drivers/gpu/drm/drm_crtc_helper.c

   1 /*
   2  * Copyright (c) 2006-2008 Intel Corporation
   3  * Copyright (c) 2007 Dave Airlie <airlied@linux.ie>
   4  *
   5  * DRM core CRTC related functions
   6  *
   7  * Permission to use, copy, modify, distribute, and sell this software and its
   8  * documentation for any purpose is hereby granted without fee, provided that
   9  * the above copyright notice appear in all copies and that both that copyright
  10  * notice and this permission notice appear in supporting documentation, and
  11  * that the name of the copyright holders not be used in advertising or
  12  * publicity pertaining to distribution of the software without specific,
  13  * written prior permission.  The copyright holders make no representations
  14  * about the suitability of this software for any purpose.  It is provided "as
  15  * is" without express or implied warranty.
  16  *
  17  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  18  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  19  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  20  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  21  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  22  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  23  * OF THIS SOFTWARE.
  24  *
  25  * Authors:
  26  *      Keith Packard
  27  *      Eric Anholt <eric@anholt.net>
  28  *      Dave Airlie <airlied@linux.ie>
  29  *      Jesse Barnes <jesse.barnes@intel.com>
  30  */
  31
  32 #include <linux/kernel.h>
  33 #include <linux/export.h>
  34 #include <linux/moduleparam.h>
  35
  36 #include <drm/drmP.h>
  37 #include <drm/drm_atomic.h>
  38 #include <drm/drm_atomic_uapi.h>
  39 #include <drm/drm_crtc.h>
  40 #include <drm/drm_encoder.h>
  41 #include <drm/drm_fourcc.h>
  42 #include <drm/drm_crtc_helper.h>
  43 #include <drm/drm_fb_helper.h>
  44 #include <drm/drm_plane_helper.h>
  45 #include <drm/drm_atomic_helper.h>
  46 #include <drm/drm_edid.h>
  47
  48 /**
  49  * DOC: overview
  50  *
  51  * The CRTC modeset helper library provides a default set_config implementation
  52  * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
  53  * the same callbacks which drivers can use to e.g. restore the modeset
  54  * configuration on resume with drm_helper_resume_force_mode().
  55  *
  56  * Note that this helper library doesn't track the current power state of CRTCs
  57  * and encoders. It can call callbacks like &drm_encoder_helper_funcs.dpms even
  58  * though the hardware is already in the desired state. This deficiency has been
  59  * fixed in the atomic helpers.
  60  *
  61  * The driver callbacks are mostly compatible with the atomic modeset helpers,
  62  * except for the handling of the primary plane: Atomic helpers require that the
  63  * primary plane is implemented as a real standalone plane and not directly tied
  64  * to the CRTC state. For easier transition this library provides functions to
  65  * implement the old semantics required by the CRTC helpers using the new plane
  66  * and atomic helper callbacks.
  67  *
  68  * Drivers are strongly urged to convert to the atomic helpers (by way of first
  69  * converting to the plane helpers). New drivers must not use these functions
  70  * but need to implement the atomic interface instead, potentially using the
  71  * atomic helpers for that.
  72  *
  73  * These legacy modeset helpers use the same function table structures as
  74  * all other modesetting helpers. See the documentation for struct
  75  * &drm_crtc_helper_funcs, &struct drm_encoder_helper_funcs and struct
  76  * &drm_connector_helper_funcs.
  77  */
  78
  79 /**
  80  * drm_helper_encoder_in_use - check if a given encoder is in use
  81  * @encoder: encoder to check
  82  *
  83  * Checks whether @encoder is with the current mode setting output configuration
  84  * in use by any connector. This doesn't mean that it is actually enabled since
  85  * the DPMS state is tracked separately.
  86  *
  87  * Returns:
  88  * True if @encoder is used, false otherwise.
  89  */
  90 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
  91 {
  92         struct drm_connector *connector;
  93         struct drm_connector_list_iter conn_iter;
  94         struct drm_device *dev = encoder->dev;
  95
  96         WARN_ON(drm_drv_uses_atomic_modeset(dev));
  97
  98         /*
  99          * We can expect this mutex to be locked if we are not panicking.
 100          * Locking is currently fubar in the panic handler.
 101          */
 102         if (!oops_in_progress) {
 103                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 104                 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 105         }
 106
 107
 108         drm_connector_list_iter_begin(dev, &conn_iter);
 109         drm_for_each_connector_iter(connector, &conn_iter) {
 110                 if (connector->encoder == encoder) {
 111                         drm_connector_list_iter_end(&conn_iter);
 112                         return true;
 113                 }
 114         }
 115         drm_connector_list_iter_end(&conn_iter);
 116         return false;
 117 }
 118 EXPORT_SYMBOL(drm_helper_encoder_in_use);
 119
 120 /**
 121  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
 122  * @crtc: CRTC to check
 123  *
 124  * Checks whether @crtc is with the current mode setting output configuration
 125  * in use by any connector. This doesn't mean that it is actually enabled since
 126  * the DPMS state is tracked separately.
