
2171
2172	/* We don't want to let commits get ahead of cleanup work too much,
2173	 * stalling on 2nd previous commit means triple-buffer won't ever stall.
2174	 */
2175	ret = wait_for_completion_interruptible_timeout(&stall_commit->cleanup_done,
2176							10*HZ);
2177	if (ret == 0)
2178		drm_err(crtc->dev, "[CRTC:%d:%s] cleanup_done timed out\n",
2179			crtc->base.id, crtc->name);
2180
2181	drm_crtc_commit_put(stall_commit);
2182
2183	return ret < 0 ? ret : 0;
2184}
2185
2186static void release_crtc_commit(struct completion *completion)
2187{
2188	struct drm_crtc_commit *commit = container_of(completion,
2189						      typeof(*commit),
2190						      flip_done);
2191
2192	drm_crtc_commit_put(commit);
2193}
2194
2195static void init_commit(struct drm_crtc_commit *commit, struct drm_crtc *crtc)
2196{
2197	init_completion(&commit->flip_done);
2198	init_completion(&commit->hw_done);
2199	init_completion(&commit->cleanup_done);
2200	INIT_LIST_HEAD(&commit->commit_entry);
2201	kref_init(&commit->ref);
2202	commit->crtc = crtc;
2203}
2204
2205static struct drm_crtc_commit *
2206crtc_or_fake_commit(struct drm_atomic_state *state, struct drm_crtc *crtc)
2207{
2208	if (crtc) {
2209		struct drm_crtc_state *new_crtc_state;
2210
2211		new_crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
2212
2213		return new_crtc_state->commit;
2214	}
2215
2216	if (!state->fake_commit) {
2217		state->fake_commit = kzalloc(sizeof(*state->fake_commit), GFP_KERNEL);
2218		if (!state->fake_commit)
2219			return NULL;
2220
2221		init_commit(state->fake_commit, NULL);
2222	}
2223
2224	return state->fake_commit;
2225}
2226
2227/**
2228 * drm_atomic_helper_setup_commit - setup possibly nonblocking commit
2229 * @state: new modeset state to be committed
2230 * @nonblock: whether nonblocking behavior is requested.
2231 *
2232 * This function prepares @state to be used by the atomic helper's support for
2233 * nonblocking commits. Drivers using the nonblocking commit infrastructure
2234 * should always call this function from their
2235 * &drm_mode_config_funcs.atomic_commit hook.
2236 *
2237 * Drivers that need to extend the commit setup to private objects can use the
2238 * &drm_mode_config_helper_funcs.atomic_commit_setup hook.
2239 *
2240 * To be able to use this support drivers need to use a few more helper
2241 * functions. drm_atomic_helper_wait_for_dependencies() must be called before
2242 * actually committing the hardware state, and for nonblocking commits this call
2243 * must be placed in the async worker. See also drm_atomic_helper_swap_state()
2244 * and its stall parameter, for when a driver's commit hooks look at the
2245 * &drm_crtc.state, &drm_plane.state or &drm_connector.state pointer directly.
2246 *
2247 * Completion of the hardware commit step must be signalled using
2248 * drm_atomic_helper_commit_hw_done(). After this step the driver is not allowed
2249 * to read or change any permanent software or hardware modeset state. The only
2250 * exception is state protected by other means than &drm_modeset_lock locks.
2251 * Only the free standing @state with pointers to the old state structures can
2252 * be inspected, e.g. to clean up old buffers using
2253 * drm_atomic_helper_cleanup_planes().
2254 *
2255 * At the very end, before cleaning up @state drivers must call
2256 * drm_atomic_helper_commit_cleanup_done().
2257 *
2258 * This is all implemented by in drm_atomic_helper_commit(), giving drivers a
2259 * complete and easy-to-use default implementation of the atomic_commit() hook.
2260 *
2261 * The tracking of asynchronously executed and still pending commits is done
2262 * using the core structure &drm_crtc_commit.
2263 *
2264 * By default there's no need to clean up resources allocated by this function
2265 * explicitly: drm_atomic_state_default_clear() will take care of that
2266 * automatically.
2267 *
2268 * Returns:
2269 * 0 on success. -EBUSY when userspace schedules nonblocking commits too fast,
2270 * -ENOMEM on allocation failures and -EINTR when a signal is pending.
2271 */
2272int drm_atomic_helper_setup_commit(struct drm_atomic_state *state,
2273				   bool nonblock)
2274{
2275	struct drm_crtc *crtc;
2276	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
2277	struct drm_connector *conn;
2278	struct drm_connector_state *old_conn_state, *new_conn_state;
2279	struct drm_plane *plane;
2280	struct drm_plane_state *old_plane_state, *new_plane_state;
2281	struct drm_crtc_commit *commit;
2282	const struct drm_mode_config_helper_funcs *funcs;
2283	int i, ret;
2284
2285	funcs = state->dev->mode_config.helper_private;
2286
2287	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
2288		commit = kzalloc(sizeof(*commit), GFP_KERNEL);
2289		if (!commit)
2290			return -ENOMEM;
2291
2292		init_commit(commit, crtc);
2293
2294		new_crtc_state->commit = commit;
2295
2296		ret = stall_checks(crtc, nonblock);
2297		if (ret)
2298			return ret;
2299
2300		/*
2301		 * Drivers only send out events when at least either current or
2302		 * new CRTC state is active. Complete right away if everything
2303		 * stays off.
2304		 */
2305		if (!old_crtc_state->active && !new_crtc_state->active) {
2306			complete_all(&commit->flip_done);
2307			continue;
2308		}
2309
2310		/* Legacy cursor updates are fully unsynced. */
2311		if (state->legacy_cursor_update) {
2312			complete_all(&commit->flip_done);
2313			continue;
2314		}
2315
2316		if (!new_crtc_state->event) {
2317			commit->event = kzalloc(sizeof(*commit->event),
2318						GFP_KERNEL);
2319			if (!commit->event)
2320				return -ENOMEM;
2321
2322			new_crtc_state->event = commit->event;
2323		}
2324
2325		new_crtc_state->event->base.completion = &commit->flip_done;
2326		new_crtc_state->event->base.completion_release = release_crtc_commit;
2327		drm_crtc_commit_get(commit);
2328
2329		commit->abort_completion = true;
2330
2331		state->crtcs[i].commit = commit;
2332		drm_crtc_commit_get(commit);
2333	}
2334
2335	for_each_oldnew_connector_in_state(state, conn, old_conn_state, new_conn_state, i) {
2336		/*
2337		 * Userspace is not allowed to get ahead of the previous
2338		 * commit with nonblocking ones.
2339		 */
2340		if (nonblock && old_conn_state->commit &&
2341		    !try_wait_for_completion(&old_conn_state->commit->flip_done)) {
2342			drm_dbg_atomic(conn->dev,
2343				       "[CONNECTOR:%d:%s] busy with a previous commit\n",
2344				       conn->base.id, conn->name);
2345
2346			return -EBUSY;
2347		}
2348
2349		/* Always track connectors explicitly for e.g. link retraining. */
2350		commit = crtc_or_fake_commit(state, new_conn_state->crtc ?: old_conn_state->crtc);
2351		if (!commit)
2352			return -ENOMEM;
2353
2354		new_conn_state->commit = drm_crtc_commit_get(commit);
2355	}
2356
2357	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
2358		/*
2359		 * Userspace is not allowed to get ahead of the previous
2360		 * commit with nonblocking ones.
