1 /*
2  * Copyright 2022 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: AMD
23  *
24  */
25 
26 /* FILE POLICY AND INTENDED USAGE:
27  * This file manages link detection states and receiver states by using various
28  * link protocols. It also provides helper functions to interpret certain
29  * capabilities or status based on the states it manages or retrieve them
30  * directly from connected receivers.
31  */
32 
33 #include "link_dpms.h"
34 #include "link_detection.h"
35 #include "link_hwss.h"
36 #include "protocols/link_edp_panel_control.h"
37 #include "protocols/link_ddc.h"
38 #include "protocols/link_hpd.h"
39 #include "protocols/link_dpcd.h"
40 #include "protocols/link_dp_capability.h"
41 #include "protocols/link_dp_dpia.h"
42 #include "protocols/link_dp_phy.h"
43 #include "protocols/link_dp_training.h"
44 #include "accessories/link_dp_trace.h"
45 
46 #include "link_enc_cfg.h"
47 #include "dm_helpers.h"
48 #include "clk_mgr.h"
49 
50 #define DC_LOGGER_INIT(logger)
51 
52 #define LINK_INFO(...) \
53 	DC_LOG_HW_HOTPLUG(  \
54 		__VA_ARGS__)
55 /*
56  * Some receivers fail to train on first try and are good
57  * on subsequent tries. 2 retries should be plenty. If we
58  * don't have a successful training then we don't expect to
59  * ever get one.
60  */
61 #define LINK_TRAINING_MAX_VERIFY_RETRY 2
62 
63 static enum ddc_transaction_type get_ddc_transaction_type(enum signal_type sink_signal)
64 {
65 	enum ddc_transaction_type transaction_type = DDC_TRANSACTION_TYPE_NONE;
66 
67 	switch (sink_signal) {
68 	case SIGNAL_TYPE_DVI_SINGLE_LINK:
69 	case SIGNAL_TYPE_DVI_DUAL_LINK:
70 	case SIGNAL_TYPE_HDMI_TYPE_A:
71 	case SIGNAL_TYPE_LVDS:
72 	case SIGNAL_TYPE_RGB:
73 		transaction_type = DDC_TRANSACTION_TYPE_I2C;
74 		break;
75 
76 	case SIGNAL_TYPE_DISPLAY_PORT:
77 	case SIGNAL_TYPE_EDP:
78 		transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
79 		break;
80 
81 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
82 		/* MST does not use I2COverAux, but there is the
83 		 * SPECIAL use case for "immediate dwnstrm device
84 		 * access" (EPR#370830).
85 		 */
86 		transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
87 		break;
88 
89 	default:
90 		break;
91 	}
92 
93 	return transaction_type;
94 }
95 
96 static enum signal_type get_basic_signal_type(struct graphics_object_id encoder,
97 					      struct graphics_object_id downstream)
98 {
99 	if (downstream.type == OBJECT_TYPE_CONNECTOR) {
100 		switch (downstream.id) {
101 		case CONNECTOR_ID_SINGLE_LINK_DVII:
102 			switch (encoder.id) {
103 			case ENCODER_ID_INTERNAL_DAC1:
104 			case ENCODER_ID_INTERNAL_KLDSCP_DAC1:
105 			case ENCODER_ID_INTERNAL_DAC2:
106 			case ENCODER_ID_INTERNAL_KLDSCP_DAC2:
107 				return SIGNAL_TYPE_RGB;
108 			default:
109 				return SIGNAL_TYPE_DVI_SINGLE_LINK;
110 			}
111 		break;
112 		case CONNECTOR_ID_DUAL_LINK_DVII:
113 		{
114 			switch (encoder.id) {
115 			case ENCODER_ID_INTERNAL_DAC1:
116 			case ENCODER_ID_INTERNAL_KLDSCP_DAC1:
117 			case ENCODER_ID_INTERNAL_DAC2:
118 			case ENCODER_ID_INTERNAL_KLDSCP_DAC2:
119 				return SIGNAL_TYPE_RGB;
120 			default:
