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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/drm_bridge.h>
36#include <drm/drm_client_event.h>
37#include <drm/drm_crtc.h>
38#include <drm/drm_edid.h>
39#include <drm/drm_fourcc.h>
40#include <drm/drm_managed.h>
41#include <drm/drm_modeset_helper_vtables.h>
42#include <drm/drm_print.h>
43#include <drm/drm_probe_helper.h>
44#include <drm/drm_sysfs.h>
45
46#include "drm_crtc_helper_internal.h"
47
48/**
49 * DOC: output probing helper overview
50 *
51 * This library provides some helper code for output probing. It provides an
52 * implementation of the core &drm_connector_funcs.fill_modes interface with
53 * drm_helper_probe_single_connector_modes().
54 *
55 * It also provides support for polling connectors with a work item and for
56 * generic hotplug interrupt handling where the driver doesn't or cannot keep
57 * track of a per-connector hpd interrupt.
58 *
59 * This helper library can be used independently of the modeset helper library.
60 * Drivers can also overwrite different parts e.g. use their own hotplug
61 * handling code to avoid probing unrelated outputs.
62 *
63 * The probe helpers share the function table structures with other display
64 * helper libraries. See &struct drm_connector_helper_funcs for the details.
65 */
66
67static bool drm_kms_helper_poll = true;
68module_param_named(poll, drm_kms_helper_poll, bool, 0600);
69
70static enum drm_mode_status
71drm_mode_validate_flag(const struct drm_display_mode *mode,
72 int flags)
73{
74 if ((mode->flags & DRM_MODE_FLAG_INTERLACE) &&
75 !(flags & DRM_MODE_FLAG_INTERLACE))
76 return MODE_NO_INTERLACE;
77
78 if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) &&
79 !(flags & DRM_MODE_FLAG_DBLSCAN))
80 return MODE_NO_DBLESCAN;
81
82 if ((mode->flags & DRM_MODE_FLAG_3D_MASK) &&
83 !(flags & DRM_MODE_FLAG_3D_MASK))
84 return MODE_NO_STEREO;
85
86 return MODE_OK;
87}
88
89static int
90drm_mode_validate_pipeline(struct drm_display_mode *mode,
91 struct drm_connector *connector,
92 struct drm_modeset_acquire_ctx *ctx,
93 enum drm_mode_status *status)
94{
95 struct drm_device *dev = connector->dev;
96 struct drm_encoder *encoder;
97 int ret;
98
99 /* Step 1: Validate against connector */
100 ret = drm_connector_mode_valid(connector, mode, ctx, status);
101 if (ret || *status != MODE_OK)
102 return ret;
103
104 /* Step 2: Validate against encoders and crtcs */
105 drm_connector_for_each_possible_encoder(connector, encoder) {
106 struct drm_bridge *bridge;
107 struct drm_crtc *crtc;
108
109 *status = drm_encoder_mode_valid(encoder, mode);
110 if (*status != MODE_OK) {
111 /* No point in continuing for crtc check as this encoder
112 * will not accept the mode anyway. If all encoders
113 * reject the mode then, at exit, ret will not be
114 * MODE_OK. */
115 continue;
116 }
117
118 bridge = drm_bridge_chain_get_first_bridge(encoder);
119 *status = drm_bridge_chain_mode_valid(bridge,
120 &connector->display_info,
121 mode);
122 if (*status != MODE_OK) {
123 /* There is also no point in continuing for crtc check
124 * here. */
125 continue;
126 }
127
128 drm_for_each_crtc(crtc, dev) {
129 if (!drm_encoder_crtc_ok(encoder, crtc))
130 continue;
131
132 *status = drm_crtc_mode_valid(crtc, mode);
133 if (*status == MODE_OK) {
134 /* If we get to this point there is at least
135 * one combination of encoder+crtc that works
136 * for this mode. Lets return now. */
137 return 0;
138 }
139 }
140 }
141
142 return 0;
143}
144
145static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector)
146{
147 struct drm_cmdline_mode *cmdline_mode;
148 struct drm_display_mode *mode;
149
150 cmdline_mode = &connector->cmdline_mode;
151 if (!cmdline_mode->specified)
152 return 0;
153
154 /* Only add a GTF mode if we find no matching probed modes */
155 list_for_each_entry(mode, &connector->probed_modes, head) {
156 if (mode->hdisplay != cmdline_mode->xres ||
157 mode->vdisplay != cmdline_mode->yres)
158 continue;
159
160 if (cmdline_mode->refresh_specified) {
161 /* The probed mode's vrefresh is set until later */
162 if (drm_mode_vrefresh(mode) != cmdline_mode->refresh)
163 continue;
164 }
165
166 /* Mark the matching mode as being preferred by the user */
167 mode->type |= DRM_MODE_TYPE_USERDEF;
168 return 0;
169 }
170
171 mode = drm_mode_create_from_cmdline_mode(connector->dev,
172 cmdline_mode);
173 if (mode == NULL)
174 return 0;
175
176 drm_mode_probed_add(connector, mode);
177 return 1;
178}
179
180enum drm_mode_status drm_crtc_mode_valid(struct drm_crtc *crtc,
181 const struct drm_display_mode *mode)
182{
183 const struct drm_crtc_helper_funcs *crtc_funcs = crtc->helper_private;
184
185 if (!crtc_funcs || !crtc_funcs->mode_valid)
186 return MODE_OK;
187
188 return crtc_funcs->mode_valid(crtc, mode);
189}
190
191enum drm_mode_status drm_encoder_mode_valid(struct drm_encoder *encoder,
192 const struct drm_display_mode *mode)
193{
194 const struct drm_encoder_helper_funcs *encoder_funcs =
195 encoder->helper_private;
196
197 if (!encoder_funcs || !encoder_funcs->mode_valid)
198 return MODE_OK;
199
200 return encoder_funcs->mode_valid(encoder, mode);
201}
202
203int
204drm_connector_mode_valid(struct drm_connector *connector,
205 struct drm_display_mode *mode,
206 struct drm_modeset_acquire_ctx *ctx,
207 enum drm_mode_status *status)
208{
209 const struct drm_connector_helper_funcs *connector_funcs =
