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 #include <linux/dynamic_debug.h>
  36
  37 #include <drm/drm_atomic.h>
  38 #include <drm/drm_atomic_helper.h>
  39 #include <drm/drm_atomic_uapi.h>
  40 #include <drm/drm_bridge.h>
  41 #include <drm/drm_crtc.h>
  42 #include <drm/drm_crtc_helper.h>
  43 #include <drm/drm_drv.h>
  44 #include <drm/drm_edid.h>
  45 #include <drm/drm_encoder.h>
  46 #include <drm/drm_fb_helper.h>
  47 #include <drm/drm_fourcc.h>
  48 #include <drm/drm_framebuffer.h>
  49 #include <drm/drm_print.h>
  50 #include <drm/drm_vblank.h>
  51
  52 #include "drm_crtc_helper_internal.h"
  53
  54 DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
  55                         "DRM_UT_CORE",
  56                         "DRM_UT_DRIVER",
  57                         "DRM_UT_KMS",
  58                         "DRM_UT_PRIME",
  59                         "DRM_UT_ATOMIC",
  60                         "DRM_UT_VBL",
  61                         "DRM_UT_STATE",
  62                         "DRM_UT_LEASE",
  63                         "DRM_UT_DP",
  64                         "DRM_UT_DRMRES");
  65
  66 /**
  67  * DOC: overview
  68  *
  69  * The CRTC modeset helper library provides a default set_config implementation
  70  * in drm_crtc_helper_set_config(). Plus a few other convenience functions using
  71  * the same callbacks which drivers can use to e.g. restore the modeset
  72  * configuration on resume with drm_helper_resume_force_mode().
  73  *
  74  * Note that this helper library doesn't track the current power state of CRTCs
  75  * and encoders. It can call callbacks like &drm_encoder_helper_funcs.dpms even
  76  * though the hardware is already in the desired state. This deficiency has been
  77  * fixed in the atomic helpers.
  78  *
  79  * The driver callbacks are mostly compatible with the atomic modeset helpers,
  80  * except for the handling of the primary plane: Atomic helpers require that the
  81  * primary plane is implemented as a real standalone plane and not directly tied
  82  * to the CRTC state. For easier transition this library provides functions to
  83  * implement the old semantics required by the CRTC helpers using the new plane
  84  * and atomic helper callbacks.
  85  *
  86  * Drivers are strongly urged to convert to the atomic helpers (by way of first
  87  * converting to the plane helpers). New drivers must not use these functions
  88  * but need to implement the atomic interface instead, potentially using the
  89  * atomic helpers for that.
  90  *
  91  * These legacy modeset helpers use the same function table structures as
  92  * all other modesetting helpers. See the documentation for struct
  93  * &drm_crtc_helper_funcs, &struct drm_encoder_helper_funcs and struct
  94  * &drm_connector_helper_funcs.
  95  */
  96
  97 /**
  98  * drm_helper_encoder_in_use - check if a given encoder is in use
  99  * @encoder: encoder to check
 100  *
 101  * Checks whether @encoder is with the current mode setting output configuration
 102  * in use by any connector. This doesn't mean that it is actually enabled since
 103  * the DPMS state is tracked separately.
 104  *
 105  * Returns:
 106  * True if @encoder is used, false otherwise.
 107  */
 108 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
 109 {
 110         struct drm_connector *connector;
 111         struct drm_connector_list_iter conn_iter;
 112         struct drm_device *dev = encoder->dev;
 113
 114         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 115
 116         /*
 117          * We can expect this mutex to be locked if we are not panicking.
 118          * Locking is currently fubar in the panic handler.
 119          */
 120         if (!oops_in_progress) {
 121                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 122                 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 123         }
 124
 125
 126         drm_connector_list_iter_begin(dev, &conn_iter);
 127         drm_for_each_connector_iter(connector, &conn_iter) {
 128                 if (connector->encoder == encoder) {
 129                         drm_connector_list_iter_end(&conn_iter);
 130                         return true;
 131                 }
 132         }
 133         drm_connector_list_iter_end(&conn_iter);
 134         return false;
 135 }
 136 EXPORT_SYMBOL(drm_helper_encoder_in_use);
 137
 138 /**
 139  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
 140  * @crtc: CRTC to check
 141  *
 142  * Checks whether @crtc is with the current mode setting output configuration
 143  * in use by any connector. This doesn't mean that it is actually enabled since
 144  * the DPMS state is tracked separately.
 145  *
 146  * Returns:
 147  * True if @crtc is used, false otherwise.
 148  */
 149 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
 150 {
 151         struct drm_encoder *encoder;
 152         struct drm_device *dev = crtc->dev;
 153
 154         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 155
 156         /*
 157          * We can expect this mutex to be locked if we are not panicking.
