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  1/*
  2 * Copyright (C) 2018 Intel Corp.
  3 *
  4 * Permission is hereby granted, free of charge, to any person obtaining a
  5 * copy of this software and associated documentation files (the "Software"),
  6 * to deal in the Software without restriction, including without limitation
  7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  8 * and/or sell copies of the Software, and to permit persons to whom the
  9 * Software is furnished to do so, subject to the following conditions:
 10 *
 11 * The above copyright notice and this permission notice shall be included in
 12 * all copies or substantial portions of the Software.
 13 *
 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 20 * OTHER DEALINGS IN THE SOFTWARE.
 21 *
 22 * Authors:
 23 * Rob Clark <robdclark@gmail.com>
 24 * Daniel Vetter <daniel.vetter@ffwll.ch>
 25 */
 26
 27#include <drm/drm_atomic.h>
 28#include <drm/drm_atomic_state_helper.h>
 29#include <drm/drm_bridge.h>
 30#include <drm/drm_connector.h>
 31#include <drm/drm_crtc.h>
 32#include <drm/drm_device.h>
 33#include <drm/drm_plane.h>
 34#include <drm/drm_print.h>
 35#include <drm/drm_vblank.h>
 36#include <drm/drm_writeback.h>
 37
 38#include <linux/slab.h>
 39#include <linux/dma-fence.h>
 40
 41/**
 42 * DOC: atomic state reset and initialization
 43 *
 44 * Both the drm core and the atomic helpers assume that there is always the full
 45 * and correct atomic software state for all connectors, CRTCs and planes
 46 * available. Which is a bit a problem on driver load and also after system
 47 * suspend. One way to solve this is to have a hardware state read-out
 48 * infrastructure which reconstructs the full software state (e.g. the i915
 49 * driver).
 50 *
 51 * The simpler solution is to just reset the software state to everything off,
 52 * which is easiest to do by calling drm_mode_config_reset(). To facilitate this
 53 * the atomic helpers provide default reset implementations for all hooks.
 54 *
 55 * On the upside the precise state tracking of atomic simplifies system suspend
 56 * and resume a lot. For drivers using drm_mode_config_reset() a complete recipe
 57 * is implemented in drm_atomic_helper_suspend() and drm_atomic_helper_resume().
 58 * For other drivers the building blocks are split out, see the documentation
 59 * for these functions.
 60 */
 61
 62/**
 63 * __drm_atomic_helper_crtc_state_reset - reset the CRTC state
 64 * @crtc_state: atomic CRTC state, must not be NULL
 65 * @crtc: CRTC object, must not be NULL
 66 *
 67 * Initializes the newly allocated @crtc_state with default
 68 * values. This is useful for drivers that subclass the CRTC state.
 69 */
 70void
 71__drm_atomic_helper_crtc_state_reset(struct drm_crtc_state *crtc_state,
 72				     struct drm_crtc *crtc)
 73{
 74	crtc_state->crtc = crtc;
 75}
 76EXPORT_SYMBOL(__drm_atomic_helper_crtc_state_reset);
 77
 78/**
 79 * __drm_atomic_helper_crtc_reset - reset state on CRTC
 80 * @crtc: drm CRTC
 81 * @crtc_state: CRTC state to assign
 82 *
 83 * Initializes the newly allocated @crtc_state and assigns it to
 84 * the &drm_crtc->state pointer of @crtc, usually required when
 85 * initializing the drivers or when called from the &drm_crtc_funcs.reset
 86 * hook.
 87 *
 88 * This is useful for drivers that subclass the CRTC state.
 89 */
 90void
 91__drm_atomic_helper_crtc_reset(struct drm_crtc *crtc,
 92			       struct drm_crtc_state *crtc_state)
 93{
 94	if (crtc_state)
 95		__drm_atomic_helper_crtc_state_reset(crtc_state, crtc);
 96
 97	if (drm_dev_has_vblank(crtc->dev))
 98		drm_crtc_vblank_reset(crtc);
 99
100	crtc->state = crtc_state;
101}
102EXPORT_SYMBOL(__drm_atomic_helper_crtc_reset);
103
104/**
105 * drm_atomic_helper_crtc_reset - default &drm_crtc_funcs.reset hook for CRTCs
106 * @crtc: drm CRTC
107 *
108 * Resets the atomic state for @crtc by freeing the state pointer (which might
109 * be NULL, e.g. at driver load time) and allocating a new empty state object.
