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 */ 70 void 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 } 76 EXPORT_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 */ 90 void 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 } 102 EXPORT_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 */ 111 void 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 } 121 EXPORT_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 */ 131 void __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 } 158 EXPORT_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 */ 167 struct drm_crtc_state * 168 drm_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 } 181 EXPORT_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 */ 191 void __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 } 217 EXPORT_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 */ 227 void 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 } 233 EXPORT_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 */ 243 void __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 } 252 EXPORT_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 */ 266 void __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 } 274 EXPORT_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 */ 283 void 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 } 293 EXPORT_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 */ 303 void __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 } 315 EXPORT_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 */ 324 struct drm_plane_state * 325 drm_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 } 338 EXPORT_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 */ 348 void __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 } 361 EXPORT_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 */ 371 void 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 } 377 EXPORT_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 */ 387 void 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 } 393 EXPORT_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 */ 407 void 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 } 416 EXPORT_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 */ 426 void 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 } 437 EXPORT_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 */ 445 void 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 } 455 EXPORT_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 */ 465 void 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 } 480 EXPORT_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 */ 489 struct drm_connector_state * 490 drm_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 } 503 EXPORT_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 */ 513 void 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 } 527 EXPORT_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 */ 537 void 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 } 543 EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state); 544 545 /** 546 * __drm_atomic_helper_private_obj_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 */ 553 void __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 } 558 EXPORT_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 */ 568 void __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 } 575 EXPORT_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 */ 586 struct drm_bridge_state * 587 drm_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 } 600 EXPORT_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 */ 613 void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge, 614 struct drm_bridge_state *state) 615 { 616 kfree(state); 617 } 618 EXPORT_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 */ 630 void __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 } 636 EXPORT_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 */ 647 struct drm_bridge_state * 648 drm_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 } 659 EXPORT_SYMBOL(drm_atomic_helper_bridge_reset); 660