 158          * Locking is currently fubar in the panic handler.
 159          */
 160         if (!oops_in_progress)
 161                 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 162
 163         drm_for_each_encoder(encoder, dev)
 164                 if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
 165                         return true;
 166         return false;
 167 }
 168 EXPORT_SYMBOL(drm_helper_crtc_in_use);
 169
 170 static void
 171 drm_encoder_disable(struct drm_encoder *encoder)
 172 {
 173         const struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 174
 175         if (!encoder_funcs)
 176                 return;
 177
 178         if (encoder_funcs->disable)
 179                 (*encoder_funcs->disable)(encoder);
 180         else if (encoder_funcs->dpms)
 181                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
 182 }
 183
 184 static void __drm_helper_disable_unused_functions(struct drm_device *dev)
 185 {
 186         struct drm_encoder *encoder;
 187         struct drm_crtc *crtc;
 188
 189         drm_warn_on_modeset_not_all_locked(dev);
 190
 191         drm_for_each_encoder(encoder, dev) {
 192                 if (!drm_helper_encoder_in_use(encoder)) {
 193                         drm_encoder_disable(encoder);
 194                         /* disconnect encoder from any connector */
 195                         encoder->crtc = NULL;
 196                 }
 197         }
 198
 199         drm_for_each_crtc(crtc, dev) {
 200                 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 201
 202                 crtc->enabled = drm_helper_crtc_in_use(crtc);
 203                 if (!crtc->enabled) {
 204                         if (crtc_funcs->disable)
 205                                 (*crtc_funcs->disable)(crtc);
 206                         else
 207                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
 208                         crtc->primary->fb = NULL;
 209                 }
 210         }
 211 }
 212
 213 /**
 214  * drm_helper_disable_unused_functions - disable unused objects
 215  * @dev: DRM device
 216  *
 217  * This function walks through the entire mode setting configuration of @dev. It
 218  * will remove any CRTC links of unused encoders and encoder links of
 219  * disconnected connectors. Then it will disable all unused encoders and CRTCs
 220  * either by calling their disable callback if available or by calling their
 221  * dpms callback with DRM_MODE_DPMS_OFF.
 222  *
 223  * NOTE:
 224  *
 225  * This function is part of the legacy modeset helper library and will cause
 226  * major confusion with atomic drivers. This is because atomic helpers guarantee
 227  * to never call ->disable() hooks on a disabled function, or ->enable() hooks
 228  * on an enabled functions. drm_helper_disable_unused_functions() on the other
 229  * hand throws such guarantees into the wind and calls disable hooks
 230  * unconditionally on unused functions.
 231  */
 232 void drm_helper_disable_unused_functions(struct drm_device *dev)
 233 {
 234         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 235
 236         drm_modeset_lock_all(dev);
 237         __drm_helper_disable_unused_functions(dev);
 238         drm_modeset_unlock_all(dev);
 239 }
 240 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
 241
 242 /*
 243  * Check the CRTC we're going to map each output to vs. its current
 244  * CRTC.  If they don't match, we have to disable the output and the CRTC
 245  * since the driver will have to re-route things.
 246  */
 247 static void
 248 drm_crtc_prepare_encoders(struct drm_device *dev)
 249 {
 250         const struct drm_encoder_helper_funcs *encoder_funcs;
 251         struct drm_encoder *encoder;
 252
 253         drm_for_each_encoder(encoder, dev) {
 254                 encoder_funcs = encoder->helper_private;
 255                 if (!encoder_funcs)
 256                         continue;
 257
 258                 /* Disable unused encoders */
 259                 if (encoder->crtc == NULL)
 260                         drm_encoder_disable(encoder);
 261         }
 262 }
 263
 264 /**
 265  * drm_crtc_helper_set_mode - internal helper to set a mode
 266  * @crtc: CRTC to program
 267  * @mode: mode to use
 268  * @x: horizontal offset into the surface
 269  * @y: vertical offset into the surface
 270  * @old_fb: old framebuffer, for cleanup
 271  *
 272  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 273  * to fixup or reject the mode prior to trying to set it. This is an internal
 274  * helper that drivers could e.g. use to update properties that require the
 275  * entire output pipe to be disabled and re-enabled in a new configuration. For
 276  * example for changing whether audio is enabled on a hdmi link or for changing
 277  * panel fitter or dither attributes. It is also called by the
 278  * drm_crtc_helper_set_config() helper function to drive the mode setting
 279  * sequence.
 280  *
 281  * Returns:
 282  * True if the mode was set successfully, false otherwise.
