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_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                 /* Disable encoders whose CRTC is about to change */
 248                 if (encoder_funcs->get_crtc &&
 249                     encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
 250                         drm_encoder_disable(encoder);
 251         }
 252 }
 253
 254 /**
 255  * drm_crtc_helper_set_mode - internal helper to set a mode
 256  * @crtc: CRTC to program
 257  * @mode: mode to use
 258  * @x: horizontal offset into the surface
 259  * @y: vertical offset into the surface
 260  * @old_fb: old framebuffer, for cleanup
 261  *
 262  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 263  * to fixup or reject the mode prior to trying to set it. This is an internal
 264  * helper that drivers could e.g. use to update properties that require the
 265  * entire output pipe to be disabled and re-enabled in a new configuration. For
 266  * example for changing whether audio is enabled on a hdmi link or for changing
 267  * panel fitter or dither attributes. It is also called by the
 268  * drm_crtc_helper_set_config() helper function to drive the mode setting
 269  * sequence.
 270  *
 271  * Returns:
 272  * True if the mode was set successfully, false otherwise.
 273  */
 274 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 275                               struct drm_display_mode *mode,
 276                               int x, int y,
 277                               struct drm_framebuffer *old_fb)
 278 {
 279         struct drm_device *dev = crtc->dev;
 280         struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
 281         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 282         const struct drm_encoder_helper_funcs *encoder_funcs;
 283         int saved_x, saved_y;
 284         bool saved_enabled;
 285         struct drm_encoder *encoder;
 286         bool ret = true;
 287
 288         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 289
 290         drm_warn_on_modeset_not_all_locked(dev);
 291
 292         saved_enabled = crtc->enabled;
 293         crtc->enabled = drm_helper_crtc_in_use(crtc);
 294         if (!crtc->enabled)
 295                 return true;
 296
 297         adjusted_mode = drm_mode_duplicate(dev, mode);
 298         if (!adjusted_mode) {
 299                 crtc->enabled = saved_enabled;
 300                 return false;
 301         }
 302
 303         saved_mode = crtc->mode;
 304         saved_hwmode = crtc->hwmode;
 305         saved_x = crtc->x;
 306         saved_y = crtc->y;
 307
 308         /* Update crtc values up front so the driver can rely on them for mode
 309          * setting.
 310          */
 311         crtc->mode = *mode;
 312         crtc->x = x;
 313         crtc->y = y;
 314
 315         /* Pass our mode to the connectors and the CRTC to give them a chance to
 316          * adjust it according to limitations or connector properties, and also
 317          * a chance to reject the mode entirely.
 318          */
 319         drm_for_each_encoder(encoder, dev) {
 320
 321                 if (encoder->crtc != crtc)
 322                         continue;
 323
 324                 encoder_funcs = encoder->helper_private;
 325                 if (!encoder_funcs)
 326                         continue;
 327
 328                 encoder_funcs = encoder->helper_private;
 329                 if (encoder_funcs->mode_fixup) {
 330                         if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 331                                                               adjusted_mode))) {
 332                                 DRM_DEBUG_KMS("Encoder fixup failed\n");
 333                                 goto done;
 334                         }
 335                 }
 336         }
 337
 338         if (crtc_funcs->mode_fixup) {
 339                 if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
 340                                                 adjusted_mode))) {
 341                         DRM_DEBUG_KMS("CRTC fixup failed\n");
 342                         goto done;
 343                 }
 344         }
 345         DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
 346
 347         crtc->hwmode = *adjusted_mode;
 348
 349         /* Prepare the encoders and CRTCs before setting the mode. */
 350         drm_for_each_encoder(encoder, dev) {
 351
 352                 if (encoder->crtc != crtc)
 353                         continue;
 354
 355                 encoder_funcs = encoder->helper_private;
 356                 if (!encoder_funcs)
 357                         continue;
 358
 359                 /* Disable the encoders as the first thing we do. */
 360                 if (encoder_funcs->prepare)
 361                         encoder_funcs->prepare(encoder);
 362         }
 363
 364         drm_crtc_prepare_encoders(dev);
 365
 366         crtc_funcs->prepare(crtc);
 367
 368         /* Set up the DPLL and any encoders state that needs to adjust or depend
 369          * on the DPLL.
