1 /* 2 * Copyright © 2006 Keith Packard 3 * Copyright © 2007-2008 Dave Airlie 4 * Copyright © 2007-2008 Intel Corporation 5 * Jesse Barnes <jesse.barnes@intel.com> 6 * Copyright © 2011-2013 Intel Corporation 7 * Copyright © 2015 Intel Corporation 8 * Daniel Vetter <daniel.vetter@ffwll.ch> 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining a 11 * copy of this software and associated documentation files (the "Software"), 12 * to deal in the Software without restriction, including without limitation 13 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 14 * and/or sell copies of the Software, and to permit persons to whom the 15 * Software is furnished to do so, subject to the following conditions: 16 * 17 * The above copyright notice and this permission notice shall be included in 18 * all copies or substantial portions of the Software. 19 * 20 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 21 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 22 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 23 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR 24 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 25 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 26 * OTHER DEALINGS IN THE SOFTWARE. 27 */ 28 29 #ifndef __DRM_MODESET_HELPER_VTABLES_H__ 30 #define __DRM_MODESET_HELPER_VTABLES_H__ 31 32 #include <drm/drm_crtc.h> 33 #include <drm/drm_encoder.h> 34 35 /** 36 * DOC: overview 37 * 38 * The DRM mode setting helper functions are common code for drivers to use if 39 * they wish. Drivers are not forced to use this code in their 40 * implementations but it would be useful if the code they do use at least 41 * provides a consistent interface and operation to userspace. Therefore it is 42 * highly recommended to use the provided helpers as much as possible. 43 * 44 * Because there is only one pointer per modeset object to hold a vfunc table 45 * for helper libraries they are by necessity shared among the different 46 * helpers. 47 * 48 * To make this clear all the helper vtables are pulled together in this location here. 49 */ 50 51 enum mode_set_atomic; 52 struct drm_writeback_connector; 53 struct drm_writeback_job; 54 55 /** 56 * struct drm_crtc_helper_funcs - helper operations for CRTCs 57 * 58 * These hooks are used by the legacy CRTC helpers, the transitional plane 59 * helpers and the new atomic modesetting helpers. 60 */ 61 struct drm_crtc_helper_funcs { 62 /** 63 * @dpms: 64 * 65 * Callback to control power levels on the CRTC. If the mode passed in 66 * is unsupported, the provider must use the next lowest power level. 67 * This is used by the legacy CRTC helpers to implement DPMS 68 * functionality in drm_helper_connector_dpms(). 69 * 70 * This callback is also used to disable a CRTC by calling it with 71 * DRM_MODE_DPMS_OFF if the @disable hook isn't used. 72 * 73 * This callback is used by the legacy CRTC helpers. Atomic helpers 74 * also support using this hook for enabling and disabling a CRTC to 75 * facilitate transitions to atomic, but it is deprecated. Instead 76 * @atomic_enable and @atomic_disable should be used. 77 */ 78 void (*dpms)(struct drm_crtc *crtc, int mode); 79 80 /** 81 * @prepare: 82 * 83 * This callback should prepare the CRTC for a subsequent modeset, which 84 * in practice means the driver should disable the CRTC if it is 85 * running. Most drivers ended up implementing this by calling their 86 * @dpms hook with DRM_MODE_DPMS_OFF. 87 * 88 * This callback is used by the legacy CRTC helpers. Atomic helpers 89 * also support using this hook for disabling a CRTC to facilitate 90 * transitions to atomic, but it is deprecated. Instead @atomic_disable 91 * should be used. 92 */ 93 void (*prepare)(struct drm_crtc *crtc); 94 95 /** 96 * @commit: 97 * 98 * This callback should commit the new mode on the CRTC after a modeset, 99 * which in practice means the driver should enable the CRTC. Most 100 * drivers ended up implementing this by calling their @dpms hook with 101 * DRM_MODE_DPMS_ON. 102 * 103 * This callback is used by the legacy CRTC helpers. Atomic helpers 104 * also support using this hook for enabling a CRTC to facilitate 105 * transitions to atomic, but it is deprecated. Instead @atomic_enable 106 * should be used. 107 */ 108 void (*commit)(struct drm_crtc *crtc); 109 110 /** 111 * @mode_valid: 112 * 113 * This callback is used to check if a specific mode is valid in this 114 * crtc. This should be implemented if the crtc has some sort of 115 * restriction in the modes it can display. For example, a given crtc 116 * may be responsible to set a clock value. If the clock can not 117 * produce all the values for the available modes then this callback 118 * can be used to restrict the number of modes to only the ones that 119 * can be displayed. 120 * 121 * This hook is used by the probe helpers to filter the mode list in 122 * drm_helper_probe_single_connector_modes(), and it is used by the 123 * atomic helpers to validate modes supplied by userspace in 124 * drm_atomic_helper_check_modeset(). 125 * 126 * This function is optional. 127 * 128 * NOTE: 129 * 130 * Since this function is both called from the check phase of an atomic 131 * commit, and the mode validation in the probe paths it is not allowed 132 * to look at anything else but the passed-in mode, and validate it 133 * against configuration-invariant hardward constraints. Any further 134 * limits which depend upon the configuration can only be checked in 135 * @mode_fixup or @atomic_check. 136 * 137 * RETURNS: 138 * 139 * drm_mode_status Enum 140 */ 141 enum drm_mode_status (*mode_valid)(struct drm_crtc *crtc, 142 const struct drm_display_mode *mode); 143 144 /** 145 * @mode_fixup: 146 * 147 * This callback is used to validate a mode. The parameter mode is the 148 * display mode that userspace requested, adjusted_mode is the mode the 149 * encoders need to be fed with. Note that this is the inverse semantics 150 * of the meaning for the &drm_encoder and &drm_bridge_funcs.mode_fixup 151 * vfunc. If the CRTC cannot support the requested conversion from mode 152 * to adjusted_mode it should reject the modeset. See also 153 * &drm_crtc_state.adjusted_mode for more details. 154 * 155 * This function is used by both legacy CRTC helpers and atomic helpers. 156 * With atomic helpers it is optional. 157 * 158 * NOTE: 159 * 160 * This function is called in the check phase of atomic modesets, which 161 * can be aborted for any reason (including on userspace's request to 162 * just check whether a configuration would be possible). Atomic drivers 163 * MUST NOT touch any persistent state (hardware or software) or data 164 * structures except the passed in adjusted_mode parameter. 