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