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/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_bridge.h>
  40 #include <drm/drm_crtc.h>
  41 #include <drm/drm_crtc_helper.h>
  42 #include <drm/drm_drv.h>
  43 #include <drm/drm_edid.h>
  44 #include <drm/drm_encoder.h>
  45 #include <drm/drm_fb_helper.h>
  46 #include <drm/drm_fourcc.h>
  47 #include <drm/drm_plane_helper.h>
  48 #include <drm/drm_print.h>
  49 #include <drm/drm_vblank.h>
  50
  51 #include "drm_crtc_helper_internal.h"
  52
  53 /**
  54  * DOC: overview
  55  *
  56  * The CRTC modeset helper library provides a default set_config implementation
  57  * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
  58  * the same callbacks which drivers can use to e.g. restore the modeset
  59  * configuration on resume with drm_helper_resume_force_mode().
  60  *
  61  * Note that this helper library doesn't track the current power state of CRTCs
  62  * and encoders. It can call callbacks like &drm_encoder_helper_funcs.dpms even
  63  * though the hardware is already in the desired state. This deficiency has been
  64  * fixed in the atomic helpers.
  65  *
  66  * The driver callbacks are mostly compatible with the atomic modeset helpers,
  67  * except for the handling of the primary plane: Atomic helpers require that the
  68  * primary plane is implemented as a real standalone plane and not directly tied
  69  * to the CRTC state. For easier transition this library provides functions to
  70  * implement the old semantics required by the CRTC helpers using the new plane
  71  * and atomic helper callbacks.
  72  *
  73  * Drivers are strongly urged to convert to the atomic helpers (by way of first
  74  * converting to the plane helpers). New drivers must not use these functions
  75  * but need to implement the atomic interface instead, potentially using the
  76  * atomic helpers for that.
  77  *
  78  * These legacy modeset helpers use the same function table structures as
  79  * all other modesetting helpers. See the documentation for struct
  80  * &drm_crtc_helper_funcs, &struct drm_encoder_helper_funcs and struct
  81  * &drm_connector_helper_funcs.
  82  */
  83
  84 /**
  85  * drm_helper_encoder_in_use - check if a given encoder is in use
  86  * @encoder: encoder to check
  87  *
  88  * Checks whether @encoder is with the current mode setting output configuration
  89  * in use by any connector. This doesn't mean that it is actually enabled since
  90  * the DPMS state is tracked separately.
  91  *
  92  * Returns:
  93  * True if @encoder is used, false otherwise.
  94  */
  95 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
  96 {
  97         struct drm_connector *connector;
  98         struct drm_connector_list_iter conn_iter;
  99         struct drm_device *dev = encoder->dev;
 100
 101         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 102
 103         /*
 104          * We can expect this mutex to be locked if we are not panicking.
 105          * Locking is currently fubar in the panic handler.
 106          */
 107         if (!oops_in_progress) {
 108                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 109                 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 110         }
 111
 112
 113         drm_connector_list_iter_begin(dev, &conn_iter);
 114         drm_for_each_connector_iter(connector, &conn_iter) {
 115                 if (connector->encoder == encoder) {
 116                         drm_connector_list_iter_end(&conn_iter);
 117                         return true;
 118                 }
 119         }
 120         drm_connector_list_iter_end(&conn_iter);
 121         return false;
 122 }
 123 EXPORT_SYMBOL(drm_helper_encoder_in_use);
 124
 125 /**
 126  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
 127  * @crtc: CRTC to check
 128  *
 129  * Checks whether @crtc is with the current mode setting output configuration
 130  * in use by any connector. This doesn't mean that it is actually enabled since
 131  * the DPMS state is tracked separately.
 132  *
 133  * Returns:
 134  * True if @crtc is used, false otherwise.
 135  */
 136 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
 137 {
 138         struct drm_encoder *encoder;
 139         struct drm_device *dev = crtc->dev;
 140
 141         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 142
 143         /*
 144          * We can expect this mutex to be locked if we are not panicking.
 145          * Locking is currently fubar in the panic handler.