210 connector->helper_private;
211 int ret = 0;
212
213 if (!connector_funcs)
214 *status = MODE_OK;
215 else if (connector_funcs->mode_valid_ctx)
216 ret = connector_funcs->mode_valid_ctx(connector, mode, ctx,
217 status);
218 else if (connector_funcs->mode_valid)
219 *status = connector_funcs->mode_valid(connector, mode);
220 else
221 *status = MODE_OK;
222
223 return ret;
224}
225
226static void drm_kms_helper_disable_hpd(struct drm_device *dev)
227{
228 struct drm_connector *connector;
229 struct drm_connector_list_iter conn_iter;
230
231 drm_connector_list_iter_begin(dev, &conn_iter);
232 drm_for_each_connector_iter(connector, &conn_iter) {
233 const struct drm_connector_helper_funcs *funcs =
234 connector->helper_private;
235
236 if (funcs && funcs->disable_hpd)
237 funcs->disable_hpd(connector);
238 }
239 drm_connector_list_iter_end(&conn_iter);
240}
241
242static bool drm_kms_helper_enable_hpd(struct drm_device *dev)
243{
244 bool poll = false;
245 struct drm_connector *connector;
246 struct drm_connector_list_iter conn_iter;
247
248 drm_connector_list_iter_begin(dev, &conn_iter);
249 drm_for_each_connector_iter(connector, &conn_iter) {
250 const struct drm_connector_helper_funcs *funcs =
251 connector->helper_private;
252
253 if (funcs && funcs->enable_hpd)
254 funcs->enable_hpd(connector);
255
256 if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
257 DRM_CONNECTOR_POLL_DISCONNECT))
258 poll = true;
259 }
260 drm_connector_list_iter_end(&conn_iter);
261
262 return poll;
263}
264
265#define DRM_OUTPUT_POLL_PERIOD (10*HZ)
266static void reschedule_output_poll_work(struct drm_device *dev)
267{
268 unsigned long delay = DRM_OUTPUT_POLL_PERIOD;
269
270 if (dev->mode_config.delayed_event)
271 /*
272 * FIXME:
273 *
274 * Use short (1s) delay to handle the initial delayed event.
275 * This delay should not be needed, but Optimus/nouveau will
276 * fail in a mysterious way if the delayed event is handled as
277 * soon as possible like it is done in
278 * drm_helper_probe_single_connector_modes() in case the poll
279 * was enabled before.
280 */
281 delay = HZ;
282
283 schedule_delayed_work(&dev->mode_config.output_poll_work, delay);
284}
285
286/**
287 * drm_kms_helper_poll_enable - re-enable output polling.
288 * @dev: drm_device
289 *
290 * This function re-enables the output polling work, after it has been
291 * temporarily disabled using drm_kms_helper_poll_disable(), for example over
292 * suspend/resume.
293 *
294 * Drivers can call this helper from their device resume implementation. It is
295 * not an error to call this even when output polling isn't enabled.
296 *
297 * If device polling was never initialized before, this call will trigger a
298 * warning and return.
299 *
300 * Note that calls to enable and disable polling must be strictly ordered, which
301 * is automatically the case when they're only call from suspend/resume
302 * callbacks.
303 */
304void drm_kms_helper_poll_enable(struct drm_device *dev)
305{
306 if (drm_WARN_ON_ONCE(dev, !dev->mode_config.poll_enabled) ||
307 !drm_kms_helper_poll || dev->mode_config.poll_running)
308 return;
309
310 if (drm_kms_helper_enable_hpd(dev) ||
311 dev->mode_config.delayed_event)
312 reschedule_output_poll_work(dev);
313
314 dev->mode_config.poll_running = true;
315}
316EXPORT_SYMBOL(drm_kms_helper_poll_enable);
317
318/**
319 * drm_kms_helper_poll_reschedule - reschedule the output polling work
320 * @dev: drm_device
321 *
322 * This function reschedules the output polling work, after polling for a
323 * connector has been enabled.
324 *
325 * Drivers must call this helper after enabling polling for a connector by
326 * setting %DRM_CONNECTOR_POLL_CONNECT / %DRM_CONNECTOR_POLL_DISCONNECT flags
327 * in drm_connector::polled. Note that after disabling polling by clearing these
328 * flags for a connector will stop the output polling work automatically if
329 * the polling is disabled for all other connectors as well.
330 *
331 * The function can be called only after polling has been enabled by calling
332 * drm_kms_helper_poll_init() / drm_kms_helper_poll_enable().
333 */
334void drm_kms_helper_poll_reschedule(struct drm_device *dev)
335{
336 if (dev->mode_config.poll_running)
337 reschedule_output_poll_work(dev);
338}
339EXPORT_SYMBOL(drm_kms_helper_poll_reschedule);
340
341static enum drm_connector_status
342drm_helper_probe_detect_ctx(struct drm_connector *connector, bool force)
343{
344 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
345 struct drm_modeset_acquire_ctx ctx;
346 int ret;
347
348 drm_modeset_acquire_init(&ctx, 0);
349
350retry:
351 ret = drm_modeset_lock(&connector->dev->mode_config.connection_mutex, &ctx);
352 if (!ret) {
353 if (funcs->detect_ctx)
354 ret = funcs->detect_ctx(connector, &ctx, force);
355 else if (connector->funcs->detect)
356 ret = connector->funcs->detect(connector, force);
357 else
358 ret = connector_status_connected;
359 }
360
361 if (ret == -EDEADLK) {
362 drm_modeset_backoff(&ctx);
363 goto retry;
364 }
365
366 if (WARN_ON(ret < 0))
367 ret = connector_status_unknown;
368
369 if (ret != connector->status)
370 connector->epoch_counter += 1;
371
372 drm_modeset_drop_locks(&ctx);
373 drm_modeset_acquire_fini(&ctx);
374
375 return ret;
376}
377
378/**
379 * drm_helper_probe_detect - probe connector status
380 * @connector: connector to probe
381 * @ctx: acquire_ctx, or NULL to let this function handle locking.