2361		 */
2362		if (nonblock && old_plane_state->commit &&
2363		    !try_wait_for_completion(&old_plane_state->commit->flip_done)) {
2364			drm_dbg_atomic(plane->dev,
2365				       "[PLANE:%d:%s] busy with a previous commit\n",
2366				       plane->base.id, plane->name);
2367
2368			return -EBUSY;
2369		}
2370
2371		/* Always track planes explicitly for async pageflip support. */
2372		commit = crtc_or_fake_commit(state, new_plane_state->crtc ?: old_plane_state->crtc);
2373		if (!commit)
2374			return -ENOMEM;
2375
2376		new_plane_state->commit = drm_crtc_commit_get(commit);
2377	}
2378
2379	if (funcs && funcs->atomic_commit_setup)
2380		return funcs->atomic_commit_setup(state);
2381
2382	return 0;
2383}
2384EXPORT_SYMBOL(drm_atomic_helper_setup_commit);
2385
2386/**
2387 * drm_atomic_helper_wait_for_dependencies - wait for required preceding commits
2388 * @old_state: atomic state object with old state structures
2389 *
2390 * This function waits for all preceding commits that touch the same CRTC as
2391 * @old_state to both be committed to the hardware (as signalled by
2392 * drm_atomic_helper_commit_hw_done()) and executed by the hardware (as signalled
2393 * by calling drm_crtc_send_vblank_event() on the &drm_crtc_state.event).
2394 *
2395 * This is part of the atomic helper support for nonblocking commits, see
2396 * drm_atomic_helper_setup_commit() for an overview.
2397 */
2398void drm_atomic_helper_wait_for_dependencies(struct drm_atomic_state *old_state)
2399{
2400	struct drm_crtc *crtc;
2401	struct drm_crtc_state *old_crtc_state;
2402	struct drm_plane *plane;
2403	struct drm_plane_state *old_plane_state;
2404	struct drm_connector *conn;
2405	struct drm_connector_state *old_conn_state;
2406	int i;
2407	long ret;
2408
2409	for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
2410		ret = drm_crtc_commit_wait(old_crtc_state->commit);
2411		if (ret)
2412			drm_err(crtc->dev,
2413				"[CRTC:%d:%s] commit wait timed out\n",
2414				crtc->base.id, crtc->name);
2415	}
2416
2417	for_each_old_connector_in_state(old_state, conn, old_conn_state, i) {
2418		ret = drm_crtc_commit_wait(old_conn_state->commit);
2419		if (ret)
2420			drm_err(conn->dev,
2421				"[CONNECTOR:%d:%s] commit wait timed out\n",
2422				conn->base.id, conn->name);
2423	}
2424
2425	for_each_old_plane_in_state(old_state, plane, old_plane_state, i) {
2426		ret = drm_crtc_commit_wait(old_plane_state->commit);
2427		if (ret)
2428			drm_err(plane->dev,
2429				"[PLANE:%d:%s] commit wait timed out\n",
2430				plane->base.id, plane->name);
2431	}
2432}
2433EXPORT_SYMBOL(drm_atomic_helper_wait_for_dependencies);
2434
2435/**
2436 * drm_atomic_helper_fake_vblank - fake VBLANK events if needed
2437 * @old_state: atomic state object with old state structures
2438 *
2439 * This function walks all CRTCs and fakes VBLANK events on those with
2440 * &drm_crtc_state.no_vblank set to true and &drm_crtc_state.event != NULL.
2441 * The primary use of this function is writeback connectors working in oneshot
2442 * mode and faking VBLANK events. In this case they only fake the VBLANK event
2443 * when a job is queued, and any change to the pipeline that does not touch the
2444 * connector is leading to timeouts when calling
2445 * drm_atomic_helper_wait_for_vblanks() or
2446 * drm_atomic_helper_wait_for_flip_done(). In addition to writeback
2447 * connectors, this function can also fake VBLANK events for CRTCs without
2448 * VBLANK interrupt.
2449 *
2450 * This is part of the atomic helper support for nonblocking commits, see
2451 * drm_atomic_helper_setup_commit() for an overview.
2452 */
2453void drm_atomic_helper_fake_vblank(struct drm_atomic_state *old_state)
2454{
2455	struct drm_crtc_state *new_crtc_state;
2456	struct drm_crtc *crtc;
2457	int i;
2458
2459	for_each_new_crtc_in_state(old_state, crtc, new_crtc_state, i) {
2460		unsigned long flags;
2461
2462		if (!new_crtc_state->no_vblank)
2463			continue;
2464
2465		spin_lock_irqsave(&old_state->dev->event_lock, flags);
2466		if (new_crtc_state->event) {
2467			drm_crtc_send_vblank_event(crtc,
2468						   new_crtc_state->event);
2469			new_crtc_state->event = NULL;
2470		}
2471		spin_unlock_irqrestore(&old_state->dev->event_lock, flags);
2472	}
2473}
2474EXPORT_SYMBOL(drm_atomic_helper_fake_vblank);
2475
2476/**
2477 * drm_atomic_helper_commit_hw_done - setup possible nonblocking commit
2478 * @old_state: atomic state object with old state structures
2479 *
2480 * This function is used to signal completion of the hardware commit step. After
2481 * this step the driver is not allowed to read or change any permanent software
2482 * or hardware modeset state. The only exception is state protected by other
2483 * means than &drm_modeset_lock locks.
2484 *
2485 * Drivers should try to postpone any expensive or delayed cleanup work after
2486 * this function is called.
2487 *
2488 * This is part of the atomic helper support for nonblocking commits, see
2489 * drm_atomic_helper_setup_commit() for an overview.
2490 */
2491void drm_atomic_helper_commit_hw_done(struct drm_atomic_state *old_state)
2492{
2493	struct drm_crtc *crtc;
2494	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
2495	struct drm_crtc_commit *commit;
2496	int i;
2497
2498	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
2499		commit = new_crtc_state->commit;
2500		if (!commit)
2501			continue;
2502
2503		/*
2504		 * copy new_crtc_state->commit to old_crtc_state->commit,
2505		 * it's unsafe to touch new_crtc_state after hw_done,
2506		 * but we still need to do so in cleanup_done().
2507		 */
2508		if (old_crtc_state->commit)
2509			drm_crtc_commit_put(old_crtc_state->commit);
2510
2511		old_crtc_state->commit = drm_crtc_commit_get(commit);
2512
2513		/* backend must have consumed any event by now */
2514		WARN_ON(new_crtc_state->event);
2515		complete_all(&commit->hw_done);
2516	}
2517
2518	if (old_state->fake_commit) {
2519		complete_all(&old_state->fake_commit->hw_done);
2520		complete_all(&old_state->fake_commit->flip_done);
2521	}
2522}
2523EXPORT_SYMBOL(drm_atomic_helper_commit_hw_done);
2524
2525/**
2526 * drm_atomic_helper_commit_cleanup_done - signal completion of commit
2527 * @old_state: atomic state object with old state structures
2528 *
2529 * This signals completion of the atomic update @old_state, including any
2530 * cleanup work. If used, it must be called right before calling
2531 * drm_atomic_state_put().
2532 *
2533 * This is part of the atomic helper support for nonblocking commits, see
2534 * drm_atomic_helper_setup_commit() for an overview.
2535 */
2536void drm_atomic_helper_commit_cleanup_done(struct drm_atomic_state *old_state)
2537{
2538	struct drm_crtc *crtc;
2539	struct drm_crtc_state *old_crtc_state;
2540	struct drm_crtc_commit *commit;
2541	int i;
2542
2543	for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
2544		commit = old_crtc_state->commit;
2545		if (WARN_ON(!commit))
2546			continue;
2547
2548		complete_all(&commit->cleanup_done);
2549		WARN_ON(!try_wait_for_completion(&commit->hw_done));
2550
2551		spin_lock(&crtc->commit_lock);
2552		list_del(&commit->commit_entry);
2553		spin_unlock(&crtc->commit_lock);
2554	}
2555
2556	if (old_state->fake_commit) {
2557		complete_all(&old_state->fake_commit->cleanup_done);
2558		WARN_ON(!try_wait_for_completion(&old_state->fake_commit->hw_done));
2559	}
2560}
2561EXPORT_SYMBOL(drm_atomic_helper_commit_cleanup_done);
2562
2563/**
2564 * drm_atomic_helper_prepare_planes - prepare plane resources before commit
2565 * @dev: DRM device
2566 * @state: atomic state object with new state structures
2567 *
2568 * This function prepares plane state, specifically framebuffers, for the new
2569 * configuration, by calling &drm_plane_helper_funcs.prepare_fb. If any failure
2570 * is encountered this function will call &drm_plane_helper_funcs.cleanup_fb on
2571 * any already successfully prepared framebuffer.
