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/moduleparam.h>
  34
  35 #include <drm/drmP.h>
  36 #include <drm/drm_crtc.h>
  37 #include <drm/drm_fourcc.h>
  38 #include <drm/drm_crtc_helper.h>
  39 #include <drm/drm_fb_helper.h>
  40 #include <drm/drm_edid.h>
  41
  42 MODULE_AUTHOR("David Airlie, Jesse Barnes");
  43 MODULE_DESCRIPTION("DRM KMS helper");
  44 MODULE_LICENSE("GPL and additional rights");
  45
  46 /**
  47  * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
  48  *                                              connector list
  49  * @dev: drm device to operate on
  50  *
  51  * Some userspace presumes that the first connected connector is the main
  52  * display, where it's supposed to display e.g. the login screen. For
  53  * laptops, this should be the main panel. Use this function to sort all
  54  * (eDP/LVDS) panels to the front of the connector list, instead of
  55  * painstakingly trying to initialize them in the right order.
  56  */
  57 void drm_helper_move_panel_connectors_to_head(struct drm_device *dev)
  58 {
  59         struct drm_connector *connector, *tmp;
  60         struct list_head panel_list;
  61
  62         INIT_LIST_HEAD(&panel_list);
  63
  64         list_for_each_entry_safe(connector, tmp,
  65                                  &dev->mode_config.connector_list, head) {
  66                 if (connector->connector_type == DRM_MODE_CONNECTOR_LVDS ||
  67                     connector->connector_type == DRM_MODE_CONNECTOR_eDP)
  68                         list_move_tail(&connector->head, &panel_list);
  69         }
  70
  71         list_splice(&panel_list, &dev->mode_config.connector_list);
  72 }
  73 EXPORT_SYMBOL(drm_helper_move_panel_connectors_to_head);
  74
  75 static bool drm_kms_helper_poll = true;
  76 module_param_named(poll, drm_kms_helper_poll, bool, 0600);
  77
  78 static void drm_mode_validate_flag(struct drm_connector *connector,
  79                                    int flags)
  80 {
  81         struct drm_display_mode *mode;
  82
  83         if (flags == (DRM_MODE_FLAG_DBLSCAN | DRM_MODE_FLAG_INTERLACE |
  84                       DRM_MODE_FLAG_3D_MASK))
  85                 return;
  86
  87         list_for_each_entry(mode, &connector->modes, head) {
  88                 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
  89                                 !(flags & DRM_MODE_FLAG_INTERLACE))
  90                         mode->status = MODE_NO_INTERLACE;
  91                 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
  92                                 !(flags & DRM_MODE_FLAG_DBLSCAN))
  93                         mode->status = MODE_NO_DBLESCAN;
  94                 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
  95                                 !(flags & DRM_MODE_FLAG_3D_MASK))
  96                         mode->status = MODE_NO_STEREO;
  97         }
  98
  99         return;
 100 }
 101
 102 /**
 103  * drm_helper_probe_single_connector_modes - get complete set of display modes
 104  * @connector: connector to probe
 105  * @maxX: max width for modes
 106  * @maxY: max height for modes
 107  *
 108  * Based on the helper callbacks implemented by @connector try to detect all
 109  * valid modes.  Modes will first be added to the connector's probed_modes list,
 110  * then culled (based on validity and the @maxX, @maxY parameters) and put into
 111  * the normal modes list.
 112  *
 113  * Intended to be use as a generic implementation of the ->fill_modes()
 114  * @connector vfunc for drivers that use the crtc helpers for output mode
 115  * filtering and detection.
 116  *
 117  * Returns:
 118  * The number of modes found on @connector.
 119  */
 120 int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
 121                                             uint32_t maxX, uint32_t maxY)
 122 {
 123         struct drm_device *dev = connector->dev;
 124         struct drm_display_mode *mode;
 125         struct drm_connector_helper_funcs *connector_funcs =
 126                 connector->helper_private;
 127         int count = 0;
 128         int mode_flags = 0;
 129         bool verbose_prune = true;
 130
 131         WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 132
 133         DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id,
 134                         drm_get_connector_name(connector));
 135         /* set all modes to the unverified state */
 136         list_for_each_entry(mode, &connector->modes, head)
 137                 mode->status = MODE_UNVERIFIED;
 138
 139         if (connector->force) {
 140                 if (connector->force == DRM_FORCE_ON)
 141                         connector->status = connector_status_connected;
 142                 else
 143                         connector->status = connector_status_disconnected;
 144                 if (connector->funcs->force)
 145                         connector->funcs->force(connector);
 146         } else {
 147                 connector->status = connector->funcs->detect(connector, true);
 148         }
 149
 150         /* Re-enable polling in case the global poll config changed. */
 151         if (drm_kms_helper_poll != dev->mode_config.poll_running)
 152                 drm_kms_helper_poll_enable(dev);
 153
 154         dev->mode_config.poll_running = drm_kms_helper_poll;
 155
 156         if (connector->status == connector_status_disconnected) {