110 */
111void drm_atomic_helper_crtc_reset(struct drm_crtc *crtc)
112{
113	struct drm_crtc_state *crtc_state =
114		kzalloc(sizeof(*crtc->state), GFP_KERNEL);
115
116	if (crtc->state)
117		crtc->funcs->atomic_destroy_state(crtc, crtc->state);
118
119	__drm_atomic_helper_crtc_reset(crtc, crtc_state);
120}
121EXPORT_SYMBOL(drm_atomic_helper_crtc_reset);
122
123/**
124 * __drm_atomic_helper_crtc_duplicate_state - copy atomic CRTC state
125 * @crtc: CRTC object
126 * @state: atomic CRTC state
127 *
128 * Copies atomic state from a CRTC's current state and resets inferred values.
129 * This is useful for drivers that subclass the CRTC state.
130 */
131void __drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc,
132					      struct drm_crtc_state *state)
133{
134	memcpy(state, crtc->state, sizeof(*state));
135
136	if (state->mode_blob)
137		drm_property_blob_get(state->mode_blob);
138	if (state->degamma_lut)
139		drm_property_blob_get(state->degamma_lut);
140	if (state->ctm)
141		drm_property_blob_get(state->ctm);
142	if (state->gamma_lut)
143		drm_property_blob_get(state->gamma_lut);
144	state->mode_changed = false;
145	state->active_changed = false;
146	state->planes_changed = false;
147	state->connectors_changed = false;
148	state->color_mgmt_changed = false;
149	state->zpos_changed = false;
150	state->commit = NULL;
151	state->event = NULL;
152	state->async_flip = false;
153
154	/* Self refresh should be canceled when a new update is available */
155	state->active = drm_atomic_crtc_effectively_active(state);
156	state->self_refresh_active = false;
157}
158EXPORT_SYMBOL(__drm_atomic_helper_crtc_duplicate_state);
159
160/**
161 * drm_atomic_helper_crtc_duplicate_state - default state duplicate hook
162 * @crtc: drm CRTC
163 *
164 * Default CRTC state duplicate hook for drivers which don't have their own
165 * subclassed CRTC state structure.
166 */
167struct drm_crtc_state *
168drm_atomic_helper_crtc_duplicate_state(struct drm_crtc *crtc)
169{
170	struct drm_crtc_state *state;
171
172	if (WARN_ON(!crtc->state))
173		return NULL;
174
175	state = kmalloc(sizeof(*state), GFP_KERNEL);
176	if (state)
177		__drm_atomic_helper_crtc_duplicate_state(crtc, state);
178
179	return state;
180}
181EXPORT_SYMBOL(drm_atomic_helper_crtc_duplicate_state);
182
183/**
184 * __drm_atomic_helper_crtc_destroy_state - release CRTC state
185 * @state: CRTC state object to release
186 *
187 * Releases all resources stored in the CRTC state without actually freeing
188 * the memory of the CRTC state. This is useful for drivers that subclass the
189 * CRTC state.
190 */
191void __drm_atomic_helper_crtc_destroy_state(struct drm_crtc_state *state)
192{
193	if (state->commit) {
194		/*
195		 * In the event that a non-blocking commit returns
196		 * -ERESTARTSYS before the commit_tail work is queued, we will
197		 * have an extra reference to the commit object. Release it, if
198		 * the event has not been consumed by the worker.
199		 *
200		 * state->event may be freed, so we can't directly look at
201		 * state->event->base.completion.
202		 */
203		if (state->event && state->commit->abort_completion)
204			drm_crtc_commit_put(state->commit);
205
206		kfree(state->commit->event);
207		state->commit->event = NULL;
208
209		drm_crtc_commit_put(state->commit);
210	}
211
212	drm_property_blob_put(state->mode_blob);
213	drm_property_blob_put(state->degamma_lut);
214	drm_property_blob_put(state->ctm);
215	drm_property_blob_put(state->gamma_lut);
216}
217EXPORT_SYMBOL(__drm_atomic_helper_crtc_destroy_state);
218
219/**
220 * drm_atomic_helper_crtc_destroy_state - default state destroy hook
221 * @crtc: drm CRTC
222 * @state: CRTC state object to release
223 *
224 * Default CRTC state destroy hook for drivers which don't have their own
225 * subclassed CRTC state structure.