382 * @force: Whether destructive probe operations should be performed.
383 *
384 * This function calls the detect callbacks of the connector.
385 * This function returns &drm_connector_status, or
386 * if @ctx is set, it might also return -EDEADLK.
387 */
388int
389drm_helper_probe_detect(struct drm_connector *connector,
390 struct drm_modeset_acquire_ctx *ctx,
391 bool force)
392{
393 const struct drm_connector_helper_funcs *funcs = connector->helper_private;
394 struct drm_device *dev = connector->dev;
395 int ret;
396
397 if (!ctx)
398 return drm_helper_probe_detect_ctx(connector, force);
399
400 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, ctx);
401 if (ret)
402 return ret;
403
404 if (funcs->detect_ctx)
405 ret = funcs->detect_ctx(connector, ctx, force);
406 else if (connector->funcs->detect)
407 ret = connector->funcs->detect(connector, force);
408 else
409 ret = connector_status_connected;
410
411 if (ret != connector->status)
412 connector->epoch_counter += 1;
413
414 return ret;
415}
416EXPORT_SYMBOL(drm_helper_probe_detect);
417
418static int drm_helper_probe_get_modes(struct drm_connector *connector)
419{
420 const struct drm_connector_helper_funcs *connector_funcs =
421 connector->helper_private;
422 int count;
423
424 count = connector_funcs->get_modes(connector);
425
426 /* The .get_modes() callback should not return negative values. */
427 if (count < 0) {
428 drm_err(connector->dev, ".get_modes() returned %pe\n",
429 ERR_PTR(count));
430 count = 0;
431 }
432
433 /*
434 * Fallback for when DDC probe failed in drm_get_edid() and thus skipped
435 * override/firmware EDID.
436 */
437 if (count == 0 && connector->status == connector_status_connected)
438 count = drm_edid_override_connector_update(connector);
439
440 return count;
441}
442
443static int __drm_helper_update_and_validate(struct drm_connector *connector,
444 uint32_t maxX, uint32_t maxY,
445 struct drm_modeset_acquire_ctx *ctx)
446{
447 struct drm_device *dev = connector->dev;
448 struct drm_display_mode *mode;
449 int mode_flags = 0;
450 int ret;
451
452 drm_connector_list_update(connector);
453
454 if (connector->interlace_allowed)
455 mode_flags |= DRM_MODE_FLAG_INTERLACE;
456 if (connector->doublescan_allowed)
457 mode_flags |= DRM_MODE_FLAG_DBLSCAN;
458 if (connector->stereo_allowed)
459 mode_flags |= DRM_MODE_FLAG_3D_MASK;
460
461 list_for_each_entry(mode, &connector->modes, head) {
462 if (mode->status != MODE_OK)
463 continue;
464
465 mode->status = drm_mode_validate_driver(dev, mode);
466 if (mode->status != MODE_OK)
467 continue;
468
469 mode->status = drm_mode_validate_size(mode, maxX, maxY);
470 if (mode->status != MODE_OK)
471 continue;
472
473 mode->status = drm_mode_validate_flag(mode, mode_flags);
474 if (mode->status != MODE_OK)
475 continue;
476
477 mode->status = drm_mode_validate_ycbcr420(mode, connector);
478 if (mode->status != MODE_OK)
479 continue;
480
481 ret = drm_mode_validate_pipeline(mode, connector, ctx,
482 &mode->status);
483 if (ret) {
484 drm_dbg_kms(dev,
485 "drm_mode_validate_pipeline failed: %d\n",
486 ret);
487
488 if (drm_WARN_ON_ONCE(dev, ret != -EDEADLK))
489 mode->status = MODE_ERROR;
490 else
491 return -EDEADLK;
492 }
493 }
494
495 return 0;
496}
497
498/**
499 * drm_helper_probe_single_connector_modes - get complete set of display modes
500 * @connector: connector to probe
501 * @maxX: max width for modes
502 * @maxY: max height for modes
503 *
504 * Based on the helper callbacks implemented by @connector in struct
505 * &drm_connector_helper_funcs try to detect all valid modes. Modes will first
506 * be added to the connector's probed_modes list, then culled (based on validity
507 * and the @maxX, @maxY parameters) and put into the normal modes list.
508 *
509 * Intended to be used as a generic implementation of the
510 * &drm_connector_funcs.fill_modes() vfunc for drivers that use the CRTC helpers
511 * for output mode filtering and detection.
512 *
513 * The basic procedure is as follows
514 *
515 * 1. All modes currently on the connector's modes list are marked as stale
516 *
517 * 2. New modes are added to the connector's probed_modes list with
518 * drm_mode_probed_add(). New modes start their life with status as OK.
519 * Modes are added from a single source using the following priority order.
520 *
521 * - &drm_connector_helper_funcs.get_modes vfunc
522 * - if the connector status is connector_status_connected, standard
523 * VESA DMT modes up to 1024x768 are automatically added
524 * (drm_add_modes_noedid())
525 *
526 * Finally modes specified via the kernel command line (video=...) are
527 * added in addition to what the earlier probes produced
528 * (drm_helper_probe_add_cmdline_mode()). These modes are generated
529 * using the VESA GTF/CVT formulas.
530 *
531 * 3. Modes are moved from the probed_modes list to the modes list. Potential
532 * duplicates are merged together (see drm_connector_list_update()).
533 * After this step the probed_modes list will be empty again.