 127  *
 128  * Returns:
 129  * True if @crtc is used, false otherwise.
 130  */
 131 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
 132 {
 133         struct drm_encoder *encoder;
 134         struct drm_device *dev = crtc->dev;
 135
 136         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 137
 138         /*
 139          * We can expect this mutex to be locked if we are not panicking.
 140          * Locking is currently fubar in the panic handler.
 141          */
 142         if (!oops_in_progress)
 143                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 144
 145         drm_for_each_encoder(encoder, dev)
 146                 if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
 147                         return true;
 148         return false;
 149 }
 150 EXPORT_SYMBOL(drm_helper_crtc_in_use);
 151
 152 static void
 153 drm_encoder_disable(struct drm_encoder *encoder)
 154 {
 155         const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 156
 157         if (!encoder_funcs)
 158                 return;
 159
 160         drm_bridge_disable(encoder->bridge);
 161
 162         if (encoder_funcs->disable)
 163                 (*encoder_funcs->disable)(encoder);
 164         else if (encoder_funcs->dpms)
 165                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
 166
 167         drm_bridge_post_disable(encoder->bridge);
 168 }
 169
 170 static void __drm_helper_disable_unused_functions(struct drm_device *dev)
 171 {
 172         struct drm_encoder *encoder;
 173         struct drm_crtc *crtc;
 174
 175         drm_warn_on_modeset_not_all_locked(dev);
 176
 177         drm_for_each_encoder(encoder, dev) {
 178                 if (!drm_helper_encoder_in_use(encoder)) {
 179                         drm_encoder_disable(encoder);
 180                         /* disconnect encoder from any connector */
 181                         encoder->crtc = NULL;
 182                 }
 183         }
 184
 185         drm_for_each_crtc(crtc, dev) {
 186                 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 187                 crtc->enabled = drm_helper_crtc_in_use(crtc);
 188                 if (!crtc->enabled) {
 189                         if (crtc_funcs->disable)
 190                                 (*crtc_funcs->disable)(crtc);
 191                         else
 192                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
 193                         crtc->primary->fb = NULL;
 194                 }
 195         }
 196 }
 197
 198 /**
 199  * drm_helper_disable_unused_functions - disable unused objects
 200  * @dev: DRM device
 201  *
 202  * This function walks through the entire mode setting configuration of @dev. It
 203  * will remove any CRTC links of unused encoders and encoder links of
 204  * disconnected connectors. Then it will disable all unused encoders and CRTCs
 205  * either by calling their disable callback if available or by calling their
 206  * dpms callback with DRM_MODE_DPMS_OFF.
 207  *
 208  * NOTE:
 209  *
 210  * This function is part of the legacy modeset helper library and will cause
 211  * major confusion with atomic drivers. This is because atomic helpers guarantee
 212  * to never call ->disable() hooks on a disabled function, or ->enable() hooks
 213  * on an enabled functions. drm_helper_disable_unused_functions() on the other
 214  * hand throws such guarantees into the wind and calls disable hooks
 215  * unconditionally on unused functions.
 216  */
 217 void drm_helper_disable_unused_functions(struct drm_device *dev)
 218 {
 219         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 220
 221         drm_modeset_lock_all(dev);
 222         __drm_helper_disable_unused_functions(dev);
 223         drm_modeset_unlock_all(dev);
 224 }
 225 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
 226
 227 /*
 228  * Check the CRTC we're going to map each output to vs. its current
 229  * CRTC.  If they don't match, we have to disable the output and the CRTC
 230  * since the driver will have to re-route things.
