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 static void __drm_helper_disable_unused_functions(struct drm_device *dev)
 282 {
 283         struct drm_encoder *encoder;
 284         struct drm_connector *connector;
 285         struct drm_crtc *crtc;
 286
 287         drm_warn_on_modeset_not_all_locked(dev);
 288
 289         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 290                 if (!connector->encoder)
 291                         continue;
 292         }
 293
 294         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 295                 if (!drm_helper_encoder_in_use(encoder)) {
 296                         drm_encoder_disable(encoder);
 297                         /* disconnector encoder from any connector */
 298                         encoder->crtc = NULL;
 299                 }
 300         }
 301
 302         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 303                 struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 304                 crtc->enabled = drm_helper_crtc_in_use(crtc);
 305                 if (!crtc->enabled) {
 306                         if (crtc_funcs->disable)
 307                                 (*crtc_funcs->disable)(crtc);
 308                         else
 309                                 (*crtc_funcs->dpms)(crtc, DRM_MODE_DPMS_OFF);
 310                         crtc->primary->fb = NULL;
 311                 }
 312         }
 313 }
 314
 315 /**
 316  * drm_helper_disable_unused_functions - disable unused objects
 317  * @dev: DRM device
 318  *
 319  * This function walks through the entire mode setting configuration of @dev. It
 320  * will remove any crtc links of unused encoders and encoder links of
 321  * disconnected connectors. Then it will disable all unused encoders and crtcs
 322  * either by calling their disable callback if available or by calling their
 323  * dpms callback with DRM_MODE_DPMS_OFF.
 324  */
 325 void drm_helper_disable_unused_functions(struct drm_device *dev)
 326 {
 327         drm_modeset_lock_all(dev);
 328         __drm_helper_disable_unused_functions(dev);
 329         drm_modeset_unlock_all(dev);
 330 }
 331 EXPORT_SYMBOL(drm_helper_disable_unused_functions);
 332
 333 /*
 334  * Check the CRTC we're going to map each output to vs. its current
 335  * CRTC.  If they don't match, we have to disable the output and the CRTC
 336  * since the driver will have to re-route things.
 337  */
 338 static void
 339 drm_crtc_prepare_encoders(struct drm_device *dev)
 340 {
 341         struct drm_encoder_helper_funcs *encoder_funcs;
 342         struct drm_encoder *encoder;
 343
 344         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 345                 encoder_funcs = encoder->helper_private;
 346                 /* Disable unused encoders */
 347                 if (encoder->crtc == NULL)
 348                         drm_encoder_disable(encoder);
 349                 /* Disable encoders whose CRTC is about to change */
 350                 if (encoder_funcs->get_crtc &&
 351                     encoder->crtc != (*encoder_funcs->get_crtc)(encoder))
 352                         drm_encoder_disable(encoder);
 353         }
 354 }
 355
 356 /**
 357  * drm_crtc_helper_set_mode - internal helper to set a mode
 358  * @crtc: CRTC to program
 359  * @mode: mode to use
 360  * @x: horizontal offset into the surface
 361  * @y: vertical offset into the surface
 362  * @old_fb: old framebuffer, for cleanup
 363  *
 364  * Try to set @mode on @crtc.  Give @crtc and its associated connectors a chance
 365  * to fixup or reject the mode prior to trying to set it. This is an internal
 366  * helper that drivers could e.g. use to update properties that require the
 367  * entire output pipe to be disabled and re-enabled in a new configuration. For
 368  * example for changing whether audio is enabled on a hdmi link or for changing
 369  * panel fitter or dither attributes. It is also called by the
 370  * drm_crtc_helper_set_config() helper function to drive the mode setting
 371  * sequence.
 372  *
 373  * Returns:
 374  * True if the mode was set successfully, false otherwise.
 375  */
 376 bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 377                               struct drm_display_mode *mode,
 378                               int x, int y,
 379                               struct drm_framebuffer *old_fb)
 380 {
 381         struct drm_device *dev = crtc->dev;
 382         struct drm_display_mode *adjusted_mode, saved_mode;
 383         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 384         struct drm_encoder_helper_funcs *encoder_funcs;
 385         int saved_x, saved_y;
 386         bool saved_enabled;
 387         struct drm_encoder *encoder;
 388         bool ret = true;
 389
 390         drm_warn_on_modeset_not_all_locked(dev);
 391
 392         saved_enabled = crtc->enabled;
 393         crtc->enabled = drm_helper_crtc_in_use(crtc);
 394         if (!crtc->enabled)
 395                 return true;
 396
 397         adjusted_mode = drm_mode_duplicate(dev, mode);
 398         if (!adjusted_mode) {
 399                 crtc->enabled = saved_enabled;
 400                 return false;
 401         }
 402
 403         saved_mode = crtc->mode;
 404         saved_x = crtc->x;
 405         saved_y = crtc->y;
 406
 407         /* Update crtc values up front so the driver can rely on them for mode
 408          * setting.
