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 #include <drm/drm_modeset_helper_vtables.h> 42 43 #include "drm_crtc_helper_internal.h" 44 45 /** 46 * DOC: output probing helper overview 47 * 48 * This library provides some helper code for output probing. It provides an 49 * implementation of the core &drm_connector_funcs.fill_modes interface with 50 * drm_helper_probe_single_connector_modes(). 51 * 52 * It also provides support for polling connectors with a work item and for 53 * generic hotplug interrupt handling where the driver doesn't or cannot keep 54 * track of a per-connector hpd interrupt. 55 * 56 * This helper library can be used independently of the modeset helper library. 57 * Drivers can also overwrite different parts e.g. use their own hotplug 58 * handling code to avoid probing unrelated outputs. 59 * 60 * The probe helpers share the function table structures with other display 61 * helper libraries. See &struct drm_connector_helper_funcs for the details. 62 */ 63 64 static bool drm_kms_helper_poll = true; 65 module_param_named(poll, drm_kms_helper_poll, bool, 0600); 66 67 static enum drm_mode_status 68 drm_mode_validate_flag(const struct drm_display_mode *mode, 69 int flags) 70 { 71 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) && 72 !(flags & DRM_MODE_FLAG_INTERLACE)) 73 return MODE_NO_INTERLACE; 74 75 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) && 76 !(flags & DRM_MODE_FLAG_DBLSCAN)) 77 return MODE_NO_DBLESCAN; 78 79 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) && 80 !(flags & DRM_MODE_FLAG_3D_MASK)) 81 return MODE_NO_STEREO; 82 83 return MODE_OK; 84 } 85 86 static enum drm_mode_status 87 drm_mode_validate_pipeline(struct drm_display_mode *mode, 88 struct drm_connector *connector) 89 { 90 struct drm_device *dev = connector->dev; 91 uint32_t *ids = connector->encoder_ids; 92 enum drm_mode_status ret = MODE_OK; 93 unsigned int i; 94 95 /* Step 1: Validate against connector */ 96 ret = drm_connector_mode_valid(connector, mode); 97 if (ret != MODE_OK) 98 return ret; 99 100 /* Step 2: Validate against encoders and crtcs */ 101 for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) { 102 struct drm_encoder *encoder = drm_encoder_find(dev, NULL, ids[i]); 103 struct drm_crtc *crtc; 104 105 if (!encoder) 106 continue; 107 108 ret = drm_encoder_mode_valid(encoder, mode); 109 if (ret != MODE_OK) { 110 /* No point in continuing for crtc check as this encoder 111 * will not accept the mode anyway. If all encoders 112 * reject the mode then, at exit, ret will not be 113 * MODE_OK. */ 114 continue; 115 } 116 117 ret = drm_bridge_mode_valid(encoder->bridge, mode); 118 if (ret != MODE_OK) { 119 /* There is also no point in continuing for crtc check 120 * here. */ 121 continue; 122 } 123 124 drm_for_each_crtc(crtc, dev) { 125 if (!drm_encoder_crtc_ok(encoder, crtc)) 126 continue; 127 128 ret = drm_crtc_mode_valid(crtc, mode); 129 if (ret == MODE_OK) { 130 /* If we get to this point there is at least 131 * one combination of encoder+crtc that works 132 * for this mode. Lets return now. */ 133 return ret; 134 } 135 } 136 } 137 138 return ret; 139 } 140 141 static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector) 142 { 143 struct drm_cmdline_mode *cmdline_mode; 144 struct drm_display_mode *mode; 145 146 cmdline_mode = &connector->cmdline_mode; 147 if (!cmdline_mode->specified) 148 return 0; 149 150 /* Only add a GTF mode if we find no matching probed modes */ 151 list_for_each_entry(mode, &connector->probed_modes, head) { 152 if (mode->hdisplay != cmdline_mode->xres || 153 mode->vdisplay != cmdline_mode->yres) 154 continue; 155 156 if (cmdline_mode->refresh_specified) { 157 /* The probed mode's vrefresh is set until later */ 158 if (drm_mode_vrefresh(mode) != cmdline_mode->refresh) 159 continue; 160 } 161 162 return 0; 163 } 164 165 mode = drm_mode_create_from_cmdline_mode(connector->dev, 166 cmdline_mode); 167 if (mode == NULL) 168 return 0; 169 170 drm_mode_probed_add(connector, mode); 171 return 1; 172 } 173 174 enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc, 175 const struct