 146          */
 147         if (!oops_in_progress)
 148                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 149
 150         drm_for_each_encoder(encoder, dev)
 151                 if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
 152                         return true;
 153         return false;
 154 }
 155 EXPORT_SYMBOL(drm_helper_crtc_in_use);
 156
 157 static void
 158 drm_encoder_disable(struct drm_encoder *encoder)
 159 {
 160         const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 161
 162         if (!encoder_funcs)
 163                 return;
 164
 165         if (encoder_funcs->disable)
 166                 (*encoder_funcs->disable)(encoder);
 167         else if (encoder_funcs->dpms)
 168                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
 169 }
 170
 171 static void __drm_helper_disable_unused_functions(struct drm_device *dev)
 172 {
 173         struct drm_encoder *encoder;
 174         struct drm_crtc *crtc;
 175
 176         drm_warn_on_modeset_not_all_locked(dev);
 177
 178         drm_for_each_encoder(encoder, dev) {
 179                 if (!drm_helper_encoder_in_use(encoder)) {
 180                         drm_encoder_disable(encoder);
 181                         /* disconnect encoder from any connector */
 182                         encoder->crtc = NULL;
 183                 }
 184         }
 185
 186         drm_for_each_crtc(crtc, dev) {
 187                 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 188                 crtc->enabled = drm_helper_crtc_in_use(crtc);
 189                 if (!crtc->enabled) {
 190                         if (crtc_funcs->disable)
 191                                 (*crtc_funcs->disable)(crtc);
 192                         else
 193                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
 194                         crtc->primary->fb = NULL;
 195                 }
 196         }
 197 }
 198
 199 /**
 200  * drm_helper_disable_unused_functions - disable unused objects
 201  * @dev: DRM device
 202  *
 203  * This function walks through the entire mode setting configuration of @dev. It
 204  * will remove any CRTC links of unused encoders and encoder links of
 205  * disconnected connectors. Then it will disable all unused encoders and CRTCs
 206  * either by calling their disable callback if available or by calling their
 207  * dpms callback with DRM_MODE_DPMS_OFF.
 208  *
 209  * NOTE:
 210  *
 211  * This function is part of the legacy modeset helper library and will cause
 212  * major confusion with atomic drivers. This is because atomic helpers guarantee
 213  * to never call ->disable() hooks on a disabled function, or ->enable() hooks
 214  * on an enabled functions. drm_helper_disable_unused_functions() on the other
 215  * hand throws such guarantees into the wind and calls disable hooks
 216  * unconditionally on unused functions.
 217  */
 218 void drm_helper_disable_unused_functions(struct drm_device *dev)
 219 {
 220         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 221
 222         drm_modeset_lock_all(dev);
 223         __drm_helper_disable_unused_functions(dev);
 224         drm_modeset_unlock_all(dev);
 225 }
 226 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
 227
 228 /*
 229  * Check the CRTC we're going to map each output to vs. its current
 230  * CRTC.  If they don't match, we have to disable the output and the CRTC
 231  * since the driver will have to re-route things.
 232  */
 233 static void
 234 drm_crtc_prepare_encoders(struct drm_device *dev)
 235 {
 236         const struct drm_encoder_helper_funcs *encoder_funcs;
 237         struct drm_encoder *encoder;
 238
 239         drm_for_each_encoder(encoder, dev) {
 240                 encoder_funcs = encoder->helper_private;
 241                 if (!encoder_funcs)
 242                         continue;
 243
 244                 /* Disable unused encoders */
 245                 if (encoder->crtc == NULL)
 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         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 285
 286         drm_warn_on_modeset_not_all_locked(dev);
 287
 288         saved_enabled = crtc->enabled;
 289         crtc->enabled = drm_helper_crtc_in_use(crtc);
 290         if (!crtc->enabled)
 291                 return true;
 292
 293         adjusted_mode = drm_mode_duplicate(dev, mode);
 294         if (!adjusted_mode) {
 295                 crtc->enabled = saved_enabled;
 296                 return false;
 297         }
 298
 299         saved_mode = crtc->mode;
 300         saved_hwmode = crtc->hwmode;
 301         saved_x = crtc->x;
 302         saved_y = crtc->y;
 303
 304         /* Update crtc values up front so the driver can rely on them for mode
 305          * setting.