 409          */
 410         crtc->mode = *mode;
 411         crtc->x = x;
 412         crtc->y = y;
 413
 414         /* Pass our mode to the connectors and the CRTC to give them a chance to
 415          * adjust it according to limitations or connector properties, and also
 416          * a chance to reject the mode entirely.
 417          */
 418         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 419
 420                 if (encoder->crtc != crtc)
 421                         continue;
 422
 423                 if (encoder->bridge && encoder->bridge->funcs->mode_fixup) {
 424                         ret = encoder->bridge->funcs->mode_fixup(
 425                                         encoder->bridge, mode, adjusted_mode);
 426                         if (!ret) {
 427                                 DRM_DEBUG_KMS("Bridge fixup failed\n");
 428                                 goto done;
 429                         }
 430                 }
 431
 432                 encoder_funcs = encoder->helper_private;
 433                 if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
 434                                                       adjusted_mode))) {
 435                         DRM_DEBUG_KMS("Encoder fixup failed\n");
 436                         goto done;
 437                 }
 438         }
 439
 440         if (!(ret = crtc_funcs->mode_fixup(crtc, mode, adjusted_mode))) {
 441                 DRM_DEBUG_KMS("CRTC fixup failed\n");
 442                 goto done;
 443         }
 444         DRM_DEBUG_KMS("[CRTC:%d]\n", crtc->base.id);
 445
 446         /* Prepare the encoders and CRTCs before setting the mode. */
 447         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 448
 449                 if (encoder->crtc != crtc)
 450                         continue;
 451
 452                 if (encoder->bridge)
 453                         encoder->bridge->funcs->disable(encoder->bridge);
 454
 455                 encoder_funcs = encoder->helper_private;
 456                 /* Disable the encoders as the first thing we do. */
 457                 encoder_funcs->prepare(encoder);
 458
 459                 if (encoder->bridge)
 460                         encoder->bridge->funcs->post_disable(encoder->bridge);
 461         }
 462
 463         drm_crtc_prepare_encoders(dev);
 464
 465         crtc_funcs->prepare(crtc);
 466
 467         /* Set up the DPLL and any encoders state that needs to adjust or depend
 468          * on the DPLL.
 469          */
 470         ret = !crtc_funcs->mode_set(crtc, mode, adjusted_mode, x, y, old_fb);
 471         if (!ret)
 472             goto done;
 473
 474         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 475
 476                 if (encoder->crtc != crtc)
 477                         continue;
 478
 479                 DRM_DEBUG_KMS("[ENCODER:%d:%s] set [MODE:%d:%s]\n",
 480                         encoder->base.id, drm_get_encoder_name(encoder),
 481                         mode->base.id, mode->name);
 482                 encoder_funcs = encoder->helper_private;
 483                 encoder_funcs->mode_set(encoder, mode, adjusted_mode);
 484
 485                 if (encoder->bridge && encoder->bridge->funcs->mode_set)
 486                         encoder->bridge->funcs->mode_set(encoder->bridge, mode,
 487                                         adjusted_mode);
 488         }
 489
 490         /* Now enable the clocks, plane, pipe, and connectors that we set up. */
 491         crtc_funcs->commit(crtc);
 492
 493         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 494
 495                 if (encoder->crtc != crtc)
 496                         continue;
 497
 498                 if (encoder->bridge)
 499                         encoder->bridge->funcs->pre_enable(encoder->bridge);
 500
 501                 encoder_funcs = encoder->helper_private;
 502                 encoder_funcs->commit(encoder);
 503
 504                 if (encoder->bridge)
 505                         encoder->bridge->funcs->enable(encoder->bridge);
 506         }
 507
 508         /* Store real post-adjustment hardware mode. */
 509         crtc->hwmode = *adjusted_mode;
 510
 511         /* Calculate and store various constants which
 512          * are later needed by vblank and swap-completion
 513          * timestamping. They are derived from true hwmode.