 157                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n",
 158                         connector->base.id, drm_get_connector_name(connector));
 159                 drm_mode_connector_update_edid_property(connector, NULL);
 160                 verbose_prune = false;
 161                 goto prune;
 162         }
 163
 164 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
 165         count = drm_load_edid_firmware(connector);
 166         if (count == 0)
 167 #endif
 168                 count = (*connector_funcs->get_modes)(connector);
 169
 170         if (count == 0 && connector->status == connector_status_connected)
 171                 count = drm_add_modes_noedid(connector, 1024, 768);
 172         if (count == 0)
 173                 goto prune;
 174
 175         drm_mode_connector_list_update(connector);
 176
 177         if (maxX && maxY)
 178                 drm_mode_validate_size(dev, &connector->modes, maxX, maxY);
 179
 180         if (connector->interlace_allowed)
 181                 mode_flags |= DRM_MODE_FLAG_INTERLACE;
 182         if (connector->doublescan_allowed)
 183                 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
 184         if (connector->stereo_allowed)
 185                 mode_flags |= DRM_MODE_FLAG_3D_MASK;
 186         drm_mode_validate_flag(connector, mode_flags);
 187
 188         list_for_each_entry(mode, &connector->modes, head) {
 189                 if (mode->status == MODE_OK)
 190                         mode->status = connector_funcs->mode_valid(connector,
 191                                                                    mode);
 192         }
 193
 194 prune:
 195         drm_mode_prune_invalid(dev, &connector->modes, verbose_prune);
 196
 197         if (list_empty(&connector->modes))
 198                 return 0;
 199
 200         list_for_each_entry(mode, &connector->modes, head)
 201                 mode->vrefresh = drm_mode_vrefresh(mode);
 202
 203         drm_mode_sort(&connector->modes);
 204
 205         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id,
 206                         drm_get_connector_name(connector));
 207         list_for_each_entry(mode, &connector->modes, head) {
 208                 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
 209                 drm_mode_debug_printmodeline(mode);
 210         }
 211
 212         return count;
 213 }
 214 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
 215
 216 /**
 217  * drm_helper_encoder_in_use - check if a given encoder is in use
 218  * @encoder: encoder to check
 219  *
 220  * Checks whether @encoder is with the current mode setting output configuration
 221  * in use by any connector. This doesn't mean that it is actually enabled since
 222  * the DPMS state is tracked separately.
 223  *
 224  * Returns:
 225  * True if @encoder is used, false otherwise.
 226  */
 227 bool drm_helper_encoder_in_use(struct drm_encoder *encoder)
 228 {
 229         struct drm_connector *connector;
 230         struct drm_device *dev = encoder->dev;
 231
 232         WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 233         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 234                 if (connector->encoder == encoder)
 235                         return true;
 236         return false;
 237 }
 238 EXPORT_SYMBOL(drm_helper_encoder_in_use);
 239
 240 /**
 241  * drm_helper_crtc_in_use - check if a given CRTC is in a mode_config
 242  * @crtc: CRTC to check
 243  *
 244  * Checks whether @crtc is with the current mode setting output configuration
 245  * in use by any connector. This doesn't mean that it is actually enabled since
 246  * the DPMS state is tracked separately.
 247  *
 248  * Returns:
 249  * True if @crtc is used, false otherwise.
 250  */
 251 bool drm_helper_crtc_in_use(struct drm_crtc *crtc)
 252 {
 253         struct drm_encoder *encoder;
 254         struct drm_device *dev = crtc->dev;
 255
 256         WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
 257         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head)
 258                 if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder))
 259                         return true;
 260         return false;
 261 }
 262 EXPORT_SYMBOL(drm_helper_crtc_in_use);
 263
 264 static void
 265 drm_encoder_disable(struct drm_encoder *encoder)
 266 {
 267         struct drm_encoder_helper_funcs *encoder_funcs = encoder->helper_private;
 268
 269         if (encoder->bridge)
 270                 encoder->bridge->funcs->disable(encoder->bridge);
 271
 272         if (encoder_funcs->disable)
 273                 (*encoder_funcs->disable)(encoder);
 274         else
 275                 (*encoder_funcs->dpms)(encoder, DRM_MODE_DPMS_OFF);
 276
 277         if (encoder->bridge)
 278                 encoder->bridge->funcs->post_disable(encoder->bridge);
 279 }
 280
 281 /**
 282  * drm_helper_disable_unused_functions - disable unused objects
 283  * @dev: DRM device
 284  *
 285  * This function walks through the entire mode setting configuration of @dev. It
 286  * will remove any crtc links of unused encoders and encoder links of
 287  * disconnected connectors. Then it will disable all unused encoders and crtcs
 288  * either by calling their disable callback if available or by calling their
 289  * dpms callback with DRM_MODE_DPMS_OFF.