534 *
535 * 4. Any non-stale mode on the modes list then undergoes validation
536 *
537 * - drm_mode_validate_basic() performs basic sanity checks
538 * - drm_mode_validate_size() filters out modes larger than @maxX and @maxY
539 * (if specified)
540 * - drm_mode_validate_flag() checks the modes against basic connector
541 * capabilities (interlace_allowed,doublescan_allowed,stereo_allowed)
542 * - the optional &drm_connector_helper_funcs.mode_valid or
543 * &drm_connector_helper_funcs.mode_valid_ctx helpers can perform driver
544 * and/or sink specific checks
545 * - the optional &drm_crtc_helper_funcs.mode_valid,
546 * &drm_bridge_funcs.mode_valid and &drm_encoder_helper_funcs.mode_valid
547 * helpers can perform driver and/or source specific checks which are also
548 * enforced by the modeset/atomic helpers
549 *
550 * 5. Any mode whose status is not OK is pruned from the connector's modes list,
551 * accompanied by a debug message indicating the reason for the mode's
552 * rejection (see drm_mode_prune_invalid()).
553 *
554 * Returns:
555 * The number of modes found on @connector.
556 */
557int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
558 uint32_t maxX, uint32_t maxY)
559{
560 struct drm_device *dev = connector->dev;
561 struct drm_display_mode *mode;
562 int count = 0, ret;
563 enum drm_connector_status old_status;
564 struct drm_modeset_acquire_ctx ctx;
565
566 WARN_ON(!mutex_is_locked(&dev->mode_config.mutex));
567
568 drm_modeset_acquire_init(&ctx, 0);
569
570 drm_dbg_kms(dev, "[CONNECTOR:%d:%s]\n", connector->base.id,
571 connector->name);
572
573retry:
574 ret = drm_modeset_lock(&dev->mode_config.connection_mutex, &ctx);
575 if (ret == -EDEADLK) {
576 drm_modeset_backoff(&ctx);
577 goto retry;
578 } else
579 WARN_ON(ret < 0);
580
581 /* set all old modes to the stale state */
582 list_for_each_entry(mode, &connector->modes, head)
583 mode->status = MODE_STALE;
584
585 old_status = connector->status;
586
587 if (connector->force) {
588 if (connector->force == DRM_FORCE_ON ||
589 connector->force == DRM_FORCE_ON_DIGITAL)
590 connector->status = connector_status_connected;
591 else
592 connector->status = connector_status_disconnected;
593 if (connector->funcs->force)
594 connector->funcs->force(connector);
595 } else {
596 ret = drm_helper_probe_detect(connector, &ctx, true);
597
598 if (ret == -EDEADLK) {
599 drm_modeset_backoff(&ctx);
600 goto retry;
601 } else if (WARN(ret < 0, "Invalid return value %i for connector detection\n", ret))
602 ret = connector_status_unknown;
603
604 connector->status = ret;
605 }
606
607 /*
608 * Normally either the driver's hpd code or the poll loop should
609 * pick up any changes and fire the hotplug event. But if
610 * userspace sneaks in a probe, we might miss a change. Hence
611 * check here, and if anything changed start the hotplug code.
612 */
613 if (old_status != connector->status) {
614 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
615 connector->base.id, connector->name,
616 drm_get_connector_status_name(old_status),
617 drm_get_connector_status_name(connector->status));
618
619 /*
620 * The hotplug event code might call into the fb
621 * helpers, and so expects that we do not hold any
622 * locks. Fire up the poll struct instead, it will
623 * disable itself again.
624 */
625 dev->mode_config.delayed_event = true;
626 if (dev->mode_config.poll_enabled)
627 mod_delayed_work(system_wq,
628 &dev->mode_config.output_poll_work,
629 0);
630 }
631
632 /*
633 * Re-enable polling in case the global poll config changed but polling
634 * is still initialized.
635 */
636 if (dev->mode_config.poll_enabled)
637 drm_kms_helper_poll_enable(dev);
638
639 if (connector->status == connector_status_disconnected) {
640 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] disconnected\n",
641 connector->base.id, connector->name);
642 drm_connector_update_edid_property(connector, NULL);
643 drm_mode_prune_invalid(dev, &connector->modes, false);
644 goto exit;
645 }
646
647 count = drm_helper_probe_get_modes(connector);
648
649 if (count == 0 && (connector->status == connector_status_connected ||
650 connector->status == connector_status_unknown)) {
651 count = drm_add_modes_noedid(connector, 1024, 768);
652
653 /*
654 * Section 4.2.2.6 (EDID Corruption Detection) of the DP 1.4a
655 * Link CTS specifies that 640x480 (the official "failsafe"
656 * mode) needs to be the default if there's no EDID.
657 */
658 if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort)
659 drm_set_preferred_mode(connector, 640, 480);
660 }
661 count += drm_helper_probe_add_cmdline_mode(connector);
662 if (count != 0) {
663 ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
664 if (ret == -EDEADLK) {
665 drm_modeset_backoff(&ctx);
666 goto retry;
667 }
668 }
669
670 drm_mode_prune_invalid(dev, &connector->modes, true);
671
672 /*
673 * Displayport spec section 5.2.1.2 ("Video Timing Format") says that
674 * all detachable sinks shall support 640x480 @60Hz as a fail safe
675 * mode. If all modes were pruned, perhaps because they need more
676 * lanes or a higher pixel clock than available, at least try to add
677 * in 640x480.
678 */
679 if (list_empty(&connector->modes) &&
680 connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
681 count = drm_add_modes_noedid(connector, 640, 480);
682 ret = __drm_helper_update_and_validate(connector, maxX, maxY, &ctx);
683 if (ret == -EDEADLK) {
684 drm_modeset_backoff(&ctx);
685 goto retry;
686 }
687 drm_mode_prune_invalid(dev, &connector->modes, true);
688 }
689
690exit:
691 drm_modeset_drop_locks(&ctx);
692 drm_modeset_acquire_fini(&ctx);
693
694 if (list_empty(&connector->modes))
695 return 0;
696
697 drm_mode_sort(&connector->modes);
698
699 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] probed modes:\n",
700 connector->base.id, connector->name);
701
702 list_for_each_entry(mode, &connector->modes, head) {
703 drm_mode_set_crtcinfo(mode, CRTC_INTERLACE_HALVE_V);
704 drm_dbg_kms(dev, "Probed mode: " DRM_MODE_FMT "\n",
705 DRM_MODE_ARG(mode));
706 }
707
708 return count;
709}
710EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
711
712/**
713 * drm_kms_helper_hotplug_event - fire off KMS hotplug events
714 * @dev: drm_device whose connector state changed
715 *
716 * This function fires off the uevent for userspace and also calls the
717 * client hotplug function, which is most commonly used to inform the fbdev
718 * emulation code and allow it to update the fbcon output configuration.