 514          */
 515         drm_calc_timestamping_constants(crtc, &crtc->hwmode);
 516
 517         /* FIXME: add subpixel order */
 518 done:
 519         drm_mode_destroy(dev, adjusted_mode);
 520         if (!ret) {
 521                 crtc->enabled = saved_enabled;
 522                 crtc->mode = saved_mode;
 523                 crtc->x = saved_x;
 524                 crtc->y = saved_y;
 525         }
 526
 527         return ret;
 528 }
 529 EXPORT_SYMBOL(drm_crtc_helper_set_mode);
 530
 531
 532 static int
 533 drm_crtc_helper_disable(struct drm_crtc *crtc)
 534 {
 535         struct drm_device *dev = crtc->dev;
 536         struct drm_connector *connector;
 537         struct drm_encoder *encoder;
 538
 539         /* Decouple all encoders and their attached connectors from this crtc */
 540         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 541                 if (encoder->crtc != crtc)
 542                         continue;
 543
 544                 list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 545                         if (connector->encoder != encoder)
 546                                 continue;
 547
 548                         connector->encoder = NULL;
 549
 550                         /*
 551                          * drm_helper_disable_unused_functions() ought to be
 552                          * doing this, but since we've decoupled the encoder
 553                          * from the connector above, the required connection
 554                          * between them is henceforth no longer available.
 555                          */
 556                         connector->dpms = DRM_MODE_DPMS_OFF;
 557                 }
 558         }
 559
 560         __drm_helper_disable_unused_functions(dev);
 561         return 0;
 562 }
 563
 564 /**
 565  * drm_crtc_helper_set_config - set a new config from userspace
 566  * @set: mode set configuration
 567  *
 568  * Setup a new configuration, provided by the upper layers (either an ioctl call
 569  * from userspace or internally e.g. from the fbdev support code) in @set, and
 570  * enable it. This is the main helper functions for drivers that implement
 571  * kernel mode setting with the crtc helper functions and the assorted
 572  * ->prepare(), ->modeset() and ->commit() helper callbacks.
 573  *
 574  * Returns:
 575  * Returns 0 on success, negative errno numbers on failure.
 576  */
 577 int drm_crtc_helper_set_config(struct drm_mode_set *set)
 578 {
 579         struct drm_device *dev;
 580         struct drm_crtc *new_crtc;
 581         struct drm_encoder *save_encoders, *new_encoder, *encoder;
 582         bool mode_changed = false; /* if true do a full mode set */
 583         bool fb_changed = false; /* if true and !mode_changed just do a flip */
 584         struct drm_connector *save_connectors, *connector;
 585         int count = 0, ro, fail = 0;
 586         struct drm_crtc_helper_funcs *crtc_funcs;
 587         struct drm_mode_set save_set;
 588         int ret;
 589         int i;
 590
 591         DRM_DEBUG_KMS("\n");
 592
 593         BUG_ON(!set);
 594         BUG_ON(!set->crtc);
 595         BUG_ON(!set->crtc->helper_private);
 596
 597         /* Enforce sane interface api - has been abused by the fb helper. */
 598         BUG_ON(!set->mode && set->fb);
 599         BUG_ON(set->fb && set->num_connectors == 0);
 600
 601         crtc_funcs = set->crtc->helper_private;
 602
 603         if (!set->mode)
 604                 set->fb = NULL;
 605
 606         if (set->fb) {
 607                 DRM_DEBUG_KMS("[CRTC:%d] [FB:%d] #connectors=%d (x y) (%i %i)\n",
 608                                 set->crtc->base.id, set->fb->base.id,
 609                                 (int)set->num_connectors, set->x, set->y);
 610         } else {
 611                 DRM_DEBUG_KMS("[CRTC:%d] [NOFB]\n", set->crtc->base.id);
 612                 return drm_crtc_helper_disable(set->crtc);
 613         }
 614
 615         dev = set->crtc->dev;
 616
 617         drm_warn_on_modeset_not_all_locked(dev);
 618
 619         /*
 620          * Allocate space for the backup of all (non-pointer) encoder and
 621          * connector data.
 622          */
 623         save_encoders = kzalloc(dev->mode_config.num_encoder *
 624                                 sizeof(struct drm_encoder), GFP_KERNEL);
 625         if (!save_encoders)
 626                 return -ENOMEM;
 627
 628         save_connectors = kzalloc(dev->mode_config.num_connector *
 629                                 sizeof(struct drm_connector), GFP_KERNEL);
 630         if (!save_connectors) {
 631                 kfree(save_encoders);
 632                 return -ENOMEM;
 633         }
 634
 635         /*
 636          * Copy data. Note that driver private data is not affected.
 637          * Should anything bad happen only the expected state is
 638          * restored, not the drivers personal bookkeeping.