 283  */
 284 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 285                               struct drm_display_mode *mode,
 286                               int x, int y,
 287                               struct drm_framebuffer *old_fb)
 288 {
 289         struct drm_device *dev = crtc->dev;
 290         struct drm_display_mode *adjusted_mode, saved_mode, saved_hwmode;
 291         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 292         const struct drm_encoder_helper_funcs *encoder_funcs;
 293         int saved_x, saved_y;
 294         bool saved_enabled;
 295         struct drm_encoder *encoder;
 296         bool ret = true;
 297
 298         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 299
 300         drm_warn_on_modeset_not_all_locked(dev);
 301
 302         saved_enabled = crtc->enabled;
 303         crtc->enabled = drm_helper_crtc_in_use(crtc);
 304         if (!crtc->enabled)
 305                 return true;
 306
 307         adjusted_mode = drm_mode_duplicate(dev, mode);
 308         if (!adjusted_mode) {
 309                 crtc->enabled = saved_enabled;
 310                 return false;
 311         }
 312
 313         drm_mode_init(&saved_mode, &crtc->mode);
 314         drm_mode_init(&saved_hwmode, &crtc->hwmode);
 315         saved_x = crtc->x;
 316         saved_y = crtc->y;
 317
 318         /* Update crtc values up front so the driver can rely on them for mode
 319          * setting.
 320          */
 321         drm_mode_copy(&crtc->mode, mode);
 322         crtc->x = x;
 323         crtc->y = y;
 324
 325         /* Pass our mode to the connectors and the CRTC to give them a chance to
 326          * adjust it according to limitations or connector properties, and also
 327          * a chance to reject the mode entirely.
 328          */
 329         drm_for_each_encoder(encoder, dev) {
 330
 331                 if (encoder->crtc != crtc)
 332                         continue;
 333
 334                 encoder_funcs = encoder->helper_private;
 335                 if (!encoder_funcs)
 336                         continue;
 337
 338                 encoder_funcs = encoder->helper_private;
 339                 if (encoder_funcs->mode_fixup) {
 340                         if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 341                                                               adjusted_mode))) {
 342                                 DRM_DEBUG_KMS("Encoder fixup failed\n");
 343                                 goto done;
 344                         }
 345                 }
 346         }
 347
 348         if (crtc_funcs->mode_fixup) {
 349                 if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
 350                                                 adjusted_mode))) {
 351                         DRM_DEBUG_KMS("CRTC fixup failed\n");
 352                         goto done;
 353                 }
 354         }
 355         DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);
 356
 357         drm_mode_copy(&crtc->hwmode, adjusted_mode);
 358
 359         /* Prepare the encoders and CRTCs before setting the mode. */
 360         drm_for_each_encoder(encoder, dev) {
 361
 362                 if (encoder->crtc != crtc)
 363                         continue;
 364
 365                 encoder_funcs = encoder->helper_private;
 366                 if (!encoder_funcs)
 367                         continue;
 368
 369                 /* Disable the encoders as the first thing we do. */
 370                 if (encoder_funcs->prepare)
 371                         encoder_funcs->prepare(encoder);
 372         }
 373
 374         drm_crtc_prepare_encoders(dev);
 375
 376         crtc_funcs->prepare(crtc);
 377
 378         /* Set up the DPLL and any encoders state that needs to adjust or depend
 379          * on the DPLL.
 380          */
 381         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 382         if (!ret)
 383             goto done;
 384
 385         drm_for_each_encoder(encoder, dev) {
 386
 387                 if (encoder->crtc != crtc)
 388                         continue;
 389
 390                 encoder_funcs = encoder->helper_private;
 391                 if (!encoder_funcs)
 392                         continue;
 393
 394                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%s]\n",
 395                         encoder->base.id, encoder->name, mode->name);
 396                 if (encoder_funcs->mode_set)
 397                         encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 398         }
 399
 400         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 401         crtc_funcs->commit(crtc);
 402
 403         drm_for_each_encoder(encoder, dev) {
 404
 405                 if (encoder->crtc != crtc)
 406                         continue;
 407
 408                 encoder_funcs = encoder->helper_private;
 409                 if (!encoder_funcs)
 410                         continue;
 411
 412                 if (encoder_funcs->commit)
 413                         encoder_funcs->commit(encoder);
 414         }
 415
 416         /* Calculate and store various constants which
 417          * are later needed by vblank and swap-completion
 418          * timestamping. They are derived from true hwmode.
