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