 639          */
 640         count = 0;
 641         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 642                 save_encoders[count++] = *encoder;
 643         }
 644
 645         count = 0;
 646         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 647                 save_connectors[count++] = *connector;
 648         }
 649
 650         save_set.crtc = set->crtc;
 651         save_set.mode = &set->crtc->mode;
 652         save_set.x = set->crtc->x;
 653         save_set.y = set->crtc->y;
 654         save_set.fb = set->crtc->primary->fb;
 655
 656         /* We should be able to check here if the fb has the same properties
 657          * and then just flip_or_move it */
 658         if (set->crtc->primary->fb != set->fb) {
 659                 /* If we have no fb then treat it as a full mode set */
 660                 if (set->crtc->primary->fb == NULL) {
 661                         DRM_DEBUG_KMS("crtc has no fb, full mode set\n");
 662                         mode_changed = true;
 663                 } else if (set->fb == NULL) {
 664                         mode_changed = true;
 665                 } else if (set->fb->pixel_format !=
 666                            set->crtc->primary->fb->pixel_format) {
 667                         mode_changed = true;
 668                 } else
 669                         fb_changed = true;
 670         }
 671
 672         if (set->x != set->crtc->x || set->y != set->crtc->y)
 673                 fb_changed = true;
 674
 675         if (set->mode && !drm_mode_equal(set->mode, &set->crtc->mode)) {
 676                 DRM_DEBUG_KMS("modes are different, full mode set\n");
 677                 drm_mode_debug_printmodeline(&set->crtc->mode);
 678                 drm_mode_debug_printmodeline(set->mode);
 679                 mode_changed = true;
 680         }
 681
 682         /* a) traverse passed in connector list and get encoders for them */
 683         count = 0;
 684         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 685                 struct drm_connector_helper_funcs *connector_funcs =
 686                         connector->helper_private;
 687                 new_encoder = connector->encoder;
 688                 for (ro = 0; ro < set->num_connectors; ro++) {
 689                         if (set->connectors[ro] == connector) {
 690                                 new_encoder = connector_funcs->best_encoder(connector);
 691                                 /* if we can't get an encoder for a connector
 692                                    we are setting now - then fail */
 693                                 if (new_encoder == NULL)
 694                                         /* don't break so fail path works correct */
 695                                         fail = 1;
 696
 697                                 if (connector->dpms != DRM_MODE_DPMS_ON) {
 698                                         DRM_DEBUG_KMS("connector dpms not on, full mode switch\n");
 699                                         mode_changed = true;
 700                                 }
 701
 702                                 break;
 703                         }
 704                 }
 705
 706                 if (new_encoder != connector->encoder) {
 707                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
 708                         mode_changed = true;
 709                         /* If the encoder is reused for another connector, then
 710                          * the appropriate crtc will be set later.
 711                          */
 712                         if (connector->encoder)
 713                                 connector->encoder->crtc = NULL;
 714                         connector->encoder = new_encoder;
 715                 }
 716         }
 717
 718         if (fail) {
 719                 ret = -EINVAL;
 720                 goto fail;
 721         }
 722
 723         count = 0;
 724         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 725                 if (!connector->encoder)
 726                         continue;
 727
 728                 if (connector->encoder->crtc == set->crtc)
 729                         new_crtc = NULL;
 730                 else
 731                         new_crtc = connector->encoder->crtc;
 732
 733                 for (ro = 0; ro < set->num_connectors; ro++) {
 734                         if (set->connectors[ro] == connector)
 735                                 new_crtc = set->crtc;
 736                 }
 737
 738                 /* Make sure the new CRTC will work with the encoder */
 739                 if (new_crtc &&
 740                     !drm_encoder_crtc_ok(connector->encoder, new_crtc)) {
 741                         ret = -EINVAL;
 742                         goto fail;
 743                 }
 744                 if (new_crtc != connector->encoder->crtc) {
 745                         DRM_DEBUG_KMS("crtc changed, full mode switch\n");
 746                         mode_changed = true;
 747                         connector->encoder->crtc = new_crtc;
 748                 }
 749                 if (new_crtc) {
 750                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [CRTC:%d]\n",
 751                                 connector->base.id, drm_get_connector_name(connector),
 752                                 new_crtc->base.id);
 753                 } else {
 754                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] to [NOCRTC]\n",
 755                                 connector->base.id, drm_get_connector_name(connector));
 756                 }
 757         }
 758
 759         /* mode_set_base is not a required function */