 290  */
 291 void drm_helper_disable_unused_functions(struct drm_device *dev)
 292 {
 293         struct drm_encoder *encoder;
 294         struct drm_connector *connector;
 295         struct drm_crtc *crtc;
 296
 297         drm_warn_on_modeset_not_all_locked(dev);
 298
 299         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 300                 if (!connector->encoder)
 301                         continue;
 302                 if (connector->status == connector_status_disconnected)
 303                         connector->encoder = NULL;
 304         }
 305
 306         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 307                 if (!drm_helper_encoder_in_use(encoder)) {
 308                         drm_encoder_disable(encoder);
 309                         /* disconnector encoder from any connector */
 310                         encoder->crtc = NULL;
 311                 }
 312         }
 313
 314         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 315                 struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 316                 crtc->enabled = drm_helper_crtc_in_use(crtc);
 317                 if (!crtc->enabled) {
 318                         if (crtc_funcs->disable)
 319                                 (*crtc_funcs->disable)(crtc);
 320                         else
 321                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
 322                         crtc->fb = NULL;
 323                 }
 324         }
 325 }
 326 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
 327
 328 /*
 329  * Check the CRTC we're going to map each output to vs. its current
 330  * CRTC.  If they don't match, we have to disable the output and the CRTC
 331  * since the driver will have to re-route things.
 332  */
 333 static void
 334 drm_crtc_prepare_encoders(struct drm_device *dev)
 335 {
 336         struct drm_encoder_helper_funcs *encoder_funcs;
 337         struct drm_encoder *encoder;
 338
 339         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 340                 encoder_funcs = encoder->helper_private;
 341                 /* Disable unused encoders */
 342                 if (encoder->crtc == NULL)
 343                         drm_encoder_disable(encoder);
 344                 /* Disable encoders whose CRTC is about to change */
 345                 if (encoder_funcs->get_crtc &&
 346                     encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
 347                         drm_encoder_disable(encoder);
 348         }
 349 }
 350
 351 /**
 352  * drm_crtc_helper_set_mode - internal helper to set a mode
 353  * @crtc: CRTC to program
 354  * @mode: mode to use
 355  * @x: horizontal offset into the surface
 356  * @y: vertical offset into the surface
 357  * @old_fb: old framebuffer, for cleanup
 358  *
 359  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 360  * to fixup or reject the mode prior to trying to set it. This is an internal
 361  * helper that drivers could e.g. use to update properties that require the
 362  * entire output pipe to be disabled and re-enabled in a new configuration. For
 363  * example for changing whether audio is enabled on a hdmi link or for changing
 364  * panel fitter or dither attributes. It is also called by the
 365  * drm_crtc_helper_set_config() helper function to drive the mode setting
 366  * sequence.
 367  *
 368  * Returns:
 369  * True if the mode was set successfully, false otherwise.
 370  */
 371 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 372                               struct drm_display_mode *mode,
 373                               int x, int y,
 374                               struct drm_framebuffer *old_fb)
 375 {
 376         struct drm_device *dev = crtc->dev;
 377         struct drm_display_mode *adjusted_mode, saved_mode;
 378         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 379         struct drm_encoder_helper_funcs *encoder_funcs;
 380         int saved_x, saved_y;
 381         bool saved_enabled;
 382         struct drm_encoder *encoder;
 383         bool ret = true;
 384
 385         drm_warn_on_modeset_not_all_locked(dev);
 386
 387         saved_enabled = crtc->enabled;
 388         crtc->enabled = drm_helper_crtc_in_use(crtc);
 389         if (!crtc->enabled)
 390                 return true;
 391
 392         adjusted_mode = drm_mode_duplicate(dev, mode);
 393         if (!adjusted_mode) {
 394                 crtc->enabled = saved_enabled;
 395                 return false;
 396         }
 397
 398         saved_mode = crtc->mode;
 399         saved_x = crtc->x;
 400         saved_y = crtc->y;
 401
 402         /* Update crtc values up front so the driver can rely on them for mode
 403          * setting.
 404          */
 405         crtc->mode = *mode;
 406         crtc->x = x;
 407         crtc->y = y;
 408
 409         /* Pass our mode to the connectors and the CRTC to give them a chance to
 410          * adjust it according to limitations or connector properties, and also
 411          * a chance to reject the mode entirely.
 412          */
 413         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 414
 415                 if (encoder->crtc != crtc)
 416                         continue;
 417
 418                 if (encoder->bridge && encoder->bridge->funcs->mode_fixup) {
 419                         ret = encoder->bridge->funcs->mode_fixup(
 420                                         encoder->bridge, mode, adjusted_mode);
 421                         if (!ret) {
 422                                 DRM_DEBUG_KMS("Bridge fixup failed\n");
 423                                 goto done;
 424                         }
 425                 }
 426
 427                 encoder_funcs = encoder->helper_private;
 428                 if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 429                                                       adjusted_mode))) {
 430                         DRM_DEBUG_KMS("Encoder fixup failed\n");
 431                         goto done;
 432                 }
 433         }
 434
 435         if (!(ret = crtc_funcs->mode_fixup(crtc, mode, adjusted_mode))) {
 436                 DRM_DEBUG_KMS("CRTC fixup failed\n");
 437                 goto done;
 438         }
 439         DRM_DEBUG_KMS("[CRTC:%d]\n", crtc->base.id);
 440
 441         /* Prepare the encoders and CRTCs before setting the mode. */
 442         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 443
 444                 if (encoder->crtc != crtc)
 445                         continue;
 446
 447                 if (encoder->bridge)
 448                         encoder->bridge->funcs->disable(encoder->bridge);
 449
 450                 encoder_funcs = encoder->helper_private;
 451                 /* Disable the encoders as the first thing we do. */
 452                 encoder_funcs->prepare(encoder);
 453
 454                 if (encoder->bridge)
 455                         encoder->bridge->funcs->post_disable(encoder->bridge);
 456         }
 457
 458         drm_crtc_prepare_encoders(dev);
 459
 460         crtc_funcs->prepare(crtc);
 461
 462         /* Set up the DPLL and any encoders state that needs to adjust or depend
 463          * on the DPLL.