 370          */
 371         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 372         if (!ret)
 373             goto done;
 374
 375         drm_for_each_encoder(encoder, dev) {
 376
 377                 if (encoder->crtc != crtc)
 378                         continue;
 379
 380                 encoder_funcs = encoder->helper_private;
 381                 if (!encoder_funcs)
 382                         continue;
 383
 384                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%s]\n",
 385                         encoder->base.id, encoder->name, mode->name);
 386                 if (encoder_funcs->mode_set)
 387                         encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 388         }
 389
 390         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 391         crtc_funcs->commit(crtc);
 392
 393         drm_for_each_encoder(encoder, dev) {
 394
 395                 if (encoder->crtc != crtc)
 396                         continue;
 397
 398                 encoder_funcs = encoder->helper_private;
 399                 if (!encoder_funcs)
 400                         continue;
 401
 402                 if (encoder_funcs->commit)
 403                         encoder_funcs->commit(encoder);
 404         }
 405
 406         /* Calculate and store various constants which
 407          * are later needed by vblank and swap-completion
 408          * timestamping. They are derived from true hwmode.
 409          */
 410         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
 411
 412         /* FIXME: add subpixel order */
 413 done:
 414         drm_mode_destroy(dev, adjusted_mode);
 415         if (!ret) {
 416                 crtc->enabled = saved_enabled;
 417                 crtc->mode = saved_mode;
 418                 crtc->hwmode = saved_hwmode;
 419                 crtc->x = saved_x;
 420                 crtc->y = saved_y;
 421         }
 422
 423         return ret;
 424 }
 425 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 426
 427 static void
 428 drm_crtc_helper_disable(struct drm_crtc *crtc)
 429 {
 430         struct drm_device *dev = crtc->dev;
 431         struct drm_connector *connector;
 432         struct drm_encoder *encoder;
 433
 434         /* Decouple all encoders and their attached connectors from this crtc */
 435         drm_for_each_encoder(encoder, dev) {
 436                 struct drm_connector_list_iter conn_iter;
 437
 438                 if (encoder->crtc != crtc)
 439                         continue;
 440
 441                 drm_connector_list_iter_begin(dev, &conn_iter);
 442                 drm_for_each_connector_iter(connector, &conn_iter) {
 443                         if (connector->encoder != encoder)
 444                                 continue;
 445
 446                         connector->encoder = NULL;
 447
 448                         /*
 449                          * drm_helper_disable_unused_functions() ought to be
 450                          * doing this, but since we've decoupled the encoder
 451                          * from the connector above, the required connection
 452                          * between them is henceforth no longer available.
 453                          */
 454                         connector->dpms = DRM_MODE_DPMS_OFF;
 455
 456                         /* we keep a reference while the encoder is bound */
 457                         drm_connector_put(connector);
 458                 }
 459                 drm_connector_list_iter_end(&conn_iter);
 460         }
 461
 462         __drm_helper_disable_unused_functions(dev);
 463 }
 464
 465 /*
 466  * For connectors that support multiple encoders, either the
 467  * .atomic_best_encoder() or .best_encoder() operation must be implemented.
 468  */
 469 struct drm_encoder *
 470 drm_connector_get_single_encoder(struct drm_connector *connector)
 471 {
 472         struct drm_encoder *encoder;
 473
 474         WARN_ON(hweight32(connector->possible_encoders) > 1);
 475         drm_connector_for_each_possible_encoder(connector, encoder)
 476                 return encoder;
 477
 478         return NULL;
 479 }
 480
 481 /**
 482  * drm_crtc_helper_set_config - set a new config from userspace
 483  * @set: mode set configuration
 484  * @ctx: lock acquire context, not used here
 485  *
 486  * The drm_crtc_helper_set_config() helper function implements the of
 487  * &drm_crtc_funcs.set_config callback for drivers using the legacy CRTC
 488  * helpers.
 489  *
 490  * It first tries to locate the best encoder for each connector by calling the
 491  * connector @drm_connector_helper_funcs.best_encoder helper operation.
 492  *
 493  * After locating the appropriate encoders, the helper function will call the
 494  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
 495  * or reject it completely in which case an error will be returned to the
 496  * application. If the new configuration after mode adjustment is identical to
 497  * the current configuration the helper function will return without performing
 498  * any other operation.