 760         if (fb_changed && !crtc_funcs->mode_set_base)
 761                 mode_changed = true;
 762
 763         if (mode_changed) {
 764                 if (drm_helper_crtc_in_use(set->crtc)) {
 765                         DRM_DEBUG_KMS("attempting to set mode from"
 766                                         " userspace\n");
 767                         drm_mode_debug_printmodeline(set->mode);
 768                         set->crtc->primary->fb = set->fb;
 769                         if (!drm_crtc_helper_set_mode(set->crtc, set->mode,
 770                                                       set->x, set->y,
 771                                                       save_set.fb)) {
 772                                 DRM_ERROR("failed to set mode on [CRTC:%d]\n",
 773                                           set->crtc->base.id);
 774                                 set->crtc->primary->fb = save_set.fb;
 775                                 ret = -EINVAL;
 776                                 goto fail;
 777                         }
 778                         DRM_DEBUG_KMS("Setting connector DPMS state to on\n");
 779                         for (i = 0; i < set->num_connectors; i++) {
 780                                 DRM_DEBUG_KMS("\t[CONNECTOR:%d:%s] set DPMS on\n", set->connectors[i]->base.id,
 781                                               drm_get_connector_name(set->connectors[i]));
 782                                 set->connectors[i]->funcs->dpms(set->connectors[i], DRM_MODE_DPMS_ON);
 783                         }
 784                 }
 785                 __drm_helper_disable_unused_functions(dev);
 786         } else if (fb_changed) {
 787                 set->crtc->x = set->x;
 788                 set->crtc->y = set->y;
 789                 set->crtc->primary->fb = set->fb;
 790                 ret = crtc_funcs->mode_set_base(set->crtc,
 791                                                 set->x, set->y, save_set.fb);
 792                 if (ret != 0) {
 793                         set->crtc->x = save_set.x;
 794                         set->crtc->y = save_set.y;
 795                         set->crtc->primary->fb = save_set.fb;
 796                         goto fail;
 797                 }
 798         }
 799
 800         kfree(save_connectors);
 801         kfree(save_encoders);
 802         return 0;
 803
 804 fail:
 805         /* Restore all previous data. */
 806         count = 0;
 807         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 808                 *encoder = save_encoders[count++];
 809         }
 810
 811         count = 0;
 812         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 813                 *connector = save_connectors[count++];
 814         }
 815
 816         /* Try to restore the config */
 817         if (mode_changed &&
 818             !drm_crtc_helper_set_mode(save_set.crtc, save_set.mode, save_set.x,
 819                                       save_set.y, save_set.fb))
 820                 DRM_ERROR("failed to restore config after modeset failure\n");
 821
 822         kfree(save_connectors);
 823         kfree(save_encoders);
 824         return ret;
 825 }
 826 EXPORT_SYMBOL(drm_crtc_helper_set_config);
 827
 828 static int drm_helper_choose_encoder_dpms(struct drm_encoder *encoder)
 829 {
 830         int dpms = DRM_MODE_DPMS_OFF;
 831         struct drm_connector *connector;
 832         struct drm_device *dev = encoder->dev;
 833
 834         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 835                 if (connector->encoder == encoder)
 836                         if (connector->dpms < dpms)
 837                                 dpms = connector->dpms;
 838         return dpms;
 839 }
 840
 841 /* Helper which handles bridge ordering around encoder dpms */
 842 static void drm_helper_encoder_dpms(struct drm_encoder *encoder, int mode)
 843 {
 844         struct drm_bridge *bridge = encoder->bridge;
 845         struct drm_encoder_helper_funcs *encoder_funcs;
 846
 847         if (bridge) {
 848                 if (mode == DRM_MODE_DPMS_ON)
 849                         bridge->funcs->pre_enable(bridge);
 850                 else
 851                         bridge->funcs->disable(bridge);
 852         }
 853
 854         encoder_funcs = encoder->helper_private;
 855         if (encoder_funcs->dpms)
 856                 encoder_funcs->dpms(encoder, mode);
 857
 858         if (bridge) {
 859                 if (mode == DRM_MODE_DPMS_ON)
 860                         bridge->funcs->enable(bridge);
 861                 else
 862                         bridge->funcs->post_disable(bridge);
 863         }
 864 }
 865
 866 static int drm_helper_choose_crtc_dpms(struct drm_crtc *crtc)
 867 {
 868         int dpms = DRM_MODE_DPMS_OFF;
 869         struct drm_connector *connector;
 870         struct drm_device *dev = crtc->dev;
 871
 872         list_for_each_entry(connector, &dev->mode_config.connector_list, head)
 873                 if (connector->encoder && connector->encoder->crtc == crtc)
 874                         if (connector->dpms < dpms)
 875                                 dpms = connector->dpms;
 876         return dpms;
 877 }
 878
 879 /**
 880  * drm_helper_connector_dpms() - connector dpms helper implementation
 881  * @connector: affected connector
 882  * @mode: DPMS mode
 883  *
 884  * This is the main helper function provided by the crtc helper framework for
 885  * implementing the DPMS connector attribute. It computes the new desired DPMS
 886  * state for all encoders and crtcs in the output mesh and calls the ->dpms()
 887  * callback provided by the driver appropriately.