 464          */
 465         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 466         if (!ret)
 467             goto done;
 468
 469         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 470
 471                 if (encoder->crtc != crtc)
 472                         continue;
 473
 474                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%d:%s]\n",
 475                         encoder->base.id, drm_get_encoder_name(encoder),
 476                         mode->base.id, mode->name);
 477                 encoder_funcs = encoder->helper_private;
 478                 encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 479
 480                 if (encoder->bridge && encoder->bridge->funcs->mode_set)
 481                         encoder->bridge->funcs->mode_set(encoder->bridge, mode,
 482                                         adjusted_mode);
 483         }
 484
 485         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 486         crtc_funcs->commit(crtc);
 487
 488         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 489
 490                 if (encoder->crtc != crtc)
 491                         continue;
 492
 493                 if (encoder->bridge)
 494                         encoder->bridge->funcs->pre_enable(encoder->bridge);
 495
 496                 encoder_funcs = encoder->helper_private;
 497                 encoder_funcs->commit(encoder);
 498
 499                 if (encoder->bridge)
 500                         encoder->bridge->funcs->enable(encoder->bridge);
 501         }
 502
 503         /* Store real post-adjustment hardware mode. */
 504         crtc->hwmode = *adjusted_mode;
 505
 506         /* Calculate and store various constants which
 507          * are later needed by vblank and swap-completion
 508          * timestamping. They are derived from true hwmode.
 509          */
 510         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
 511
 512         /* FIXME: add subpixel order */
 513 done:
 514         drm_mode_destroy(dev, adjusted_mode);
 515         if (!ret) {
 516                 crtc->enabled = saved_enabled;
 517                 crtc->mode = saved_mode;
 518                 crtc->x = saved_x;
 519                 crtc->y = saved_y;
 520         }
 521
 522         return ret;
 523 }
 524 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 525
 526
 527 static int
 528 drm_crtc_helper_disable(struct drm_crtc *crtc)
 529 {
 530         struct drm_device *dev = crtc->dev;
 531         struct drm_connector *connector;
 532         struct drm_encoder *encoder;
 533
 534         /* Decouple all encoders and their attached connectors from this crtc */
 535         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 536                 if (encoder->crtc != crtc)
 537                         continue;
 538
 539                 list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 540                         if (connector->encoder != encoder)
 541                                 continue;
 542
 543                         connector->encoder = NULL;
 544
 545                         /*
 546                          * drm_helper_disable_unused_functions() ought to be
 547                          * doing this, but since we've decoupled the encoder
 548                          * from the connector above, the required connection
 549                          * between them is henceforth no longer available.
 550                          */
 551                         connector->dpms = DRM_MODE_DPMS_OFF;
 552                 }
 553         }
 554
 555         drm_helper_disable_unused_functions(dev);
 556         return 0;
 557 }
 558
 559 /**
 560  * drm_crtc_helper_set_config - set a new config from userspace
 561  * @set: mode set configuration
 562  *
 563  * Setup a new configuration, provided by the upper layers (either an ioctl call
 564  * from userspace or internally e.g. from the fbdev suppport code) in @set, and
 565  * enable it. This is the main helper functions for drivers that implement
 566  * kernel mode setting with the crtc helper functions and the assorted
 567  * ->prepare(), ->modeset() and ->commit() helper callbacks.
 568  *
 569  * Returns:
 570  * Returns 0 on success, negative errno numbers on failure.
 571  */
 572 int drm_crtc_helper_set_config(struct drm_mode_set *set)
 573 {
 574         struct drm_device *dev;
 575         struct drm_crtc *new_crtc;
 576         struct drm_encoder *save_encoders, *new_encoder, *encoder;
 577         bool mode_changed = false; /* if true do a full mode set */
 578         bool fb_changed = false; /* if true and !mode_changed just do a flip */
 579         struct drm_connector *save_connectors, *connector;
 580         int count = 0, ro, fail = 0;
 581         struct drm_crtc_helper_funcs *crtc_funcs;
 582         struct drm_mode_set save_set;
 583         int ret;
 584         int i;
 585
 586         DRM_DEBUG_KMS("\n");
 587
 588         BUG_ON(!set);
 589         BUG_ON(!set->crtc);
 590         BUG_ON(!set->crtc->helper_private);
 591
 592         /* Enforce sane interface api - has been abused by the fb helper. */
 593         BUG_ON(!set->mode && set->fb);
 594         BUG_ON(set->fb && set->num_connectors == 0);
 595
 596         crtc_funcs = set->crtc->helper_private;
 597
 598         if (!set->mode)
 599                 set->fb = NULL;
 600
 601         if (set->fb) {
 602                 DRM_DEBUG_KMS("[CRTC:%d] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 603                                 set->crtc->base.id, set->fb->base.id,
 604                                 (int)set->num_connectors, set->x, set->y);
 605         } else {
 606                 DRM_DEBUG_KMS("[CRTC:%d] [NOFB]\n", set->crtc->base.id);
 607                 return drm_crtc_helper_disable(set->crtc);
 608         }
 609
 610         dev = set->crtc->dev;
 611
 612         drm_warn_on_modeset_not_all_locked(dev);
 613
 614         /*
 615          * Allocate space for the backup of all (non-pointer) encoder and
 616          * connector data.