drm_display_mode *mode) 176 { 177 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private; 178 179 if (!crtc_funcs || !crtc_funcs->mode_valid) 180 return MODE_OK; 181 182 return crtc_funcs->mode_valid(crtc, mode); 183 } 184 185 enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder, 186 const struct drm_display_mode *mode) 187 { 188 const struct drm_encoder_helper_funcs *encoder_funcs = 189 encoder->helper_private; 190 191 if (!encoder_funcs || !encoder_funcs->mode_valid) 192 return MODE_OK; 193 194 return encoder_funcs->mode_valid(encoder, mode); 195 } 196 197 enum drm_mode_status drm_connector_mode_valid(struct drm_connector *connector, 198 struct drm_display_mode *mode) 199 { 200 const struct drm_connector_helper_funcs *connector_funcs = 201 connector->helper_private; 202 203 if (!connector_funcs || !connector_funcs->mode_valid) 204 return MODE_OK; 205 206 return connector_funcs->mode_valid(connector, mode); 207 } 208 209 #define DRM_OUTPUT_POLL_PERIOD (10*HZ) 210 /** 211 * drm_kms_helper_poll_enable - re-enable output polling. 212 * @dev: drm_device 213 * 214 * This function re-enables the output polling work, after it has been 215 * temporarily disabled using drm_kms_helper_poll_disable(), for example over 216 * suspend/resume. 217 * 218 * Drivers can call this helper from their device resume implementation. It is 219 * an error to call this when the output polling support has not yet been set 220 * up. 221 * 222 * Note that calls to enable and disable polling must be strictly ordered, which 223 * is automatically the case when they're only call from suspend/resume 224 * callbacks. 225 */ 226 void drm_kms_helper_poll_enable(struct drm_device *dev) 227 { 228 bool poll = false; 229 struct drm_connector *connector; 230 struct drm_connector_list_iter conn_iter; 231 unsigned long delay = DRM_OUTPUT_POLL_PERIOD; 232 233 if (!dev->mode_config.poll_enabled || !drm_kms_helper_poll) 234 return; 235 236 drm_connector_list_iter_begin(dev, &conn_iter); 237 drm_for_each_connector_iter(connector, &conn_iter) { 238 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT | 239 DRM_CONNECTOR_POLL_DISCONNECT)) 240 poll = true; 241 } 242 drm_connector_list_iter_end(&conn_iter); 243 244 if (dev->mode_config.delayed_event) { 245 /* 246 * FIXME: 247 * 248 * Use short (1s) delay to handle the initial delayed event. 249 * This delay should not be needed, but Optimus/nouveau will 250 * fail in a mysterious way if the delayed event is handled as 251 * soon as possible like it is done in 252 * drm_helper_probe_single_connector_modes() in case the poll 253 * was enabled before. 254 */ 255 poll = true; 256 delay = HZ; 257 } 258 259 if (poll) 260 schedule_delayed_work(&dev->mode_config.output_poll_work, delay); 261 } 262 EXPORT_SYMBOL(drm_kms_helper_poll_enable); 263 264 static enum drm_connector_status 265 drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force) 266 { 267 const struct drm_connector_helper_funcs *funcs = connector->helper_private; 268 struct drm_modeset_acquire_ctx ctx; 269 int ret; 270 271 drm_modeset_acquire_init(&ctx, 0); 272 273 retry: 274 ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx); 275 if (!ret) { 276 if (funcs->detect_ctx) 277 ret = funcs->detect_ctx(connector, &ctx, force); 278 else if (connector->funcs->detect) 279 ret = connector->funcs->detect(connector, force); 280 else 281 ret = connector_status_connected; 282 } 283 284 if (ret == -EDEADLK) { 285 drm_modeset_backoff(&ctx); 286 goto retry; 287 } 288 289 if (WARN_ON(ret < 0)) 290 ret = connector_status_unknown; 291 292 drm_modeset_drop_locks(&ctx); 293 drm_modeset_acquire_fini(&ctx); 294 295 return ret; 296 } 297 298 /** 299 * drm_helper_probe_detect - probe connector status 300 * @connector: connector to probe 301 * @ctx: acquire_ctx, or NULL to let this function handle locking. 302 * @force: Whether destructive probe operations should be performed. 303 * 304 * This function calls the detect callbacks of the connector. 305 * This function returns &drm_connector_status, or 306 * if @ctx is set, it might also return -EDEADLK. 