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 u64 val; 247 248 plane_state->plane = plane; 249 plane_state->rotation = DRM_MODE_ROTATE_0; 250 251 plane_state->alpha = DRM_BLEND_ALPHA_OPAQUE; 252 plane_state->pixel_blend_mode = DRM_MODE_BLEND_PREMULTI; 253 254 if (plane->color_encoding_property) { 255 if (!drm_object_property_get_default_value(&plane->base, 256 plane->color_encoding_property, 257 &val)) 258 plane_state->color_encoding = val; 259 } 260 261 if (plane->color_range_property) { 262 if (!drm_object_property_get_default_value(&plane->base, 263 plane->color_range_property, 264 &val)) 265 plane_state->color_range = val; 266 } 267 268 if (plane->zpos_property) { 269 if (!drm_object_property_get_default_value(&plane->base, 270 plane->zpos_property, 271 &val)) { 272 plane_state->zpos = val; 273 plane_state->normalized_zpos = val; 274 } 275 } 276 } 277 EXPORT_SYMBOL(__drm_atomic_helper_plane_state_reset); 278 279 /** 280 * __drm_atomic_helper_plane_reset - reset state on plane 281 * @plane: drm plane 282 * @plane_state: plane state to assign 283 * 284 * Initializes the newly allocated @plane_state and assigns it to 285 * the &drm_crtc->state pointer of @plane, usually required when 286 * initializing the drivers or when called from the &drm_plane_funcs.reset 287 * hook. 288 * 289 * This is useful for drivers that subclass the plane state. 290 */ 291 void __drm_atomic_helper_plane_reset(struct drm_plane *plane, 292 struct drm_plane_state *plane_state) 293 { 294 if (plane_state) 295 __drm_atomic_helper_plane_state_reset(plane_state, plane); 296 297 plane->state = plane_state; 298 } 299 EXPORT_SYMBOL(__drm_atomic_helper_plane_reset); 300 301 /** 302 * drm_atomic_helper_plane_reset - default &drm_plane_funcs.reset hook for planes 303 * @plane: drm plane 304 * 305 * Resets the atomic state for @plane by freeing the state pointer (which might 306 * be NULL, e.g. at driver load time) and allocating a new empty state object. 307 */ 308 void drm_atomic_helper_plane_reset(struct drm_plane *plane) 309 { 310 if (plane->state) 311 __drm_atomic_helper_plane_destroy_state(plane->state); 312 313 kfree(plane->state); 314 plane->state = kzalloc(sizeof(*plane->state), GFP_KERNEL); 315 if (plane->state) 316 __drm_atomic_helper_plane_reset(plane, plane->state); 317 } 318 EXPORT_SYMBOL(drm_atomic_helper_plane_reset); 319 320 /** 321 * __drm_atomic_helper_plane_duplicate_state - copy atomic plane state 322 * @plane: plane object 323 * @state: atomic plane state 324 * 325 * Copies atomic state from a plane's current state. This is useful for 326 * drivers that subclass the plane state. 327 */ 328 void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane, 329 struct drm_plane_state *state) 330 { 331 memcpy(state, plane->state, sizeof(*state)); 332 333 if (state->fb) 334 drm_framebuffer_get(state->fb); 335 336 state->fence = NULL; 337 state->commit = NULL; 338 state->fb_damage_clips = NULL; 339 } 340 EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state); 341 342 /** 343 * drm_atomic_helper_plane_duplicate_state - default state duplicate hook 344 * @plane: drm plane 345 * 346 * Default plane state duplicate hook for drivers which don't have their own 347 * subclassed plane state structure. 348 */ 349 struct drm_plane_state * 350 drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane) 351 { 352 struct drm_plane_state *state; 353 354 if (WARN_ON(!plane->state)) 355 return NULL; 356 357 state = kmalloc(sizeof(*state), GFP_KERNEL); 358 if (state) 359 __drm_atomic_helper_plane_duplicate_state(plane, state); 360 361 return state; 362 } 363 EXPORT_SYMBOL(drm_atomic_helper_plane_duplicate_state); 364 365 /** 366 * __drm_atomic_helper_plane_destroy_state - release plane state 367 * @state: plane state object to release 368 * 369 * Releases all resources stored in the plane state without actually freeing 370 * the memory of the plane state. This is useful for drivers that subclass the 371 * plane state. 