 617          */
 618         save_encoders = kzalloc(dev->mode_config.num_encoder *
 619                                 sizeof(struct drm_encoder), GFP_KERNEL);
 620         if (!save_encoders)
 621                 return -ENOMEM;
 622
 623         save_connectors = kzalloc(dev->mode_config.num_connector *
 624                                 sizeof(struct drm_connector), GFP_KERNEL);
 625         if (!save_connectors) {
 626                 kfree(save_encoders);
 627                 return -ENOMEM;
 628         }
 629
 630         /*
 631          * Copy data. Note that driver private data is not affected.
 632          * Should anything bad happen only the expected state is
 633          * restored, not the drivers personal bookkeeping.
 634          */
 635         count = 0;
 636         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 637                 save_encoders[count++] = *encoder;
 638         }
 639
 640         count = 0;
 641         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 642                 save_connectors[count++] = *connector;
 643         }
 644
 645         save_set.crtc = set->crtc;
 646         save_set.mode = &set->crtc->mode;
 647         save_set.x = set->crtc->x;
 648         save_set.y = set->crtc->y;
 649         save_set.fb = set->crtc->fb;
 650
 651         /* We should be able to check here if the fb has the same properties
 652          * and then just flip_or_move it */
 653         if (set->crtc->fb != set->fb) {
 654                 /* If we have no fb then treat it as a full mode set */
 655                 if (set->crtc->fb == NULL) {
 656                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 657                         mode_changed = true;
 658                 } else if (set->fb == NULL) {
 659                         mode_changed = true;
 660                 } else if (set->fb->pixel_format !=
 661                            set->crtc->fb->pixel_format) {
 662                         mode_changed = true;
 663                 } else
 664                         fb_changed = true;
 665         }
 666
 667         if (set->x != set->crtc->x || set->y != set->crtc->y)
 668                 fb_changed = true;
 669
 670         if (set->mode && !drm_mode_equal(set->mode, &set->crtc->mode)) {
 671                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 672                 drm_mode_debug_printmodeline(&set->crtc->mode);
 673                 drm_mode_debug_printmodeline(set->mode);
 674                 mode_changed = true;
 675         }
 676
 677         /* a) traverse passed in connector list and get encoders for them */
 678         count = 0;
 679         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 680                 struct drm_connector_helper_funcs *connector_funcs =
 681                         connector->helper_private;
 682                 new_encoder = connector->encoder;
 683                 for (ro = 0; ro < set->num_connectors; ro++) {
 684                         if (set->connectors[ro] == connector) {
 685                                 new_encoder = connector_funcs->best_encoder(connector);
 686                                 /* if we can't get an encoder for a connector
 687                                    we are setting now - then fail */
 688                                 if (new_encoder == NULL)
 689                                         /* don't break so fail path works correct */
 690                                         fail = 1;
 691                                 break;
 692
 693                                 if (connector->dpms != DRM_MODE_DPMS_ON) {
 694                                         DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
 695                                         mode_changed = true;
 696                                 }
 697                         }
 698                 }
 699
 700                 if (new_encoder != connector->encoder) {
 701                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
 702                         mode_changed = true;
 703                         /* If the encoder is reused for another connector, then
 704                          * the appropriate crtc will be set later.
 705                          */
 706                         if (connector->encoder)
 707                                 connector->encoder->crtc = NULL;
 708                         connector->encoder = new_encoder;
 709                 }
 710         }
 711
 712         if (fail) {
 713                 ret = -EINVAL;
 714                 goto fail;
 715         }
 716
 717         count = 0;
 718         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 719                 if (!connector->encoder)
 720                         continue;
 721
 722                 if (connector->encoder->crtc == set->crtc)
 723                         new_crtc = NULL;
 724                 else
 725                         new_crtc = connector->encoder->crtc;
 726
 727                 for (ro = 0; ro < set->num_connectors; ro++) {
 728                         if (set->connectors[ro] == connector)
 729                                 new_crtc = set->crtc;
 730                 }
 731
 732                 /* Make sure the new CRTC will work with the encoder */
 733                 if (new_crtc &&
 734                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
 735                         ret = -EINVAL;
 736                         goto fail;
 737                 }
 738                 if (new_crtc != connector->encoder->crtc) {
 739                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
 740                         mode_changed = true;
 741                         connector->encoder->crtc = new_crtc;
 742                 }
 743                 if (new_crtc) {
 744                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d]\n",
 745                                 connector->base.id, drm_get_connector_name(connector),
 746                                 new_crtc->base.id);
 747                 } else {
 748                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
 749                                 connector->base.id, drm_get_connector_name(connector));
 750                 }
 751         }
 752
 753         /* mode_set_base is not a required function */
 754         if (fb_changed && !crtc_funcs->mode_set_base)
 755                 mode_changed = true;
 756
 757         if (mode_changed) {
 758                 if (drm_helper_crtc_in_use(set->crtc)) {
 759                         DRM_DEBUG_KMS("attempting to set mode from"
 760                                         " userspace\n");