 231  */
 232 static void
 233 drm_crtc_prepare_encoders(struct drm_device *dev)
 234 {
 235         const struct drm_encoder_helper_funcs *encoder_funcs;
 236         struct drm_encoder *encoder;
 237
 238         drm_for_each_encoder(encoder, dev) {
 239                 encoder_funcs = encoder->helper_private;
 240                 if (!encoder_funcs)
 241                         continue;
 242
 243                 /* Disable unused encoders */
 244                 if (encoder->crtc == NULL)
 245                         drm_encoder_disable(encoder);
 246                 /* Disable encoders whose CRTC is about to change */
 247                 if (encoder_funcs->get_crtc &&
 248                     encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
 249                         drm_encoder_disable(encoder);
 250         }
 251 }
 252
 253 /**
 254  * drm_crtc_helper_set_mode - internal helper to set a mode
 255  * @crtc: CRTC to program
 256  * @mode: mode to use
 257  * @x: horizontal offset into the surface
 258  * @y: vertical offset into the surface
 259  * @old_fb: old framebuffer, for cleanup
 260  *
 261  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 262  * to fixup or reject the mode prior to trying to set it. This is an internal
 263  * helper that drivers could e.g. use to update properties that require the
 264  * entire output pipe to be disabled and re-enabled in a new configuration. For
 265  * example for changing whether audio is enabled on a hdmi link or for changing
 266  * panel fitter or dither attributes. It is also called by the
 267  * drm_crtc_helper_set_config() helper function to drive the mode setting
 268  * sequence.
 269  *
 270  * Returns:
 271  * True if the mode was set successfully, false otherwise.
 272  */
 273 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 274                               struct drm_display_mode *mode,
 275                               int x, int y,
 276                               struct drm_framebuffer *old_fb)
 277 {
 278         struct drm_device *dev = crtc->dev;
 279         struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
 280         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 281         const struct drm_encoder_helper_funcs *encoder_funcs;
 282         int saved_x, saved_y;
 283         bool saved_enabled;
 284         struct drm_encoder *encoder;
 285         bool ret = true;
 286
 287         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 288
 289         drm_warn_on_modeset_not_all_locked(dev);
 290
 291         saved_enabled = crtc->enabled;
 292         crtc->enabled = drm_helper_crtc_in_use(crtc);
 293         if (!crtc->enabled)
 294                 return true;
 295
 296         adjusted_mode = drm_mode_duplicate(dev, mode);
 297         if (!adjusted_mode) {
 298                 crtc->enabled = saved_enabled;
 299                 return false;
 300         }
 301
 302         saved_mode = crtc->mode;
 303         saved_hwmode = crtc->hwmode;
 304         saved_x = crtc->x;
 305         saved_y = crtc->y;
 306
 307         /* Update crtc values up front so the driver can rely on them for mode
 308          * setting.
 309          */
 310         crtc->mode = *mode;
 311         crtc->x = x;
 312         crtc->y = y;
 313
 314         /* Pass our mode to the connectors and the CRTC to give them a chance to
 315          * adjust it according to limitations or connector properties, and also
 316          * a chance to reject the mode entirely.
 317          */
 318         drm_for_each_encoder(encoder, dev) {
 319
 320                 if (encoder->crtc != crtc)
 321                         continue;
 322
 323                 encoder_funcs = encoder->helper_private;
 324                 if (!encoder_funcs)
 325                         continue;
 326
 327                 ret = drm_bridge_mode_fixup(encoder->bridge,
 328                         mode, adjusted_mode);
 329                 if (!ret) {
 330                         DRM_DEBUG_KMS("Bridge fixup failed\n");
 331                         goto done;
 332                 }
 333
 334                 encoder_funcs = encoder->helper_private;
 335                 if (encoder_funcs->mode_fixup) {
 336                         if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 337                                                               adjusted_mode))) {
 338                                 DRM_DEBUG_KMS("Encoder fixup failed\n");
 339                                 goto done;
 340                         }
 341                 }
 342         }
 343
 344         if (crtc_funcs->mode_fixup) {
 345                 if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
 346                                                 adjusted_mode))) {
 347                         DRM_DEBUG_KMS("CRTC fixup failed\n");
 348                         goto done;
 349                 }
 350         }
 351         DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
 352
 353         crtc->hwmode = *adjusted_mode;
 354
 355         /* Prepare the encoders and CRTCs before setting the mode. */
 356         drm_for_each_encoder(encoder, dev) {
 357
 358                 if (encoder->crtc != crtc)
 359                         continue;
 360
 361                 encoder_funcs = encoder->helper_private;
 362                 if (!encoder_funcs)
 363                         continue;
 364
 365                 drm_bridge_disable(encoder->bridge);
 366
 367                 /* Disable the encoders as the first thing we do. */
 368                 if (encoder_funcs->prepare)
 369                         encoder_funcs->prepare(encoder);
 370
 371                 drm_bridge_post_disable(encoder->bridge);
 372         }
 373
 374         drm_crtc_prepare_encoders(dev);
 375
 376         crtc_funcs->prepare(crtc);
 377
 378         /* Set up the DPLL and any encoders state that needs to adjust or depend
 379          * on the DPLL.