 419          */
 420         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
 421
 422         /* FIXME: add subpixel order */
 423 done:
 424         drm_mode_destroy(dev, adjusted_mode);
 425         if (!ret) {
 426                 crtc->enabled = saved_enabled;
 427                 drm_mode_copy(&crtc->mode, &saved_mode);
 428                 drm_mode_copy(&crtc->hwmode, &saved_hwmode);
 429                 crtc->x = saved_x;
 430                 crtc->y = saved_y;
 431         }
 432
 433         return ret;
 434 }
 435 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 436
 437 static void
 438 drm_crtc_helper_disable(struct drm_crtc *crtc)
 439 {
 440         struct drm_device *dev = crtc->dev;
 441         struct drm_connector *connector;
 442         struct drm_encoder *encoder;
 443
 444         /* Decouple all encoders and their attached connectors from this crtc */
 445         drm_for_each_encoder(encoder, dev) {
 446                 struct drm_connector_list_iter conn_iter;
 447
 448                 if (encoder->crtc != crtc)
 449                         continue;
 450
 451                 drm_connector_list_iter_begin(dev, &conn_iter);
 452                 drm_for_each_connector_iter(connector, &conn_iter) {
 453                         if (connector->encoder != encoder)
 454                                 continue;
 455
 456                         connector->encoder = NULL;
 457
 458                         /*
 459                          * drm_helper_disable_unused_functions() ought to be
 460                          * doing this, but since we've decoupled the encoder
 461                          * from the connector above, the required connection
 462                          * between them is henceforth no longer available.
 463                          */
 464                         connector->dpms = DRM_MODE_DPMS_OFF;
 465
 466                         /* we keep a reference while the encoder is bound */
 467                         drm_connector_put(connector);
 468                 }
 469                 drm_connector_list_iter_end(&conn_iter);
 470         }
 471
 472         __drm_helper_disable_unused_functions(dev);
 473 }
 474
 475 /*
 476  * For connectors that support multiple encoders, either the
 477  * .atomic_best_encoder() or .best_encoder() operation must be implemented.
 478  */
 479 struct drm_encoder *
 480 drm_connector_get_single_encoder(struct drm_connector *connector)
 481 {
 482         struct drm_encoder *encoder;
 483
 484         WARN_ON(hweight32(connector->possible_encoders) > 1);
 485         drm_connector_for_each_possible_encoder(connector, encoder)
 486                 return encoder;
 487
 488         return NULL;
 489 }
 490
 491 /**
 492  * drm_crtc_helper_set_config - set a new config from userspace
 493  * @set: mode set configuration
 494  * @ctx: lock acquire context, not used here
 495  *
 496  * The drm_crtc_helper_set_config() helper function implements the of
 497  * &drm_crtc_funcs.set_config callback for drivers using the legacy CRTC
 498  * helpers.
 499  *
 500  * It first tries to locate the best encoder for each connector by calling the
 501  * connector @drm_connector_helper_funcs.best_encoder helper operation.
 502  *
 503  * After locating the appropriate encoders, the helper function will call the
 504  * mode_fixup encoder and CRTC helper operations to adjust the requested mode,
 505  * or reject it completely in which case an error will be returned to the
 506  * application. If the new configuration after mode adjustment is identical to
 507  * the current configuration the helper function will return without performing
 508  * any other operation.
 509  *
 510  * If the adjusted mode is identical to the current mode but changes to the
 511  * frame buffer need to be applied, the drm_crtc_helper_set_config() function
 512  * will call the CRTC &drm_crtc_helper_funcs.mode_set_base helper operation.
 513  *
 514  * If the adjusted mode differs from the current mode, or if the
 515  * ->mode_set_base() helper operation is not provided, the helper function
 516  * performs a full mode set sequence by calling the ->prepare(), ->mode_set()
 517  * and ->commit() CRTC and encoder helper operations, in that order.
 518  * Alternatively it can also use the dpms and disable helper operations. For
 519  * details see &struct drm_crtc_helper_funcs and struct
 520  * &drm_encoder_helper_funcs.
 521  *
 522  * This function is deprecated.  New drivers must implement atomic modeset
 523  * support, for which this function is unsuitable. Instead drivers should use
 524  * drm_atomic_helper_set_config().
 525  *
 526  * Returns:
 527  * Returns 0 on success, negative errno numbers on failure.