 306          */
 307         crtc->mode = *mode;
 308         crtc->x = x;
 309         crtc->y = y;
 310
 311         /* Pass our mode to the connectors and the CRTC to give them a chance to
 312          * adjust it according to limitations or connector properties, and also
 313          * a chance to reject the mode entirely.
 314          */
 315         drm_for_each_encoder(encoder, dev) {
 316
 317                 if (encoder->crtc != crtc)
 318                         continue;
 319
 320                 encoder_funcs = encoder->helper_private;
 321                 if (!encoder_funcs)
 322                         continue;
 323
 324                 encoder_funcs = encoder->helper_private;
 325                 if (encoder_funcs->mode_fixup) {
 326                         if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 327                                                               adjusted_mode))) {
 328                                 DRM_DEBUG_KMS("Encoder fixup failed\n");
 329                                 goto done;
 330                         }
 331                 }
 332         }
 333
 334         if (crtc_funcs->mode_fixup) {
 335                 if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
 336                                                 adjusted_mode))) {
 337                         DRM_DEBUG_KMS("CRTC fixup failed\n");
 338                         goto done;
 339                 }
 340         }
 341         DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
 342
 343         crtc->hwmode = *adjusted_mode;
 344
 345         /* Prepare the encoders and CRTCs before setting the mode. */
 346         drm_for_each_encoder(encoder, dev) {
 347
 348                 if (encoder->crtc != crtc)
 349                         continue;
 350
 351                 encoder_funcs = encoder->helper_private;
 352                 if (!encoder_funcs)
 353                         continue;
 354
 355                 /* Disable the encoders as the first thing we do. */
 356                 if (encoder_funcs->prepare)
 357                         encoder_funcs->prepare(encoder);
 358         }
 359
 360         drm_crtc_prepare_encoders(dev);
 361
 362         crtc_funcs->prepare(crtc);
 363
 364         /* Set up the DPLL and any encoders state that needs to adjust or depend
 365          * on the DPLL.
 366          */
 367         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 368         if (!ret)
 369             goto done;
 370
 371         drm_for_each_encoder(encoder, dev) {
 372
 373                 if (encoder->crtc != crtc)
 374                         continue;
 375
 376                 encoder_funcs = encoder->helper_private;
 377                 if (!encoder_funcs)
 378                         continue;
 379
 380                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%s]\n",
 381                         encoder->base.id, encoder->name, mode->name);
 382                 if (encoder_funcs->mode_set)
 383                         encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 384         }
 385
 386         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 387         crtc_funcs->commit(crtc);
 388
 389         drm_for_each_encoder(encoder, dev) {
 390
 391                 if (encoder->crtc != crtc)
 392                         continue;
 393
 394                 encoder_funcs = encoder->helper_private;
 395                 if (!encoder_funcs)
 396                         continue;
 397
 398                 if (encoder_funcs->commit)
 399                         encoder_funcs->commit(encoder);
 400         }
 401
 402         /* Calculate and store various constants which
 403          * are later needed by vblank and swap-completion
 404          * timestamping. They are derived from true hwmode.
 405          */
 406         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
 407
 408         /* FIXME: add subpixel order */
 409 done:
 410         drm_mode_destroy(dev, adjusted_mode);
 411         if (!ret) {
 412                 crtc->enabled = saved_enabled;
 413                 crtc->mode = saved_mode;
 414                 crtc->hwmode = saved_hwmode;
 415                 crtc->x = saved_x;
 416                 crtc->y = saved_y;
 417         }
 418
 419         return ret;
 420 }
 421 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 422
 423 static void
 424 drm_crtc_helper_disable(struct drm_crtc *crtc)
 425 {
 426         struct drm_device *dev = crtc->dev;
 427         struct drm_connector *connector;
 428         struct drm_encoder *encoder;
 429
 430         /* Decouple all encoders and their attached connectors from this crtc */
 431         drm_for_each_encoder(encoder, dev) {
 432                 struct drm_connector_list_iter conn_iter;
 433
 434                 if (encoder->crtc != crtc)
 435                         continue;
 436
 437                 drm_connector_list_iter_begin(dev, &conn_iter);
 438                 drm_for_each_connector_iter(connector, &conn_iter) {
 439                         if (connector->encoder != encoder)
 440                                 continue;
 441
 442                         connector->encoder = NULL;
 443
 444                         /*
 445                          * drm_helper_disable_unused_functions() ought to be
 446                          * doing this, but since we've decoupled the encoder
 447                          * from the connector above, the required connection
 448                          * between them is henceforth no longer available.