372 */ 373 void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state) 374 { 375 if (state->fb) 376 drm_framebuffer_put(state->fb); 377 378 if (state->fence) 379 dma_fence_put(state->fence); 380 381 if (state->commit) 382 drm_crtc_commit_put(state->commit); 383 384 drm_property_blob_put(state->fb_damage_clips); 385 } 386 EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state); 387 388 /** 389 * drm_atomic_helper_plane_destroy_state - default state destroy hook 390 * @plane: drm plane 391 * @state: plane state object to release 392 * 393 * Default plane state destroy hook for drivers which don't have their own 394 * subclassed plane state structure. 395 */ 396 void drm_atomic_helper_plane_destroy_state(struct drm_plane *plane, 397 struct drm_plane_state *state) 398 { 399 __drm_atomic_helper_plane_destroy_state(state); 400 kfree(state); 401 } 402 EXPORT_SYMBOL(drm_atomic_helper_plane_destroy_state); 403 404 /** 405 * __drm_atomic_helper_connector_state_reset - reset the connector state 406 * @conn_state: atomic connector state, must not be NULL 407 * @connector: connectotr object, must not be NULL 408 * 409 * Initializes the newly allocated @conn_state with default 410 * values. This is useful for drivers that subclass the connector state. 411 */ 412 void 413 __drm_atomic_helper_connector_state_reset(struct drm_connector_state *conn_state, 414 struct drm_connector *connector) 415 { 416 conn_state->connector = connector; 417 } 418 EXPORT_SYMBOL(__drm_atomic_helper_connector_state_reset); 419 420 /** 421 * __drm_atomic_helper_connector_reset - reset state on connector 422 * @connector: drm connector 423 * @conn_state: connector state to assign 424 * 425 * Initializes the newly allocated @conn_state and assigns it to 426 * the &drm_connector->state pointer of @connector, usually required when 427 * initializing the drivers or when called from the &drm_connector_funcs.reset 428 * hook. 429 * 430 * This is useful for drivers that subclass the connector state. 431 */ 432 void 433 __drm_atomic_helper_connector_reset(struct drm_connector *connector, 434 struct drm_connector_state *conn_state) 435 { 436 if (conn_state) 437 __drm_atomic_helper_connector_state_reset(conn_state, connector); 438 439 connector->state = conn_state; 440 } 441 EXPORT_SYMBOL(__drm_atomic_helper_connector_reset); 442 443 /** 444 * drm_atomic_helper_connector_reset - default &drm_connector_funcs.reset hook for connectors 445 * @connector: drm connector 446 * 447 * Resets the atomic state for @connector by freeing the state pointer (which 448 * might be NULL, e.g. at driver load time) and allocating a new empty state 449 * object. 450 */ 451 void drm_atomic_helper_connector_reset(struct drm_connector *connector) 452 { 453 struct drm_connector_state *conn_state = 454 kzalloc(sizeof(*conn_state), GFP_KERNEL); 455 456 if (connector->state) 457 __drm_atomic_helper_connector_destroy_state(connector->state); 458 459 kfree(connector->state); 460 __drm_atomic_helper_connector_reset(connector, conn_state); 461 } 462 EXPORT_SYMBOL(drm_atomic_helper_connector_reset); 463 464 /** 465 * drm_atomic_helper_connector_tv_reset - Resets TV connector properties 466 * @connector: DRM connector 467 * 468 * Resets the TV-related properties attached to a connector. 