 528  */
 529 int drm_crtc_helper_set_config(struct drm_mode_set *set,
 530                                struct drm_modeset_acquire_ctx *ctx)
 531 {
 532         struct drm_device *dev;
 533         struct drm_crtc **save_encoder_crtcs, *new_crtc;
 534         struct drm_encoder **save_connector_encoders, *new_encoder, *encoder;
 535         bool mode_changed = false; /* if true do a full mode set */
 536         bool fb_changed = false; /* if true and !mode_changed just do a flip */
 537         struct drm_connector *connector;
 538         struct drm_connector_list_iter conn_iter;
 539         int count = 0, ro, fail = 0;
 540         const struct drm_crtc_helper_funcs *crtc_funcs;
 541         struct drm_mode_set save_set;
 542         int ret;
 543         int i;
 544
 545         DRM_DEBUG_KMS("\n");
 546
 547         BUG_ON(!set);
 548         BUG_ON(!set->crtc);
 549         BUG_ON(!set->crtc->helper_private);
 550
 551         /* Enforce sane interface api - has been abused by the fb helper. */
 552         BUG_ON(!set->mode && set->fb);
 553         BUG_ON(set->fb && set->num_connectors == 0);
 554
 555         crtc_funcs = set->crtc->helper_private;
 556
 557         dev = set->crtc->dev;
 558         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 559
 560         if (!set->mode)
 561                 set->fb = NULL;
 562
 563         if (set->fb) {
 564                 DRM_DEBUG_KMS("[CRTC:%d:%s] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 565                               set->crtc->base.id, set->crtc->name,
 566                               set->fb->base.id,
 567                               (int)set->num_connectors, set->x, set->y);
 568         } else {
 569                 DRM_DEBUG_KMS("[CRTC:%d:%s] [NOFB]\n",
 570                               set->crtc->base.id, set->crtc->name);
 571                 drm_crtc_helper_disable(set->crtc);
 572                 return 0;
 573         }
 574
 575         drm_warn_on_modeset_not_all_locked(dev);
 576
 577         /*
 578          * Allocate space for the backup of all (non-pointer) encoder and
 579          * connector data.
 580          */
 581         save_encoder_crtcs = kcalloc(dev->mode_config.num_encoder,
 582                                 sizeof(struct drm_crtc *), GFP_KERNEL);
 583         if (!save_encoder_crtcs)
 584                 return -ENOMEM;
 585
 586         save_connector_encoders = kcalloc(dev->mode_config.num_connector,
 587                                 sizeof(struct drm_encoder *), GFP_KERNEL);
 588         if (!save_connector_encoders) {
 589                 kfree(save_encoder_crtcs);
 590                 return -ENOMEM;
 591         }
 592
 593         /*
 594          * Copy data. Note that driver private data is not affected.
 595          * Should anything bad happen only the expected state is
 596          * restored, not the drivers personal bookkeeping.
 597          */
 598         count = 0;
 599         drm_for_each_encoder(encoder, dev) {
 600                 save_encoder_crtcs[count++] = encoder->crtc;
 601         }
 602
 603         count = 0;
 604         drm_connector_list_iter_begin(dev, &conn_iter);
 605         drm_for_each_connector_iter(connector, &conn_iter)
 606                 save_connector_encoders[count++] = connector->encoder;
 607         drm_connector_list_iter_end(&conn_iter);
 608
 609         save_set.crtc = set->crtc;
 610         save_set.mode = &set->crtc->mode;
 611         save_set.x = set->crtc->x;
 612         save_set.y = set->crtc->y;
 613         save_set.fb = set->crtc->primary->fb;
 614
 615         /* We should be able to check here if the fb has the same properties
 616          * and then just flip_or_move it */
 617         if (set->crtc->primary->fb != set->fb) {
 618                 /* If we have no fb then treat it as a full mode set */
 619                 if (set->crtc->primary->fb == NULL) {
 620                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 621                         mode_changed = true;
 622                 } else if (set->fb->format != set->crtc->primary->fb->format) {
 623                         mode_changed = true;
 624                 } else
 625                         fb_changed = true;
 626         }
 627
 628         if (set->x != set->crtc->x || set->y != set->crtc->y)
 629                 fb_changed = true;
 630
 631         if (!drm_mode_equal(set->mode, &set->crtc->mode)) {
 632                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 633                 drm_mode_debug_printmodeline(&set->crtc->mode);
 634                 drm_mode_debug_printmodeline(set->mode);
 635                 mode_changed = true;
 636         }
 637
 638         /* take a reference on all unbound connectors in set, reuse the
 639          * already taken reference for bound connectors
 640          */
 641         for (ro = 0; ro < set->num_connectors; ro++) {
 642                 if (set->connectors[ro]->encoder)
 643                         continue;
 644                 drm_connector_get(set->connectors[ro]);
 645         }
 646
 647         /* a) traverse passed in connector list and get encoders for them */
 648         count = 0;
 649         drm_connector_list_iter_begin(dev, &conn_iter);
 650         drm_for_each_connector_iter(connector, &conn_iter) {
 651                 const struct drm_connector_helper_funcs *connector_funcs =
 652                         connector->helper_private;
 653                 new_encoder = connector->encoder;
 654                 for (ro = 0; ro < set->num_connectors; ro++) {
 655                         if (set->connectors[ro] == connector) {
 656                                 if (connector_funcs->best_encoder)
 657                                         new_encoder = connector_funcs->best_encoder(connector);
 658                                 else
 659                                         new_encoder = drm_connector_get_single_encoder(connector);
 660
 661                                 /* if we can't get an encoder for a connector
 662                                    we are setting now - then fail */
 663                                 if (new_encoder == NULL)
 664                                         /* don't break so fail path works correct */
 665                                         fail = 1;
 666
 667                                 if (connector->dpms != DRM_MODE_DPMS_ON) {
 668                                         DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
 669                                         mode_changed = true;
 670                                 }
 671
 672                                 break;
 673                         }
 674                 }
 675
 676                 if (new_encoder != connector->encoder) {
 677                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
 678                         mode_changed = true;
 679                         /* If the encoder is reused for another connector, then
 680                          * the appropriate crtc will be set later.