 380          */
 381         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 382         if (!ret)
 383             goto done;
 384
 385         drm_for_each_encoder(encoder, dev) {
 386
 387                 if (encoder->crtc != crtc)
 388                         continue;
 389
 390                 encoder_funcs = encoder->helper_private;
 391                 if (!encoder_funcs)
 392                         continue;
 393
 394                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%s]\n",
 395                         encoder->base.id, encoder->name, mode->name);
 396                 if (encoder_funcs->mode_set)
 397                         encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 398
 399                 drm_bridge_mode_set(encoder->bridge, mode, adjusted_mode);
 400         }
 401
 402         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 403         crtc_funcs->commit(crtc);
 404
 405         drm_for_each_encoder(encoder, dev) {
 406
 407                 if (encoder->crtc != crtc)
 408                         continue;
 409
 410                 encoder_funcs = encoder->helper_private;
 411                 if (!encoder_funcs)
 412                         continue;
 413
 414                 drm_bridge_pre_enable(encoder->bridge);
 415
 416                 if (encoder_funcs->commit)
 417                         encoder_funcs->commit(encoder);
 418
 419                 drm_bridge_enable(encoder->bridge);
 420         }
 421
 422         /* Calculate and store various constants which
 423          * are later needed by vblank and swap-completion
 424          * timestamping. They are derived from true hwmode.
 425          */
 426         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
 427
 428         /* FIXME: add subpixel order */
 429 done:
 430         drm_mode_destroy(dev, adjusted_mode);
 431         if (!ret) {
 432                 crtc->enabled = saved_enabled;
 433                 crtc->mode = saved_mode;
 434                 crtc->hwmode = saved_hwmode;
 435                 crtc->x = saved_x;
 436                 crtc->y = saved_y;
 437         }
 438
 439         return ret;
 440 }
 441 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 442
 443 static void
 444 drm_crtc_helper_disable(struct drm_crtc *crtc)
 445 {
 446         struct drm_device *dev = crtc->dev;
 447         struct drm_connector *connector;
 448         struct drm_encoder *encoder;
 449
 450         /* Decouple all encoders and their attached connectors from this crtc */
 451         drm_for_each_encoder(encoder, dev) {
 452                 struct drm_connector_list_iter conn_iter;
 453
 454                 if (encoder->crtc != crtc)
 455                         continue;
 456
 457                 drm_connector_list_iter_begin(dev, &conn_iter);
 458                 drm_for_each_connector_iter(connector, &conn_iter) {
 459                         if (connector->encoder != encoder)
 460                                 continue;
 461
 462                         connector->encoder = NULL;
 463
 464                         /*
 465                          * drm_helper_disable_unused_functions() ought to be
 466                          * doing this, but since we've decoupled the encoder
 467                          * from the connector above, the required connection
 468                          * between them is henceforth no longer available.
 469                          */
 470                         connector->dpms = DRM_MODE_DPMS_OFF;
 471
 472                         /* we keep a reference while the encoder is bound */
 473                         drm_connector_put(connector);
 474                 }
 475                 drm_connector_list_iter_end(&conn_iter);
 476         }
 477
 478         __drm_helper_disable_unused_functions(dev);
 479 }
 480
 481 /**
 482  * drm_crtc_helper_set_config - set a new config from userspace
 483  * @set: mode set configuration
 484  * @ctx: lock acquire context, not used here
 485  *
 486  * The drm_crtc_helper_set_config() helper function implements the of
 487  * &drm_crtc_funcs.set_config callback for drivers using the legacy CRTC
 488  * helpers.
 489  *
 490  * It first tries to locate the best encoder for each connector by calling the
 491  * connector @drm_connector_helper_funcs.best_encoder helper operation.
 492  *
 493  * After locating the appropriate encoders, the helper function will call the
 494  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
 495  * or reject it completely in which case an error will be returned to the
 496  * application. If the new configuration after mode adjustment is identical to
 497  * the current configuration the helper function will return without performing
 498  * any other operation.
 499  *
 500  * If the adjusted mode is identical to the current mode but changes to the
 501  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
 502  * will call the CRTC &drm_crtc_helper_funcs.mode_set_base helper operation.
 503  *
 504  * If the adjusted mode differs from the current mode, or if the
 505  * ->mode_set_base() helper operation is not provided, the helper function
 506  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
 507  * and ->commit() CRTC and encoder helper operations, in that order.
 508  * Alternatively it can also use the dpms and disable helper operations. For
 509  * details see &struct drm_crtc_helper_funcs and struct
 510  * &drm_encoder_helper_funcs.
 511  *
 512  * This function is deprecated.  New drivers must implement atomic modeset
 513  * support, for which this function is unsuitable. Instead drivers should use
 514  * drm_atomic_helper_set_config().
 515  *
 516  * Returns:
 517  * Returns 0 on success, negative errno numbers on failure.