 888  */
 889 void drm_helper_connector_dpms(struct drm_connector *connector, int mode)
 890 {
 891         struct drm_encoder *encoder = connector->encoder;
 892         struct drm_crtc *crtc = encoder ? encoder->crtc : NULL;
 893         int old_dpms, encoder_dpms = DRM_MODE_DPMS_OFF;
 894
 895         if (mode == connector->dpms)
 896                 return;
 897
 898         old_dpms = connector->dpms;
 899         connector->dpms = mode;
 900
 901         if (encoder)
 902                 encoder_dpms = drm_helper_choose_encoder_dpms(encoder);
 903
 904         /* from off to on, do crtc then encoder */
 905         if (mode < old_dpms) {
 906                 if (crtc) {
 907                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 908                         if (crtc_funcs->dpms)
 909                                 (*crtc_funcs->dpms) (crtc,
 910                                                      drm_helper_choose_crtc_dpms(crtc));
 911                 }
 912                 if (encoder)
 913                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 914         }
 915
 916         /* from on to off, do encoder then crtc */
 917         if (mode > old_dpms) {
 918                 if (encoder)
 919                         drm_helper_encoder_dpms(encoder, encoder_dpms);
 920                 if (crtc) {
 921                         struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
 922                         if (crtc_funcs->dpms)
 923                                 (*crtc_funcs->dpms) (crtc,
 924                                                      drm_helper_choose_crtc_dpms(crtc));
 925                 }
 926         }
 927
 928         return;
 929 }
 930 EXPORT_SYMBOL(drm_helper_connector_dpms);
 931
 932 /**
 933  * drm_helper_mode_fill_fb_struct - fill out framebuffer metadata
 934  * @fb: drm_framebuffer object to fill out
 935  * @mode_cmd: metadata from the userspace fb creation request
 936  *
 937  * This helper can be used in a drivers fb_create callback to pre-fill the fb's
 938  * metadata fields.
 939  */
 940 void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
 941                                     struct drm_mode_fb_cmd2 *mode_cmd)
 942 {
 943         int i;
 944
 945         fb->width = mode_cmd->width;
 946         fb->height = mode_cmd->height;
 947         for (i = 0; i < 4; i++) {
 948                 fb->pitches[i] = mode_cmd->pitches[i];
 949                 fb->offsets[i] = mode_cmd->offsets[i];
 950         }
 951         drm_fb_get_bpp_depth(mode_cmd->pixel_format, &fb->depth,
 952                                     &fb->bits_per_pixel);
 953         fb->pixel_format = mode_cmd->pixel_format;
 954 }
 955 EXPORT_SYMBOL(drm_helper_mode_fill_fb_struct);
 956
 957 /**
 958  * drm_helper_resume_force_mode - force-restore mode setting configuration
 959  * @dev: drm_device which should be restored
 960  *
 961  * Drivers which use the mode setting helpers can use this function to
 962  * force-restore the mode setting configuration e.g. on resume or when something
 963  * else might have trampled over the hw state (like some overzealous old BIOSen
 964  * tended to do).
 965  *
 966  * This helper doesn't provide a error return value since restoring the old
 967  * config should never fail due to resource allocation issues since the driver
 968  * has successfully set the restored configuration already. Hence this should
 969  * boil down to the equivalent of a few dpms on calls, which also don't provide
 970  * an error code.
 971  *
 972  * Drivers where simply restoring an old configuration again might fail (e.g.
 973  * due to slight differences in allocating shared resources when the
 974  * configuration is restored in a different order than when userspace set it up)
 975  * need to use their own restore logic.