 681                          */
 682                         if (connector->encoder)
 683                                 connector->encoder->crtc = NULL;
 684                         connector->encoder = new_encoder;
 685                 }
 686         }
 687         drm_connector_list_iter_end(&conn_iter);
 688
 689         if (fail) {
 690                 ret = -EINVAL;
 691                 goto fail;
 692         }
 693
 694         count = 0;
 695         drm_connector_list_iter_begin(dev, &conn_iter);
 696         drm_for_each_connector_iter(connector, &conn_iter) {
 697                 if (!connector->encoder)
 698                         continue;
 699
 700                 if (connector->encoder->crtc == set->crtc)
 701                         new_crtc = NULL;
 702                 else
 703                         new_crtc = connector->encoder->crtc;
 704
 705                 for (ro = 0; ro < set->num_connectors; ro++) {
 706                         if (set->connectors[ro] == connector)
 707                                 new_crtc = set->crtc;
 708                 }
 709
 710                 /* Make sure the new CRTC will work with the encoder */
 711                 if (new_crtc &&
 712                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
 713                         ret = -EINVAL;
 714                         drm_connector_list_iter_end(&conn_iter);
 715                         goto fail;
 716                 }
 717                 if (new_crtc != connector->encoder->crtc) {
 718                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
 719                         mode_changed = true;
 720                         connector->encoder->crtc = new_crtc;
 721                 }
 722                 if (new_crtc) {
 723                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d:%s]\n",
 724                                       connector->base.id, connector->name,
 725                                       new_crtc->base.id, new_crtc->name);
 726                 } else {
 727                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
 728                                       connector->base.id, connector->name);
 729                 }
 730         }
 731         drm_connector_list_iter_end(&conn_iter);
 732
 733         /* mode_set_base is not a required function */
 734         if (fb_changed && !crtc_funcs->mode_set_base)
 735                 mode_changed = true;
 736
 737         if (mode_changed) {
 738                 if (drm_helper_crtc_in_use(set->crtc)) {
 739                         DRM_DEBUG_KMS("attempting to set mode from"
 740                                         " userspace\n");
 741                         drm_mode_debug_printmodeline(set->mode);
 742                         set->crtc->primary->fb = set->fb;
 743                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
 744                                                       set->x, set->y,
 745                                                       save_set.fb)) {
 746                                 DRM_ERROR("failed to set mode on [CRTC:%d:%s]\n",
 747                                           set->crtc->base.id, set->crtc->name);
 748                                 set->crtc->primary->fb = save_set.fb;
 749                                 ret = -EINVAL;
 750                                 goto fail;
 751                         }
 752                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
 753                         for (i = 0; i < set->num_connectors; i++) {
 754                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
 755                                               set->connectors[i]->name);
 756                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
 757                         }
 758                 }
 759                 __drm_helper_disable_unused_functions(dev);
 760         } else if (fb_changed) {
 761                 set->crtc->x = set->x;
 762                 set->crtc->y = set->y;
 763                 set->crtc->primary->fb = set->fb;
 764                 ret = crtc_funcs->mode_set_base(set->crtc,
 765                                                 set->x, set->y, save_set.fb);
 766                 if (ret != 0) {
 767                         set->crtc->x = save_set.x;