469 */ 470 void drm_atomic_helper_connector_tv_reset(struct drm_connector *connector) 471 { 472 struct drm_cmdline_mode *cmdline = &connector->cmdline_mode; 473 struct drm_connector_state *state = connector->state; 474 475 state->tv.margins.left = cmdline->tv_margins.left; 476 state->tv.margins.right = cmdline->tv_margins.right; 477 state->tv.margins.top = cmdline->tv_margins.top; 478 state->tv.margins.bottom = cmdline->tv_margins.bottom; 479 } 480 EXPORT_SYMBOL(drm_atomic_helper_connector_tv_reset); 481 482 /** 483 * __drm_atomic_helper_connector_duplicate_state - copy atomic connector state 484 * @connector: connector object 485 * @state: atomic connector state 486 * 487 * Copies atomic state from a connector's current state. This is useful for 488 * drivers that subclass the connector state. 489 */ 490 void 491 __drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector, 492 struct drm_connector_state *state) 493 { 494 memcpy(state, connector->state, sizeof(*state)); 495 if (state->crtc) 496 drm_connector_get(connector); 497 state->commit = NULL; 498 499 if (state->hdr_output_metadata) 500 drm_property_blob_get(state->hdr_output_metadata); 501 502 /* Don't copy over a writeback job, they are used only once */ 503 state->writeback_job = NULL; 504 } 505 EXPORT_SYMBOL(__drm_atomic_helper_connector_duplicate_state); 506 507 /** 508 * drm_atomic_helper_connector_duplicate_state - default state duplicate hook 509 * @connector: drm connector 510 * 511 * Default connector state duplicate hook for drivers which don't have their own 512 * subclassed connector state structure. 513 */ 514 struct drm_connector_state * 515 drm_atomic_helper_connector_duplicate_state(struct drm_connector *connector) 516 { 517 struct drm_connector_state *state; 518 519 if (WARN_ON(!connector->state)) 520 return NULL; 521 522 state = kmalloc(sizeof(*state), GFP_KERNEL); 523 if (state) 524 __drm_atomic_helper_connector_duplicate_state(connector, state); 525 526 return state; 527 } 528 EXPORT_SYMBOL(drm_atomic_helper_connector_duplicate_state); 529 530 /** 531 * __drm_atomic_helper_connector_destroy_state - release connector state 532 * @state: connector state object to release 533 * 534 * Releases all resources stored in the connector state without actually 535 * freeing the memory of the connector state. This is useful for drivers that 536 * subclass the connector state. 537 */ 538 void 539 __drm_atomic_helper_connector_destroy_state(struct drm_connector_state *state) 540 { 541 if (state->crtc) 542 drm_connector_put(state->connector); 543 544 if (state->commit) 545 drm_crtc_commit_put(state->commit); 546 547 if (state->writeback_job) 548 drm_writeback_cleanup_job(state->writeback_job); 549 550 drm_property_blob_put(state->hdr_output_metadata); 551 } 552 EXPORT_SYMBOL(__drm_atomic_helper_connector_destroy_state); 553 554 /** 555 * drm_atomic_helper_connector_destroy_state - default state destroy hook 556 * @connector: drm connector 557 * @state: connector state object to release 558 * 559 * Default connector state destroy hook for drivers which don't have their own 560 * subclassed connector state structure. 561 */ 562 void drm_atomic_helper_connector_destroy_state(struct drm_connector *connector, 563 struct drm_connector_state *state) 564 { 565 __drm_atomic_helper_connector_destroy_state(state); 566 kfree(state); 567 } 568 EXPORT_SYMBOL(drm_atomic_helper_connector_destroy_state); 569 570 /** 571 * __drm_atomic_helper_private_obj_duplicate_state - copy atomic private state 572 * @obj: CRTC object 573 * @state: new private object state 574 * 575 * Copies atomic state from a private objects's current state and resets inferred values. 576 * This is useful for drivers that subclass the private state. 