 449                          */
 450                         connector->dpms = DRM_MODE_DPMS_OFF;
 451
 452                         /* we keep a reference while the encoder is bound */
 453                         drm_connector_put(connector);
 454                 }
 455                 drm_connector_list_iter_end(&conn_iter);
 456         }
 457
 458         __drm_helper_disable_unused_functions(dev);
 459 }
 460
 461 /*
 462  * For connectors that support multiple encoders, either the
 463  * .atomic_best_encoder() or .best_encoder() operation must be implemented.
 464  */
 465 struct drm_encoder *
 466 drm_connector_get_single_encoder(struct drm_connector *connector)
 467 {
 468         struct drm_encoder *encoder;
 469
 470         WARN_ON(hweight32(connector->possible_encoders) > 1);
 471         drm_connector_for_each_possible_encoder(connector, encoder)
 472                 return encoder;
 473
 474         return NULL;
 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         dev = set->crtc->dev;
 544         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 545
 546         if (!set->mode)
 547                 set->fb = NULL;
 548
 549         if (set->fb) {
 550                 DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 551                               set->crtc->base.id, set->crtc->name,
 552                               set->fb->base.id,
 553                               (int)set->num_connectors, set->x, set->y);
 554         } else {
 555                 DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
 556                               set->crtc->base.id, set->crtc->name);
 557                 drm_crtc_helper_disable(set->crtc);
 558                 return 0;
 559         }
 560
 561         drm_warn_on_modeset_not_all_locked(dev);
 562
 563         /*
 564          * Allocate space for the backup of all (non-pointer) encoder and
 565          * connector data.
 566          */
 567         save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
 568                                 sizeof(struct drm_crtc *), GFP_KERNEL);
 569         if (!save_encoder_crtcs)
 570                 return -ENOMEM;
 571
 572         save_connector_encoders = kcalloc(dev->mode_config.num_connector,
 573                                 sizeof(struct drm_encoder *), GFP_KERNEL);
 574         if (!save_connector_encoders) {
 575                 kfree(save_encoder_crtcs);
 576                 return -ENOMEM;
 577         }
 578
 579         /*
 580          * Copy data. Note that driver private data is not affected.
 581          * Should anything bad happen only the expected state is
 582          * restored, not the drivers personal bookkeeping.
 583          */
 584         count = 0;
 585         drm_for_each_encoder(encoder, dev) {
 586                 save_encoder_crtcs[count++] = encoder->crtc;
 587         }
 588
 589         count = 0;
 590         drm_connector_list_iter_begin(dev, &conn_iter);
 591         drm_for_each_connector_iter(connector, &conn_iter)
 592                 save_connector_encoders[count++] = connector->encoder;
 593         drm_connector_list_iter_end(&conn_iter);
 594
 595         save_set.crtc = set->crtc;
 596         save_set.mode = &set->crtc->mode;
 597         save_set.x = set->crtc->x;
 598         save_set.y = set->crtc->y;
 599         save_set.fb = set->crtc->primary->fb;
 600
 601         /* We should be able to check here if the fb has the same properties
 602          * and then just flip_or_move it */
 603         if (set->crtc->primary->fb != set->fb) {
 604                 /* If we have no fb then treat it as a full mode set */
 605                 if (set->crtc->primary->fb == NULL) {
 606                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 607                         mode_changed = true;
 608                 } else if (set->fb->format != set->crtc->primary->fb->format) {
 609                         mode_changed = true;
 610                 } else
 611                         fb_changed = true;
 612         }
 613
 614         if (set->x != set->crtc->x || set->y != set->crtc->y)
 615                 fb_changed = true;
 616
 617         if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
 618                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 619                 drm_mode_debug_printmodeline(&set->crtc->mode);
 620                 drm_mode_debug_printmodeline(set->mode);
 621                 mode_changed = true;
 622         }
 623
 624         /* take a reference on all unbound connectors in set, reuse the
 625          * already taken reference for bound connectors
 626          */
 627         for (ro = 0; ro < set->num_connectors; ro++) {
 628                 if (set->connectors[ro]->encoder)
 629                         continue;
 630                 drm_connector_get(set->connectors[ro]);
 631         }
 632