 499  *
 500  * If the adjusted mode is identical to the current mode but changes to the
 501  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
 502  * will call the CRTC &drm_crtc_helper_funcs.mode_set_base helper operation.
 503  *
 504  * If the adjusted mode differs from the current mode, or if the
 505  * ->mode_set_base() helper operation is not provided, the helper function
 506  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
 507  * and ->commit() CRTC and encoder helper operations, in that order.
 508  * Alternatively it can also use the dpms and disable helper operations. For
 509  * details see &struct drm_crtc_helper_funcs and struct
 510  * &drm_encoder_helper_funcs.
 511  *
 512  * This function is deprecated.  New drivers must implement atomic modeset
 513  * support, for which this function is unsuitable. Instead drivers should use
 514  * drm_atomic_helper_set_config().
 515  *
 516  * Returns:
 517  * Returns 0 on success, negative errno numbers on failure.
 518  */
 519 int drm_crtc_helper_set_config(struct drm_mode_set *set,
 520                                struct drm_modeset_acquire_ctx *ctx)
 521 {
 522         struct drm_device *dev;
 523         struct drm_crtc **save_encoder_crtcs, *new_crtc;
 524         struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
 525         bool mode_changed = false; /* if true do a full mode set */
 526         bool fb_changed = false; /* if true and !mode_changed just do a flip */
 527         struct drm_connector *connector;
 528         struct drm_connector_list_iter conn_iter;
 529         int count = 0, ro, fail = 0;
 530         const struct drm_crtc_helper_funcs *crtc_funcs;
 531         struct drm_mode_set save_set;
 532         int ret;
 533         int i;
 534
 535         DRM_DEBUG_KMS("\n");
 536
 537         BUG_ON(!set);
 538         BUG_ON(!set->crtc);
 539         BUG_ON(!set->crtc->helper_private);
 540
 541         /* Enforce sane interface api - has been abused by the fb helper. */
 542         BUG_ON(!set->mode && set->fb);
 543         BUG_ON(set->fb && set->num_connectors == 0);
 544
 545         crtc_funcs = set->crtc->helper_private;
 546
 547         dev = set->crtc->dev;
 548         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 549
 550         if (!set->mode)
 551                 set->fb = NULL;
 552
 553         if (set->fb) {
 554                 DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 555                               set->crtc->base.id, set->crtc->name,
 556                               set->fb->base.id,
 557                               (int)set->num_connectors, set->x, set->y);
 558         } else {
 559                 DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
 560                               set->crtc->base.id, set->crtc->name);
 561                 drm_crtc_helper_disable(set->crtc);
 562                 return 0;
 563         }
 564
 565         drm_warn_on_modeset_not_all_locked(dev);
 566
 567         /*
 568          * Allocate space for the backup of all (non-pointer) encoder and
 569          * connector data.
 570          */
 571         save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
 572                                 sizeof(struct drm_crtc *), GFP_KERNEL);
 573         if (!save_encoder_crtcs)
 574                 return -ENOMEM;
 575
 576         save_connector_encoders = kcalloc(dev->mode_config.num_connector,
 577                                 sizeof(struct drm_encoder *), GFP_KERNEL);
 578         if (!save_connector_encoders) {
 579                 kfree(save_encoder_crtcs);
 580                 return -ENOMEM;
 581         }
 582
 583         /*
 584          * Copy data. Note that driver private data is not affected.
 585          * Should anything bad happen only the expected state is
 586          * restored, not the drivers personal bookkeeping.