307 */ 308 int 309 drm_helper_probe_detect(struct drm_connector *connector, 310 struct drm_modeset_acquire_ctx *ctx, 311 bool force) 312 { 313 const struct drm_connector_helper_funcs *funcs = connector->helper_private; 314 struct drm_device *dev = connector->dev; 315 int ret; 316 317 if (!ctx) 318 return drm_helper_probe_detect_ctx(connector, force); 319 320 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx); 321 if (ret) 322 return ret; 323 324 if (funcs->detect_ctx) 325 return funcs->detect_ctx(connector, ctx, force); 326 else if (connector->funcs->detect) 327 return connector->funcs->detect(connector, force); 328 else 329 return connector_status_connected; 330 } 331 EXPORT_SYMBOL(drm_helper_probe_detect); 332 333 /** 334 * drm_helper_probe_single_connector_modes - get complete set of display modes 335 * @connector: connector to probe 336 * @maxX: max width for modes 337 * @maxY: max height for modes 338 * 339 * Based on the helper callbacks implemented by @connector in struct 340 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first 341 * be added to the connector's probed_modes list, then culled (based on validity 342 * and the @maxX, @maxY parameters) and put into the normal modes list. 343 * 344 * Intended to be used as a generic implementation of the 345 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers 346 * for output mode filtering and detection. 347 * 348 * The basic procedure is as follows 349 * 350 * 1. All modes currently on the connector's modes list are marked as stale 351 * 352 * 2. New modes are added to the connector's probed_modes list with 353 * drm_mode_probed_add(). New modes start their life with status as OK. 354 * Modes are added from a single source using the following priority order. 355 * 356 * - &drm_connector_helper_funcs.get_modes vfunc 357 * - if the connector status is connector_status_connected, standard 358 * VESA DMT modes up to 1024x768 are automatically added 359 * (drm_add_modes_noedid()) 360 * 361 * Finally modes specified via the kernel command line (video=...) are 362 * added in addition to what the earlier probes produced 363 * (drm_helper_probe_add_cmdline_mode()). These modes are generated 364 * using the VESA GTF/CVT formulas. 365 * 366 * 3. Modes are moved from the probed_modes list to the modes list. Potential 367 * duplicates are merged together (see drm_mode_connector_list_update()). 368 * After this step the probed_modes list will be empty again. 369 * 370 * 4. Any non-stale mode on the modes list then undergoes validation 371 * 372 * - drm_mode_validate_basic() performs basic sanity checks 373 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY 374 * (if specified) 375 * - drm_mode_validate_flag() checks the modes against basic connector 376 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed) 377 * - the optional &drm_connector_helper_funcs.mode_valid helper can perform 378 * driver and/or sink specific checks 379 * - the optional &drm_crtc_helper_funcs.mode_valid, 380 * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid 381 * helpers can perform driver and/or source specific checks which are also 382 * enforced by the modeset/atomic helpers 383 * 384 * 5. Any mode whose status is not OK is pruned from the connector's modes list, 385 * accompanied by a debug message indicating the reason for the mode's 386 * rejection (see drm_mode_prune_invalid()). 387 * 388 * Returns: 389 * The number of modes found on @connector. 390 */ 391 int drm_helper_probe_single_connector_modes(struct drm_connector *connector, 392 uint32_t maxX, uint32_t maxY) 393 { 394 struct drm_device *dev = connector->dev; 395 struct drm_display_mode *mode; 396 const struct drm_connector_helper_funcs *connector_funcs = 397 connector->helper_private; 398 int count = 0, ret; 399 int mode_flags = 0; 400 bool verbose_prune = true; 401 enum drm_connector_status old_status; 402 struct drm_modeset_acquire_ctx ctx; 403 404 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); 405 406 drm_modeset_acquire_init(&ctx, 0); 407 408 DRM_DEBUG_KMS("[CONNECTOR:%d:%s]\n", connector->base.id, 409 connector->name); 410 411 retry: 412 