2572 *
2573 * Returns:
2574 * 0 on success, negative error code on failure.
2575 */
2576int drm_atomic_helper_prepare_planes(struct drm_device *dev,
2577				     struct drm_atomic_state *state)
2578{
2579	struct drm_connector *connector;
2580	struct drm_connector_state *new_conn_state;
2581	struct drm_plane *plane;
2582	struct drm_plane_state *new_plane_state;
2583	int ret, i, j;
2584
2585	for_each_new_connector_in_state(state, connector, new_conn_state, i) {
2586		if (!new_conn_state->writeback_job)
2587			continue;
2588
2589		ret = drm_writeback_prepare_job(new_conn_state->writeback_job);
2590		if (ret < 0)
2591			return ret;
2592	}
2593
2594	for_each_new_plane_in_state(state, plane, new_plane_state, i) {
2595		const struct drm_plane_helper_funcs *funcs;
2596
2597		funcs = plane->helper_private;
2598
2599		if (funcs->prepare_fb) {
2600			ret = funcs->prepare_fb(plane, new_plane_state);
2601			if (ret)
2602				goto fail_prepare_fb;
2603		} else {
2604			WARN_ON_ONCE(funcs->cleanup_fb);
2605
2606			if (!drm_core_check_feature(dev, DRIVER_GEM))
2607				continue;
2608
2609			ret = drm_gem_plane_helper_prepare_fb(plane, new_plane_state);
2610			if (ret)
2611				goto fail_prepare_fb;
2612		}
2613	}
2614
2615	for_each_new_plane_in_state(state, plane, new_plane_state, i) {
2616		const struct drm_plane_helper_funcs *funcs = plane->helper_private;
2617
2618		if (funcs->begin_fb_access) {
2619			ret = funcs->begin_fb_access(plane, new_plane_state);
2620			if (ret)
2621				goto fail_begin_fb_access;
2622		}
2623	}
2624
2625	return 0;
2626
2627fail_begin_fb_access:
2628	for_each_new_plane_in_state(state, plane, new_plane_state, j) {
2629		const struct drm_plane_helper_funcs *funcs = plane->helper_private;
2630
2631		if (j >= i)
2632			continue;
2633
2634		if (funcs->end_fb_access)
2635			funcs->end_fb_access(plane, new_plane_state);
2636	}
2637	i = j; /* set i to upper limit to cleanup all planes */
2638fail_prepare_fb:
2639	for_each_new_plane_in_state(state, plane, new_plane_state, j) {
2640		const struct drm_plane_helper_funcs *funcs;
2641
2642		if (j >= i)
2643			continue;
2644
2645		funcs = plane->helper_private;
2646
2647		if (funcs->cleanup_fb)
2648			funcs->cleanup_fb(plane, new_plane_state);
2649	}
2650
2651	return ret;
2652}
2653EXPORT_SYMBOL(drm_atomic_helper_prepare_planes);
2654
2655/**
2656 * drm_atomic_helper_unprepare_planes - release plane resources on aborts
2657 * @dev: DRM device
2658 * @state: atomic state object with old state structures
2659 *
2660 * This function cleans up plane state, specifically framebuffers, from the
2661 * atomic state. It undoes the effects of drm_atomic_helper_prepare_planes()
2662 * when aborting an atomic commit. For cleaning up after a successful commit
2663 * use drm_atomic_helper_cleanup_planes().
2664 */
2665void drm_atomic_helper_unprepare_planes(struct drm_device *dev,
2666					struct drm_atomic_state *state)
2667{
2668	struct drm_plane *plane;
2669	struct drm_plane_state *new_plane_state;
2670	int i;
2671
2672	for_each_new_plane_in_state(state, plane, new_plane_state, i) {
2673		const struct drm_plane_helper_funcs *funcs = plane->helper_private;
2674
2675		if (funcs->end_fb_access)
2676			funcs->end_fb_access(plane, new_plane_state);
2677	}
2678
2679	for_each_new_plane_in_state(state, plane, new_plane_state, i) {
2680		const struct drm_plane_helper_funcs *funcs = plane->helper_private;
2681
2682		if (funcs->cleanup_fb)
2683			funcs->cleanup_fb(plane, new_plane_state);
2684	}
2685}
2686EXPORT_SYMBOL(drm_atomic_helper_unprepare_planes);
2687
2688static bool plane_crtc_active(const struct drm_plane_state *state)
2689{
2690	return state->crtc && state->crtc->state->active;
2691}
2692
2693/**
2694 * drm_atomic_helper_commit_planes - commit plane state
2695 * @dev: DRM device
2696 * @old_state: atomic state object with old state structures
2697 * @flags: flags for committing plane state
2698 *
2699 * This function commits the new plane state using the plane and atomic helper
2700 * functions for planes and CRTCs. It assumes that the atomic state has already
2701 * been pushed into the relevant object state pointers, since this step can no
2702 * longer fail.
2703 *
2704 * It still requires the global state object @old_state to know which planes and
2705 * crtcs need to be updated though.
2706 *
2707 * Note that this function does all plane updates across all CRTCs in one step.
2708 * If the hardware can't support this approach look at
2709 * drm_atomic_helper_commit_planes_on_crtc() instead.
2710 *
2711 * Plane parameters can be updated by applications while the associated CRTC is
2712 * disabled. The DRM/KMS core will store the parameters in the plane state,
2713 * which will be available to the driver when the CRTC is turned on. As a result
2714 * most drivers don't need to be immediately notified of plane updates for a
2715 * disabled CRTC.
2716 *
2717 * Unless otherwise needed, drivers are advised to set the ACTIVE_ONLY flag in
2718 * @flags in order not to receive plane update notifications related to a
2719 * disabled CRTC. This avoids the need to manually ignore plane updates in
2720 * driver code when the driver and/or hardware can't or just don't need to deal
2721 * with updates on disabled CRTCs, for example when supporting runtime PM.
2722 *
2723 * Drivers may set the NO_DISABLE_AFTER_MODESET flag in @flags if the relevant
2724 * display controllers require to disable a CRTC's planes when the CRTC is
2725 * disabled. This function would skip the &drm_plane_helper_funcs.atomic_disable
2726 * call for a plane if the CRTC of the old plane state needs a modesetting
2727 * operation. Of course, the drivers need to disable the planes in their CRTC
2728 * disable callbacks since no one else would do that.
2729 *
2730 * The drm_atomic_helper_commit() default implementation doesn't set the
2731 * ACTIVE_ONLY flag to most closely match the behaviour of the legacy helpers.
2732 * This should not be copied blindly by drivers.
2733 */
2734void drm_atomic_helper_commit_planes(struct drm_device *dev,
2735				     struct drm_atomic_state *old_state,
2736				     uint32_t flags)
2737{
2738	struct drm_crtc *crtc;
2739	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
2740	struct drm_plane *plane;
2741	struct drm_plane_state *old_plane_state, *new_plane_state;
2742	int i;
2743	bool active_only = flags & DRM_PLANE_COMMIT_ACTIVE_ONLY;
2744	bool no_disable = flags & DRM_PLANE_COMMIT_NO_DISABLE_AFTER_MODESET;
2745
2746	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
2747		const struct drm_crtc_helper_funcs *funcs;
2748
2749		funcs = crtc->helper_private;
2750
2751		if (!funcs || !funcs->atomic_begin)
2752			continue;
2753
2754		if (active_only && !new_crtc_state->active)
2755			continue;
2756
2757		funcs->atomic_begin(crtc, old_state);
2758	}
2759
2760	for_each_oldnew_plane_in_state(old_state, plane, old_plane_state, new_plane_state, i) {
2761		const struct drm_plane_helper_funcs *funcs;
2762		bool disabling;
2763
2764		funcs = plane->helper_private;
2765
2766		if (!funcs)
2767			continue;
2768
2769		disabling = drm_atomic_plane_disabling(old_plane_state,
2770						       new_plane_state);
2771
2772		if (active_only) {
2773			/*
2774			 * Skip planes related to inactive CRTCs. If the plane
2775			 * is enabled use the state of the current CRTC. If the
2776			 * plane is being disabled use the state of the old
2777			 * CRTC to avoid skipping planes being disabled on an
2778			 * active CRTC.