 768                         set->crtc->y = save_set.y;
 769                         set->crtc->primary->fb = save_set.fb;
 770                         goto fail;
 771                 }
 772         }
 773
 774         kfree(save_connector_encoders);
 775         kfree(save_encoder_crtcs);
 776         return 0;
 777
 778 fail:
 779         /* Restore all previous data. */
 780         count = 0;
 781         drm_for_each_encoder(encoder, dev) {
 782                 encoder->crtc = save_encoder_crtcs[count++];
 783         }
 784
 785         count = 0;
 786         drm_connector_list_iter_begin(dev, &conn_iter);
 787         drm_for_each_connector_iter(connector, &conn_iter)
 788                 connector->encoder = save_connector_encoders[count++];
 789         drm_connector_list_iter_end(&conn_iter);
 790
 791         /* after fail drop reference on all unbound connectors in set, let
 792          * bound connectors keep their reference
 793          */
 794         for (ro = 0; ro < set->num_connectors; ro++) {
 795                 if (set->connectors[ro]->encoder)
 796                         continue;
 797                 drm_connector_put(set->connectors[ro]);
 798         }
 799
 800         /* Try to restore the config */
 801         if (mode_changed &&
 802             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
 803                                       save_set.y, save_set.fb))
 804                 DRM_ERROR("failed to restore config after modeset failure\n");
 805
 806         kfree(save_connector_encoders);
 807         kfree(save_encoder_crtcs);
 808         return ret;
 809 }
 810 EXPORT_SYMBOL(drm_crtc_helper_set_config);
 811
 812 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 813 {
 814         int dpms = DRM_MODE_DPMS_OFF;
 815         struct drm_connector *connector;
 816         struct drm_connector_list_iter conn_iter;
 817         struct drm_device *dev = encoder->dev;
 818
 819         drm_connector_list_iter_begin(dev, &conn_iter);
 820         drm_for_each_connector_iter(connector, &conn_iter)
 821                 if (connector->encoder == encoder)
 822                         if (connector->dpms < dpms)
 823                                 dpms = connector->dpms;
 824         drm_connector_list_iter_end(&conn_iter);
 825
 826         return dpms;
 827 }
 828
 829 /* Helper which handles bridge ordering around encoder dpms */
 830 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
 831 {
 832         const struct drm_encoder_helper_funcs *encoder_funcs;
 833
 834         encoder_funcs = encoder->helper_private;
 835         if (!encoder_funcs)
 836                 return;
 837
 838         if (encoder_funcs->dpms)
 839                 encoder_funcs->dpms(encoder, mode);
 840 }
 841
 842 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 843 {
 844         int dpms = DRM_MODE_DPMS_OFF;
 845         struct drm_connector *connector;
 846         struct drm_connector_list_iter conn_iter;
 847         struct drm_device *dev = crtc->dev;
 848
 849         drm_connector_list_iter_begin(dev, &conn_iter);
 850         drm_for_each_connector_iter(connector, &conn_iter)
 851                 if (connector->encoder && connector->encoder->crtc == crtc)
 852                         if (connector->dpms < dpms)
 853                                 dpms = connector->dpms;
 854         drm_connector_list_iter_end(&conn_iter);
 855
 856         return dpms;
 857 }
 858
 859 /**
 860  * drm_helper_connector_dpms() - connector dpms helper implementation
 861  * @connector: affected connector
 862  * @mode: DPMS mode
 863  *
 864  * The drm_helper_connector_dpms() helper function implements the
 865  * &drm_connector_funcs.dpms callback for drivers using the legacy CRTC
 866  * helpers.
 867  *
 868  * This is the main helper function provided by the CRTC helper framework for
 869  * implementing the DPMS connector attribute. It computes the new desired DPMS
 870  * state for all encoders and CRTCs in the output mesh and calls the
 871  * &drm_crtc_helper_funcs.dpms and &drm_encoder_helper_funcs.dpms callbacks
 872  * provided by the driver.
 873  *
 874  * This function is deprecated.  New drivers must implement atomic modeset
 875  * support, where DPMS is handled in the DRM core.
 876  *
 877  * Returns:
 878  * Always returns 0.