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx); 413 if (ret == -EDEADLK) { 414 drm_modeset_backoff(&ctx); 415 goto retry; 416 } else 417 WARN_ON(ret < 0); 418 419 /* set all old modes to the stale state */ 420 list_for_each_entry(mode, &connector->modes, head) 421 mode->status = MODE_STALE; 422 423 old_status = connector->status; 424 425 if (connector->force) { 426 if (connector->force == DRM_FORCE_ON || 427 connector->force == DRM_FORCE_ON_DIGITAL) 428 connector->status = connector_status_connected; 429 else 430 connector->status = connector_status_disconnected; 431 if (connector->funcs->force) 432 connector->funcs->force(connector); 433 } else { 434 ret = drm_helper_probe_detect(connector, &ctx, true); 435 436 if (ret == -EDEADLK) { 437 drm_modeset_backoff(&ctx); 438 goto retry; 439 } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret)) 440 ret = connector_status_unknown; 441 442 connector->status = ret; 443 } 444 445 /* 446 * Normally either the driver's hpd code or the poll loop should 447 * pick up any changes and fire the hotplug event. But if 448 * userspace sneaks in a probe, we might miss a change. Hence 449 * check here, and if anything changed start the hotplug code. 450 */ 451 if (old_status != connector->status) { 452 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n", 453 connector->base.id, 454 connector->name, 455 drm_get_connector_status_name(old_status), 456 drm_get_connector_status_name(connector->status)); 457 458 /* 459 * The hotplug event code might call into the fb 460 * helpers, and so expects that we do not hold any 461 * locks. Fire up the poll struct instead, it will 462 * disable itself again. 463 */ 464 dev->mode_config.delayed_event = true; 465 if (dev->mode_config.poll_enabled) 466 schedule_delayed_work(&dev->mode_config.output_poll_work, 467 0); 468 } 469 470 /* Re-enable polling in case the global poll config changed. */ 471 if (drm_kms_helper_poll != dev->mode_config.poll_running) 472 drm_kms_helper_poll_enable(dev); 473 474 dev->mode_config.poll_running = drm_kms_helper_poll; 475 476 if (connector->status == connector_status_disconnected) { 477 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] disconnected\n", 478 connector->base.id, connector->name); 479 drm_mode_connector_update_edid_property(connector, NULL); 480 verbose_prune = false; 481 goto prune; 482 } 483 484 count = (*connector_funcs->get_modes)(connector); 485 486 if (count == 0 && connector->status == connector_status_connected) 487 count = drm_add_modes_noedid(connector, 1024, 768); 488 count += drm_helper_probe_add_cmdline_mode(connector); 489 if (count == 0) 490 goto prune; 491 492 drm_mode_connector_list_update(connector); 493 494 if (connector->interlace_allowed) 495 mode_flags |= DRM_MODE_FLAG_INTERLACE; 496 if (connector->doublescan_allowed) 497 mode_flags |= DRM_MODE_FLAG_DBLSCAN; 498 if (connector->stereo_allowed) 499 mode_flags |= DRM_MODE_FLAG_3D_MASK; 500 501 list_for_each_entry(mode, &connector->modes, head) { 502 if (mode->status == MODE_OK) 503 mode->status = drm_mode_validate_basic(mode); 504 505 if (mode->status == MODE_OK) 506 mode->status = drm_mode_validate_size(mode, maxX, maxY); 507 508 if (mode->status == MODE_OK) 509 mode->status = drm_mode_validate_flag(mode, mode_flags); 510 511 if (mode->status == MODE_OK) 512 mode->status = drm_mode_validate_pipeline(mode, 513 connector); 514 515 if (mode->status == MODE_OK) 516 mode->status = drm_mode_validate_ycbcr420(mode, 517 connector); 518 } 519 520 prune: 521 drm_mode_prune_invalid(dev, &connector->modes, verbose_prune); 522 523 drm_modeset_drop_locks(&ctx); 524 drm_modeset_acquire_fini(&ctx); 525 526 if (list_empty(&connector->modes)) 527 return 0; 528 529 list_for_each_entry(mode, &connector->modes, head) 530 mode->vrefresh = drm_mode_vrefresh(mode); 531 532 drm_mode_sort(&connector->modes); 533 534 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] probed modes :\n", connector->base.id, 535 connector->name); 536 list_for_each_entry(mode, &connector->modes, head) { 537 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V); 538 drm_mode_debug_printmodeline(mode); 539 } 540 541 return count; 542 } 543 EXPORT_SYMBOL(drm_helper_probe_single_connector_modes); 544 545 /** 546 * drm_kms_helper_hotplug_event - fire off KMS hotplug events 547 * @dev: drm_device whose connector state changed 548 * 549 * This function fires off the uevent for userspace and also calls the 550 * output_poll_changed function, which is most commonly used to inform the fbdev 551 * emulation code and allow it to update the fbcon output configuration. 