 587          */
 588         count = 0;
 589         drm_for_each_encoder(encoder, dev) {
 590                 save_encoder_crtcs[count++] = encoder->crtc;
 591         }
 592
 593         count = 0;
 594         drm_connector_list_iter_begin(dev, &conn_iter);
 595         drm_for_each_connector_iter(connector, &conn_iter)
 596                 save_connector_encoders[count++] = connector->encoder;
 597         drm_connector_list_iter_end(&conn_iter);
 598
 599         save_set.crtc = set->crtc;
 600         save_set.mode = &set->crtc->mode;
 601         save_set.x = set->crtc->x;
 602         save_set.y = set->crtc->y;
 603         save_set.fb = set->crtc->primary->fb;
 604
 605         /* We should be able to check here if the fb has the same properties
 606          * and then just flip_or_move it */
 607         if (set->crtc->primary->fb != set->fb) {
 608                 /* If we have no fb then treat it as a full mode set */
 609                 if (set->crtc->primary->fb == NULL) {
 610                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 611                         mode_changed = true;
 612                 } else if (set->fb->format != set->crtc->primary->fb->format) {
 613                         mode_changed = true;
 614                 } else
 615                         fb_changed = true;
 616         }
 617
 618         if (set->x != set->crtc->x || set->y != set->crtc->y)
 619                 fb_changed = true;
 620
 621         if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
 622                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 623                 drm_mode_debug_printmodeline(&set->crtc->mode);
 624                 drm_mode_debug_printmodeline(set->mode);
 625                 mode_changed = true;
 626         }
 627
 628         /* take a reference on all unbound connectors in set, reuse the
 629          * already taken reference for bound connectors
 630          */
 631         for (ro = 0; ro < set->num_connectors; ro++) {
 632                 if (set->connectors[ro]->encoder)
 633                         continue;
 634                 drm_connector_get(set->connectors[ro]);
 635         }
 636
 637         /* a) traverse passed in connector list and get encoders for them */
 638         count = 0;
 639         drm_connector_list_iter_begin(dev, &conn_iter);
 640         drm_for_each_connector_iter(connector, &conn_iter) {
 641                 const struct drm_connector_helper_funcs *connector_funcs =
 642                         connector->helper_private;
 643                 new_encoder = connector->encoder;
 644                 for (ro = 0; ro < set->num_connectors; ro++) {
 645                         if (set->connectors[ro] == connector) {
 646                                 if (connector_funcs->best_encoder)
 647                                         new_encoder = connector_funcs->best_encoder(connector);
 648                                 else
 649                                         new_encoder = drm_connector_get_single_encoder(connector);
 650
 651                                 /* if we can't get an encoder for a connector
 652                                    we are setting now - then fail */
 653                                 if (new_encoder == NULL)
 654                                         /* don't break so fail path works correct */
 655                                         fail = 1;
 656
 657                                 if (connector->dpms != DRM_MODE_DPMS_ON) {
 658                                         DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
 659                                         mode_changed = true;
 660                                 }
 661
 662                                 break;
 663                         }
 664                 }
 665
 666                 if (new_encoder != connector->encoder) {
 667                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
 668                         mode_changed = true;
 669                         /* If the encoder is reused for another connector, then
 670                          * the appropriate crtc will be set later.
 671                          */
 672                         if (connector->encoder)
 673                                 connector->encoder->crtc = NULL;
 674                         connector->encoder = new_encoder;
 675                 }
 676         }
 677         drm_connector_list_iter_end(&conn_iter);
 678
 679         if (fail) {
 680                 ret = -EINVAL;
 681                 goto fail;
 682         }
 683
 684         count = 0;
 685         drm_connector_list_iter_begin(dev, &conn_iter);
 686         drm_for_each_connector_iter(connector, &conn_iter) {
 687                 if (!connector->encoder)
 688                         continue;
 689
 690                 if (connector->encoder->crtc == set->crtc)
 691                         new_crtc = NULL;
 692                 else
 693                         new_crtc = connector->encoder->crtc;
 694
 695                 for (ro = 0; ro < set->num_connectors; ro++) {
 696                         if (set->connectors[ro] == connector)
 697                                 new_crtc = set->crtc;
 698                 }
 699
 700                 /* Make sure the new CRTC will work with the encoder */
 701                 if (new_crtc &&
 702                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
 703                         ret = -EINVAL;
 704                         drm_connector_list_iter_end(&conn_iter);
 705                         goto fail;
 706                 }
 707                 if (new_crtc != connector->encoder->crtc) {
 708                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
 709                         mode_changed = true;
 710                         connector->encoder->crtc = new_crtc;
 711                 }
 712                 if (new_crtc) {
 713                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
 714                                       connector->base.id, connector->name,