 761                         drm_mode_debug_printmodeline(set->mode);
 762                         set->crtc->fb = set->fb;
 763                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
 764                                                       set->x, set->y,
 765                                                       save_set.fb)) {
 766                                 DRM_ERROR("failed to set mode on [CRTC:%d]\n",
 767                                           set->crtc->base.id);
 768                                 set->crtc->fb = save_set.fb;
 769                                 ret = -EINVAL;
 770                                 goto fail;
 771                         }
 772                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
 773                         for (i = 0; i < set->num_connectors; i++) {
 774                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
 775                                               drm_get_connector_name(set->connectors[i]));
 776                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
 777                         }
 778                 }
 779                 drm_helper_disable_unused_functions(dev);
 780         } else if (fb_changed) {
 781                 set->crtc->x = set->x;
 782                 set->crtc->y = set->y;
 783                 set->crtc->fb = set->fb;
 784                 ret = crtc_funcs->mode_set_base(set->crtc,
 785                                                 set->x, set->y, save_set.fb);
 786                 if (ret != 0) {
 787                         set->crtc->x = save_set.x;
 788                         set->crtc->y = save_set.y;
 789                         set->crtc->fb = save_set.fb;
 790                         goto fail;
 791                 }
 792         }
 793
 794         kfree(save_connectors);
 795         kfree(save_encoders);
 796         return 0;
 797
 798 fail:
 799         /* Restore all previous data. */
 800         count = 0;
 801         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 802                 *encoder = save_encoders[count++];
 803         }
 804
 805         count = 0;
 806         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 807                 *connector = save_connectors[count++];
 808         }
 809
 810         /* Try to restore the config */
 811         if (mode_changed &&
 812             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
 813                                       save_set.y, save_set.fb))
 814                 DRM_ERROR("failed to restore config after modeset failure\n");
 815
 816         kfree(save_connectors);
 817         kfree(save_encoders);
 818         return ret;
 819 }
 820 EXPORT_SYMBOL(drm_crtc_helper_set_config);
 821
 822 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 823 {
 824         int dpms = DRM_MODE_DPMS_OFF;
 825         struct drm_connector *connector;
 826         struct drm_device *dev = encoder->dev;
 827
 828         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 829                 if (connector->encoder == encoder)
 830                         if (connector->dpms < dpms)
 831                                 dpms = connector->dpms;
 832         return dpms;
 833 }
 834
 835 /* Helper which handles bridge ordering around encoder dpms */
 836 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
 837 {
 838         struct drm_bridge *bridge = encoder->bridge;
 839         struct drm_encoder_helper_funcs *encoder_funcs;
 840
 841         if (bridge) {
 842                 if (mode == DRM_MODE_DPMS_ON)
 843                         bridge->funcs->pre_enable(bridge);
 844                 else
 845                         bridge->funcs->disable(bridge);
 846         }
 847
 848         encoder_funcs = encoder->helper_private;
 849         if (encoder_funcs->dpms)
 850                 encoder_funcs->dpms(encoder, mode);
 851
 852         if (bridge) {
 853                 if (mode == DRM_MODE_DPMS_ON)
 854                         bridge->funcs->enable(bridge);
 855                 else
 856                         bridge->funcs->post_disable(bridge);
 857         }
 858 }
 859
 860 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 861 {
 862         int dpms = DRM_MODE_DPMS_OFF;
 863         struct drm_connector *connector;
 864         struct drm_device *dev = crtc->dev;
 865
 866         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 867                 if (connector->encoder && connector->encoder->crtc == crtc)
 868                         if (connector->dpms < dpms)
 869                                 dpms = connector->dpms;
 870         return dpms;
 871 }
 872
 873 /**
 874  * drm_helper_connector_dpms() - connector dpms helper implementation
 875  * @connector: affected connector
 876  * @mode: DPMS mode
 877  *
 878  * This is the main helper function provided by the crtc helper framework for
 879  * implementing the DPMS connector attribute. It computes the new desired DPMS
 880  * state for all encoders and crtcs in the output mesh and calls the ->dpms()
 881  * callback provided by the driver appropriately.
 882  */
 883 void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 884 {
 885         struct drm_encoder *encoder = connector->encoder;
 886         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 887         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 888
 889         if (mode == connector->dpms)
 890                 return;
 891
 892         old_dpms = connector->dpms;
 893         connector->dpms = mode;
 894
 895         if (encoder)
 896                 encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
 897
 898         /* from off to on, do crtc then encoder */
 899         if (mode < old_dpms) {
 900                 if (crtc) {
 901                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 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                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 916                         if (crtc_funcs->dpms)
 917                                 (*crtc_funcs->dpms) (crtc,
 918                                                      drm_helper_choose_crtc_dpms(crtc));
 919                 }
 920         }
 921
 922         return;
 923 }
 924 EXPORT_SYMBOL(drm_helper_connector_dpms);
 925
 926 /**
 927  * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
 928  * @fb: drm_framebuffer object to fill out
 929  * @mode_cmd: metadata from the userspace fb creation request
 930  *
 931  * This helper can be used in a drivers fb_create callback to pre-fill the fb's
 932  * metadata fields.