165 * 166 * This is in contrast to the legacy CRTC helpers where this was 167 * allowed. 168 * 169 * Atomic drivers which need to inspect and adjust more state should 170 * instead use the @atomic_check callback, but note that they're not 171 * perfectly equivalent: @mode_valid is called from 172 * drm_atomic_helper_check_modeset(), but @atomic_check is called from 173 * drm_atomic_helper_check_planes(), because originally it was meant for 174 * plane update checks only. 175 * 176 * Also beware that userspace can request its own custom modes, neither 177 * core nor helpers filter modes to the list of probe modes reported by 178 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 179 * that modes are filtered consistently put any CRTC constraints and 180 * limits checks into @mode_valid. 181 * 182 * RETURNS: 183 * 184 * True if an acceptable configuration is possible, false if the modeset 185 * operation should be rejected. 186 */ 187 bool (*mode_fixup)(struct drm_crtc *crtc, 188 const struct drm_display_mode *mode, 189 struct drm_display_mode *adjusted_mode); 190 191 /** 192 * @mode_set: 193 * 194 * This callback is used by the legacy CRTC helpers to set a new mode, 195 * position and framebuffer. Since it ties the primary plane to every 196 * mode change it is incompatible with universal plane support. And 197 * since it can't update other planes it's incompatible with atomic 198 * modeset support. 199 * 200 * This callback is only used by CRTC helpers and deprecated. 201 * 202 * RETURNS: 203 * 204 * 0 on success or a negative error code on failure. 205 */ 206 int (*mode_set)(struct drm_crtc *crtc, struct drm_display_mode *mode, 207 struct drm_display_mode *adjusted_mode, int x, int y, 208 struct drm_framebuffer *old_fb); 209 210 /** 211 * @mode_set_nofb: 212 * 213 * This callback is used to update the display mode of a CRTC without 214 * changing anything of the primary plane configuration. This fits the 215 * requirement of atomic and hence is used by the atomic helpers. It is 216 * also used by the transitional plane helpers to implement a 217 * @mode_set hook in drm_helper_crtc_mode_set(). 218 * 219 * Note that the display pipe is completely off when this function is 220 * called. Atomic drivers which need hardware to be running before they 221 * program the new display mode (e.g. because they implement runtime PM) 222 * should not use this hook. This is because the helper library calls 223 * this hook only once per mode change and not every time the display 224 * pipeline is suspended using either DPMS or the new "ACTIVE" property. 225 * Which means register values set in this callback might get reset when 226 * the CRTC is suspended, but not restored. Such drivers should instead 227 * move all their CRTC setup into the @atomic_enable callback. 228 * 229 * This callback is optional. 230 */ 231 void (*mode_set_nofb)(struct drm_crtc *crtc); 232 233 /** 234 * @mode_set_base: 235 * 236 * This callback is used by the legacy CRTC helpers to set a new 237 * framebuffer and scanout position. It is optional and used as an 238 * optimized fast-path instead of a full mode set operation with all the 239 * resulting flickering. If it is not present 240 * drm_crtc_helper_set_config() will fall back to a full modeset, using 241 * the @mode_set callback. Since it can't update other planes it's 242 * incompatible with atomic modeset support. 243 * 244 * This callback is only used by the CRTC helpers and deprecated. 245 * 246 * RETURNS: 247 * 248 * 0 on success or a negative error code on failure. 249 */ 250 int (*mode_set_base)(struct drm_crtc *crtc, int x, int y, 251 struct drm_framebuffer *old_fb); 252 253 /** 254 * @mode_set_base_atomic: 255 * 256 * This callback is used by the fbdev helpers to set a new framebuffer 257 * and scanout without sleeping, i.e. from an atomic calling context. It 258 * is only used to implement kgdb support. 259 * 260 * This callback is optional and only needed for kgdb support in the fbdev 261 * helpers. 262 * 263 * RETURNS: 264 * 265 * 0 on success or a negative error code on failure. 266 */ 267 int (*mode_set_base_atomic)(struct drm_crtc *crtc, 268 struct drm_framebuffer *fb, int x, int y, 269 enum mode_set_atomic); 270 271 /** 272 * @disable: 273 * 274 * This callback should be used to disable the CRTC. With the atomic 275 * drivers it is called after all encoders connected to this CRTC have 276 * been shut off already using their own 277 * &drm_encoder_helper_funcs.disable hook. If that sequence is too 278 * simple drivers can just add their own hooks and call it from this 279 * CRTC callback here by looping over all encoders connected to it using 280 * for_each_encoder_on_crtc(). 281 * 282 * This hook is used both by legacy CRTC helpers and atomic helpers. 283 * Atomic drivers don't need to implement it if there's no need to 284 * disable anything at the CRTC level. To ensure that runtime PM 285 * handling (using either DPMS or the new "ACTIVE" property) works 286 * @disable must be the inverse of @atomic_enable for atomic drivers. 287 * Atomic drivers should consider to use @atomic_disable instead of 288 * this one. 289 * 290 * NOTE: 291 * 292 * With legacy CRTC helpers there's a big semantic difference between 293 * @disable and other hooks (like @prepare or @dpms) used to shut down a 294 * CRTC: @disable is only called when also logically disabling the 295 * display pipeline and needs to release any resources acquired in 296 * @mode_set (like shared PLLs, or again release pinned framebuffers). 297 * 298 * Therefore @disable must be the inverse of @mode_set plus @commit for 299 * drivers still using legacy CRTC helpers, which is different from the 300 * rules under atomic. 301 */ 302 void (*disable)(struct drm_crtc *crtc); 303 304 /** 305 * @atomic_check: 306 * 307 * Drivers should check plane-update related CRTC constraints in this 308 * hook. They can also check mode related limitations but need to be 309 * aware of the calling order, since this hook is used by 310 * drm_atomic_helper_check_planes() whereas the preparations needed to 311 * check output routing and the display mode is done in 312 * drm_atomic_helper_check_modeset(). Therefore drivers that want to 313 * check output routing and display mode constraints in this callback 314 * must ensure that drm_atomic_helper_check_modeset() has been called 315 * beforehand. This is calling order used by the default helper 316 * implementation in drm_atomic_helper_check(). 