552 * 553 * Drivers should call this from their hotplug handling code when a change is 554 * detected. Note that this function does not do any output detection of its 555 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the 556 * driver already. 557 * 558 * This function must be called from process context with no mode 559 * setting locks held. 560 */ 561 void drm_kms_helper_hotplug_event(struct drm_device *dev) 562 { 563 /* send a uevent + call fbdev */ 564 drm_sysfs_hotplug_event(dev); 565 if (dev->mode_config.funcs->output_poll_changed) 566 dev->mode_config.funcs->output_poll_changed(dev); 567 } 568 EXPORT_SYMBOL(drm_kms_helper_hotplug_event); 569 570 static void output_poll_execute(struct work_struct *work) 571 { 572 struct delayed_work *delayed_work = to_delayed_work(work); 573 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work); 574 struct drm_connector *connector; 575 struct drm_connector_list_iter conn_iter; 576 enum drm_connector_status old_status; 577 bool repoll = false, changed; 578 579 /* Pick up any changes detected by the probe functions. */ 580 changed = dev->mode_config.delayed_event; 581 dev->mode_config.delayed_event = false; 582 583 if (!drm_kms_helper_poll) 584 goto out; 585 586 if (!mutex_trylock(&dev->mode_config.mutex)) { 587 repoll = true; 588 goto out; 589 } 590 591 drm_connector_list_iter_begin(dev, &conn_iter); 592 drm_for_each_connector_iter(connector, &conn_iter) { 593 /* Ignore forced connectors. */ 594 if (connector->force) 595 continue; 596 597 /* Ignore HPD capable connectors and connectors where we don't 598 * want any hotplug detection at all for polling. */ 599 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD) 600 continue; 601 602 old_status = connector->status; 603 /* if we are connected and don't want to poll for disconnect 604 skip it */ 605 if (old_status == connector_status_connected && 606 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT)) 607 continue; 608 609 repoll = true; 610 611 connector->status = drm_helper_probe_detect(connector, NULL, false); 612 if (old_status != connector->status) { 613 const char *old, *new; 614 615 /* 616 * The poll work sets force=false when calling detect so 617 * that drivers can avoid to do disruptive tests (e.g. 618 * when load detect cycles could cause flickering on 619 * other, running displays). This bears the risk that we 620 * flip-flop between unknown here in the poll work and 621 * the real state when userspace forces a full detect 622 * call after receiving a hotplug event due to this 623 * change. 624 * 625 * Hence clamp an unknown detect status to the old 626 * value. 627 */ 628 if (connector->status == connector_status_unknown) { 629 connector->status = old_status; 630 continue; 631 } 632 633 old = drm_get_connector_status_name(old_status); 634 new = drm_get_connector_status_name(connector->status); 635 636 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] " 637 "status updated from %s to %s\n", 638 connector->base.id, 639 connector->name, 640 old, new); 641 642 changed = true; 643 } 644 } 645 drm_connector_list_iter_end(&conn_iter); 646 647 mutex_unlock(&dev->mode_config.mutex); 648 649 out: 650 if (changed) 651 drm_kms_helper_hotplug_event(dev); 652 653 if (repoll) 654 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD); 655 } 656 657 /** 658 * drm_kms_helper_poll_disable - disable output polling 659 * @dev: drm_device 660 * 661 * This function disables the output polling work. 662 * 663 * Drivers can call this helper from their device suspend implementation. It is 664 * not an error to call this even when output polling isn't enabled or already 665 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable(). 