2779			 */
2780			if (!disabling && !plane_crtc_active(new_plane_state))
2781				continue;
2782			if (disabling && !plane_crtc_active(old_plane_state))
2783				continue;
2784		}
2785
2786		/*
2787		 * Special-case disabling the plane if drivers support it.
2788		 */
2789		if (disabling && funcs->atomic_disable) {
2790			struct drm_crtc_state *crtc_state;
2791
2792			crtc_state = old_plane_state->crtc->state;
2793
2794			if (drm_atomic_crtc_needs_modeset(crtc_state) &&
2795			    no_disable)
2796				continue;
2797
2798			funcs->atomic_disable(plane, old_state);
2799		} else if (new_plane_state->crtc || disabling) {
2800			funcs->atomic_update(plane, old_state);
2801
2802			if (!disabling && funcs->atomic_enable) {
2803				if (drm_atomic_plane_enabling(old_plane_state, new_plane_state))
2804					funcs->atomic_enable(plane, old_state);
2805			}
2806		}
2807	}
2808
2809	for_each_oldnew_crtc_in_state(old_state, crtc, old_crtc_state, new_crtc_state, i) {
2810		const struct drm_crtc_helper_funcs *funcs;
2811
2812		funcs = crtc->helper_private;
2813
2814		if (!funcs || !funcs->atomic_flush)
2815			continue;
2816
2817		if (active_only && !new_crtc_state->active)
2818			continue;
2819
2820		funcs->atomic_flush(crtc, old_state);
2821	}
2822
2823	/*
2824	 * Signal end of framebuffer access here before hw_done. After hw_done,
2825	 * a later commit might have already released the plane state.
2826	 */
2827	for_each_old_plane_in_state(old_state, plane, old_plane_state, i) {
2828		const struct drm_plane_helper_funcs *funcs = plane->helper_private;
2829
2830		if (funcs->end_fb_access)
2831			funcs->end_fb_access(plane, old_plane_state);
2832	}
2833}
2834EXPORT_SYMBOL(drm_atomic_helper_commit_planes);
2835
2836/**
2837 * drm_atomic_helper_commit_planes_on_crtc - commit plane state for a CRTC
2838 * @old_crtc_state: atomic state object with the old CRTC state
2839 *
2840 * This function commits the new plane state using the plane and atomic helper
2841 * functions for planes on the specific CRTC. It assumes that the atomic state
2842 * has already been pushed into the relevant object state pointers, since this
2843 * step can no longer fail.
2844 *
2845 * This function is useful when plane updates should be done CRTC-by-CRTC
2846 * instead of one global step like drm_atomic_helper_commit_planes() does.
2847 *
2848 * This function can only be savely used when planes are not allowed to move
2849 * between different CRTCs because this function doesn't handle inter-CRTC
2850 * dependencies. Callers need to ensure that either no such dependencies exist,
2851 * resolve them through ordering of commit calls or through some other means.
2852 */
2853void
2854drm_atomic_helper_commit_planes_on_crtc(struct drm_crtc_state *old_crtc_state)
2855{
2856	const struct drm_crtc_helper_funcs *crtc_funcs;
2857	struct drm_crtc *crtc = old_crtc_state->crtc;
2858	struct drm_atomic_state *old_state = old_crtc_state->state;
2859	struct drm_crtc_state *new_crtc_state =
2860		drm_atomic_get_new_crtc_state(old_state, crtc);
2861	struct drm_plane *plane;
2862	unsigned int plane_mask;
2863
2864	plane_mask = old_crtc_state->plane_mask;
2865	plane_mask |= new_crtc_state->plane_mask;
2866
2867	crtc_funcs = crtc->helper_private;
2868	if (crtc_funcs && crtc_funcs->atomic_begin)
2869		crtc_funcs->atomic_begin(crtc, old_state);
2870
2871	drm_for_each_plane_mask(plane, crtc->dev, plane_mask) {
2872		struct drm_plane_state *old_plane_state =
2873			drm_atomic_get_old_plane_state(old_state, plane);
2874		struct drm_plane_state *new_plane_state =
2875			drm_atomic_get_new_plane_state(old_state, plane);
2876		const struct drm_plane_helper_funcs *plane_funcs;
2877		bool disabling;
2878
2879		plane_funcs = plane->helper_private;
2880
2881		if (!old_plane_state || !plane_funcs)
2882			continue;
2883
2884		WARN_ON(new_plane_state->crtc &&
2885			new_plane_state->crtc != crtc);
2886
2887		disabling = drm_atomic_plane_disabling(old_plane_state, new_plane_state);
2888
2889		if (disabling && plane_funcs->atomic_disable) {
2890			plane_funcs->atomic_disable(plane, old_state);
2891		} else if (new_plane_state->crtc || disabling) {
2892			plane_funcs->atomic_update(plane, old_state);
2893
2894			if (!disabling && plane_funcs->atomic_enable) {
2895				if (drm_atomic_plane_enabling(old_plane_state, new_plane_state))
2896					plane_funcs->atomic_enable(plane, old_state);
2897			}
2898		}
2899	}
2900
2901	if (crtc_funcs && crtc_funcs->atomic_flush)
2902		crtc_funcs->atomic_flush(crtc, old_state);
2903}
2904EXPORT_SYMBOL(drm_atomic_helper_commit_planes_on_crtc);
2905
2906/**
2907 * drm_atomic_helper_disable_planes_on_crtc - helper to disable CRTC's planes
2908 * @old_crtc_state: atomic state object with the old CRTC state
2909 * @atomic: if set, synchronize with CRTC's atomic_begin/flush hooks
2910 *
2911 * Disables all planes associated with the given CRTC. This can be
2912 * used for instance in the CRTC helper atomic_disable callback to disable
2913 * all planes.
2914 *
2915 * If the atomic-parameter is set the function calls the CRTC's
2916 * atomic_begin hook before and atomic_flush hook after disabling the
2917 * planes.
2918 *
2919 * It is a bug to call this function without having implemented the
2920 * &drm_plane_helper_funcs.atomic_disable plane hook.
2921 */
2922void
2923drm_atomic_helper_disable_planes_on_crtc(struct drm_crtc_state *old_crtc_state,
2924					 bool atomic)
2925{
2926	struct drm_crtc *crtc = old_crtc_state->crtc;
2927	const struct drm_crtc_helper_funcs *crtc_funcs =
2928		crtc->helper_private;
2929	struct drm_plane *plane;
2930
2931	if (atomic && crtc_funcs && crtc_funcs->atomic_begin)
2932		crtc_funcs->atomic_begin(crtc, NULL);
2933
2934	drm_atomic_crtc_state_for_each_plane(plane, old_crtc_state) {
2935		const struct drm_plane_helper_funcs *plane_funcs =
2936			plane->helper_private;
2937
2938		if (!plane_funcs)
2939			continue;
2940
2941		WARN_ON(!plane_funcs->atomic_disable);
2942		if (plane_funcs->atomic_disable)
2943			plane_funcs->atomic_disable(plane, NULL);
2944	}
2945
2946	if (atomic && crtc_funcs && crtc_funcs->atomic_flush)
2947		crtc_funcs->atomic_flush(crtc, NULL);
2948}
2949EXPORT_SYMBOL(drm_atomic_helper_disable_planes_on_crtc);
2950
2951/**
2952 * drm_atomic_helper_cleanup_planes - cleanup plane resources after commit
2953 * @dev: DRM device
2954 * @old_state: atomic state object with old state structures
2955 *
2956 * This function cleans up plane state, specifically framebuffers, from the old
2957 * configuration. Hence the old configuration must be perserved in @old_state to
2958 * be able to call this function.