 715                                       new_crtc->base.id, new_crtc->name);
 716                 } else {
 717                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
 718                                       connector->base.id, connector->name);
 719                 }
 720         }
 721         drm_connector_list_iter_end(&conn_iter);
 722
 723         /* mode_set_base is not a required function */
 724         if (fb_changed && !crtc_funcs->mode_set_base)
 725                 mode_changed = true;
 726
 727         if (mode_changed) {
 728                 if (drm_helper_crtc_in_use(set->crtc)) {
 729                         DRM_DEBUG_KMS("attempting to set mode from"
 730                                         " userspace\n");
 731                         drm_mode_debug_printmodeline(set->mode);
 732                         set->crtc->primary->fb = set->fb;
 733                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
 734                                                       set->x, set->y,
 735                                                       save_set.fb)) {
 736                                 DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
 737                                           set->crtc->base.id, set->crtc->name);
 738                                 set->crtc->primary->fb = save_set.fb;
 739                                 ret = -EINVAL;
 740                                 goto fail;
 741                         }
 742                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
 743                         for (i = 0; i < set->num_connectors; i++) {
 744                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
 745                                               set->connectors[i]->name);
 746                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
 747                         }
 748                 }
 749                 __drm_helper_disable_unused_functions(dev);
 750         } else if (fb_changed) {
 751                 set->crtc->x = set->x;
 752                 set->crtc->y = set->y;
 753                 set->crtc->primary->fb = set->fb;
 754                 ret = crtc_funcs->mode_set_base(set->crtc,
 755                                                 set->x, set->y, save_set.fb);
 756                 if (ret != 0) {
 757                         set->crtc->x = save_set.x;
 758                         set->crtc->y = save_set.y;
 759                         set->crtc->primary->fb = save_set.fb;
 760                         goto fail;
 761                 }
 762         }
 763
 764         kfree(save_connector_encoders);
 765         kfree(save_encoder_crtcs);
 766         return 0;
 767
 768 fail:
 769         /* Restore all previous data. */
 770         count = 0;
 771         drm_for_each_encoder(encoder, dev) {
 772                 encoder->crtc = save_encoder_crtcs[count++];
 773         }
 774
 775         count = 0;
 776         drm_connector_list_iter_begin(dev, &conn_iter);
 777         drm_for_each_connector_iter(connector, &conn_iter)
 778                 connector->encoder = save_connector_encoders[count++];
 779         drm_connector_list_iter_end(&conn_iter);
 780
 781         /* after fail drop reference on all unbound connectors in set, let
 782          * bound connectors keep their reference
 783          */
 784         for (ro = 0; ro < set->num_connectors; ro++) {
 785                 if (set->connectors[ro]->encoder)
 786                         continue;
 787                 drm_connector_put(set->connectors[ro]);
 788         }
 789
 790         /* Try to restore the config */
 791         if (mode_changed &&
 792             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
 793                                       save_set.y, save_set.fb))
 794                 DRM_ERROR("failed to restore config after modeset failure\n");
 795
 796         kfree(save_connector_encoders);
 797         kfree(save_encoder_crtcs);
 798         return ret;
 799 }
 800 EXPORT_SYMBOL(drm_crtc_helper_set_config);
 801
 802 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 803 {
 804         int dpms = DRM_MODE_DPMS_OFF;
 805         struct drm_connector *connector;
 806         struct drm_connector_list_iter conn_iter;
 807         struct drm_device *dev = encoder->dev;
 808
 809         drm_connector_list_iter_begin(dev, &conn_iter);
 810         drm_for_each_connector_iter(connector, &conn_iter)
 811                 if (connector->encoder == encoder)
 812                         if (connector->dpms < dpms)
 813                                 dpms = connector->dpms;
 814         drm_connector_list_iter_end(&conn_iter);
 815
 816         return dpms;
 817 }
 818
 819 /* Helper which handles bridge ordering around encoder dpms */
 820 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
 821 {
 822         const struct drm_encoder_helper_funcs *encoder_funcs;
 823
 824         encoder_funcs = encoder->helper_private;
 825         if (!encoder_funcs)
 826                 return;
 827
 828         if (encoder_funcs->dpms)
 829                 encoder_funcs->dpms(encoder, mode);
 830 }
 831
 832 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 833 {
 834         int dpms = DRM_MODE_DPMS_OFF;
 835         struct drm_connector *connector;
 836         struct drm_connector_list_iter conn_iter;
 837         struct drm_device *dev = crtc->dev;
 838
 839         drm_connector_list_iter_begin(dev, &conn_iter);
 840         drm_for_each_connector_iter(connector, &conn_iter)
 841                 if (connector->encoder && connector->encoder->crtc == crtc)
 842                         if (connector->dpms < dpms)
 843                                 dpms = connector->dpms;
 844         drm_connector_list_iter_end(&conn_iter);
 845
 846         return dpms;
 847 }
 848
 849 /**
 850  * drm_helper_connector_dpms() - connector dpms helper implementation
 851  * @connector: affected connector
 852  * @mode: DPMS mode
 853  *
 854  * The drm_helper_connector_dpms() helper function implements the
 855  * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
 856  * helpers.