226 */
227void drm_atomic_helper_crtc_destroy_state(struct drm_crtc *crtc,
228					  struct drm_crtc_state *state)
229{
230	__drm_atomic_helper_crtc_destroy_state(state);
231	kfree(state);
232}
233EXPORT_SYMBOL(drm_atomic_helper_crtc_destroy_state);
234
235/**
236 * __drm_atomic_helper_plane_state_reset - resets plane state to default values
237 * @plane_state: atomic plane state, must not be NULL
238 * @plane: plane object, must not be NULL
239 *
240 * Initializes the newly allocated @plane_state with default
241 * values. This is useful for drivers that subclass the CRTC state.
242 */
243void __drm_atomic_helper_plane_state_reset(struct drm_plane_state *plane_state,
244					   struct drm_plane *plane)
245{
246	plane_state->plane = plane;
247	plane_state->rotation = DRM_MODE_ROTATE_0;
248
249	plane_state->alpha = DRM_BLEND_ALPHA_OPAQUE;
250	plane_state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI;
251}
252EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset);
253
254/**
255 * __drm_atomic_helper_plane_reset - reset state on plane
256 * @plane: drm plane
257 * @plane_state: plane state to assign
258 *
259 * Initializes the newly allocated @plane_state and assigns it to
260 * the &drm_crtc->state pointer of @plane, usually required when
261 * initializing the drivers or when called from the &drm_plane_funcs.reset
262 * hook.
263 *
264 * This is useful for drivers that subclass the plane state.
265 */
266void __drm_atomic_helper_plane_reset(struct drm_plane *plane,
267				     struct drm_plane_state *plane_state)
268{
269	if (plane_state)
270		__drm_atomic_helper_plane_state_reset(plane_state, plane);
271
272	plane->state = plane_state;
273}
274EXPORT_SYMBOL(__drm_atomic_helper_plane_reset);
275
276/**
277 * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes
278 * @plane: drm plane
279 *
280 * Resets the atomic state for @plane by freeing the state pointer (which might
281 * be NULL, e.g. at driver load time) and allocating a new empty state object.
282 */
283void drm_atomic_helper_plane_reset(struct drm_plane *plane)
284{
285	if (plane->state)
286		__drm_atomic_helper_plane_destroy_state(plane->state);
287
288	kfree(plane->state);
289	plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL);
290	if (plane->state)
291		__drm_atomic_helper_plane_reset(plane, plane->state);
292}
293EXPORT_SYMBOL(drm_atomic_helper_plane_reset);
294
295/**
296 * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state
297 * @plane: plane object
298 * @state: atomic plane state
299 *
300 * Copies atomic state from a plane's current state. This is useful for
301 * drivers that subclass the plane state.
302 */
303void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
304					       struct drm_plane_state *state)
305{
306	memcpy(state, plane->state, sizeof(*state));
307
308	if (state->fb)
309		drm_framebuffer_get(state->fb);
310
311	state->fence = NULL;
312	state->commit = NULL;
313	state->fb_damage_clips = NULL;
314}
315EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
316
317/**
318 * drm_atomic_helper_plane_duplicate_state - default state duplicate hook
319 * @plane: drm plane
320 *
321 * Default plane state duplicate hook for drivers which don't have their own
322 * subclassed plane state structure.
323 */
324struct drm_plane_state *
325drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane)
326{
327	struct drm_plane_state *state;
328
329	if (WARN_ON(!plane->state))
330		return NULL;
331
332	state = kmalloc(sizeof(*state), GFP_KERNEL);
333	if (state)
334		__drm_atomic_helper_plane_duplicate_state(plane, state);
335
336	return state;
337}
338EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state);
339
340/**
341 * __drm_atomic_helper_plane_destroy_state - release plane state
342 * @state: plane state object to release
343 *
344 * Releases all resources stored in the plane state without actually freeing
345 * the memory of the plane state. This is useful for drivers that subclass the
346 * plane state.
347 */
348void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
349{
350	if (state->fb)
351		drm_framebuffer_put(state->fb);
352
353	if (state->fence)
354		dma_fence_put(state->fence);
355
356	if (state->commit)
357		drm_crtc_commit_put(state->commit);
358
359	drm_property_blob_put(state->fb_damage_clips);
360}
361EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
362
363/**
364 * drm_atomic_helper_plane_destroy_state - default state destroy hook
365 * @plane: drm plane
366 * @state: plane state object to release
367 *
368 * Default plane state destroy hook for drivers which don't have their own
369 * subclassed plane state structure.
370 */
371void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane,
372					   struct drm_plane_state *state)
373{
374	__drm_atomic_helper_plane_destroy_state(state);
375	kfree(state);
376}
377EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state);
378
379/**
380 * __drm_atomic_helper_connector_state_reset - reset the connector state
381 * @conn_state: atomic connector state, must not be NULL
382 * @connector: connectotr object, must not be NULL
383 *
384 * Initializes the newly allocated @conn_state with default
385 * values. This is useful for drivers that subclass the connector state.