 976  */
 977 void drm_helper_resume_force_mode(struct drm_device *dev)
 978 {
 979         struct drm_crtc *crtc;
 980         struct drm_encoder *encoder;
 981         struct drm_crtc_helper_funcs *crtc_funcs;
 982         int encoder_dpms;
 983         bool ret;
 984
 985         drm_modeset_lock_all(dev);
 986         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 987
 988                 if (!crtc->enabled)
 989                         continue;
 990
 991                 ret = drm_crtc_helper_set_mode(crtc, &crtc->mode,
 992                                                crtc->x, crtc->y, crtc->primary->fb);
 993
 994                 /* Restoring the old config should never fail! */
 995                 if (ret == false)
 996                         DRM_ERROR("failed to set mode on crtc %p\n", crtc);
 997
 998                 /* Turn off outputs that were already powered off */
 999                 if (drm_helper_choose_crtc_dpms(crtc)) {
1000                         list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
1001
1002                                 if(encoder->crtc != crtc)
1003                                         continue;
1004
1005                                 encoder_dpms = drm_helper_choose_encoder_dpms(
1006                                                         encoder);
1007
1008                                 drm_helper_encoder_dpms(encoder, encoder_dpms);
1009                         }
1010
1011                         crtc_funcs = crtc->helper_private;
1012                         if (crtc_funcs->dpms)
1013                                 (*crtc_funcs->dpms) (crtc,
1014                                                      drm_helper_choose_crtc_dpms(crtc));
1015                 }
1016         }
1017
1018         /* disable the unused connectors while restoring the modesetting */
1019         __drm_helper_disable_unused_functions(dev);
1020         drm_modeset_unlock_all(dev);
1021 }
1022 EXPORT_SYMBOL(drm_helper_resume_force_mode);
1023
1024 /**
1025  * drm_kms_helper_hotplug_event - fire off KMS hotplug events
1026  * @dev: drm_device whose connector state changed
1027  *
1028  * This function fires off the uevent for userspace and also calls the
1029  * output_poll_changed function, which is most commonly used to inform the fbdev
1030  * emulation code and allow it to update the fbcon output configuration.
1031  *
1032  * Drivers should call this from their hotplug handling code when a change is
1033  * detected. Note that this function does not do any output detection of its
1034  * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
1035  * driver already.
1036  *
1037  * This function must be called from process context with no mode
1038  * setting locks held.
1039  */
1040 void drm_kms_helper_hotplug_event(struct drm_device *dev)
1041 {
1042         /* send a uevent + call fbdev */
1043         drm_sysfs_hotplug_event(dev);
1044         if (dev->mode_config.funcs->output_poll_changed)
1045                 dev->mode_config.funcs->output_poll_changed(dev);
1046 }
1047 EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
1048
1049 #define DRM_OUTPUT_POLL_PERIOD (10*HZ)
1050 static void output_poll_execute(struct work_struct *work)
1051 {
1052         struct delayed_work *delayed_work = to_delayed_work(work);
1053         struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
1054         struct drm_connector *connector;
1055         enum drm_connector_status old_status;
1056         bool repoll = false, changed = false;
1057
1058         if (!drm_kms_helper_poll)
1059                 return;
1060
1061         mutex_lock(&dev->mode_config.mutex);
1062         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
1063
1064                 /* Ignore forced connectors. */
1065                 if (connector->force)
1066                         continue;
1067
1068                 /* Ignore HPD capable connectors and connectors where we don't
1069                  * want any hotplug detection at all for polling. */
1070                 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
1071                         continue;
1072
1073                 repoll = true;
1074
1075                 old_status = connector->status;
1076                 /* if we are connected and don't want to poll for disconnect
1077                    skip it */
1078                 if (old_status == connector_status_connected &&
1079                     !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
1080                         continue;
1081
1082                 connector->status = connector->funcs->detect(connector, false);
1083                 if (old_status != connector->status) {
1084                         const char *old, *new;
1085
1086                         old = drm_get_connector_status_name(old_status);
1087                         new = drm_get_connector_status_name(connector->status);
1088
1089                         DRM_DEBUG_KMS("[CONNECTOR:%d:%s] "
1090                                       "status updated from %s to %s\n",
1091                                       connector->base.id,
1092                                       drm_get_connector_name(connector),
1093                                       old, new);
1094
1095                         changed = true;
1096                 }
1097         }
1098
1099         mutex_unlock(&dev->mode_config.mutex);
1100
1101         if (changed)
1102                 drm_kms_helper_hotplug_event(dev);
1103
1104         if (repoll)
1105                 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
1106 }
1107
1108 /**
1109  * drm_kms_helper_poll_disable - disable output polling
1110  * @dev: drm_device
1111  *
1112  * This function disables the output polling work.
1113  *
1114  * Drivers can call this helper from their device suspend implementation. It is
1115  * not an error to call this even when output polling isn't enabled or arlready
1116  * disabled.