 518  */
 519 int drm_crtc_helper_set_config(struct drm_mode_set *set,
 520                                struct drm_modeset_acquire_ctx *ctx)
 521 {
 522         struct drm_device *dev;
 523         struct drm_crtc **save_encoder_crtcs, *new_crtc;
 524         struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
 525         bool mode_changed = false; /* if true do a full mode set */
 526         bool fb_changed = false; /* if true and !mode_changed just do a flip */
 527         struct drm_connector *connector;
 528         struct drm_connector_list_iter conn_iter;
 529         int count = 0, ro, fail = 0;
 530         const struct drm_crtc_helper_funcs *crtc_funcs;
 531         struct drm_mode_set save_set;
 532         int ret;
 533         int i;
 534
 535         DRM_DEBUG_KMS("\n");
 536
 537         BUG_ON(!set);
 538         BUG_ON(!set->crtc);
 539         BUG_ON(!set->crtc->helper_private);
 540
 541         /* Enforce sane interface api - has been abused by the fb helper. */
 542         BUG_ON(!set->mode && set->fb);
 543         BUG_ON(set->fb && set->num_connectors == 0);
 544
 545         crtc_funcs = set->crtc->helper_private;
 546
 547         dev = set->crtc->dev;
 548         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 549
 550         if (!set->mode)
 551                 set->fb = NULL;
 552
 553         if (set->fb) {
 554                 DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 555                               set->crtc->base.id, set->crtc->name,
 556                               set->fb->base.id,
 557                               (int)set->num_connectors, set->x, set->y);
 558         } else {
 559                 DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
 560                               set->crtc->base.id, set->crtc->name);
 561                 drm_crtc_helper_disable(set->crtc);
 562                 return 0;
 563         }
 564
 565         drm_warn_on_modeset_not_all_locked(dev);
 566
 567         /*
 568          * Allocate space for the backup of all (non-pointer) encoder and
 569          * connector data.
 570          */
 571         save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
 572                                 sizeof(struct drm_crtc *), GFP_KERNEL);
 573         if (!save_encoder_crtcs)
 574                 return -ENOMEM;
 575
 576         save_connector_encoders = kcalloc(dev->mode_config.num_connector,
 577                                 sizeof(struct drm_encoder *), GFP_KERNEL);
 578         if (!save_connector_encoders) {
 579                 kfree(save_encoder_crtcs);
 580                 return -ENOMEM;
 581         }
 582
 583         /*
 584          * Copy data. Note that driver private data is not affected.
 585          * Should anything bad happen only the expected state is
 586          * restored, not the drivers personal bookkeeping.
 587          */
 588         count = 0;
 589         drm_for_each_encoder(encoder, dev) {
 590                 save_encoder_crtcs[count++] = encoder->crtc;
 591         }
 592
 593         count = 0;
 594         drm_connector_list_iter_begin(dev, &conn_iter);
 595         drm_for_each_connector_iter(connector, &conn_iter)
 596                 save_connector_encoders[count++] = connector->encoder;
 597         drm_connector_list_iter_end(&conn_iter);
 598
 599         save_set.crtc = set->crtc;
 600         save_set.mode = &set->crtc->mode;
 601         save_set.x = set->crtc->x;
 602         save_set.y = set->crtc->y;
 603         save_set.fb = set->crtc->primary->fb;
 604
 605         /* We should be able to check here if the fb has the same properties
 606          * and then just flip_or_move it */
 607         if (set->crtc->primary->fb != set->fb) {
 608                 /* If we have no fb then treat it as a full mode set */
 609                 if (set->crtc->primary->fb == NULL) {
 610                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 611                         mode_changed = true;
 612                 } else if (set->fb->format != set->crtc->primary->fb->format) {
 613                         mode_changed = true;
 614                 } else
 615                         fb_changed = true;
 616         }
 617
 618         if (set->x != set->crtc->x || set->y != set->crtc->y)
 619                 fb_changed = true;
 620
 621         if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
 622                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 623                 drm_mode_debug_printmodeline(&set->crtc->mode);
 624                 drm_mode_debug_printmodeline(set->mode);
 625                 mode_changed = true;
 626         }
 627
 628         /* take a reference on all unbound connectors in set, reuse the
 629          * already taken reference for bound connectors
 630          */
 631         for (ro = 0; ro < set->num_connectors; ro++) {
 632                 if (set->connectors[ro]->encoder)
 633                         continue;
 634                 drm_connector_get(set->connectors[ro]);
 635         }
 636
 637         /* a) traverse passed in connector list and get encoders for them */
 638         count = 0;
 639         drm_connector_list_iter_begin(dev, &conn_iter);
 640         drm_for_each_connector_iter(connector, &conn_iter) {
 641                 const struct drm_connector_helper_funcs *connector_funcs =
 642                         connector->helper_private;
 643                 new_encoder = connector->encoder;
 644                 for (ro = 0; ro < set->num_connectors; ro++) {
 645                         if (set->connectors[ro] == connector) {
 646                                 new_encoder = connector_funcs->best_encoder(connector);
 647                                 /* if we can't get an encoder for a connector
 648                                    we are setting now - then fail */
 649                                 if (new_encoder == NULL)
 650                                         /* don't break so fail path works correct */
 651                                         fail = 1;
 652
 653                                 if (connector->dpms != DRM_MODE_DPMS_ON) {
 654                                         DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
 655                                         mode_changed = true;
 656                                 }
 657
 658                                 break;
 659                         }
 660                 }
 661
 662                 if (new_encoder != connector->encoder) {
 663                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
 664                         mode_changed = true;
 665                         /* If the encoder is reused for another connector, then
 666                          * the appropriate crtc will be set later.