 879  */
 880 int drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 881 {
 882         struct drm_encoder *encoder = connector->encoder;
 883         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 884         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 885
 886         WARN_ON(drm_drv_uses_atomic_modeset(connector->dev));
 887
 888         if (mode == connector->dpms)
 889                 return 0;
 890
 891         old_dpms = connector->dpms;
 892         connector->dpms = mode;
 893
 894         if (encoder)
 895                 encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
 896
 897         /* from off to on, do crtc then encoder */
 898         if (mode < old_dpms) {
 899                 if (crtc) {
 900                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 901
 902                         if (crtc_funcs->dpms)
 903                                 (*crtc_funcs->dpms) (crtc,
 904                                                      drm_helper_choose_crtc_dpms(crtc));
 905                 }
 906                 if (encoder)
 907                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 908         }
 909
 910         /* from on to off, do encoder then crtc */
 911         if (mode > old_dpms) {
 912                 if (encoder)
 913                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 914                 if (crtc) {
 915                         const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 916
 917                         if (crtc_funcs->dpms)
 918                                 (*crtc_funcs->dpms) (crtc,
 919                                                      drm_helper_choose_crtc_dpms(crtc));
 920                 }
 921         }
 922
 923         return 0;
 924 }
 925 EXPORT_SYMBOL(drm_helper_connector_dpms);
 926
 927 /**
 928  * drm_helper_resume_force_mode - force-restore mode setting configuration
 929  * @dev: drm_device which should be restored
 930  *
 931  * Drivers which use the mode setting helpers can use this function to
 932  * force-restore the mode setting configuration e.g. on resume or when something
 933  * else might have trampled over the hw state (like some overzealous old BIOSen
 934  * tended to do).
 935  *
 936  * This helper doesn't provide a error return value since restoring the old
 937  * config should never fail due to resource allocation issues since the driver
 938  * has successfully set the restored configuration already. Hence this should
 939  * boil down to the equivalent of a few dpms on calls, which also don't provide
 940  * an error code.
 941  *
 942  * Drivers where simply restoring an old configuration again might fail (e.g.
 943  * due to slight differences in allocating shared resources when the
 944  * configuration is restored in a different order than when userspace set it up)
 945  * need to use their own restore logic.
 946  *
 947  * This function is deprecated. New drivers should implement atomic mode-
 948  * setting and use the atomic suspend/resume helpers.
 949  *
 950  * See also:
 951  * drm_atomic_helper_suspend(), drm_atomic_helper_resume()
 952  */
 953 void drm_helper_resume_force_mode(struct drm_device *dev)
 954 {
 955         struct drm_crtc *crtc;
 956         struct drm_encoder *encoder;
 957         const struct drm_crtc_helper_funcs *crtc_funcs;
 958         int encoder_dpms;
 959         bool ret;
 960
 961         WARN_ON(drm_drv_uses_atomic_modeset(dev));
 962
 963         drm_modeset_lock_all(dev);
 964         drm_for_each_crtc(crtc, dev) {
 965
 966                 if (!crtc->enabled)
 967                         continue;
 968
 969                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 970                                                crtc->x, crtc->y, crtc->primary->fb);
 971
 972                 /* Restoring the old config should never fail! */
 973                 if (ret == false)
 974                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
 975
 976                 /* Turn off outputs that were already powered off */
 977                 if (drm_helper_choose_crtc_dpms(crtc)) {
 978                         drm_for_each_encoder(encoder, dev) {
 979
 980                                 if(encoder->crtc != crtc)
 981                                         continue;
 982
 983                                 encoder_dpms = drm_helper_choose_encoder_dpms(
 984                                                         encoder);
 985
 986                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
 987                         }
 988
 989                         crtc_funcs = crtc->helper_private;
 990                         if (crtc_funcs->dpms)
 991                                 (*crtc_funcs->dpms) (crtc,
 992                                                      drm_helper_choose_crtc_dpms(crtc));
 993                 }
 994         }
 995
 996         /* disable the unused connectors while restoring the modesetting */
 997         __drm_helper_disable_unused_functions(dev);
 998         drm_modeset_unlock_all(dev);
 999 }
1000 EXPORT_SYMBOL(drm_helper_resume_force_mode);
1001
1002 /**
1003  * drm_helper_force_disable_all - Forcibly turn off all enabled CRTCs
1004  * @dev: DRM device whose CRTCs to turn off
1005  *
1006  * Drivers may want to call this on unload to ensure that all displays are
1007  * unlit and the GPU is in a consistent, low power state. Takes modeset locks.
1008  *
1009  * Note: This should only be used by non-atomic legacy drivers. For an atomic
1010  * version look at drm_atomic_helper_shutdown().
1011  *
1012  * Returns:
1013  * Zero on success, error code on failure.
1014  */
1015 int drm_helper_force_disable_all(struct drm_device *dev)
1016 {
1017         struct drm_crtc *crtc;
1018         int ret = 0;
1019
1020         drm_modeset_lock_all(dev);
1021         drm_for_each_crtc(crtc, dev)
1022                 if (crtc->enabled) {
1023                         struct drm_mode_set set = {
1024                                 .crtc = crtc,
1025                         };
1026
1027                         ret = drm_mode_set_config_internal(&set);
1028                         if (ret)
1029                                 goto out;
1030                 }
1031 out:
1032         drm_modeset_unlock_all(dev);
1033         return ret;
1034 }
1035 EXPORT_SYMBOL(drm_helper_force_disable_all);