317 * 318 * When using drm_atomic_helper_check_planes() this hook is called 319 * after the &drm_plane_helper_funcs.atomic_check hook for planes, which 320 * allows drivers to assign shared resources requested by planes in this 321 * callback here. For more complicated dependencies the driver can call 322 * the provided check helpers multiple times until the computed state 323 * has a final configuration and everything has been checked. 324 * 325 * This function is also allowed to inspect any other object's state and 326 * can add more state objects to the atomic commit if needed. Care must 327 * be taken though to ensure that state check and compute functions for 328 * these added states are all called, and derived state in other objects 329 * all updated. Again the recommendation is to just call check helpers 330 * until a maximal configuration is reached. 331 * 332 * This callback is used by the atomic modeset helpers and by the 333 * transitional plane helpers, but it is optional. 334 * 335 * NOTE: 336 * 337 * This function is called in the check phase of an atomic update. The 338 * driver is not allowed to change anything outside of the free-standing 339 * state objects passed-in or assembled in the overall &drm_atomic_state 340 * update tracking structure. 341 * 342 * Also beware that userspace can request its own custom modes, neither 343 * core nor helpers filter modes to the list of probe modes reported by 344 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 345 * that modes are filtered consistently put any CRTC constraints and 346 * limits checks into @mode_valid. 347 * 348 * RETURNS: 349 * 350 * 0 on success, -EINVAL if the state or the transition can't be 351 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 352 * attempt to obtain another state object ran into a &drm_modeset_lock 353 * deadlock. 354 */ 355 int (*atomic_check)(struct drm_crtc *crtc, 356 struct drm_crtc_state *state); 357 358 /** 359 * @atomic_begin: 360 * 361 * Drivers should prepare for an atomic update of multiple planes on 362 * a CRTC in this hook. Depending upon hardware this might be vblank 363 * evasion, blocking updates by setting bits or doing preparatory work 364 * for e.g. manual update display. 365 * 366 * This hook is called before any plane commit functions are called. 367 * 368 * Note that the power state of the display pipe when this function is 369 * called depends upon the exact helpers and calling sequence the driver 370 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 371 * the tradeoffs and variants of plane commit helpers. 372 * 373 * This callback is used by the atomic modeset helpers and by the 374 * transitional plane helpers, but it is optional. 375 */ 376 void (*atomic_begin)(struct drm_crtc *crtc, 377 struct drm_crtc_state *old_crtc_state); 378 /** 379 * @atomic_flush: 380 * 381 * Drivers should finalize an atomic update of multiple planes on 382 * a CRTC in this hook. Depending upon hardware this might include 383 * checking that vblank evasion was successful, unblocking updates by 384 * setting bits or setting the GO bit to flush out all updates. 385 * 386 * Simple hardware or hardware with special requirements can commit and 387 * flush out all updates for all planes from this hook and forgo all the 388 * other commit hooks for plane updates. 389 * 390 * This hook is called after any plane commit functions are called. 391 * 392 * Note that the power state of the display pipe when this function is 393 * called depends upon the exact helpers and calling sequence the driver 394 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 395 * the tradeoffs and variants of plane commit helpers. 396 * 397 * This callback is used by the atomic modeset helpers and by the 398 * transitional plane helpers, but it is optional. 399 */ 400 void (*atomic_flush)(struct drm_crtc *crtc, 401 struct drm_crtc_state *old_crtc_state); 402 403 /** 404 * @atomic_enable: 405 * 406 * This callback should be used to enable the CRTC. With the atomic 407 * drivers it is called before all encoders connected to this CRTC are 408 * enabled through the encoder's own &drm_encoder_helper_funcs.enable 409 * hook. If that sequence is too simple drivers can just add their own 410 * hooks and call it from this CRTC callback here by looping over all 411 * encoders connected to it using for_each_encoder_on_crtc(). 412 * 413 * This hook is used only by atomic helpers, for symmetry with 414 * @atomic_disable. Atomic drivers don't need to implement it if there's 415 * no need to enable anything at the CRTC level. To ensure that runtime 416 * PM handling (using either DPMS or the new "ACTIVE" property) works 417 * @atomic_enable must be the inverse of @atomic_disable for atomic 418 * drivers. 419 * 420 * Drivers can use the @old_crtc_state input parameter if the operations 421 * needed to enable the CRTC don't depend solely on the new state but 422 * also on the transition between the old state and the new state. 423 */ 424 void (*atomic_enable)(struct drm_crtc *crtc, 425 struct drm_crtc_state *old_crtc_state); 426 427 /** 428 * @atomic_disable: 429 * 430 * This callback should be used to disable the CRTC. With the atomic 431 * drivers it is called after all encoders connected to this CRTC have 432 * been shut off already using their own 433 * &drm_encoder_helper_funcs.disable hook. If that sequence is too 434 * simple drivers can just add their own hooks and call it from this 435 * CRTC callback here by looping over all encoders connected to it using 436 * for_each_encoder_on_crtc(). 437 * 438 * This hook is used only by atomic helpers. Atomic drivers don't 439 * need to implement it if there's no need to disable anything at the 440 * CRTC level. 441 * 442 * Comparing to @disable, this one provides the additional input 443 * parameter @old_crtc_state which could be used to access the old 444 * state. Atomic drivers should consider to use this one instead 445 * of @disable. 446 */ 447 void (*atomic_disable)(struct drm_crtc *crtc, 448 struct drm_crtc_state *old_crtc_state); 449 }; 450 451 /** 452 * drm_crtc_helper_add - sets the helper vtable for a crtc 453 * @crtc: DRM CRTC 454 * @funcs: helper vtable to set for @crtc 455 */ 456 static inline void drm_crtc_helper_add(struct drm_crtc *crtc, 457 const struct drm_crtc_helper_funcs *funcs) 458 { 459 crtc->helper_private = funcs; 460 } 461 462 /** 463 * struct drm_encoder_helper_funcs - helper operations for encoders 464 * 465 * These hooks are used by the legacy CRTC helpers, the transitional plane 466 * helpers and the new atomic modesetting helpers. 