 667                          */
 668                         if (connector->encoder)
 669                                 connector->encoder->crtc = NULL;
 670                         connector->encoder = new_encoder;
 671                 }
 672         }
 673         drm_connector_list_iter_end(&conn_iter);
 674
 675         if (fail) {
 676                 ret = -EINVAL;
 677                 goto fail;
 678         }
 679
 680         count = 0;
 681         drm_connector_list_iter_begin(dev, &conn_iter);
 682         drm_for_each_connector_iter(connector, &conn_iter) {
 683                 if (!connector->encoder)
 684                         continue;
 685
 686                 if (connector->encoder->crtc == set->crtc)
 687                         new_crtc = NULL;
 688                 else
 689                         new_crtc = connector->encoder->crtc;
 690
 691                 for (ro = 0; ro < set->num_connectors; ro++) {
 692                         if (set->connectors[ro] == connector)
 693                                 new_crtc = set->crtc;
 694                 }
 695
 696                 /* Make sure the new CRTC will work with the encoder */
 697                 if (new_crtc &&
 698                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
 699                         ret = -EINVAL;
 700                         drm_connector_list_iter_end(&conn_iter);
 701                         goto fail;
 702                 }
 703                 if (new_crtc != connector->encoder->crtc) {
 704                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
 705                         mode_changed = true;
 706                         connector->encoder->crtc = new_crtc;
 707                 }
 708                 if (new_crtc) {
 709                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
 710                                       connector->base.id, connector->name,
 711                                       new_crtc->base.id, new_crtc->name);
 712                 } else {
 713                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
 714                                       connector->base.id, connector->name);
 715                 }
 716         }
 717         drm_connector_list_iter_end(&conn_iter);
 718
 719         /* mode_set_base is not a required function */
 720         if (fb_changed && !crtc_funcs->mode_set_base)
 721                 mode_changed = true;
 722
 723         if (mode_changed) {
 724                 if (drm_helper_crtc_in_use(set->crtc)) {
 725                         DRM_DEBUG_KMS("attempting to set mode from"
 726                                         " userspace\n");
 727                         drm_mode_debug_printmodeline(set->mode);
 728                         set->crtc->primary->fb = set->fb;
 729                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
 730                                                       set->x, set->y,
 731                                                       save_set.fb)) {
 732                                 DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
 733                                           set->crtc->base.id, set->crtc->name);
 734                                 set->crtc->primary->fb = save_set.fb;
 735                                 ret = -EINVAL;
 736                                 goto fail;
 737                         }
 738                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
 739                         for (i = 0; i < set->num_connectors; i++) {
 740                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
 741                                               set->connectors[i]->name);
 742                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
 743                         }
 744                 }
 745                 __drm_helper_disable_unused_functions(dev);
 746         } else if (fb_changed) {
 747                 set->crtc->x = set->x;
 748                 set->crtc->y = set->y;
 749                 set->crtc->primary->fb = set->fb;
 750                 ret = crtc_funcs->mode_set_base(set->crtc,
 751                                                 set->x, set->y, save_set.fb);
 752                 if (ret != 0) {
 753                         set->crtc->x = save_set.x;
 754                         set->crtc->y = save_set.y;
 755                         set->crtc->primary->fb = save_set.fb;
 756                         goto fail;
 757                 }