577 */ 578 void __drm_atomic_helper_private_obj_duplicate_state(struct drm_private_obj *obj, 579 struct drm_private_state *state) 580 { 581 memcpy(state, obj->state, sizeof(*state)); 582 } 583 EXPORT_SYMBOL(__drm_atomic_helper_private_obj_duplicate_state); 584 585 /** 586 * __drm_atomic_helper_bridge_duplicate_state() - Copy atomic bridge state 587 * @bridge: bridge object 588 * @state: atomic bridge state 589 * 590 * Copies atomic state from a bridge's current state and resets inferred values. 591 * This is useful for drivers that subclass the bridge state. 592 */ 593 void __drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge, 594 struct drm_bridge_state *state) 595 { 596 __drm_atomic_helper_private_obj_duplicate_state(&bridge->base, 597 &state->base); 598 state->bridge = bridge; 599 } 600 EXPORT_SYMBOL(__drm_atomic_helper_bridge_duplicate_state); 601 602 /** 603 * drm_atomic_helper_bridge_duplicate_state() - Duplicate a bridge state object 604 * @bridge: bridge object 605 * 606 * Allocates a new bridge state and initializes it with the current bridge 607 * state values. This helper is meant to be used as a bridge 608 * &drm_bridge_funcs.atomic_duplicate_state hook for bridges that don't 609 * subclass the bridge state. 610 */ 611 struct drm_bridge_state * 612 drm_atomic_helper_bridge_duplicate_state(struct drm_bridge *bridge) 613 { 614 struct drm_bridge_state *new; 615 616 if (WARN_ON(!bridge->base.state)) 617 return NULL; 618 619 new = kzalloc(sizeof(*new), GFP_KERNEL); 620 if (new) 621 __drm_atomic_helper_bridge_duplicate_state(bridge, new); 622 623 return new; 624 } 625 EXPORT_SYMBOL(drm_atomic_helper_bridge_duplicate_state); 626 627 /** 628 * drm_atomic_helper_bridge_destroy_state() - Destroy a bridge state object 629 * @bridge: the bridge this state refers to 630 * @state: bridge state to destroy 631 * 632 * Destroys a bridge state previously created by 633 * &drm_atomic_helper_bridge_reset() or 634 * &drm_atomic_helper_bridge_duplicate_state(). This helper is meant to be 635 * used as a bridge &drm_bridge_funcs.atomic_destroy_state hook for bridges 636 * that don't subclass the bridge state. 637 */ 638 void drm_atomic_helper_bridge_destroy_state(struct drm_bridge *bridge, 639 struct drm_bridge_state *state) 640 { 641 kfree(state); 642 } 643 EXPORT_SYMBOL(drm_atomic_helper_bridge_destroy_state); 644 645 /** 646 * __drm_atomic_helper_bridge_reset() - Initialize a bridge state to its 647 * default 648 * @bridge: the bridge this state refers to 649 * @state: bridge state to initialize 650 * 651 * Initializes the bridge state to default values. This is meant to be called 652 * by the bridge &drm_bridge_funcs.atomic_reset hook for bridges that subclass 653 * the bridge state. 654 */ 655 void __drm_atomic_helper_bridge_reset(struct drm_bridge *bridge, 656 struct drm_bridge_state *state) 657 { 658 memset(state, 0, sizeof(*state)); 659 state->bridge = bridge; 660 } 661 EXPORT_SYMBOL(__drm_atomic_helper_bridge_reset); 662 663 /** 664 * drm_atomic_helper_bridge_reset() - Allocate and initialize a bridge state 665 * to its default 666 * @bridge: the bridge this state refers to 667 * 668 * Allocates the bridge state and initializes it to default values. This helper 669 * is meant to be used as a bridge &drm_bridge_funcs.atomic_reset hook for 670 * bridges that don't subclass the bridge state. 671 */ 672 struct drm_bridge_state * 673 drm_atomic_helper_bridge_reset(struct drm_bridge *bridge) 674 { 675 struct drm_bridge_state *bridge_state; 676 677 bridge_state = kzalloc(sizeof(*bridge_state), GFP_KERNEL); 678 if (!bridge_state) 679 return ERR_PTR(-ENOMEM); 680 681 __drm_atomic_helper_bridge_reset(bridge, bridge_state); 682 return bridge_state; 683 } 684 EXPORT_SYMBOL(drm_atomic_helper_bridge_reset); 685