467 */ 468 struct drm_encoder_helper_funcs { 469 /** 470 * @dpms: 471 * 472 * Callback to control power levels on the encoder. If the mode passed in 473 * is unsupported, the provider must use the next lowest power level. 474 * This is used by the legacy encoder helpers to implement DPMS 475 * functionality in drm_helper_connector_dpms(). 476 * 477 * This callback is also used to disable an encoder by calling it with 478 * DRM_MODE_DPMS_OFF if the @disable hook isn't used. 479 * 480 * This callback is used by the legacy CRTC helpers. Atomic helpers 481 * also support using this hook for enabling and disabling an encoder to 482 * facilitate transitions to atomic, but it is deprecated. Instead 483 * @enable and @disable should be used. 484 */ 485 void (*dpms)(struct drm_encoder *encoder, int mode); 486 487 /** 488 * @mode_valid: 489 * 490 * This callback is used to check if a specific mode is valid in this 491 * encoder. This should be implemented if the encoder has some sort 492 * of restriction in the modes it can display. For example, a given 493 * encoder may be responsible to set a clock value. If the clock can 494 * not produce all the values for the available modes then this callback 495 * can be used to restrict the number of modes to only the ones that 496 * can be displayed. 497 * 498 * This hook is used by the probe helpers to filter the mode list in 499 * drm_helper_probe_single_connector_modes(), and it is used by the 500 * atomic helpers to validate modes supplied by userspace in 501 * drm_atomic_helper_check_modeset(). 502 * 503 * This function is optional. 504 * 505 * NOTE: 506 * 507 * Since this function is both called from the check phase of an atomic 508 * commit, and the mode validation in the probe paths it is not allowed 509 * to look at anything else but the passed-in mode, and validate it 510 * against configuration-invariant hardward constraints. Any further 511 * limits which depend upon the configuration can only be checked in 512 * @mode_fixup or @atomic_check. 513 * 514 * RETURNS: 515 * 516 * drm_mode_status Enum 517 */ 518 enum drm_mode_status (*mode_valid)(struct drm_encoder *crtc, 519 const struct drm_display_mode *mode); 520 521 /** 522 * @mode_fixup: 523 * 524 * This callback is used to validate and adjust a mode. The parameter 525 * mode is the display mode that should be fed to the next element in 526 * the display chain, either the final &drm_connector or a &drm_bridge. 527 * The parameter adjusted_mode is the input mode the encoder requires. It 528 * can be modified by this callback and does not need to match mode. See 529 * also &drm_crtc_state.adjusted_mode for more details. 530 * 531 * This function is used by both legacy CRTC helpers and atomic helpers. 532 * This hook is optional. 533 * 534 * NOTE: 535 * 536 * This function is called in the check phase of atomic modesets, which 537 * can be aborted for any reason (including on userspace's request to 538 * just check whether a configuration would be possible). Atomic drivers 539 * MUST NOT touch any persistent state (hardware or software) or data 540 * structures except the passed in adjusted_mode parameter. 541 * 542 * This is in contrast to the legacy CRTC helpers where this was 543 * allowed. 544 * 545 * Atomic drivers which need to inspect and adjust more state should 546 * instead use the @atomic_check callback. If @atomic_check is used, 547 * this hook isn't called since @atomic_check allows a strict superset 548 * of the functionality of @mode_fixup. 549 * 550 * Also beware that userspace can request its own custom modes, neither 551 * core nor helpers filter modes to the list of probe modes reported by 552 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 553 * that modes are filtered consistently put any encoder constraints and 554 * limits checks into @mode_valid. 555 * 556 * RETURNS: 557 * 558 * True if an acceptable configuration is possible, false if the modeset 559 * operation should be rejected. 560 */ 561 bool (*mode_fixup)(struct drm_encoder *encoder, 562 const struct drm_display_mode *mode, 563 struct drm_display_mode *adjusted_mode); 564 565 /** 566 * @prepare: 567 * 568 * This callback should prepare the encoder for a subsequent modeset, 569 * which in practice means the driver should disable the encoder if it 570 * is running. Most drivers ended up implementing this by calling their 571 * @dpms hook with DRM_MODE_DPMS_OFF. 572 * 573 * This callback is used by the legacy CRTC helpers. Atomic helpers 574 * also support using this hook for disabling an encoder to facilitate 575 * transitions to atomic, but it is deprecated. Instead @disable should 576 * be used. 577 */ 578 void (*prepare)(struct drm_encoder *encoder); 579 580 /** 581 * @commit: 582 * 583 * This callback should commit the new mode on the encoder after a modeset, 584 * which in practice means the driver should enable the encoder. Most 585 * drivers ended up implementing this by calling their @dpms hook with 586 * DRM_MODE_DPMS_ON. 587 * 588 * This callback is used by the legacy CRTC helpers. Atomic helpers 589 * also support using this hook for enabling an encoder to facilitate 590 * transitions to atomic, but it is deprecated. Instead @enable should 591 * be used. 592 */ 593 void (*commit)(struct drm_encoder *encoder); 594 595 /** 596 * @mode_set: 597 * 598 * This callback is used to update the display mode of an encoder. 599 * 600 * Note that the display pipe is completely off when this function is 601 * called. Drivers which need hardware to be running before they program 602 * the new display mode (because they implement runtime PM) should not 603 * use this hook, because the helper library calls it only once and not 604 * every time the display pipeline is suspend using either DPMS or the 605 * new "ACTIVE" property. Such drivers should instead move all their 606 * encoder setup into the @enable callback. 607 * 608 * This callback is used both by the legacy CRTC helpers and the atomic 609 * modeset helpers. It is optional in the atomic helpers. 610 * 611 * NOTE: 612 * 613 * If the driver uses the atomic modeset helpers and needs to inspect 614 * the connector state or connector display info during mode setting, 615 * @atomic_mode_set can be used instead. 616 */ 617 void (*mode_set)(struct drm_encoder *encoder, 618 struct drm_display_mode *mode, 619 struct drm_display_mode *adjusted_mode); 620 621 /** 622 * @atomic_mode_set: 623 * 624 * This callback is used to update the display mode of an encoder. 