719 *
720 * Drivers should call this from their hotplug handling code when a change is
721 * detected. Note that this function does not do any output detection of its
722 * own, like drm_helper_hpd_irq_event() does - this is assumed to be done by the
723 * driver already.
724 *
725 * This function must be called from process context with no mode
726 * setting locks held.
727 *
728 * If only a single connector has changed, consider calling
729 * drm_kms_helper_connector_hotplug_event() instead.
730 */
731void drm_kms_helper_hotplug_event(struct drm_device *dev)
732{
733 drm_sysfs_hotplug_event(dev);
734 drm_client_dev_hotplug(dev);
735}
736EXPORT_SYMBOL(drm_kms_helper_hotplug_event);
737
738/**
739 * drm_kms_helper_connector_hotplug_event - fire off a KMS connector hotplug event
740 * @connector: drm_connector which has changed
741 *
742 * This is the same as drm_kms_helper_hotplug_event(), except it fires a more
743 * fine-grained uevent for a single connector.
744 */
745void drm_kms_helper_connector_hotplug_event(struct drm_connector *connector)
746{
747 struct drm_device *dev = connector->dev;
748
749 drm_sysfs_connector_hotplug_event(connector);
750 drm_client_dev_hotplug(dev);
751}
752EXPORT_SYMBOL(drm_kms_helper_connector_hotplug_event);
753
754static void output_poll_execute(struct work_struct *work)
755{
756 struct delayed_work *delayed_work = to_delayed_work(work);
757 struct drm_device *dev = container_of(delayed_work, struct drm_device, mode_config.output_poll_work);
758 struct drm_connector *connector;
759 struct drm_connector_list_iter conn_iter;
760 enum drm_connector_status old_status;
761 bool repoll = false, changed;
762 u64 old_epoch_counter;
763
764 if (!dev->mode_config.poll_enabled)
765 return;
766
767 /* Pick up any changes detected by the probe functions. */
768 changed = dev->mode_config.delayed_event;
769 dev->mode_config.delayed_event = false;
770
771 if (!drm_kms_helper_poll) {
772 if (dev->mode_config.poll_running) {
773 drm_kms_helper_disable_hpd(dev);
774 dev->mode_config.poll_running = false;
775 }
776 goto out;
777 }
778
779 if (!mutex_trylock(&dev->mode_config.mutex)) {
780 repoll = true;
781 goto out;
782 }
783
784 drm_connector_list_iter_begin(dev, &conn_iter);
785 drm_for_each_connector_iter(connector, &conn_iter) {
786 /* Ignore forced connectors. */
787 if (connector->force)
788 continue;
789
790 /* Ignore HPD capable connectors and connectors where we don't
791 * want any hotplug detection at all for polling. */
792 if (!connector->polled || connector->polled == DRM_CONNECTOR_POLL_HPD)
793 continue;
794
795 old_status = connector->status;
796 /* if we are connected and don't want to poll for disconnect
797 skip it */
798 if (old_status == connector_status_connected &&
799 !(connector->polled & DRM_CONNECTOR_POLL_DISCONNECT))
800 continue;
801
802 repoll = true;
803
804 old_epoch_counter = connector->epoch_counter;
805 connector->status = drm_helper_probe_detect(connector, NULL, false);
806 if (old_epoch_counter != connector->epoch_counter) {
807 const char *old, *new;
808
809 /*
810 * The poll work sets force=false when calling detect so
811 * that drivers can avoid to do disruptive tests (e.g.
812 * when load detect cycles could cause flickering on
813 * other, running displays). This bears the risk that we
814 * flip-flop between unknown here in the poll work and
815 * the real state when userspace forces a full detect
816 * call after receiving a hotplug event due to this
817 * change.
818 *
819 * Hence clamp an unknown detect status to the old
820 * value.
821 */
822 if (connector->status == connector_status_unknown) {
823 connector->status = old_status;
824 continue;
825 }
826
827 old = drm_get_connector_status_name(old_status);
828 new = drm_get_connector_status_name(connector->status);
829
830 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
831 connector->base.id, connector->name,
832 old, new);
833 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] epoch counter %llu -> %llu\n",
834 connector->base.id, connector->name,
835 old_epoch_counter, connector->epoch_counter);
836
837 changed = true;
838 }
839 }
840 drm_connector_list_iter_end(&conn_iter);
841
842 mutex_unlock(&dev->mode_config.mutex);
843
844out:
845 if (changed)
846 drm_kms_helper_hotplug_event(dev);
847
848 if (repoll)
849 schedule_delayed_work(delayed_work, DRM_OUTPUT_POLL_PERIOD);
850}
851
852/**
853 * drm_kms_helper_is_poll_worker - is %current task an output poll worker?
854 *
855 * Determine if %current task is an output poll worker. This can be used
856 * to select distinct code paths for output polling versus other contexts.
857 *
858 * One use case is to avoid a deadlock between the output poll worker and
859 * the autosuspend worker wherein the latter waits for polling to finish
860 * upon calling drm_kms_helper_poll_disable(), while the former waits for
861 * runtime suspend to finish upon calling pm_runtime_get_sync() in a
862 * connector ->detect hook.
863 */
864bool drm_kms_helper_is_poll_worker(void)
865{
866 struct work_struct *work = current_work();
867
868 return work && work->func == output_poll_execute;
869}
870EXPORT_SYMBOL(drm_kms_helper_is_poll_worker);
871
872/**
873 * drm_kms_helper_poll_disable - disable output polling
874 * @dev: drm_device
875 *
876 * This function disables the output polling work.