 633         /* a) traverse passed in connector list and get encoders for them */
 634         count = 0;
 635         drm_connector_list_iter_begin(dev, &conn_iter);
 636         drm_for_each_connector_iter(connector, &conn_iter) {
 637                 const struct drm_connector_helper_funcs *connector_funcs =
 638                         connector->helper_private;
 639                 new_encoder = connector->encoder;
 640                 for (ro = 0; ro < set->num_connectors; ro++) {
 641                         if (set->connectors[ro] == connector) {
 642                                 if (connector_funcs->best_encoder)
 643                                         new_encoder = connector_funcs->best_encoder(connector);
 644                                 else
 645                                         new_encoder = drm_connector_get_single_encoder(connector);
 646
 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         const struct drm_encoder_helper_funcs *encoder_funcs;
 819
 820         encoder_funcs = encoder->helper_private;
 821         if (!encoder_funcs)
 822                 return;
 823
 824         if (encoder_funcs->dpms)
 825                 encoder_funcs->dpms(encoder, mode);
 826 }
 827
 828 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 829 {
 830         int dpms = DRM_MODE_DPMS_OFF;
 831         struct drm_connector *connector;
 832         struct drm_connector_list_iter conn_iter;
 833         struct drm_device *dev = crtc->dev;
 834
 835         drm_connector_list_iter_begin(dev, &conn_iter);
 836         drm_for_each_connector_iter(connector, &conn_iter)
 837                 if (connector->encoder && connector->encoder->crtc == crtc)
 838                         if (connector->dpms < dpms)
 839                                 dpms = connector->dpms;
 840         drm_connector_list_iter_end(&conn_iter);
 841
 842         return dpms;
 843 }
 844
 845 /**
 846  * drm_helper_connector_dpms() - connector dpms helper implementation
 847  * @connector: affected connector
 848  * @mode: DPMS mode
 849  *
 850  * The drm_helper_connector_dpms() helper function implements the
 851  * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
 852  * helpers.
 853  *
 854  * This is the main helper function provided by the CRTC helper framework for
 855  * implementing the DPMS connector attribute. It computes the new desired DPMS
 856  * state for all encoders and CRTCs in the output mesh and calls the
 857  * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
 858  * provided by the driver.
 859  *
 860  * This function is deprecated.  New drivers must implement atomic modeset
 861  * support, where DPMS is handled in the DRM core.
 862  *
 863  * Returns:
 864  * Always returns 0.
 865  */
 866 int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 867 {
 868         struct drm_encoder *encoder = connector->encoder;
 869         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 870         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 871
 872         WARN_ON(drm_drv_uses_atomic_modeset(connector->dev));
 873
 874         if (mode == connector->dpms)
 875                 return 0;
 876
 877         old_dpms = connector->dpms;
 878         connector->dpms = mode;
 879
 880         if (encoder)
 881                 encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
 882
 883         /* from off to on, do crtc then encoder */
 884         if (mode < old_dpms) {
 885                 if (crtc) {
 886                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 887                         if (crtc_funcs->dpms)
 888                                 (*crtc_funcs->dpms) (crtc,
 889                                                      drm_helper_choose_crtc_dpms(crtc));
 890                 }
 891                 if (encoder)
 892                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 893         }
 894
 895         /* from on to off, do encoder then crtc */
 896         if (mode > old_dpms) {
 897                 if (encoder)
 898                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 899                 if (crtc) {
 900                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 901                         if (crtc_funcs->dpms)
 902                                 (*crtc_funcs->dpms) (crtc,
 903                                                      drm_helper_choose_crtc_dpms(crtc));
 904                 }
 905         }
 906
 907         return 0;
 908 }
 909 EXPORT_SYMBOL(drm_helper_connector_dpms);
 910
 911 /**
 912  * drm_helper_resume_force_mode - force-restore mode setting configuration
 913  * @dev: drm_device which should be restored
 914  *
 915  * Drivers which use the mode setting helpers can use this function to
 916  * force-restore the mode setting configuration e.g. on resume or when something
 917  * else might have trampled over the hw state (like some overzealous old BIOSen
 918  * tended to do).