386 */
387void
388__drm_atomic_helper_connector_state_reset(struct drm_connector_state *conn_state,
389					  struct drm_connector *connector)
390{
391	conn_state->connector = connector;
392}
393EXPORT_SYMBOL(__drm_atomic_helper_connector_state_reset);
394
395/**
396 * __drm_atomic_helper_connector_reset - reset state on connector
397 * @connector: drm connector
398 * @conn_state: connector state to assign
399 *
400 * Initializes the newly allocated @conn_state and assigns it to
401 * the &drm_connector->state pointer of @connector, usually required when
402 * initializing the drivers or when called from the &drm_connector_funcs.reset
403 * hook.
404 *
405 * This is useful for drivers that subclass the connector state.
406 */
407void
408__drm_atomic_helper_connector_reset(struct drm_connector *connector,
409				    struct drm_connector_state *conn_state)
410{
411	if (conn_state)
412		__drm_atomic_helper_connector_state_reset(conn_state, connector);
413
414	connector->state = conn_state;
415}
416EXPORT_SYMBOL(__drm_atomic_helper_connector_reset);
417
418/**
419 * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors
420 * @connector: drm connector
421 *
422 * Resets the atomic state for @connector by freeing the state pointer (which
423 * might be NULL, e.g. at driver load time) and allocating a new empty state
424 * object.
425 */
426void drm_atomic_helper_connector_reset(struct drm_connector *connector)
427{
428	struct drm_connector_state *conn_state =
429		kzalloc(sizeof(*conn_state), GFP_KERNEL);
430
431	if (connector->state)
432		__drm_atomic_helper_connector_destroy_state(connector->state);
433
434	kfree(connector->state);
435	__drm_atomic_helper_connector_reset(connector, conn_state);
436}
437EXPORT_SYMBOL(drm_atomic_helper_connector_reset);
438
439/**
440 * drm_atomic_helper_connector_tv_reset - Resets TV connector properties
441 * @connector: DRM connector
442 *
443 * Resets the TV-related properties attached to a connector.
444 */
445void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector)
446{
447	struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
448	struct drm_connector_state *state = connector->state;
449
450	state->tv.margins.left = cmdline->tv_margins.left;
451	state->tv.margins.right = cmdline->tv_margins.right;
452	state->tv.margins.top = cmdline->tv_margins.top;
453	state->tv.margins.bottom = cmdline->tv_margins.bottom;
454}
455EXPORT_SYMBOL(drm_atomic_helper_connector_tv_reset);
456
457/**
458 * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state
459 * @connector: connector object
460 * @state: atomic connector state
461 *
462 * Copies atomic state from a connector's current state. This is useful for
463 * drivers that subclass the connector state.
464 */
465void
466__drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector,
467					    struct drm_connector_state *state)
468{
469	memcpy(state, connector->state, sizeof(*state));
470	if (state->crtc)
471		drm_connector_get(connector);
472	state->commit = NULL;
473
474	if (state->hdr_output_metadata)
475		drm_property_blob_get(state->hdr_output_metadata);
476
477	/* Don't copy over a writeback job, they are used only once */
478	state->writeback_job = NULL;
479}
480EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state);
481
482/**
483 * drm_atomic_helper_connector_duplicate_state - default state duplicate hook
484 * @connector: drm connector
485 *
486 * Default connector state duplicate hook for drivers which don't have their own
487 * subclassed connector state structure.
488 */
489struct drm_connector_state *
490drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector)
491{
492	struct drm_connector_state *state;
493
494	if (WARN_ON(!connector->state))
495		return NULL;
496
497	state = kmalloc(sizeof(*state), GFP_KERNEL);
498	if (state)
499		__drm_atomic_helper_connector_duplicate_state(connector, state);
500
501	return state;
502}
503EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state);
504
505/**
506 * __drm_atomic_helper_connector_destroy_state - release connector state
507 * @state: connector state object to release
508 *
509 * Releases all resources stored in the connector state without actually
510 * freeing the memory of the connector state. This is useful for drivers that
511 * subclass the connector state.