666 * 667 * Note that calls to enable and disable polling must be strictly ordered, which 668 * is automatically the case when they're only call from suspend/resume 669 * callbacks. 670 */ 671 void drm_kms_helper_poll_disable(struct drm_device *dev) 672 { 673 if (!dev->mode_config.poll_enabled) 674 return; 675 cancel_delayed_work_sync(&dev->mode_config.output_poll_work); 676 } 677 EXPORT_SYMBOL(drm_kms_helper_poll_disable); 678 679 /** 680 * drm_kms_helper_poll_init - initialize and enable output polling 681 * @dev: drm_device 682 * 683 * This function intializes and then also enables output polling support for 684 * @dev. Drivers which do not have reliable hotplug support in hardware can use 685 * this helper infrastructure to regularly poll such connectors for changes in 686 * their connection state. 687 * 688 * Drivers can control which connectors are polled by setting the 689 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On 690 * connectors where probing live outputs can result in visual distortion drivers 691 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this. 692 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are 693 * completely ignored by the polling logic. 694 * 695 * Note that a connector can be both polled and probed from the hotplug handler, 696 * in case the hotplug interrupt is known to be unreliable. 697 */ 698 void drm_kms_helper_poll_init(struct drm_device *dev) 699 { 700 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute); 701 dev->mode_config.poll_enabled = true; 702 703 drm_kms_helper_poll_enable(dev); 704 } 705 EXPORT_SYMBOL(drm_kms_helper_poll_init); 706 707 /** 708 * drm_kms_helper_poll_fini - disable output polling and clean it up 709 * @dev: drm_device 710 */ 711 void drm_kms_helper_poll_fini(struct drm_device *dev) 712 { 713 drm_kms_helper_poll_disable(dev); 714 } 715 EXPORT_SYMBOL(drm_kms_helper_poll_fini); 716 717 /** 718 * drm_helper_hpd_irq_event - hotplug processing 719 * @dev: drm_device 720 * 721 * Drivers can use this helper function to run a detect cycle on all connectors 722 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All 723 * other connectors are ignored, which is useful to avoid reprobing fixed 724 * panels. 725 * 726 * This helper function is useful for drivers which can't or don't track hotplug 727 * interrupts for each connector. 728 * 729 * Drivers which support hotplug interrupts for each connector individually and 730 * which have a more fine-grained detect logic should bypass this code and 731 * directly call drm_kms_helper_hotplug_event() in case the connector state 732 * changed. 733 * 734 * This function must be called from process context with no mode 735 * setting locks held. 736 * 737 * Note that a connector can be both polled and probed from the hotplug handler, 738 * in case the hotplug interrupt is known to be unreliable. 739 */ 740 bool drm_helper_hpd_irq_event(struct drm_device *dev) 741 { 742 struct drm_connector *connector; 743 struct drm_connector_list_iter conn_iter; 744 enum drm_connector_status old_status; 745 bool changed = false; 746 747 if (!dev->mode_config.poll_enabled) 748 return false; 749 750 mutex_lock(&dev->mode_config.mutex); 751 drm_connector_list_iter_begin(dev, &conn_iter); 752 drm_for_each_connector_iter(connector, &conn_iter) { 753 /* Only handle HPD capable connectors. */ 754 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD)) 755 continue; 756 757 old_status = connector->status; 758 759 connector->status = drm_helper_probe_detect(connector, NULL, false); 760 DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %s to %s\n", 761 connector->base.id, 762 connector->name, 763 drm_get_connector_status_name(old_status), 764 drm_get_connector_status_name(connector->status)); 765 if (old_status != connector->status) 766 changed = true; 767 } 768 drm_connector_list_iter_end(&conn_iter); 769 mutex_unlock(&dev->mode_config.mutex); 770 771 if (changed) 772 drm_kms_helper_hotplug_event(dev); 773 774 return changed; 775 } 776 EXPORT_SYMBOL(drm_helper_hpd_irq_event); 777