 933  */
 934 void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
 935                                     struct drm_mode_fb_cmd2 *mode_cmd)
 936 {
 937         int i;
 938
 939         fb->width = mode_cmd->width;
 940         fb->height = mode_cmd->height;
 941         for (i = 0; i < 4; i++) {
 942                 fb->pitches[i] = mode_cmd->pitches[i];
 943                 fb->offsets[i] = mode_cmd->offsets[i];
 944         }
 945         drm_fb_get_bpp_depth(mode_cmd->pixel_format, &fb->depth,
 946                                     &fb->bits_per_pixel);
 947         fb->pixel_format = mode_cmd->pixel_format;
 948 }
 949 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
 950
 951 /**
 952  * drm_helper_resume_force_mode - force-restore mode setting configuration
 953  * @dev: drm_device which should be restored
 954  *
 955  * Drivers which use the mode setting helpers can use this function to
 956  * force-restore the mode setting configuration e.g. on resume or when something
 957  * else might have trampled over the hw state (like some overzealous old BIOSen
 958  * tended to do).
 959  *
 960  * This helper doesn't provide a error return value since restoring the old
 961  * config should never fail due to resource allocation issues since the driver
 962  * has successfully set the restored configuration already. Hence this should
 963  * boil down to the equivalent of a few dpms on calls, which also don't provide
 964  * an error code.
 965  *
 966  * Drivers where simply restoring an old configuration again might fail (e.g.
 967  * due to slight differences in allocating shared resources when the
 968  * configuration is restored in a different order than when userspace set it up)
 969  * need to use their own restore logic.
 970  */
 971 void drm_helper_resume_force_mode(struct drm_device *dev)
 972 {
 973         struct drm_crtc *crtc;
 974         struct drm_encoder *encoder;
 975         struct drm_crtc_helper_funcs *crtc_funcs;
 976         int encoder_dpms;
 977         bool ret;
 978
 979         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 980
 981                 if (!crtc->enabled)
 982                         continue;
 983
 984                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 985                                                crtc->x, crtc->y, crtc->fb);
 986
 987                 /* Restoring the old config should never fail! */
 988                 if (ret == false)
 989                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
 990
 991                 /* Turn off outputs that were already powered off */
 992                 if (drm_helper_choose_crtc_dpms(crtc)) {
 993                         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 994
 995                                 if(encoder->crtc != crtc)
 996                                         continue;
 997
 998                                 encoder_dpms = drm_helper_choose_encoder_dpms(
 999                                                         encoder);
1000
1001                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
1002                         }
1003
1004                         crtc_funcs = crtc->helper_private;
1005                         if (crtc_funcs->dpms)
1006                                 (*crtc_funcs->dpms) (crtc,
1007                                                      drm_helper_choose_crtc_dpms(crtc));
1008                 }
1009         }
1010
1011         /* disable the unused connectors while restoring the modesetting */
1012         drm_helper_disable_unused_functions(dev);
1013 }
1014 EXPORT_SYMBOL(drm_helper_resume_force_mode);
1015
1016 /**
1017  * drm_kms_helper_hotplug_event - fire off KMS hotplug events
1018  * @dev: drm_device whose connector state changed
1019  *
1020  * This function fires off the uevent for userspace and also calls the
1021  * output_poll_changed function, which is most commonly used to inform the fbdev
1022  * emulation code and allow it to update the fbcon output configuration.
1023  *
1024  * Drivers should call this from their hotplug handling code when a change is
1025  * detected. Note that this function does not do any output detection of its
1026  * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
1027  * driver already.
1028  *
1029  * This function must be called from process context with no mode
1030  * setting locks held.
1031  */
1032 void drm_kms_helper_hotplug_event(struct drm_device *dev)
1033 {
1034         /* send a uevent + call fbdev */
1035         drm_sysfs_hotplug_event(dev);
1036         if (dev->mode_config.funcs->output_poll_changed)
1037                 dev->mode_config.funcs->output_poll_changed(dev);
1038 }
1039 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
1040
1041 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
1042 static void output_poll_execute(struct work_struct *work)
1043 {
1044         struct delayed_work *delayed_work = to_delayed_work(work);
1045         struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
1046         struct drm_connector *connector;
1047         enum drm_connector_status old_status;
1048         bool repoll = false, changed = false;
1049
1050         if (!drm_kms_helper_poll)
1051                 return;
1052
1053         mutex_lock(&dev->mode_config.mutex);
1054         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
1055
1056                 /* Ignore forced connectors. */
1057                 if (connector->force)
1058                         continue;
1059
1060                 /* Ignore HPD capable connectors and connectors where we don't
1061                  * want any hotplug detection at all for polling. */
1062                 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
1063                         continue;
1064
1065                 repoll = true;
1066
1067                 old_status = connector->status;
1068                 /* if we are connected and don't want to poll for disconnect
1069                    skip it */
1070                 if (old_status == connector_status_connected &&
1071                     !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
1072                         continue;
1073
1074                 connector->status = connector->funcs->detect(connector, false);
1075                 if (old_status != connector->status) {
1076                         const char *old, *new;
1077
1078                         old = drm_get_connector_status_name(old_status);
1079                         new = drm_get_connector_status_name(connector->status);
1080
1081                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
1082                                       "status updated from %s to %s\n",
1083                                       connector->base.id,
1084                                       drm_get_connector_name(connector),
1085                                       old, new);
1086
1087                         changed = true;
1088                 }
1089         }
1090
1091         mutex_unlock(&dev->mode_config.mutex);
1092
1093         if (changed)
1094                 drm_kms_helper_hotplug_event(dev);
1095
1096         if (repoll)
1097                 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
1098 }
1099
1100 /**
1101  * drm_kms_helper_poll_disable - disable output polling
1102  * @dev: drm_device
1103  *
1104  * This function disables the output polling work.