512 */
513void
514__drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state)
515{
516	if (state->crtc)
517		drm_connector_put(state->connector);
518
519	if (state->commit)
520		drm_crtc_commit_put(state->commit);
521
522	if (state->writeback_job)
523		drm_writeback_cleanup_job(state->writeback_job);
524
525	drm_property_blob_put(state->hdr_output_metadata);
526}
527EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state);
528
529/**
530 * drm_atomic_helper_connector_destroy_state - default state destroy hook
531 * @connector: drm connector
532 * @state: connector state object to release
533 *
534 * Default connector state destroy hook for drivers which don't have their own
535 * subclassed connector state structure.
536 */
537void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector,
538					  struct drm_connector_state *state)
539{
540	__drm_atomic_helper_connector_destroy_state(state);
541	kfree(state);
542}
543EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state);
544
545/**
546 * __drm_atomic_helper_private_duplicate_state - copy atomic private state
547 * @obj: CRTC object
548 * @state: new private object state
549 *
550 * Copies atomic state from a private objects's current state and resets inferred values.
551 * This is useful for drivers that subclass the private state.
552 */
553void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj,
554						     struct drm_private_state *state)
555{
556	memcpy(state, obj->state, sizeof(*state));
557}
558EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state);
559
560/**
561 * __drm_atomic_helper_bridge_duplicate_state() - Copy atomic bridge state
562 * @bridge: bridge object
563 * @state: atomic bridge state
564 *
565 * Copies atomic state from a bridge's current state and resets inferred values.
566 * This is useful for drivers that subclass the bridge state.
567 */
568void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge,
569						struct drm_bridge_state *state)
570{
571	__drm_atomic_helper_private_obj_duplicate_state(&bridge->base,
572							&state->base);
573	state->bridge = bridge;
574}
575EXPORT_SYMBOL(__drm_atomic_helper_bridge_duplicate_state);
576
577/**
578 * drm_atomic_helper_bridge_duplicate_state() - Duplicate a bridge state object
579 * @bridge: bridge object
580 *
581 * Allocates a new bridge state and initializes it with the current bridge
582 * state values. This helper is meant to be used as a bridge
583 * &drm_bridge_funcs.atomic_duplicate_state hook for bridges that don't
584 * subclass the bridge state.
585 */
586struct drm_bridge_state *
587drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge)
588{
589	struct drm_bridge_state *new;
590
591	if (WARN_ON(!bridge->base.state))
592		return NULL;
593
594	new = kzalloc(sizeof(*new), GFP_KERNEL);
595	if (new)
596		__drm_atomic_helper_bridge_duplicate_state(bridge, new);
597
598	return new;
599}
600EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state);
601
602/**
603 * drm_atomic_helper_bridge_destroy_state() - Destroy a bridge state object
604 * @bridge: the bridge this state refers to
605 * @state: bridge state to destroy
606 *
607 * Destroys a bridge state previously created by
608 * &drm_atomic_helper_bridge_reset() or
609 * &drm_atomic_helper_bridge_duplicate_state(). This helper is meant to be
610 * used as a bridge &drm_bridge_funcs.atomic_destroy_state hook for bridges
611 * that don't subclass the bridge state.
612 */
613void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge,
614					    struct drm_bridge_state *state)
615{
616	kfree(state);
617}
618EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state);
619
620/**
621 * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its
622 *					default
623 * @bridge: the bridge this state refers to
624 * @state: bridge state to initialize
625 *
626 * Initializes the bridge state to default values. This is meant to be called
627 * by the bridge &drm_bridge_funcs.atomic_reset hook for bridges that subclass
628 * the bridge state.
629 */
630void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge,
631				      struct drm_bridge_state *state)
632{
633	memset(state, 0, sizeof(*state));
634	state->bridge = bridge;
635}
636EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset);
637
638/**
639 * drm_atomic_helper_bridge_reset() - Allocate and initialize a bridge state
640 *				      to its default
641 * @bridge: the bridge this state refers to
642 *
643 * Allocates the bridge state and initializes it to default values. This helper
644 * is meant to be used as a bridge &drm_bridge_funcs.atomic_reset hook for
645 * bridges that don't subclass the bridge state.
646 */
647struct drm_bridge_state *
648drm_atomic_helper_bridge_reset(struct drm_bridge *bridge)
649{
650	struct drm_bridge_state *bridge_state;
651
652	bridge_state = kzalloc(sizeof(*bridge_state), GFP_KERNEL);
653	if (!bridge_state)
654		return ERR_PTR(-ENOMEM);
655
656	__drm_atomic_helper_bridge_reset(bridge, bridge_state);
657	return bridge_state;
658}
659EXPORT_SYMBOL(drm_atomic_helper_bridge_reset);