2959 *
2960 * This function may not be called on the new state when the atomic update
2961 * fails at any point after calling drm_atomic_helper_prepare_planes(). Use
2962 * drm_atomic_helper_unprepare_planes() in this case.
2963 */
2964void drm_atomic_helper_cleanup_planes(struct drm_device *dev,
2965				      struct drm_atomic_state *old_state)
2966{
2967	struct drm_plane *plane;
2968	struct drm_plane_state *old_plane_state;
2969	int i;
2970
2971	for_each_old_plane_in_state(old_state, plane, old_plane_state, i) {
2972		const struct drm_plane_helper_funcs *funcs = plane->helper_private;
2973
2974		if (funcs->cleanup_fb)
2975			funcs->cleanup_fb(plane, old_plane_state);
2976	}
2977}
2978EXPORT_SYMBOL(drm_atomic_helper_cleanup_planes);
2979
2980/**
2981 * drm_atomic_helper_swap_state - store atomic state into current sw state
2982 * @state: atomic state
2983 * @stall: stall for preceding commits
2984 *
2985 * This function stores the atomic state into the current state pointers in all
2986 * driver objects. It should be called after all failing steps have been done
2987 * and succeeded, but before the actual hardware state is committed.
2988 *
2989 * For cleanup and error recovery the current state for all changed objects will
2990 * be swapped into @state.
2991 *
2992 * With that sequence it fits perfectly into the plane prepare/cleanup sequence:
2993 *
2994 * 1. Call drm_atomic_helper_prepare_planes() with the staged atomic state.
2995 *
2996 * 2. Do any other steps that might fail.
2997 *
2998 * 3. Put the staged state into the current state pointers with this function.
2999 *
3000 * 4. Actually commit the hardware state.
3001 *
3002 * 5. Call drm_atomic_helper_cleanup_planes() with @state, which since step 3
3003 * contains the old state. Also do any other cleanup required with that state.
3004 *
3005 * @stall must be set when nonblocking commits for this driver directly access
3006 * the &drm_plane.state, &drm_crtc.state or &drm_connector.state pointer. With
3007 * the current atomic helpers this is almost always the case, since the helpers
3008 * don't pass the right state structures to the callbacks.
3009 *
3010 * Returns:
3011 * Returns 0 on success. Can return -ERESTARTSYS when @stall is true and the
3012 * waiting for the previous commits has been interrupted.
3013 */
3014int drm_atomic_helper_swap_state(struct drm_atomic_state *state,
3015				  bool stall)
3016{
3017	int i, ret;
3018	unsigned long flags = 0;
3019	struct drm_connector *connector;
3020	struct drm_connector_state *old_conn_state, *new_conn_state;
3021	struct drm_crtc *crtc;
3022	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
3023	struct drm_plane *plane;
3024	struct drm_plane_state *old_plane_state, *new_plane_state;
3025	struct drm_crtc_commit *commit;
3026	struct drm_private_obj *obj;
3027	struct drm_private_state *old_obj_state, *new_obj_state;
3028
3029	if (stall) {
3030		/*
3031		 * We have to stall for hw_done here before
3032		 * drm_atomic_helper_wait_for_dependencies() because flip
3033		 * depth > 1 is not yet supported by all drivers. As long as
3034		 * obj->state is directly dereferenced anywhere in the drivers
3035		 * atomic_commit_tail function, then it's unsafe to swap state
3036		 * before drm_atomic_helper_commit_hw_done() is called.
3037		 */
3038
3039		for_each_old_crtc_in_state(state, crtc, old_crtc_state, i) {
3040			commit = old_crtc_state->commit;
3041
3042			if (!commit)
3043				continue;
3044
3045			ret = wait_for_completion_interruptible(&commit->hw_done);
3046			if (ret)
3047				return ret;
3048		}
3049
3050		for_each_old_connector_in_state(state, connector, old_conn_state, i) {
3051			commit = old_conn_state->commit;
3052
3053			if (!commit)
3054				continue;
3055
3056			ret = wait_for_completion_interruptible(&commit->hw_done);
3057			if (ret)
3058				return ret;
3059		}
3060
3061		for_each_old_plane_in_state(state, plane, old_plane_state, i) {
3062			commit = old_plane_state->commit;
3063
3064			if (!commit)
3065				continue;
3066
3067			ret = wait_for_completion_interruptible(&commit->hw_done);
3068			if (ret)
3069				return ret;
3070		}
3071	}
3072
3073	for_each_oldnew_connector_in_state(state, connector, old_conn_state, new_conn_state, i) {
3074		WARN_ON(connector->state != old_conn_state);
3075
3076		old_conn_state->state = state;
3077		new_conn_state->state = NULL;
3078
3079		state->connectors[i].state = old_conn_state;
3080		connector->state = new_conn_state;
3081	}
3082
3083	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
3084		WARN_ON(crtc->state != old_crtc_state);
3085
3086		old_crtc_state->state = state;
3087		new_crtc_state->state = NULL;
3088
3089		state->crtcs[i].state = old_crtc_state;
3090		crtc->state = new_crtc_state;
3091
3092		if (new_crtc_state->commit) {
3093			spin_lock(&crtc->commit_lock);
3094			list_add(&new_crtc_state->commit->commit_entry,
3095				 &crtc->commit_list);
3096			spin_unlock(&crtc->commit_lock);
3097
3098			new_crtc_state->commit->event = NULL;
3099		}
3100	}
3101
3102	drm_panic_lock(state->dev, flags);
3103	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
3104		WARN_ON(plane->state != old_plane_state);
3105
3106		old_plane_state->state = state;
3107		new_plane_state->state = NULL;
3108
3109		state->planes[i].state = old_plane_state;
3110		plane->state = new_plane_state;
3111	}
3112	drm_panic_unlock(state->dev, flags);
3113
3114	for_each_oldnew_private_obj_in_state(state, obj, old_obj_state, new_obj_state, i) {
3115		WARN_ON(obj->state != old_obj_state);
3116
3117		old_obj_state->state = state;
3118		new_obj_state->state = NULL;
3119
3120		state->private_objs[i].state = old_obj_state;
3121		obj->state = new_obj_state;
3122	}
3123
3124	return 0;
3125}
3126EXPORT_SYMBOL(drm_atomic_helper_swap_state);
3127
3128/**
3129 * drm_atomic_helper_update_plane - Helper for primary plane update using atomic
3130 * @plane: plane object to update
3131 * @crtc: owning CRTC of owning plane
3132 * @fb: framebuffer to flip onto plane
3133 * @crtc_x: x offset of primary plane on @crtc
3134 * @crtc_y: y offset of primary plane on @crtc
3135 * @crtc_w: width of primary plane rectangle on @crtc
3136 * @crtc_h: height of primary plane rectangle on @crtc
3137 * @src_x: x offset of @fb for panning
3138 * @src_y: y offset of @fb for panning
3139 * @src_w: width of source rectangle in @fb
3140 * @src_h: height of source rectangle in @fb
3141 * @ctx: lock acquire context
3142 *
3143 * Provides a default plane update handler using the atomic driver interface.
