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