877 *
878 * Drivers can call this helper from their device suspend implementation. It is
879 * not an error to call this even when output polling isn't enabled or already
880 * disabled. Polling is re-enabled by calling drm_kms_helper_poll_enable().
881 *
882 * If however, the polling was never initialized, this call will trigger a
883 * warning and return.
884 *
885 * Note that calls to enable and disable polling must be strictly ordered, which
886 * is automatically the case when they're only call from suspend/resume
887 * callbacks.
888 */
889void drm_kms_helper_poll_disable(struct drm_device *dev)
890{
891 if (drm_WARN_ON(dev, !dev->mode_config.poll_enabled))
892 return;
893
894 if (dev->mode_config.poll_running)
895 drm_kms_helper_disable_hpd(dev);
896
897 cancel_delayed_work_sync(&dev->mode_config.output_poll_work);
898
899 dev->mode_config.poll_running = false;
900}
901EXPORT_SYMBOL(drm_kms_helper_poll_disable);
902
903/**
904 * drm_kms_helper_poll_init - initialize and enable output polling
905 * @dev: drm_device
906 *
907 * This function initializes and then also enables output polling support for
908 * @dev. Drivers which do not have reliable hotplug support in hardware can use
909 * this helper infrastructure to regularly poll such connectors for changes in
910 * their connection state.
911 *
912 * Drivers can control which connectors are polled by setting the
913 * DRM_CONNECTOR_POLL_CONNECT and DRM_CONNECTOR_POLL_DISCONNECT flags. On
914 * connectors where probing live outputs can result in visual distortion drivers
915 * should not set the DRM_CONNECTOR_POLL_DISCONNECT flag to avoid this.
916 * Connectors which have no flag or only DRM_CONNECTOR_POLL_HPD set are
917 * completely ignored by the polling logic.
918 *
919 * Note that a connector can be both polled and probed from the hotplug handler,
920 * in case the hotplug interrupt is known to be unreliable.
921 */
922void drm_kms_helper_poll_init(struct drm_device *dev)
923{
924 INIT_DELAYED_WORK(&dev->mode_config.output_poll_work, output_poll_execute);
925 dev->mode_config.poll_enabled = true;
926
927 drm_kms_helper_poll_enable(dev);
928}
929EXPORT_SYMBOL(drm_kms_helper_poll_init);
930
931/**
932 * drm_kms_helper_poll_fini - disable output polling and clean it up
933 * @dev: drm_device
934 */
935void drm_kms_helper_poll_fini(struct drm_device *dev)
936{
937 if (!dev->mode_config.poll_enabled)
938 return;
939
940 drm_kms_helper_poll_disable(dev);
941
942 dev->mode_config.poll_enabled = false;
943}
944EXPORT_SYMBOL(drm_kms_helper_poll_fini);
945
946static void drm_kms_helper_poll_init_release(struct drm_device *dev, void *res)
947{
948 drm_kms_helper_poll_fini(dev);
949}
950
951/**
952 * drmm_kms_helper_poll_init - initialize and enable output polling
953 * @dev: drm_device
954 *
955 * This function initializes and then also enables output polling support for
956 * @dev similar to drm_kms_helper_poll_init(). Polling will automatically be
957 * cleaned up when the DRM device goes away.
958 *
959 * See drm_kms_helper_poll_init() for more information.
960 *
961 * Returns:
962 * 0 on success, or a negative errno code otherwise.
963 */
964int drmm_kms_helper_poll_init(struct drm_device *dev)
965{
966 drm_kms_helper_poll_init(dev);
967
968 return drmm_add_action_or_reset(dev, drm_kms_helper_poll_init_release, dev);
969}
970EXPORT_SYMBOL(drmm_kms_helper_poll_init);
971
972static bool check_connector_changed(struct drm_connector *connector)
973{
974 struct drm_device *dev = connector->dev;
975 enum drm_connector_status old_status;
976 u64 old_epoch_counter;
977
978 /* Only handle HPD capable connectors. */
979 drm_WARN_ON(dev, !(connector->polled & DRM_CONNECTOR_POLL_HPD));
980
981 drm_WARN_ON(dev, !mutex_is_locked(&dev->mode_config.mutex));
982
983 old_status = connector->status;
984 old_epoch_counter = connector->epoch_counter;
985 connector->status = drm_helper_probe_detect(connector, NULL, false);
986
987 if (old_epoch_counter == connector->epoch_counter) {
988 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Same epoch counter %llu\n",
989 connector->base.id,
990 connector->name,
991 connector->epoch_counter);
992
993 return false;
994 }
995
996 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] status updated from %s to %s\n",
997 connector->base.id,
998 connector->name,
999 drm_get_connector_status_name(old_status),
1000 drm_get_connector_status_name(connector->status));
1001
1002 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Changed epoch counter %llu => %llu\n",
1003 connector->base.id,
1004 connector->name,
1005 old_epoch_counter,
1006 connector->epoch_counter);
1007
1008 return true;
1009}
1010
1011/**
1012 * drm_connector_helper_hpd_irq_event - hotplug processing
1013 * @connector: drm_connector
1014 *
1015 * Drivers can use this helper function to run a detect cycle on a connector
1016 * which has the DRM_CONNECTOR_POLL_HPD flag set in its &polled member.
1017 *
1018 * This helper function is useful for drivers which can track hotplug
1019 * interrupts for a single connector. Drivers that want to send a
1020 * hotplug event for all connectors or can't track hotplug interrupts
1021 * per connector need to use drm_helper_hpd_irq_event().
1022 *
1023 * This function must be called from process context with no mode
1024 * setting locks held.
1025 *
1026 * Note that a connector can be both polled and probed from the hotplug
1027 * handler, in case the hotplug interrupt is known to be unreliable.