3144 *
3145 * RETURNS:
3146 * Zero on success, error code on failure
3147 */
3148int drm_atomic_helper_update_plane(struct drm_plane *plane,
3149				   struct drm_crtc *crtc,
3150				   struct drm_framebuffer *fb,
3151				   int crtc_x, int crtc_y,
3152				   unsigned int crtc_w, unsigned int crtc_h,
3153				   uint32_t src_x, uint32_t src_y,
3154				   uint32_t src_w, uint32_t src_h,
3155				   struct drm_modeset_acquire_ctx *ctx)
3156{
3157	struct drm_atomic_state *state;
3158	struct drm_plane_state *plane_state;
3159	int ret = 0;
3160
3161	state = drm_atomic_state_alloc(plane->dev);
3162	if (!state)
3163		return -ENOMEM;
3164
3165	state->acquire_ctx = ctx;
3166	plane_state = drm_atomic_get_plane_state(state, plane);
3167	if (IS_ERR(plane_state)) {
3168		ret = PTR_ERR(plane_state);
3169		goto fail;
3170	}
3171
3172	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
3173	if (ret != 0)
3174		goto fail;
3175	drm_atomic_set_fb_for_plane(plane_state, fb);
3176	plane_state->crtc_x = crtc_x;
3177	plane_state->crtc_y = crtc_y;
3178	plane_state->crtc_w = crtc_w;
3179	plane_state->crtc_h = crtc_h;
3180	plane_state->src_x = src_x;
3181	plane_state->src_y = src_y;
3182	plane_state->src_w = src_w;
3183	plane_state->src_h = src_h;
3184
3185	if (plane == crtc->cursor)
3186		state->legacy_cursor_update = true;
3187
3188	ret = drm_atomic_commit(state);
3189fail:
3190	drm_atomic_state_put(state);
3191	return ret;
3192}
3193EXPORT_SYMBOL(drm_atomic_helper_update_plane);
3194
3195/**
3196 * drm_atomic_helper_disable_plane - Helper for primary plane disable using atomic
3197 * @plane: plane to disable
3198 * @ctx: lock acquire context
3199 *
3200 * Provides a default plane disable handler using the atomic driver interface.
3201 *
3202 * RETURNS:
3203 * Zero on success, error code on failure
3204 */
3205int drm_atomic_helper_disable_plane(struct drm_plane *plane,
3206				    struct drm_modeset_acquire_ctx *ctx)
3207{
3208	struct drm_atomic_state *state;
3209	struct drm_plane_state *plane_state;
3210	int ret = 0;
3211
3212	state = drm_atomic_state_alloc(plane->dev);
3213	if (!state)
3214		return -ENOMEM;
3215
3216	state->acquire_ctx = ctx;
3217	plane_state = drm_atomic_get_plane_state(state, plane);
3218	if (IS_ERR(plane_state)) {
3219		ret = PTR_ERR(plane_state);
3220		goto fail;
3221	}
3222
3223	if (plane_state->crtc && plane_state->crtc->cursor == plane)
3224		plane_state->state->legacy_cursor_update = true;
3225
3226	ret = __drm_atomic_helper_disable_plane(plane, plane_state);
3227	if (ret != 0)
3228		goto fail;
3229
3230	ret = drm_atomic_commit(state);
3231fail:
3232	drm_atomic_state_put(state);
3233	return ret;
3234}
3235EXPORT_SYMBOL(drm_atomic_helper_disable_plane);
3236
3237/**
3238 * drm_atomic_helper_set_config - set a new config from userspace
3239 * @set: mode set configuration
3240 * @ctx: lock acquisition context
3241 *
3242 * Provides a default CRTC set_config handler using the atomic driver interface.
3243 *
3244 * NOTE: For backwards compatibility with old userspace this automatically
3245 * resets the "link-status" property to GOOD, to force any link
3246 * re-training. The SETCRTC ioctl does not define whether an update does
3247 * need a full modeset or just a plane update, hence we're allowed to do
3248 * that. See also drm_connector_set_link_status_property().
3249 *
3250 * Returns:
3251 * Returns 0 on success, negative errno numbers on failure.
3252 */
3253int drm_atomic_helper_set_config(struct drm_mode_set *set,
3254				 struct drm_modeset_acquire_ctx *ctx)
3255{
3256	struct drm_atomic_state *state;
3257	struct drm_crtc *crtc = set->crtc;
3258	int ret = 0;
3259
3260	state = drm_atomic_state_alloc(crtc->dev);
3261	if (!state)
3262		return -ENOMEM;
3263
3264	state->acquire_ctx = ctx;
3265	ret = __drm_atomic_helper_set_config(set, state);
3266	if (ret != 0)
3267		goto fail;
3268
3269	ret = handle_conflicting_encoders(state, true);
3270	if (ret)
3271		goto fail;
3272
3273	ret = drm_atomic_commit(state);
3274
3275fail:
3276	drm_atomic_state_put(state);
3277	return ret;
3278}
3279EXPORT_SYMBOL(drm_atomic_helper_set_config);
3280
3281/**
3282 * drm_atomic_helper_disable_all - disable all currently active outputs
3283 * @dev: DRM device
3284 * @ctx: lock acquisition context
3285 *
3286 * Loops through all connectors, finding those that aren't turned off and then
3287 * turns them off by setting their DPMS mode to OFF and deactivating the CRTC
3288 * that they are connected to.
3289 *
3290 * This is used for example in suspend/resume to disable all currently active
3291 * functions when suspending. If you just want to shut down everything at e.g.
3292 * driver unload, look at drm_atomic_helper_shutdown().
3293 *
3294 * Note that if callers haven't already acquired all modeset locks this might
3295 * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
3296 *
3297 * Returns:
3298 * 0 on success or a negative error code on failure.
3299 *
3300 * See also:
3301 * drm_atomic_helper_suspend(), drm_atomic_helper_resume() and
3302 * drm_atomic_helper_shutdown().
3303 */
3304int drm_atomic_helper_disable_all(struct drm_device *dev,
3305				  struct drm_modeset_acquire_ctx *ctx)
3306{
3307	struct drm_atomic_state *state;
3308	struct drm_connector_state *conn_state;
3309	struct drm_connector *conn;
3310	struct drm_plane_state *plane_state;
3311	struct drm_plane *plane;
3312	struct drm_crtc_state *crtc_state;
3313	struct drm_crtc *crtc;
3314	int ret, i;
3315
3316	state = drm_atomic_state_alloc(dev);
3317	if (!state)
3318		return -ENOMEM;
3319
3320	state->acquire_ctx = ctx;
3321
3322	drm_for_each_crtc(crtc, dev) {
3323		crtc_state = drm_atomic_get_crtc_state(state, crtc);
3324		if (IS_ERR(crtc_state)) {
3325			ret = PTR_ERR(crtc_state);
3326			goto free;
3327		}
3328
3329		crtc_state->active = false;
3330
3331		ret = drm_atomic_set_mode_prop_for_crtc(crtc_state, NULL);
3332		if (ret < 0)
3333			goto free;
3334
3335		ret = drm_atomic_add_affected_planes(state, crtc);
3336		if (ret < 0)
3337			goto free;
3338
3339		ret = drm_atomic_add_affected_connectors(state, crtc);
3340		if (ret < 0)
3341			goto free;
3342	}
3343
3344	for_each_new_connector_in_state(state, conn, conn_state, i) {
3345		ret = drm_atomic_set_crtc_for_connector(conn_state, NULL);
3346		if (ret < 0)
3347			goto free;
3348	}
3349
3350	for_each_new_plane_in_state(state, plane, plane_state, i) {
3351		ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
3352		if (ret < 0)
3353			goto free;
3354
3355		drm_atomic_set_fb_for_plane(plane_state, NULL);
3356	}
3357
3358	ret = drm_atomic_commit(state);
3359free:
3360	drm_atomic_state_put(state);
3361	return ret;
3362}
3363EXPORT_SYMBOL(drm_atomic_helper_disable_all);
3364
3365/**
3366 * drm_atomic_helper_shutdown - shutdown all CRTC
3367 * @dev: DRM device
3368 *
3369 * This shuts down all CRTC, which is useful for driver unloading. Shutdown on
3370 * suspend should instead be handled with drm_atomic_helper_suspend(), since
3371 * that also takes a snapshot of the modeset state to be restored on resume.
3372 *
3373 * This is just a convenience wrapper around drm_atomic_helper_disable_all(),
3374 * and it is the atomic version of drm_helper_force_disable_all().