625 * 626 * Note that the display pipe is completely off when this function is 627 * called. Drivers which need hardware to be running before they program 628 * the new display mode (because they implement runtime PM) should not 629 * use this hook, because the helper library calls it only once and not 630 * every time the display pipeline is suspended using either DPMS or the 631 * new "ACTIVE" property. Such drivers should instead move all their 632 * encoder setup into the @enable callback. 633 * 634 * This callback is used by the atomic modeset helpers in place of the 635 * @mode_set callback, if set by the driver. It is optional and should 636 * be used instead of @mode_set if the driver needs to inspect the 637 * connector state or display info, since there is no direct way to 638 * go from the encoder to the current connector. 639 */ 640 void (*atomic_mode_set)(struct drm_encoder *encoder, 641 struct drm_crtc_state *crtc_state, 642 struct drm_connector_state *conn_state); 643 644 /** 645 * @get_crtc: 646 * 647 * This callback is used by the legacy CRTC helpers to work around 648 * deficiencies in its own book-keeping. 649 * 650 * Do not use, use atomic helpers instead, which get the book keeping 651 * right. 652 * 653 * FIXME: 654 * 655 * Currently only nouveau is using this, and as soon as nouveau is 656 * atomic we can ditch this hook. 657 */ 658 struct drm_crtc *(*get_crtc)(struct drm_encoder *encoder); 659 660 /** 661 * @detect: 662 * 663 * This callback can be used by drivers who want to do detection on the 664 * encoder object instead of in connector functions. 665 * 666 * It is not used by any helper and therefore has purely driver-specific 667 * semantics. New drivers shouldn't use this and instead just implement 668 * their own private callbacks. 669 * 670 * FIXME: 671 * 672 * This should just be converted into a pile of driver vfuncs. 673 * Currently radeon, amdgpu and nouveau are using it. 674 */ 675 enum drm_connector_status (*detect)(struct drm_encoder *encoder, 676 struct drm_connector *connector); 677 678 /** 679 * @disable: 680 * 681 * This callback should be used to disable the encoder. With the atomic 682 * drivers it is called before this encoder's CRTC has been shut off 683 * using their own &drm_crtc_helper_funcs.disable hook. If that 684 * sequence is too simple drivers can just add their own driver private 685 * encoder hooks and call them from CRTC's callback by looping over all 686 * encoders connected to it using for_each_encoder_on_crtc(). 687 * 688 * This hook is used both by legacy CRTC helpers and atomic helpers. 689 * Atomic drivers don't need to implement it if there's no need to 690 * disable anything at the encoder level. To ensure that runtime PM 691 * handling (using either DPMS or the new "ACTIVE" property) works 692 * @disable must be the inverse of @enable for atomic drivers. 693 * 694 * NOTE: 695 * 696 * With legacy CRTC helpers there's a big semantic difference between 697 * @disable and other hooks (like @prepare or @dpms) used to shut down a 698 * encoder: @disable is only called when also logically disabling the 699 * display pipeline and needs to release any resources acquired in 700 * @mode_set (like shared PLLs, or again release pinned framebuffers). 701 * 702 * Therefore @disable must be the inverse of @mode_set plus @commit for 703 * drivers still using legacy CRTC helpers, which is different from the 704 * rules under atomic. 705 */ 706 void (*disable)(struct drm_encoder *encoder); 707 708 /** 709 * @enable: 710 * 711 * This callback should be used to enable the encoder. With the atomic 712 * drivers it is called after this encoder's CRTC has been enabled using 713 * their own &drm_crtc_helper_funcs.enable hook. If that sequence is 714 * too simple drivers can just add their own driver private encoder 715 * hooks and call them from CRTC's callback by looping over all encoders 716 * connected to it using for_each_encoder_on_crtc(). 717 * 718 * This hook is used only by atomic helpers, for symmetry with @disable. 719 * Atomic drivers don't need to implement it if there's no need to 720 * enable anything at the encoder level. To ensure that runtime PM handling 721 * (using either DPMS or the new "ACTIVE" property) works 722 * @enable must be the inverse of @disable for atomic drivers. 723 */ 724 void (*enable)(struct drm_encoder *encoder); 725 726 /** 727 * @atomic_check: 728 * 729 * This callback is used to validate encoder state for atomic drivers. 730 * Since the encoder is the object connecting the CRTC and connector it 731 * gets passed both states, to be able to validate interactions and 732 * update the CRTC to match what the encoder needs for the requested 733 * connector. 734 * 735 * Since this provides a strict superset of the functionality of 736 * @mode_fixup (the requested and adjusted modes are both available 737 * through the passed in &struct drm_crtc_state) @mode_fixup is not 738 * called when @atomic_check is implemented. 739 * 740 * This function is used by the atomic helpers, but it is optional. 741 * 742 * NOTE: 743 * 744 * This function is called in the check phase of an atomic update. The 745 * driver is not allowed to change anything outside of the free-standing 746 * state objects passed-in or assembled in the overall &drm_atomic_state 747 * update tracking structure. 748 * 749 * Also beware that userspace can request its own custom modes, neither 750 * core nor helpers filter modes to the list of probe modes reported by 751 * the GETCONNECTOR IOCTL and stored in &drm_connector.modes. To ensure 752 * that modes are filtered consistently put any encoder constraints and 753 * limits checks into @mode_valid. 754 * 755 * RETURNS: 756 * 757 * 0 on success, -EINVAL if the state or the transition can't be 758 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 759 * attempt to obtain another state object ran into a &drm_modeset_lock 760 * deadlock. 761 */ 762 int (*atomic_check)(struct drm_encoder *encoder, 763 struct drm_crtc_state *crtc_state, 764 struct drm_connector_state *conn_state); 765 }; 766 767 /** 768 * drm_encoder_helper_add - sets the helper vtable for an encoder 769 * @encoder: DRM encoder 770 * @funcs: helper vtable to set for @encoder 771 */ 772 static inline void drm_encoder_helper_add(struct drm_encoder *encoder, 773 const struct drm_encoder_helper_funcs *funcs) 774 { 775 encoder->helper_private = funcs; 776 } 777 778 /** 779 * struct drm_connector_helper_funcs - helper operations for connectors 780 * 781 * These functions are used by the atomic and legacy modeset helpers and by the 782 * probe helpers. 