 758         }
 759
 760         kfree(save_connector_encoders);
 761         kfree(save_encoder_crtcs);
 762         return 0;
 763
 764 fail:
 765         /* Restore all previous data. */
 766         count = 0;
 767         drm_for_each_encoder(encoder, dev) {
 768                 encoder->crtc = save_encoder_crtcs[count++];
 769         }
 770
 771         count = 0;
 772         drm_connector_list_iter_begin(dev, &conn_iter);
 773         drm_for_each_connector_iter(connector, &conn_iter)
 774                 connector->encoder = save_connector_encoders[count++];
 775         drm_connector_list_iter_end(&conn_iter);
 776
 777         /* after fail drop reference on all unbound connectors in set, let
 778          * bound connectors keep their reference
 779          */
 780         for (ro = 0; ro < set->num_connectors; ro++) {
 781                 if (set->connectors[ro]->encoder)
 782                         continue;
 783                 drm_connector_put(set->connectors[ro]);
 784         }
 785
 786         /* Try to restore the config */
 787         if (mode_changed &&
 788             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
 789                                       save_set.y, save_set.fb))
 790                 DRM_ERROR("failed to restore config after modeset failure\n");
 791
 792         kfree(save_connector_encoders);
 793         kfree(save_encoder_crtcs);
 794         return ret;
 795 }
 796 EXPORT_SYMBOL(drm_crtc_helper_set_config);
 797
 798 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 799 {
 800         int dpms = DRM_MODE_DPMS_OFF;
 801         struct drm_connector *connector;
 802         struct drm_connector_list_iter conn_iter;
 803         struct drm_device *dev = encoder->dev;
 804
 805         drm_connector_list_iter_begin(dev, &conn_iter);
 806         drm_for_each_connector_iter(connector, &conn_iter)
 807                 if (connector->encoder == encoder)
 808                         if (connector->dpms < dpms)
 809                                 dpms = connector->dpms;
 810         drm_connector_list_iter_end(&conn_iter);
 811
 812         return dpms;
 813 }
 814
 815 /* Helper which handles bridge ordering around encoder dpms */
 816 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
 817 {
 818         struct drm_bridge *bridge = encoder->bridge;
 819         const struct drm_encoder_helper_funcs *encoder_funcs;
 820
 821         encoder_funcs = encoder->helper_private;
 822         if (!encoder_funcs)
 823                 return;
 824
 825         if (mode == DRM_MODE_DPMS_ON)
 826                 drm_bridge_pre_enable(bridge);
 827         else
 828                 drm_bridge_disable(bridge);
 829
 830         if (encoder_funcs->dpms)
 831                 encoder_funcs->dpms(encoder, mode);
 832
 833         if (mode == DRM_MODE_DPMS_ON)
 834                 drm_bridge_enable(bridge);
 835         else
 836                 drm_bridge_post_disable(bridge);
 837 }
 838
 839 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 840 {
 841         int dpms = DRM_MODE_DPMS_OFF;
 842         struct drm_connector *connector;
 843         struct drm_connector_list_iter conn_iter;
 844         struct drm_device *dev = crtc->dev;
 845
 846         drm_connector_list_iter_begin(dev, &conn_iter);
 847         drm_for_each_connector_iter(connector, &conn_iter)
 848                 if (connector->encoder && connector->encoder->crtc == crtc)
 849                         if (connector->dpms < dpms)
 850                                 dpms = connector->dpms;
 851         drm_connector_list_iter_end(&conn_iter);
 852
 853         return dpms;
 854 }
 855
 856 /**
 857  * drm_helper_connector_dpms() - connector dpms helper implementation
 858  * @connector: affected connector
 859  * @mode: DPMS mode
 860  *
 861  * The drm_helper_connector_dpms() helper function implements the
 862  * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
 863  * helpers.
 864  *
 865  * This is the main helper function provided by the CRTC helper framework for
 866  * implementing the DPMS connector attribute. It computes the new desired DPMS
 867  * state for all encoders and CRTCs in the output mesh and calls the
 868  * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
 869  * provided by the driver.
 870  *
 871  * This function is deprecated.  New drivers must implement atomic modeset
 872  * support, where DPMS is handled in the DRM core.
 873  *
 874  * Returns:
 875  * Always returns 0.