3375 */
3376void drm_atomic_helper_shutdown(struct drm_device *dev)
3377{
3378	struct drm_modeset_acquire_ctx ctx;
3379	int ret;
3380
3381	if (dev == NULL)
3382		return;
3383
3384	DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, ret);
3385
3386	ret = drm_atomic_helper_disable_all(dev, &ctx);
3387	if (ret)
3388		drm_err(dev,
3389			"Disabling all crtc's during unload failed with %i\n",
3390			ret);
3391
3392	DRM_MODESET_LOCK_ALL_END(dev, ctx, ret);
3393}
3394EXPORT_SYMBOL(drm_atomic_helper_shutdown);
3395
3396/**
3397 * drm_atomic_helper_duplicate_state - duplicate an atomic state object
3398 * @dev: DRM device
3399 * @ctx: lock acquisition context
3400 *
3401 * Makes a copy of the current atomic state by looping over all objects and
3402 * duplicating their respective states. This is used for example by suspend/
3403 * resume support code to save the state prior to suspend such that it can
3404 * be restored upon resume.
3405 *
3406 * Note that this treats atomic state as persistent between save and restore.
3407 * Drivers must make sure that this is possible and won't result in confusion
3408 * or erroneous behaviour.
3409 *
3410 * Note that if callers haven't already acquired all modeset locks this might
3411 * return -EDEADLK, which must be handled by calling drm_modeset_backoff().
3412 *
3413 * Returns:
3414 * A pointer to the copy of the atomic state object on success or an
3415 * ERR_PTR()-encoded error code on failure.
3416 *
3417 * See also:
3418 * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
3419 */
3420struct drm_atomic_state *
3421drm_atomic_helper_duplicate_state(struct drm_device *dev,
3422				  struct drm_modeset_acquire_ctx *ctx)
3423{
3424	struct drm_atomic_state *state;
3425	struct drm_connector *conn;
3426	struct drm_connector_list_iter conn_iter;
3427	struct drm_plane *plane;
3428	struct drm_crtc *crtc;
3429	int err = 0;
3430
3431	state = drm_atomic_state_alloc(dev);
3432	if (!state)
3433		return ERR_PTR(-ENOMEM);
3434
3435	state->acquire_ctx = ctx;
3436	state->duplicated = true;
3437
3438	drm_for_each_crtc(crtc, dev) {
3439		struct drm_crtc_state *crtc_state;
3440
3441		crtc_state = drm_atomic_get_crtc_state(state, crtc);
3442		if (IS_ERR(crtc_state)) {
3443			err = PTR_ERR(crtc_state);
3444			goto free;
3445		}
3446	}
3447
3448	drm_for_each_plane(plane, dev) {
3449		struct drm_plane_state *plane_state;
3450
3451		plane_state = drm_atomic_get_plane_state(state, plane);
3452		if (IS_ERR(plane_state)) {
3453			err = PTR_ERR(plane_state);
3454			goto free;
3455		}
3456	}
3457
3458	drm_connector_list_iter_begin(dev, &conn_iter);
3459	drm_for_each_connector_iter(conn, &conn_iter) {
3460		struct drm_connector_state *conn_state;
3461
3462		conn_state = drm_atomic_get_connector_state(state, conn);
3463		if (IS_ERR(conn_state)) {
3464			err = PTR_ERR(conn_state);
3465			drm_connector_list_iter_end(&conn_iter);
3466			goto free;
3467		}
3468	}
3469	drm_connector_list_iter_end(&conn_iter);
3470
3471	/* clear the acquire context so that it isn't accidentally reused */
3472	state->acquire_ctx = NULL;
3473
3474free:
3475	if (err < 0) {
3476		drm_atomic_state_put(state);
3477		state = ERR_PTR(err);
3478	}
3479
3480	return state;
3481}
3482EXPORT_SYMBOL(drm_atomic_helper_duplicate_state);
3483
3484/**
3485 * drm_atomic_helper_suspend - subsystem-level suspend helper
3486 * @dev: DRM device
3487 *
3488 * Duplicates the current atomic state, disables all active outputs and then
3489 * returns a pointer to the original atomic state to the caller. Drivers can
3490 * pass this pointer to the drm_atomic_helper_resume() helper upon resume to
3491 * restore the output configuration that was active at the time the system
3492 * entered suspend.
3493 *
3494 * Note that it is potentially unsafe to use this. The atomic state object
3495 * returned by this function is assumed to be persistent. Drivers must ensure
3496 * that this holds true. Before calling this function, drivers must make sure
3497 * to suspend fbdev emulation so that nothing can be using the device.
3498 *
3499 * Returns:
3500 * A pointer to a copy of the state before suspend on success or an ERR_PTR()-
3501 * encoded error code on failure. Drivers should store the returned atomic
3502 * state object and pass it to the drm_atomic_helper_resume() helper upon
3503 * resume.
3504 *
3505 * See also:
3506 * drm_atomic_helper_duplicate_state(), drm_atomic_helper_disable_all(),
3507 * drm_atomic_helper_resume(), drm_atomic_helper_commit_duplicated_state()
3508 */
3509struct drm_atomic_state *drm_atomic_helper_suspend(struct drm_device *dev)
3510{
3511	struct drm_modeset_acquire_ctx ctx;
3512	struct drm_atomic_state *state;
3513	int err;
3514
3515	/* This can never be returned, but it makes the compiler happy */
3516	state = ERR_PTR(-EINVAL);
3517
3518	DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, err);
3519
3520	state = drm_atomic_helper_duplicate_state(dev, &ctx);
3521	if (IS_ERR(state))
3522		goto unlock;
3523
3524	err = drm_atomic_helper_disable_all(dev, &ctx);
3525	if (err < 0) {
3526		drm_atomic_state_put(state);
3527		state = ERR_PTR(err);
3528		goto unlock;
3529	}
3530
3531unlock:
3532	DRM_MODESET_LOCK_ALL_END(dev, ctx, err);
3533	if (err)
3534		return ERR_PTR(err);
3535
3536	return state;
3537}
3538EXPORT_SYMBOL(drm_atomic_helper_suspend);
3539
3540/**
3541 * drm_atomic_helper_commit_duplicated_state - commit duplicated state
3542 * @state: duplicated atomic state to commit
3543 * @ctx: pointer to acquire_ctx to use for commit.
3544 *
3545 * The state returned by drm_atomic_helper_duplicate_state() and
3546 * drm_atomic_helper_suspend() is partially invalid, and needs to
3547 * be fixed up before commit.
3548 *
3549 * Returns:
3550 * 0 on success or a negative error code on failure.
3551 *
3552 * See also:
3553 * drm_atomic_helper_suspend()
3554 */
3555int drm_atomic_helper_commit_duplicated_state(struct drm_atomic_state *state,
3556					      struct drm_modeset_acquire_ctx *ctx)
3557{
3558	int i, ret;
3559	struct drm_plane *plane;
3560	struct drm_plane_state *new_plane_state;
3561	struct drm_connector *connector;
3562	struct drm_connector_state *new_conn_state;
3563	struct drm_crtc *crtc;
3564	struct drm_crtc_state *new_crtc_state;
3565
3566	state->acquire_ctx = ctx;
3567
3568	for_each_new_plane_in_state(state, plane, new_plane_state, i)
3569		state->planes[i].old_state = plane->state;
3570
3571	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i)
3572		state->crtcs[i].old_state = crtc->state;
3573
3574	for_each_new_connector_in_state(state, connector, new_conn_state, i)
3575		state->connectors[i].old_state = connector->state;
3576
3577	ret = drm_atomic_commit(state);
3578
3579	state->acquire_ctx = NULL;
3580
3581	return ret;
3582}
3583EXPORT_SYMBOL(drm_atomic_helper_commit_duplicated_state);
3584
3585/**
3586 * drm_atomic_helper_resume - subsystem-level resume helper
3587 * @dev: DRM device
3588 * @state: atomic state to resume to
3589 *
3590 * Calls drm_mode_config_reset() to synchronize hardware and software states,
3591 * grabs all modeset locks and commits the atomic state object. This can be
3592 * used in conjunction with the drm_atomic_helper_suspend() helper to
3593 * implement suspend/resume for drivers that support atomic mode-setting.