783 */ 784 struct drm_connector_helper_funcs { 785 /** 786 * @get_modes: 787 * 788 * This function should fill in all modes currently valid for the sink 789 * into the &drm_connector.probed_modes list. It should also update the 790 * EDID property by calling drm_connector_update_edid_property(). 791 * 792 * The usual way to implement this is to cache the EDID retrieved in the 793 * probe callback somewhere in the driver-private connector structure. 794 * In this function drivers then parse the modes in the EDID and add 795 * them by calling drm_add_edid_modes(). But connectors that driver a 796 * fixed panel can also manually add specific modes using 797 * drm_mode_probed_add(). Drivers which manually add modes should also 798 * make sure that the &drm_connector.display_info, 799 * &drm_connector.width_mm and &drm_connector.height_mm fields are 800 * filled in. 801 * 802 * Virtual drivers that just want some standard VESA mode with a given 803 * resolution can call drm_add_modes_noedid(), and mark the preferred 804 * one using drm_set_preferred_mode(). 805 * 806 * This function is only called after the @detect hook has indicated 807 * that a sink is connected and when the EDID isn't overridden through 808 * sysfs or the kernel commandline. 809 * 810 * This callback is used by the probe helpers in e.g. 811 * drm_helper_probe_single_connector_modes(). 812 * 813 * To avoid races with concurrent connector state updates, the helper 814 * libraries always call this with the &drm_mode_config.connection_mutex 815 * held. Because of this it's safe to inspect &drm_connector->state. 816 * 817 * RETURNS: 818 * 819 * The number of modes added by calling drm_mode_probed_add(). 820 */ 821 int (*get_modes)(struct drm_connector *connector); 822 823 /** 824 * @detect_ctx: 825 * 826 * Check to see if anything is attached to the connector. The parameter 827 * force is set to false whilst polling, true when checking the 828 * connector due to a user request. force can be used by the driver to 829 * avoid expensive, destructive operations during automated probing. 830 * 831 * This callback is optional, if not implemented the connector will be 832 * considered as always being attached. 833 * 834 * This is the atomic version of &drm_connector_funcs.detect. 835 * 836 * To avoid races against concurrent connector state updates, the 837 * helper libraries always call this with ctx set to a valid context, 838 * and &drm_mode_config.connection_mutex will always be locked with 839 * the ctx parameter set to this ctx. This allows taking additional 840 * locks as required. 841 * 842 * RETURNS: 843 * 844 * &drm_connector_status indicating the connector's status, 845 * or the error code returned by drm_modeset_lock(), -EDEADLK. 846 */ 847 int (*detect_ctx)(struct drm_connector *connector, 848 struct drm_modeset_acquire_ctx *ctx, 849 bool force); 850 851 /** 852 * @mode_valid: 853 * 854 * Callback to validate a mode for a connector, irrespective of the 855 * specific display configuration. 856 * 857 * This callback is used by the probe helpers to filter the mode list 858 * (which is usually derived from the EDID data block from the sink). 859 * See e.g. drm_helper_probe_single_connector_modes(). 860 * 861 * This function is optional. 862 * 863 * NOTE: 864 * 865 * This only filters the mode list supplied to userspace in the 866 * GETCONNECTOR IOCTL. Compared to &drm_encoder_helper_funcs.mode_valid, 867 * &drm_crtc_helper_funcs.mode_valid and &drm_bridge_funcs.mode_valid, 868 * which are also called by the atomic helpers from 869 * drm_atomic_helper_check_modeset(). This allows userspace to force and 870 * ignore sink constraint (like the pixel clock limits in the screen's 871 * EDID), which is useful for e.g. testing, or working around a broken 872 * EDID. Any source hardware constraint (which always need to be 873 * enforced) therefore should be checked in one of the above callbacks, 874 * and not this one here. 875 * 876 * To avoid races with concurrent connector state updates, the helper 877 * libraries always call this with the &drm_mode_config.connection_mutex 878 * held. Because of this it's safe to inspect &drm_connector->state. 879 * 880 * RETURNS: 881 * 882 * Either &drm_mode_status.MODE_OK or one of the failure reasons in &enum 883 * drm_mode_status. 884 */ 885 enum drm_mode_status (*mode_valid)(struct drm_connector *connector, 886 struct drm_display_mode *mode); 887 /** 888 * @best_encoder: 889 * 890 * This function should select the best encoder for the given connector. 891 * 892 * This function is used by both the atomic helpers (in the 893 * drm_atomic_helper_check_modeset() function) and in the legacy CRTC 894 * helpers. 895 * 896 * NOTE: 897 * 898 * In atomic drivers this function is called in the check phase of an 899 * atomic update. The driver is not allowed to change or inspect 900 * anything outside of arguments passed-in. Atomic drivers which need to 901 * inspect dynamic configuration state should instead use 902 * @atomic_best_encoder. 903 * 904 * You can leave this function to NULL if the connector is only 905 * attached to a single encoder and you are using the atomic helpers. 906 * In this case, the core will call drm_atomic_helper_best_encoder() 907 * for you. 908 * 909 * RETURNS: 910 * 911 * Encoder that should be used for the given connector and connector 912 * state, or NULL if no suitable encoder exists. Note that the helpers 913 * will ensure that encoders aren't used twice, drivers should not check 914 * for this. 915 */ 916 struct drm_encoder *(*best_encoder)(struct drm_connector *connector); 917 918 /** 919 * @atomic_best_encoder: 920 * 921 * This is the atomic version of @best_encoder for atomic drivers which 922 * need to select the best encoder depending upon the desired 923 * configuration and can't select it statically. 924 * 925 * This function is used by drm_atomic_helper_check_modeset(). 926 * If it is not implemented, the core will fallback to @best_encoder 927 * (or drm_atomic_helper_best_encoder() if @best_encoder is NULL). 928 * 929 * NOTE: 930 * 931 * This function is called in the check phase of an atomic update. The 932 * driver is not allowed to change anything outside of the free-standing 933 * state objects passed-in or assembled in the overall &drm_atomic_state 934 * update tracking structure. 