1028 *
1029 * Returns:
1030 * A boolean indicating whether the connector status changed or not
1031 */
1032bool drm_connector_helper_hpd_irq_event(struct drm_connector *connector)
1033{
1034 struct drm_device *dev = connector->dev;
1035 bool changed;
1036
1037 mutex_lock(&dev->mode_config.mutex);
1038 changed = check_connector_changed(connector);
1039 mutex_unlock(&dev->mode_config.mutex);
1040
1041 if (changed) {
1042 drm_kms_helper_connector_hotplug_event(connector);
1043 drm_dbg_kms(dev, "[CONNECTOR:%d:%s] Sent hotplug event\n",
1044 connector->base.id,
1045 connector->name);
1046 }
1047
1048 return changed;
1049}
1050EXPORT_SYMBOL(drm_connector_helper_hpd_irq_event);
1051
1052/**
1053 * drm_helper_hpd_irq_event - hotplug processing
1054 * @dev: drm_device
1055 *
1056 * Drivers can use this helper function to run a detect cycle on all connectors
1057 * which have the DRM_CONNECTOR_POLL_HPD flag set in their &polled member. All
1058 * other connectors are ignored, which is useful to avoid reprobing fixed
1059 * panels.
1060 *
1061 * This helper function is useful for drivers which can't or don't track hotplug
1062 * interrupts for each connector.
1063 *
1064 * Drivers which support hotplug interrupts for each connector individually and
1065 * which have a more fine-grained detect logic can use
1066 * drm_connector_helper_hpd_irq_event(). Alternatively, they should bypass this
1067 * code and directly call drm_kms_helper_hotplug_event() in case the connector
1068 * state changed.
1069 *
1070 * This function must be called from process context with no mode
1071 * setting locks held.
1072 *
1073 * Note that a connector can be both polled and probed from the hotplug handler,
1074 * in case the hotplug interrupt is known to be unreliable.
1075 *
1076 * Returns:
1077 * A boolean indicating whether the connector status changed or not
1078 */
1079bool drm_helper_hpd_irq_event(struct drm_device *dev)
1080{
1081 struct drm_connector *connector, *first_changed_connector = NULL;
1082 struct drm_connector_list_iter conn_iter;
1083 int changed = 0;
1084
1085 if (!dev->mode_config.poll_enabled)
1086 return false;
1087
1088 mutex_lock(&dev->mode_config.mutex);
1089 drm_connector_list_iter_begin(dev, &conn_iter);
1090 drm_for_each_connector_iter(connector, &conn_iter) {
1091 /* Only handle HPD capable connectors. */
1092 if (!(connector->polled & DRM_CONNECTOR_POLL_HPD))
1093 continue;
1094
1095 if (check_connector_changed(connector)) {
1096 if (!first_changed_connector) {
1097 drm_connector_get(connector);
1098 first_changed_connector = connector;
1099 }
1100
1101 changed++;
1102 }
1103 }
1104 drm_connector_list_iter_end(&conn_iter);
1105 mutex_unlock(&dev->mode_config.mutex);
1106
1107 if (changed == 1)
1108 drm_kms_helper_connector_hotplug_event(first_changed_connector);
1109 else if (changed > 0)
1110 drm_kms_helper_hotplug_event(dev);
1111
1112 if (first_changed_connector)
1113 drm_connector_put(first_changed_connector);
1114
1115 return changed;
1116}
1117EXPORT_SYMBOL(drm_helper_hpd_irq_event);
1118
1119/**
1120 * drm_crtc_helper_mode_valid_fixed - Validates a display mode
1121 * @crtc: the crtc
1122 * @mode: the mode to validate
1123 * @fixed_mode: the display hardware's mode
1124 *
1125 * Returns:
1126 * MODE_OK on success, or another mode-status code otherwise.
1127 */
1128enum drm_mode_status drm_crtc_helper_mode_valid_fixed(struct drm_crtc *crtc,
1129 const struct drm_display_mode *mode,
1130 const struct drm_display_mode *fixed_mode)
1131{
1132 if (mode->hdisplay != fixed_mode->hdisplay && mode->vdisplay != fixed_mode->vdisplay)
1133 return MODE_ONE_SIZE;
1134 else if (mode->hdisplay != fixed_mode->hdisplay)
1135 return MODE_ONE_WIDTH;
1136 else if (mode->vdisplay != fixed_mode->vdisplay)
1137 return MODE_ONE_HEIGHT;
1138
1139 return MODE_OK;
1140}
1141EXPORT_SYMBOL(drm_crtc_helper_mode_valid_fixed);
1142
1143/**
1144 * drm_connector_helper_get_modes_fixed - Duplicates a display mode for a connector
1145 * @connector: the connector
1146 * @fixed_mode: the display hardware's mode
1147 *
1148 * This function duplicates a display modes for a connector. Drivers for hardware
1149 * that only supports a single fixed mode can use this function in their connector's
1150 * get_modes helper.
1151 *
1152 * Returns:
1153 * The number of created modes.
1154 */
1155int drm_connector_helper_get_modes_fixed(struct drm_connector *connector,
1156 const struct drm_display_mode *fixed_mode)
1157{
1158 struct drm_device *dev = connector->dev;
1159 struct drm_display_mode *mode;
1160
1161 mode = drm_mode_duplicate(dev, fixed_mode);
1162 if (!mode) {
1163 drm_err(dev, "Failed to duplicate mode " DRM_MODE_FMT "\n",
1164 DRM_MODE_ARG(fixed_mode));
1165 return 0;
1166 }
1167
1168 if (mode->name[0] == '\0')
1169 drm_mode_set_name(mode);
1170
1171 mode->type |= DRM_MODE_TYPE_PREFERRED;
1172 drm_mode_probed_add(connector, mode);
1173
1174 if (mode->width_mm)
1175 connector->display_info.width_mm = mode->width_mm;
1176 if (mode->height_mm)
1177 connector->display_info.height_mm = mode->height_mm;
1178
1179 return 1;
1180}
1181EXPORT_SYMBOL(drm_connector_helper_get_modes_fixed);
1182
1183/**
1184 * drm_connector_helper_get_modes - Read EDID and update connector.
