drivers/gpu/drm/drm_crtc_helper.c

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