935 * 936 * RETURNS: 937 * 938 * Encoder that should be used for the given connector and connector 939 * state, or NULL if no suitable encoder exists. Note that the helpers 940 * will ensure that encoders aren't used twice, drivers should not check 941 * for this. 942 */ 943 struct drm_encoder *(*atomic_best_encoder)(struct drm_connector *connector, 944 struct drm_connector_state *connector_state); 945 946 /** 947 * @atomic_check: 948 * 949 * This hook is used to validate connector state. This function is 950 * called from &drm_atomic_helper_check_modeset, and is called when 951 * a connector property is set, or a modeset on the crtc is forced. 952 * 953 * Because &drm_atomic_helper_check_modeset may be called multiple times, 954 * this function should handle being called multiple times as well. 955 * 956 * This function is also allowed to inspect any other object's state and 957 * can add more state objects to the atomic commit if needed. Care must 958 * be taken though to ensure that state check and compute functions for 959 * these added states are all called, and derived state in other objects 960 * all updated. Again the recommendation is to just call check helpers 961 * until a maximal configuration is reached. 962 * 963 * NOTE: 964 * 965 * This function is called in the check phase of an atomic update. The 966 * driver is not allowed to change anything outside of the free-standing 967 * state objects passed-in or assembled in the overall &drm_atomic_state 968 * update tracking structure. 969 * 970 * RETURNS: 971 * 972 * 0 on success, -EINVAL if the state or the transition can't be 973 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 974 * attempt to obtain another state object ran into a &drm_modeset_lock 975 * deadlock. 976 */ 977 int (*atomic_check)(struct drm_connector *connector, 978 struct drm_connector_state *state); 979 980 /** 981 * @atomic_commit: 982 * 983 * This hook is to be used by drivers implementing writeback connectors 984 * that need a point when to commit the writeback job to the hardware. 985 * The writeback_job to commit is available in 986 * &drm_connector_state.writeback_job. 987 * 988 * This hook is optional. 989 * 990 * This callback is used by the atomic modeset helpers. 991 */ 992 void (*atomic_commit)(struct drm_connector *connector, 993 struct drm_connector_state *state); 994 995 int (*prepare_writeback_job)(struct drm_writeback_connector *connector, 996 struct drm_writeback_job *job); 997 void (*cleanup_writeback_job)(struct drm_writeback_connector *connector, 998 struct drm_writeback_job *job); 999 }; 1000 1001 /** 1002 * drm_connector_helper_add - sets the helper vtable for a connector 1003 * @connector: DRM connector 1004 * @funcs: helper vtable to set for @connector 1005 */ 1006 static inline void drm_connector_helper_add(struct drm_connector *connector, 1007 const struct drm_connector_helper_funcs *funcs) 1008 { 1009 connector->helper_private = funcs; 1010 } 1011 1012 /** 1013 * struct drm_plane_helper_funcs - helper operations for planes 1014 * 1015 * These functions are used by the atomic helpers and by the transitional plane 1016 * helpers. 1017 */ 1018 struct drm_plane_helper_funcs { 1019 /** 1020 * @prepare_fb: 1021 * 1022 * This hook is to prepare a framebuffer for scanout by e.g. pinning 1023 * its backing storage or relocating it into a contiguous block of 1024 * VRAM. Other possible preparatory work includes flushing caches. 1025 * 1026 * This function must not block for outstanding rendering, since it is 1027 * called in the context of the atomic IOCTL even for async commits to 1028 * be able to return any errors to userspace. Instead the recommended 1029 * way is to fill out the &drm_plane_state.fence of the passed-in 1030 * &drm_plane_state. If the driver doesn't support native fences then 1031 * equivalent functionality should be implemented through private 1032 * members in the plane structure. 1033 * 1034 * Drivers which always have their buffers pinned should use 1035 * drm_gem_fb_prepare_fb() for this hook. 1036 * 1037 * The helpers will call @cleanup_fb with matching arguments for every 1038 * successful call to this hook. 1039 * 1040 * This callback is used by the atomic modeset helpers and by the 1041 * transitional plane helpers, but it is optional. 1042 * 1043 * RETURNS: 1044 * 1045 * 0 on success or one of the following negative error codes allowed by 1046 * the &drm_mode_config_funcs.atomic_commit vfunc. When using helpers 1047 * this callback is the only one which can fail an atomic commit, 1048 * everything else must complete successfully. 1049 */ 1050 int (*prepare_fb)(struct drm_plane *plane, 1051 struct drm_plane_state *new_state); 1052 /** 1053 * @cleanup_fb: 1054 * 1055 * This hook is called to clean up any resources allocated for the given 1056 * framebuffer and plane configuration in @prepare_fb. 1057 * 1058 * This callback is used by the atomic modeset helpers and by the 1059 * transitional plane helpers, but it is optional. 1060 */ 1061 void (*cleanup_fb)(struct drm_plane *plane, 1062 struct drm_plane_state *old_state); 1063 1064 /** 1065 * @atomic_check: 1066 * 1067 * Drivers should check plane specific constraints in this hook. 1068 * 1069 * When using drm_atomic_helper_check_planes() plane's @atomic_check 1070 * hooks are called before the ones for CRTCs, which allows drivers to 1071 * request shared resources that the CRTC controls here. For more 1072 * complicated dependencies the driver can call the provided check helpers 1073 * multiple times until the computed state has a final configuration and 1074 * everything has been checked. 1075 * 1076 * This function is also allowed to inspect any other object's state and 1077 * can add more state objects to the atomic commit if needed. Care must 1078 * be taken though to ensure that state check and compute functions for 1079 * these added states are all called, and derived state in other objects 1080 * all updated. Again the recommendation is to just call check helpers 1081 * until a maximal configuration is reached. 1082 * 1083 * This callback is used by the atomic modeset helpers and by the 1084 * transitional plane helpers, but it is optional. 1085 * 1086 * NOTE: 1087 * 1088 * This function is called in the check phase of an atomic update. The 1089 * driver is not allowed to change anything outside of the free-standing 1090 * state objects passed-in or assembled in the overall &drm_atomic_state 1091 * update tracking structure. 1092 * 1093 * RETURNS: 1094 * 1095 * 0 on success, -EINVAL if the state or the transition can't be 1096 * supported, -ENOMEM on memory allocation failure and -EDEADLK if an 1097 * attempt to obtain another state object ran into a &drm_modeset_lock 1098 * deadlock. 