 876  */
 877 int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 878 {
 879         struct drm_encoder *encoder = connector->encoder;
 880         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 881         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 882
 883         WARN_ON(drm_drv_uses_atomic_modeset(connector->dev));
 884
 885         if (mode == connector->dpms)
 886                 return 0;
 887
 888         old_dpms = connector->dpms;
 889         connector->dpms = mode;
 890
 891         if (encoder)
 892                 encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
 893
 894         /* from off to on, do crtc then encoder */
 895         if (mode < old_dpms) {
 896                 if (crtc) {
 897                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 898                         if (crtc_funcs->dpms)
 899                                 (*crtc_funcs->dpms) (crtc,
 900                                                      drm_helper_choose_crtc_dpms(crtc));
 901                 }
 902                 if (encoder)
 903                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 904         }
 905
 906         /* from on to off, do encoder then crtc */
 907         if (mode > old_dpms) {
 908                 if (encoder)
 909                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 910                 if (crtc) {
 911                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 912                         if (crtc_funcs->dpms)
 913                                 (*crtc_funcs->dpms) (crtc,
 914                                                      drm_helper_choose_crtc_dpms(crtc));
 915                 }
 916         }
 917
 918         return 0;
 919 }
 920 EXPORT_SYMBOL(drm_helper_connector_dpms);
 921
 922 /**
 923  * drm_helper_resume_force_mode - force-restore mode setting configuration
 924  * @dev: drm_device which should be restored
 925  *
 926  * Drivers which use the mode setting helpers can use this function to
 927  * force-restore the mode setting configuration e.g. on resume or when something
 928  * else might have trampled over the hw state (like some overzealous old BIOSen
 929  * tended to do).
 930  *
 931  * This helper doesn't provide a error return value since restoring the old
 932  * config should never fail due to resource allocation issues since the driver
 933  * has successfully set the restored configuration already. Hence this should
 934  * boil down to the equivalent of a few dpms on calls, which also don't provide
 935  * an error code.
 936  *
 937  * Drivers where simply restoring an old configuration again might fail (e.g.
 938  * due to slight differences in allocating shared resources when the
 939  * configuration is restored in a different order than when userspace set it up)
 940  * need to use their own restore logic.
 941  *
 942  * This function is deprecated. New drivers should implement atomic mode-
 943  * setting and use the atomic suspend/resume helpers.
 944  *
 945  * See also:
 946  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
 947  */
 948 void drm_helper_resume_force_mode(struct drm_device *dev)
 949 {
 950         struct drm_crtc *crtc;
 951         struct drm_encoder *encoder;
 952         const struct drm_crtc_helper_funcs *crtc_funcs;
 953         int encoder_dpms;
 954         bool ret;
 955
 956         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 957
 958         drm_modeset_lock_all(dev);
 959         drm_for_each_crtc(crtc, dev) {
 960
 961                 if (!crtc->enabled)
 962                         continue;
 963
 964                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 965                                                crtc->x, crtc->y, crtc->primary->fb);
 966
 967                 /* Restoring the old config should never fail! */
 968                 if (ret == false)
 969                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
 970
 971                 /* Turn off outputs that were already powered off */
 972                 if (drm_helper_choose_crtc_dpms(crtc)) {
 973                         drm_for_each_encoder(encoder, dev) {
 974
 975                                 if(encoder->crtc != crtc)
 976                                         continue;
 977
 978                                 encoder_dpms = drm_helper_choose_encoder_dpms(
 979                                                         encoder);
 980
 981                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
 982                         }
 983
 984                         crtc_funcs = crtc->helper_private;
 985                         if (crtc_funcs->dpms)
 986                                 (*crtc_funcs->dpms) (crtc,
 987                                                      drm_helper_choose_crtc_dpms(crtc));
 988                 }
 989         }
 990
 991         /* disable the unused connectors while restoring the modesetting */
 992         __drm_helper_disable_unused_functions(dev);
 993         drm_modeset_unlock_all(dev);
 994 }
 995 EXPORT_SYMBOL(drm_helper_resume_force_mode);
 996
 997 /**
 998  * drm_helper_force_disable_all - Forcibly turn off all enabled CRTCs
 999  * @dev: DRM device whose CRTCs to turn off
1000  *
1001  * Drivers may want to call this on unload to ensure that all displays are
1002  * unlit and the GPU is in a consistent, low power state. Takes modeset locks.
1003  *
1004  * Note: This should only be used by non-atomic legacy drivers. For an atomic
1005  * version look at drm_atomic_helper_shutdown().
1006  *
1007  * Returns:
1008  * Zero on success, error code on failure.
1009  */
1010 int drm_helper_force_disable_all(struct drm_device *dev)
1011 {
1012         struct drm_crtc *crtc;
1013         int ret = 0;
1014
1015         drm_modeset_lock_all(dev);
1016         drm_for_each_crtc(crtc, dev)
1017                 if (crtc->enabled) {
1018                         struct drm_mode_set set = {
1019                                 .crtc = crtc,
1020                         };
1021
1022                         ret = drm_mode_set_config_internal(&set);
1023                         if (ret)
1024                                 goto out;
1025                 }
1026 out:
1027         drm_modeset_unlock_all(dev);
1028         return ret;
1029 }
1030 EXPORT_SYMBOL(drm_helper_force_disable_all);