1117  */
1118 void drm_kms_helper_poll_disable(struct drm_device *dev)
1119 {
1120         if (!dev->mode_config.poll_enabled)
1121                 return;
1122         cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
1123 }
1124 EXPORT_SYMBOL(drm_kms_helper_poll_disable);
1125
1126 /**
1127  * drm_kms_helper_poll_enable - re-enable output polling.
1128  * @dev: drm_device
1129  *
1130  * This function re-enables the output polling work.
1131  *
1132  * Drivers can call this helper from their device resume implementation. It is
1133  * an error to call this when the output polling support has not yet been set
1134  * up.
1135  */
1136 void drm_kms_helper_poll_enable(struct drm_device *dev)
1137 {
1138         bool poll = false;
1139         struct drm_connector *connector;
1140
1141         if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll)
1142                 return;
1143
1144         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
1145                 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
1146                                          DRM_CONNECTOR_POLL_DISCONNECT))
1147                         poll = true;
1148         }
1149
1150         if (poll)
1151                 schedule_delayed_work(&dev->mode_config.output_poll_work, DRM_OUTPUT_POLL_PERIOD);
1152 }
1153 EXPORT_SYMBOL(drm_kms_helper_poll_enable);
1154
1155 /**
1156  * drm_kms_helper_poll_init - initialize and enable output polling
1157  * @dev: drm_device
1158  *
1159  * This function intializes and then also enables output polling support for
1160  * @dev. Drivers which do not have reliable hotplug support in hardware can use
1161  * this helper infrastructure to regularly poll such connectors for changes in
1162  * their connection state.
1163  *
1164  * Drivers can control which connectors are polled by setting the
1165  * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
1166  * connectors where probing live outputs can result in visual distortion drivers
1167  * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
1168  * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
1169  * completely ignored by the polling logic.
1170  *
1171  * Note that a connector can be both polled and probed from the hotplug handler,
1172  * in case the hotplug interrupt is known to be unreliable.
1173  */
1174 void drm_kms_helper_poll_init(struct drm_device *dev)
1175 {
1176         INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
1177         dev->mode_config.poll_enabled = true;
1178
1179         drm_kms_helper_poll_enable(dev);
1180 }
1181 EXPORT_SYMBOL(drm_kms_helper_poll_init);
1182
1183 /**
1184  * drm_kms_helper_poll_fini - disable output polling and clean it up
1185  * @dev: drm_device
1186  */
1187 void drm_kms_helper_poll_fini(struct drm_device *dev)
1188 {
1189         drm_kms_helper_poll_disable(dev);
1190 }
1191 EXPORT_SYMBOL(drm_kms_helper_poll_fini);
1192
1193 /**
1194  * drm_helper_hpd_irq_event - hotplug processing
1195  * @dev: drm_device
1196  *
1197  * Drivers can use this helper function to run a detect cycle on all connectors
1198  * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
1199  * other connectors are ignored, which is useful to avoid reprobing fixed
1200  * panels.
1201  *
1202  * This helper function is useful for drivers which can't or don't track hotplug
1203  * interrupts for each connector.
1204  *
1205  * Drivers which support hotplug interrupts for each connector individually and
1206  * which have a more fine-grained detect logic should bypass this code and
1207  * directly call drm_kms_helper_hotplug_event() in case the connector state
1208  * changed.
1209  *
1210  * This function must be called from process context with no mode
1211  * setting locks held.
1212  *
1213  * Note that a connector can be both polled and probed from the hotplug handler,
1214  * in case the hotplug interrupt is known to be unreliable.
1215  */
1216 bool drm_helper_hpd_irq_event(struct drm_device *dev)
1217 {
1218         struct drm_connector *connector;
1219         enum drm_connector_status old_status;
1220         bool changed = false;
1221
1222         if (!dev->mode_config.poll_enabled)
1223                 return false;
1224
1225         mutex_lock(&dev->mode_config.mutex);
1226         list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
1227
1228                 /* Only handle HPD capable connectors. */
1229                 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
1230                         continue;
1231
1232                 old_status = connector->status;
1233
1234                 connector->status = connector->funcs->detect(connector, false);
1235                 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n",
1236                               connector->base.id,
1237                               drm_get_connector_name(connector),
1238                               drm_get_connector_status_name(old_status),
1239                               drm_get_connector_status_name(connector->status));
1240                 if (old_status != connector->status)
1241                         changed = true;
1242         }
1243
1244         mutex_unlock(&dev->mode_config.mutex);
1245
1246         if (changed)
1247                 drm_kms_helper_hotplug_event(dev);
1248
1249         return changed;
1250 }
1251 EXPORT_SYMBOL(drm_helper_hpd_irq_event);