1099 */ 1100 int (*atomic_check)(struct drm_plane *plane, 1101 struct drm_plane_state *state); 1102 1103 /** 1104 * @atomic_update: 1105 * 1106 * Drivers should use this function to update the plane state. This 1107 * hook is called in-between the &drm_crtc_helper_funcs.atomic_begin and 1108 * drm_crtc_helper_funcs.atomic_flush callbacks. 1109 * 1110 * Note that the power state of the display pipe when this function is 1111 * called depends upon the exact helpers and calling sequence the driver 1112 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 1113 * the tradeoffs and variants of plane commit helpers. 1114 * 1115 * This callback is used by the atomic modeset helpers and by the 1116 * transitional plane helpers, but it is optional. 1117 */ 1118 void (*atomic_update)(struct drm_plane *plane, 1119 struct drm_plane_state *old_state); 1120 /** 1121 * @atomic_disable: 1122 * 1123 * Drivers should use this function to unconditionally disable a plane. 1124 * This hook is called in-between the 1125 * &drm_crtc_helper_funcs.atomic_begin and 1126 * drm_crtc_helper_funcs.atomic_flush callbacks. It is an alternative to 1127 * @atomic_update, which will be called for disabling planes, too, if 1128 * the @atomic_disable hook isn't implemented. 1129 * 1130 * This hook is also useful to disable planes in preparation of a modeset, 1131 * by calling drm_atomic_helper_disable_planes_on_crtc() from the 1132 * &drm_crtc_helper_funcs.disable hook. 1133 * 1134 * Note that the power state of the display pipe when this function is 1135 * called depends upon the exact helpers and calling sequence the driver 1136 * has picked. See drm_atomic_helper_commit_planes() for a discussion of 1137 * the tradeoffs and variants of plane commit helpers. 1138 * 1139 * This callback is used by the atomic modeset helpers and by the 1140 * transitional plane helpers, but it is optional. 1141 */ 1142 void (*atomic_disable)(struct drm_plane *plane, 1143 struct drm_plane_state *old_state); 1144 1145 /** 1146 * @atomic_async_check: 1147 * 1148 * Drivers should set this function pointer to check if the plane state 1149 * can be updated in a async fashion. Here async means "not vblank 1150 * synchronized". 1151 * 1152 * This hook is called by drm_atomic_async_check() to establish if a 1153 * given update can be committed asynchronously, that is, if it can 1154 * jump ahead of the state currently queued for update. 1155 * 1156 * RETURNS: 1157 * 1158 * Return 0 on success and any error returned indicates that the update 1159 * can not be applied in asynchronous manner. 1160 */ 1161 int (*atomic_async_check)(struct drm_plane *plane, 1162 struct drm_plane_state *state); 1163 1164 /** 1165 * @atomic_async_update: 1166 * 1167 * Drivers should set this function pointer to perform asynchronous 1168 * updates of planes, that is, jump ahead of the currently queued 1169 * state and update the plane. Here async means "not vblank 1170 * synchronized". 1171 * 1172 * This hook is called by drm_atomic_helper_async_commit(). 1173 * 1174 * An async update will happen on legacy cursor updates. An async 1175 * update won't happen if there is an outstanding commit modifying 1176 * the same plane. 1177 * 1178 * Note that unlike &drm_plane_helper_funcs.atomic_update this hook 1179 * takes the new &drm_plane_state as parameter. When doing async_update 1180 * drivers shouldn't replace the &drm_plane_state but update the 1181 * current one with the new plane configurations in the new 1182 * plane_state. 1183 * 1184 * FIXME: 1185 * - It only works for single plane updates 1186 * - Async Pageflips are not supported yet 1187 * - Some hw might still scan out the old buffer until the next 1188 * vblank, however we let go of the fb references as soon as 1189 * we run this hook. For now drivers must implement their own workers 1190 * for deferring if needed, until a common solution is created. 1191 */ 1192 void (*atomic_async_update)(struct drm_plane *plane, 1193 struct drm_plane_state *new_state); 1194 }; 1195 1196 /** 1197 * drm_plane_helper_add - sets the helper vtable for a plane 1198 * @plane: DRM plane 1199 * @funcs: helper vtable to set for @plane 1200 */ 1201 static inline void drm_plane_helper_add(struct drm_plane *plane, 1202 const struct drm_plane_helper_funcs *funcs) 1203 { 1204 plane->helper_private = funcs; 1205 } 1206 1207 /** 1208 * struct drm_mode_config_helper_funcs - global modeset helper operations 1209 * 1210 * These helper functions are used by the atomic helpers. 1211 */ 1212 struct drm_mode_config_helper_funcs { 1213 /** 1214 * @atomic_commit_tail: 1215 * 1216 * This hook is used by the default atomic_commit() hook implemented in 1217 * drm_atomic_helper_commit() together with the nonblocking commit 1218 * helpers (see drm_atomic_helper_setup_commit() for a starting point) 1219 * to implement blocking and nonblocking commits easily. It is not used 1220 * by the atomic helpers 1221 * 1222 * This function is called when the new atomic state has already been 1223 * swapped into the various state pointers. The passed in state 1224 * therefore contains copies of the old/previous state. This hook should 1225 * commit the new state into hardware. Note that the helpers have 1226 * already waited for preceeding atomic commits and fences, but drivers 1227 * can add more waiting calls at the start of their implementation, e.g. 1228 * to wait for driver-internal request for implicit syncing, before 1229 * starting to commit the update to the hardware. 1230 * 1231 * After the atomic update is committed to the hardware this hook needs 1232 * to call drm_atomic_helper_commit_hw_done(). Then wait for the upate 1233 * to be executed by the hardware, for example using 1234 * drm_atomic_helper_wait_for_vblanks() or 1235 * drm_atomic_helper_wait_for_flip_done(), and then clean up the old 1236 * framebuffers using drm_atomic_helper_cleanup_planes(). 1237 * 1238 * When disabling a CRTC this hook _must_ stall for the commit to 1239 * complete. Vblank waits don't work on disabled CRTC, hence the core 1240 * can't take care of this. And it also can't rely on the vblank event, 1241 * since that can be signalled already when the screen shows black, 1242 * which can happen much earlier than the last hardware access needed to 1243 * shut off the display pipeline completely. 1244 * 1245 * This hook is optional, the default implementation is 1246 * drm_atomic_helper_commit_tail(). 1247 */ 1248 void (*atomic_commit_tail)(struct drm_atomic_state *state); 1249 }; 1250 1251 #endif 1252