1185 * @connector: The connector
1186 *
1187 * Read the EDID using drm_edid_read() (which requires that connector->ddc is
1188 * set), and update the connector using the EDID.
1189 *
1190 * This can be used as the "default" connector helper .get_modes() hook if the
1191 * driver does not need any special processing. This is sets the example what
1192 * custom .get_modes() hooks should do regarding EDID read and connector update.
1193 *
1194 * Returns: Number of modes.
1195 */
1196int drm_connector_helper_get_modes(struct drm_connector *connector)
1197{
1198 const struct drm_edid *drm_edid;
1199 int count;
1200
1201 drm_edid = drm_edid_read(connector);
1202
1203 /*
1204 * Unconditionally update the connector. If the EDID was read
1205 * successfully, fill in the connector information derived from the
1206 * EDID. Otherwise, if the EDID is NULL, clear the connector
1207 * information.
1208 */
1209 drm_edid_connector_update(connector, drm_edid);
1210
1211 count = drm_edid_connector_add_modes(connector);
1212
1213 drm_edid_free(drm_edid);
1214
1215 return count;
1216}
1217EXPORT_SYMBOL(drm_connector_helper_get_modes);
1218
1219/**
1220 * drm_connector_helper_tv_get_modes - Fills the modes availables to a TV connector
1221 * @connector: The connector
1222 *
1223 * Fills the available modes for a TV connector based on the supported
1224 * TV modes, and the default mode expressed by the kernel command line.
1225 *
1226 * This can be used as the default TV connector helper .get_modes() hook
1227 * if the driver does not need any special processing.
1228 *
1229 * Returns:
1230 * The number of modes added to the connector.
1231 */
1232int drm_connector_helper_tv_get_modes(struct drm_connector *connector)
1233{
1234 struct drm_device *dev = connector->dev;
1235 struct drm_property *tv_mode_property =
1236 dev->mode_config.tv_mode_property;
1237 struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
1238 unsigned int ntsc_modes = BIT(DRM_MODE_TV_MODE_NTSC) |
1239 BIT(DRM_MODE_TV_MODE_NTSC_443) |
1240 BIT(DRM_MODE_TV_MODE_NTSC_J) |
1241 BIT(DRM_MODE_TV_MODE_PAL_M);
1242 unsigned int pal_modes = BIT(DRM_MODE_TV_MODE_PAL) |
1243 BIT(DRM_MODE_TV_MODE_PAL_N) |
1244 BIT(DRM_MODE_TV_MODE_SECAM);
1245 unsigned int tv_modes[2] = { UINT_MAX, UINT_MAX };
1246 unsigned int i, supported_tv_modes = 0;
1247
1248 if (!tv_mode_property)
1249 return 0;
1250
1251 for (i = 0; i < tv_mode_property->num_values; i++)
1252 supported_tv_modes |= BIT(tv_mode_property->values[i]);
1253
1254 if (((supported_tv_modes & ntsc_modes) &&
1255 (supported_tv_modes & pal_modes)) ||
1256 (supported_tv_modes & BIT(DRM_MODE_TV_MODE_MONOCHROME))) {
1257 uint64_t default_mode;
1258
1259 if (drm_object_property_get_default_value(&connector->base,
1260 tv_mode_property,
1261 &default_mode))
1262 return 0;
1263
1264 if (cmdline->tv_mode_specified)
1265 default_mode = cmdline->tv_mode;
1266
1267 if (BIT(default_mode) & ntsc_modes) {
1268 tv_modes[0] = DRM_MODE_TV_MODE_NTSC;
1269 tv_modes[1] = DRM_MODE_TV_MODE_PAL;
1270 } else {
1271 tv_modes[0] = DRM_MODE_TV_MODE_PAL;
1272 tv_modes[1] = DRM_MODE_TV_MODE_NTSC;
1273 }
1274 } else if (supported_tv_modes & ntsc_modes) {
1275 tv_modes[0] = DRM_MODE_TV_MODE_NTSC;
1276 } else if (supported_tv_modes & pal_modes) {
1277 tv_modes[0] = DRM_MODE_TV_MODE_PAL;
1278 } else {
1279 return 0;
1280 }
1281
1282 for (i = 0; i < ARRAY_SIZE(tv_modes); i++) {
1283 struct drm_display_mode *mode;
1284
1285 if (tv_modes[i] == DRM_MODE_TV_MODE_NTSC)
1286 mode = drm_mode_analog_ntsc_480i(dev);
1287 else if (tv_modes[i] == DRM_MODE_TV_MODE_PAL)
1288 mode = drm_mode_analog_pal_576i(dev);
1289 else
1290 break;
1291 if (!mode)
1292 return i;
1293 if (!i)
1294 mode->type |= DRM_MODE_TYPE_PREFERRED;
1295 drm_mode_probed_add(connector, mode);
1296 }
1297
1298 return i;
1299}
1300EXPORT_SYMBOL(drm_connector_helper_tv_get_modes);
1301
1302/**
1303 * drm_connector_helper_detect_from_ddc - Read EDID and detect connector status.
1304 * @connector: The connector
1305 * @ctx: Acquire context
1306 * @force: Perform screen-destructive operations, if necessary
1307 *
1308 * Detects the connector status by reading the EDID using drm_probe_ddc(),
1309 * which requires connector->ddc to be set. Returns connector_status_connected
1310 * on success or connector_status_disconnected on failure.
1311 *
1312 * Returns:
1313 * The connector status as defined by enum drm_connector_status.
1314 */
1315int drm_connector_helper_detect_from_ddc(struct drm_connector *connector,
1316 struct drm_modeset_acquire_ctx *ctx,
1317 bool force)
1318{
1319 struct i2c_adapter *ddc = connector->ddc;
1320
1321 if (!ddc)
1322 return connector_status_unknown;
1323
1324 if (drm_probe_ddc(ddc))
1325 return connector_status_connected;
1326
1327 return connector_status_disconnected;
1328}
1329EXPORT_SYMBOL(drm_connector_helper_detect_from_ddc);