1105  *
1106  * Drivers can call this helper from their device suspend implementation. It is
1107  * not an error to call this even when output polling isn't enabled or arlready
1108  * disabled.
1109  */
1110 void drm_kms_helper_poll_disable(struct drm_device *dev)
1111 {
1112         if (!dev->mode_config.poll_enabled)
1113                 return;
1114         cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
1115 }
1116 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
1117
1118 /**
1119  * drm_kms_helper_poll_enable - re-enable output polling.
1120  * @dev: drm_device
1121  *
1122  * This function re-enables the output polling work.
1123  *
1124  * Drivers can call this helper from their device resume implementation. It is
1125  * an error to call this when the output polling support has not yet been set
1126  * up.
1127  */
1128 void drm_kms_helper_poll_enable(struct drm_device *dev)
1129 {
1130         bool poll = false;
1131         struct drm_connector *connector;
1132
1133         if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
1134                 return;
1135
1136         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
1137                 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
1138                                          DRM_CONNECTOR_POLL_DISCONNECT))
1139                         poll = true;
1140         }
1141
1142         if (poll)
1143                 schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
1144 }
1145 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
1146
1147 /**
1148  * drm_kms_helper_poll_init - initialize and enable output polling
1149  * @dev: drm_device
1150  *
1151  * This function intializes and then also enables output polling support for
1152  * @dev. Drivers which do not have reliable hotplug support in hardware can use
1153  * this helper infrastructure to regularly poll such connectors for changes in
1154  * their connection state.
1155  *
1156  * Drivers can control which connectors are polled by setting the
1157  * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
1158  * connectors where probing live outputs can result in visual distortion drivers
1159  * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
1160  * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
1161  * completely ignored by the polling logic.
1162  *
1163  * Note that a connector can be both polled and probed from the hotplug handler,
1164  * in case the hotplug interrupt is known to be unreliable.
1165  */
1166 void drm_kms_helper_poll_init(struct drm_device *dev)
1167 {
1168         INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
1169         dev->mode_config.poll_enabled = true;
1170
1171         drm_kms_helper_poll_enable(dev);
1172 }
1173 EXPORT_SYMBOL(drm_kms_helper_poll_init);
1174
1175 /**
1176  * drm_kms_helper_poll_fini - disable output polling and clean it up
1177  * @dev: drm_device
1178  */
1179 void drm_kms_helper_poll_fini(struct drm_device *dev)
1180 {
1181         drm_kms_helper_poll_disable(dev);
1182 }
1183 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
1184
1185 /**
1186  * drm_helper_hpd_irq_event - hotplug processing
1187  * @dev: drm_device
1188  *
1189  * Drivers can use this helper function to run a detect cycle on all connectors
1190  * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
1191  * other connectors are ignored, which is useful to avoid reprobing fixed
1192  * panels.
1193  *
1194  * This helper function is useful for drivers which can't or don't track hotplug
1195  * interrupts for each connector.
1196  *
1197  * Drivers which support hotplug interrupts for each connector individually and
1198  * which have a more fine-grained detect logic should bypass this code and
1199  * directly call drm_kms_helper_hotplug_event() in case the connector state
1200  * changed.
1201  *
1202  * This function must be called from process context with no mode
1203  * setting locks held.
1204  *
1205  * Note that a connector can be both polled and probed from the hotplug handler,
1206  * in case the hotplug interrupt is known to be unreliable.
1207  */
1208 bool drm_helper_hpd_irq_event(struct drm_device *dev)
1209 {
1210         struct drm_connector *connector;
1211         enum drm_connector_status old_status;
1212         bool changed = false;
1213
1214         if (!dev->mode_config.poll_enabled)
1215                 return false;
1216
1217         mutex_lock(&dev->mode_config.mutex);
1218         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
1219
1220                 /* Only handle HPD capable connectors. */
1221                 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
1222                         continue;
1223
1224                 old_status = connector->status;
1225
1226                 connector->status = connector->funcs->detect(connector, false);
1227                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
1228                               connector->base.id,
1229                               drm_get_connector_name(connector),
1230                               drm_get_connector_status_name(old_status),
1231                               drm_get_connector_status_name(connector->status));
1232                 if (old_status != connector->status)
1233                         changed = true;
1234         }
1235
1236         mutex_unlock(&dev->mode_config.mutex);
1237
1238         if (changed)
1239                 drm_kms_helper_hotplug_event(dev);
1240
1241         return changed;
1242 }
1243 EXPORT_SYMBOL(drm_helper_hpd_irq_event);