3594 *
3595 * Returns:
3596 * 0 on success or a negative error code on failure.
3597 *
3598 * See also:
3599 * drm_atomic_helper_suspend()
3600 */
3601int drm_atomic_helper_resume(struct drm_device *dev,
3602			     struct drm_atomic_state *state)
3603{
3604	struct drm_modeset_acquire_ctx ctx;
3605	int err;
3606
3607	drm_mode_config_reset(dev);
3608
3609	DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, err);
3610
3611	err = drm_atomic_helper_commit_duplicated_state(state, &ctx);
3612
3613	DRM_MODESET_LOCK_ALL_END(dev, ctx, err);
3614	drm_atomic_state_put(state);
3615
3616	return err;
3617}
3618EXPORT_SYMBOL(drm_atomic_helper_resume);
3619
3620static int page_flip_common(struct drm_atomic_state *state,
3621			    struct drm_crtc *crtc,
3622			    struct drm_framebuffer *fb,
3623			    struct drm_pending_vblank_event *event,
3624			    uint32_t flags)
3625{
3626	struct drm_plane *plane = crtc->primary;
3627	struct drm_plane_state *plane_state;
3628	struct drm_crtc_state *crtc_state;
3629	int ret = 0;
3630
3631	crtc_state = drm_atomic_get_crtc_state(state, crtc);
3632	if (IS_ERR(crtc_state))
3633		return PTR_ERR(crtc_state);
3634
3635	crtc_state->event = event;
3636	crtc_state->async_flip = flags & DRM_MODE_PAGE_FLIP_ASYNC;
3637
3638	plane_state = drm_atomic_get_plane_state(state, plane);
3639	if (IS_ERR(plane_state))
3640		return PTR_ERR(plane_state);
3641
3642	ret = drm_atomic_set_crtc_for_plane(plane_state, crtc);
3643	if (ret != 0)
3644		return ret;
3645	drm_atomic_set_fb_for_plane(plane_state, fb);
3646
3647	/* Make sure we don't accidentally do a full modeset. */
3648	state->allow_modeset = false;
3649	if (!crtc_state->active) {
3650		drm_dbg_atomic(crtc->dev,
3651			       "[CRTC:%d:%s] disabled, rejecting legacy flip\n",
3652			       crtc->base.id, crtc->name);
3653		return -EINVAL;
3654	}
3655
3656	return ret;
3657}
3658
3659/**
3660 * drm_atomic_helper_page_flip - execute a legacy page flip
3661 * @crtc: DRM CRTC
3662 * @fb: DRM framebuffer
3663 * @event: optional DRM event to signal upon completion
3664 * @flags: flip flags for non-vblank sync'ed updates
3665 * @ctx: lock acquisition context
3666 *
3667 * Provides a default &drm_crtc_funcs.page_flip implementation
3668 * using the atomic driver interface.
3669 *
3670 * Returns:
3671 * Returns 0 on success, negative errno numbers on failure.
3672 *
3673 * See also:
3674 * drm_atomic_helper_page_flip_target()
3675 */
3676int drm_atomic_helper_page_flip(struct drm_crtc *crtc,
3677				struct drm_framebuffer *fb,
3678				struct drm_pending_vblank_event *event,
3679				uint32_t flags,
3680				struct drm_modeset_acquire_ctx *ctx)
3681{
3682	struct drm_plane *plane = crtc->primary;
3683	struct drm_atomic_state *state;
3684	int ret = 0;
3685
3686	state = drm_atomic_state_alloc(plane->dev);
3687	if (!state)
3688		return -ENOMEM;
3689
3690	state->acquire_ctx = ctx;
3691
3692	ret = page_flip_common(state, crtc, fb, event, flags);
3693	if (ret != 0)
3694		goto fail;
3695
3696	ret = drm_atomic_nonblocking_commit(state);
3697fail:
3698	drm_atomic_state_put(state);
3699	return ret;
3700}
3701EXPORT_SYMBOL(drm_atomic_helper_page_flip);
3702
3703/**
3704 * drm_atomic_helper_page_flip_target - do page flip on target vblank period.
3705 * @crtc: DRM CRTC
3706 * @fb: DRM framebuffer
3707 * @event: optional DRM event to signal upon completion
3708 * @flags: flip flags for non-vblank sync'ed updates
3709 * @target: specifying the target vblank period when the flip to take effect
3710 * @ctx: lock acquisition context
3711 *
3712 * Provides a default &drm_crtc_funcs.page_flip_target implementation.
3713 * Similar to drm_atomic_helper_page_flip() with extra parameter to specify
3714 * target vblank period to flip.
3715 *
3716 * Returns:
3717 * Returns 0 on success, negative errno numbers on failure.
3718 */
3719int drm_atomic_helper_page_flip_target(struct drm_crtc *crtc,
3720				       struct drm_framebuffer *fb,
3721				       struct drm_pending_vblank_event *event,
3722				       uint32_t flags,
3723				       uint32_t target,
3724				       struct drm_modeset_acquire_ctx *ctx)
3725{
3726	struct drm_plane *plane = crtc->primary;
3727	struct drm_atomic_state *state;
3728	struct drm_crtc_state *crtc_state;
3729	int ret = 0;
3730
3731	state = drm_atomic_state_alloc(plane->dev);
3732	if (!state)
3733		return -ENOMEM;
3734
3735	state->acquire_ctx = ctx;
3736
3737	ret = page_flip_common(state, crtc, fb, event, flags);
3738	if (ret != 0)
3739		goto fail;
3740
3741	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
3742	if (WARN_ON(!crtc_state)) {
3743		ret = -EINVAL;
3744		goto fail;
3745	}
3746	crtc_state->target_vblank = target;
3747
3748	ret = drm_atomic_nonblocking_commit(state);
3749fail:
3750	drm_atomic_state_put(state);
3751	return ret;
3752}
3753EXPORT_SYMBOL(drm_atomic_helper_page_flip_target);
3754
3755/**
3756 * drm_atomic_helper_bridge_propagate_bus_fmt() - Propagate output format to
3757 *						  the input end of a bridge
3758 * @bridge: bridge control structure
3759 * @bridge_state: new bridge state
3760 * @crtc_state: new CRTC state
3761 * @conn_state: new connector state
3762 * @output_fmt: tested output bus format
3763 * @num_input_fmts: will contain the size of the returned array
3764 *
3765 * This helper is a pluggable implementation of the
3766 * &drm_bridge_funcs.atomic_get_input_bus_fmts operation for bridges that don't
3767 * modify the bus configuration between their input and their output. It
3768 * returns an array of input formats with a single element set to @output_fmt.
3769 *
3770 * RETURNS:
3771 * a valid format array of size @num_input_fmts, or NULL if the allocation
3772 * failed
3773 */
3774u32 *
3775drm_atomic_helper_bridge_propagate_bus_fmt(struct drm_bridge *bridge,
3776					struct drm_bridge_state *bridge_state,
3777					struct drm_crtc_state *crtc_state,
3778					struct drm_connector_state *conn_state,
3779					u32 output_fmt,
3780					unsigned int *num_input_fmts)
3781{
3782	u32 *input_fmts;
3783
3784	input_fmts = kzalloc(sizeof(*input_fmts), GFP_KERNEL);
3785	if (!input_fmts) {
3786		*num_input_fmts = 0;
3787		return NULL;
3788	}
3789
3790	*num_input_fmts = 1;
3791	input_fmts[0] = output_fmt;
3792	return input_fmts;
3793}
3794EXPORT_SYMBOL(drm_atomic_helper_bridge_propagate_bus_fmt);