 857  *
 858  * This is the main helper function provided by the CRTC helper framework for
 859  * implementing the DPMS connector attribute. It computes the new desired DPMS
 860  * state for all encoders and CRTCs in the output mesh and calls the
 861  * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
 862  * provided by the driver.
 863  *
 864  * This function is deprecated.  New drivers must implement atomic modeset
 865  * support, where DPMS is handled in the DRM core.
 866  *
 867  * Returns:
 868  * Always returns 0.
 869  */
 870 int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 871 {
 872         struct drm_encoder *encoder = connector->encoder;
 873         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 874         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 875
 876         WARN_ON(drm_drv_uses_atomic_modeset(connector->dev));
 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         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 950
 951         drm_modeset_lock_all(dev);
 952         drm_for_each_crtc(crtc, dev) {
 953
 954                 if (!crtc->enabled)
 955                         continue;
 956
 957                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 958                                                crtc->x, crtc->y, crtc->primary->fb);
 959
 960                 /* Restoring the old config should never fail! */
 961                 if (ret == false)
 962                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
 963
 964                 /* Turn off outputs that were already powered off */
 965                 if (drm_helper_choose_crtc_dpms(crtc)) {
 966                         drm_for_each_encoder(encoder, dev) {
 967
 968                                 if(encoder->crtc != crtc)
 969                                         continue;
 970
 971                                 encoder_dpms = drm_helper_choose_encoder_dpms(
 972                                                         encoder);
 973
 974                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
 975                         }
 976
 977                         crtc_funcs = crtc->helper_private;
 978                         if (crtc_funcs->dpms)
 979                                 (*crtc_funcs->dpms) (crtc,
 980                                                      drm_helper_choose_crtc_dpms(crtc));
 981                 }
 982         }
 983
 984         /* disable the unused connectors while restoring the modesetting */
 985         __drm_helper_disable_unused_functions(dev);
 986         drm_modeset_unlock_all(dev);
 987 }
 988 EXPORT_SYMBOL(drm_helper_resume_force_mode);
 989
 990 /**
 991  * drm_helper_force_disable_all - Forcibly turn off all enabled CRTCs
 992  * @dev: DRM device whose CRTCs to turn off
 993  *
 994  * Drivers may want to call this on unload to ensure that all displays are
 995  * unlit and the GPU is in a consistent, low power state. Takes modeset locks.
 996  *
 997  * Note: This should only be used by non-atomic legacy drivers. For an atomic
 998  * version look at drm_atomic_helper_shutdown().
 999  *
1000  * Returns:
1001  * Zero on success, error code on failure.
1002  */
1003 int drm_helper_force_disable_all(struct drm_device *dev)
1004 {
1005         struct drm_crtc *crtc;
1006         int ret = 0;
1007
1008         drm_modeset_lock_all(dev);
1009         drm_for_each_crtc(crtc, dev)
1010                 if (crtc->enabled) {
1011                         struct drm_mode_set set = {
1012                                 .crtc = crtc,
1013                         };
1014
1015                         ret = drm_mode_set_config_internal(&set);
1016                         if (ret)
1017                                 goto out;
1018                 }
1019 out:
1020         drm_modeset_unlock_all(dev);
1021         return ret;
1022 }
1023 EXPORT_SYMBOL(drm_helper_force_disable_all);