 919  *
 920  * This helper doesn't provide a error return value since restoring the old
 921  * config should never fail due to resource allocation issues since the driver
 922  * has successfully set the restored configuration already. Hence this should
 923  * boil down to the equivalent of a few dpms on calls, which also don't provide
 924  * an error code.
 925  *
 926  * Drivers where simply restoring an old configuration again might fail (e.g.
 927  * due to slight differences in allocating shared resources when the
 928  * configuration is restored in a different order than when userspace set it up)
 929  * need to use their own restore logic.
 930  *
 931  * This function is deprecated. New drivers should implement atomic mode-
 932  * setting and use the atomic suspend/resume helpers.
 933  *
 934  * See also:
 935  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
 936  */
 937 void drm_helper_resume_force_mode(struct drm_device *dev)
 938 {
 939         struct drm_crtc *crtc;
 940         struct drm_encoder *encoder;
 941         const struct drm_crtc_helper_funcs *crtc_funcs;
 942         int encoder_dpms;
 943         bool ret;
 944
 945         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 946
 947         drm_modeset_lock_all(dev);
 948         drm_for_each_crtc(crtc, dev) {
 949
 950                 if (!crtc->enabled)
 951                         continue;
 952
 953                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 954                                                crtc->x, crtc->y, crtc->primary->fb);
 955
 956                 /* Restoring the old config should never fail! */
 957                 if (ret == false)
 958                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
 959
 960                 /* Turn off outputs that were already powered off */
 961                 if (drm_helper_choose_crtc_dpms(crtc)) {
 962                         drm_for_each_encoder(encoder, dev) {
 963
 964                                 if(encoder->crtc != crtc)
 965                                         continue;
 966
 967                                 encoder_dpms = drm_helper_choose_encoder_dpms(
 968                                                         encoder);
 969
 970                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
 971                         }
 972
 973                         crtc_funcs = crtc->helper_private;
 974                         if (crtc_funcs->dpms)
 975                                 (*crtc_funcs->dpms) (crtc,
 976                                                      drm_helper_choose_crtc_dpms(crtc));
 977                 }
 978         }
 979
 980         /* disable the unused connectors while restoring the modesetting */
 981         __drm_helper_disable_unused_functions(dev);
 982         drm_modeset_unlock_all(dev);
 983 }
 984 EXPORT_SYMBOL(drm_helper_resume_force_mode);
 985
 986 /**
 987  * drm_helper_force_disable_all - Forcibly turn off all enabled CRTCs
 988  * @dev: DRM device whose CRTCs to turn off
 989  *
 990  * Drivers may want to call this on unload to ensure that all displays are
 991  * unlit and the GPU is in a consistent, low power state. Takes modeset locks.
 992  *
 993  * Note: This should only be used by non-atomic legacy drivers. For an atomic
 994  * version look at drm_atomic_helper_shutdown().
 995  *
 996  * Returns:
 997  * Zero on success, error code on failure.
 998  */
 999 int drm_helper_force_disable_all(struct drm_device *dev)
1000 {
1001         struct drm_crtc *crtc;
1002         int ret = 0;
1003
1004         drm_modeset_lock_all(dev);
1005         drm_for_each_crtc(crtc, dev)
1006                 if (crtc->enabled) {
1007                         struct drm_mode_set set = {
1008                                 .crtc = crtc,
1009                         };
1010
1011                         ret = drm_mode_set_config_internal(&set);
1012                         if (ret)
1013                                 goto out;
1014                 }
1015 out:
1016         drm_modeset_unlock_all(dev);
1017         return ret;
1018 }
1019 EXPORT_SYMBOL(drm_helper_force_disable_all);