121 				return SIGNAL_TYPE_DVI_DUAL_LINK;
122 			}
123 		}
124 		break;
125 		case CONNECTOR_ID_SINGLE_LINK_DVID:
126 			return SIGNAL_TYPE_DVI_SINGLE_LINK;
127 		case CONNECTOR_ID_DUAL_LINK_DVID:
128 			return SIGNAL_TYPE_DVI_DUAL_LINK;
129 		case CONNECTOR_ID_VGA:
130 			return SIGNAL_TYPE_RGB;
131 		case CONNECTOR_ID_HDMI_TYPE_A:
132 			return SIGNAL_TYPE_HDMI_TYPE_A;
133 		case CONNECTOR_ID_LVDS:
134 			return SIGNAL_TYPE_LVDS;
135 		case CONNECTOR_ID_DISPLAY_PORT:
136 		case CONNECTOR_ID_USBC:
137 			return SIGNAL_TYPE_DISPLAY_PORT;
138 		case CONNECTOR_ID_EDP:
139 			return SIGNAL_TYPE_EDP;
140 		default:
141 			return SIGNAL_TYPE_NONE;
142 		}
143 	} else if (downstream.type == OBJECT_TYPE_ENCODER) {
144 		switch (downstream.id) {
145 		case ENCODER_ID_EXTERNAL_NUTMEG:
146 		case ENCODER_ID_EXTERNAL_TRAVIS:
147 			return SIGNAL_TYPE_DISPLAY_PORT;
148 		default:
149 			return SIGNAL_TYPE_NONE;
150 		}
151 	}
152 
153 	return SIGNAL_TYPE_NONE;
154 }
155 
156 /*
157  * @brief
158  * Detect output sink type
159  */
160 static enum signal_type link_detect_sink_signal_type(struct dc_link *link,
161 					 enum dc_detect_reason reason)
162 {
163 	enum signal_type result;
164 	struct graphics_object_id enc_id;
165 
166 	if (link->is_dig_mapping_flexible)
167 		enc_id = (struct graphics_object_id){.id = ENCODER_ID_UNKNOWN};
168 	else
169 		enc_id = link->link_enc->id;
170 	result = get_basic_signal_type(enc_id, link->link_id);
171 
172 	/* Use basic signal type for link without physical connector. */
173 	if (link->ep_type != DISPLAY_ENDPOINT_PHY)
174 		return result;
175 
176 	/* Internal digital encoder will detect only dongles
177 	 * that require digital signal
178 	 */
179 
180 	/* Detection mechanism is different
181 	 * for different native connectors.
182 	 * LVDS connector supports only LVDS signal;
183 	 * PCIE is a bus slot, the actual connector needs to be detected first;
184 	 * eDP connector supports only eDP signal;
185 	 * HDMI should check straps for audio
186 	 */
187 
188 	/* PCIE detects the actual connector on add-on board */
189 	if (link->link_id.id == CONNECTOR_ID_PCIE) {
190 		/* ZAZTODO implement PCIE add-on card detection */
191 	}
192 
193 	switch (link->link_id.id) {
194 	case CONNECTOR_ID_HDMI_TYPE_A: {
195 		/* check audio support:
196 		 * if native HDMI is not supported, switch to DVI
197 		 */
198 		struct audio_support *aud_support =
199 					&link->dc->res_pool->audio_support;
200 
201 		if (!aud_support->hdmi_audio_native)
202 			if (link->link_id.id == CONNECTOR_ID_HDMI_TYPE_A)
203 				result = SIGNAL_TYPE_DVI_SINGLE_LINK;
204 	}
205 	break;
206 	case CONNECTOR_ID_DISPLAY_PORT:
207 	case CONNECTOR_ID_USBC: {
208 		/* DP HPD short pulse. Passive DP dongle will not
209 		 * have short pulse
210 		 */
211 		if (reason != DETECT_REASON_HPDRX) {
212 			/* Check whether DP signal detected: if not -
213 			 * we assume signal is DVI; it could be corrected
214 			 * to HDMI after dongle detection
215 			 */
216 			if (!dm_helpers_is_dp_sink_present(link))
217 				result = SIGNAL_TYPE_DVI_SINGLE_LINK;
218 		}
219 	}
220 	break;
221 	default:
222 	break;
223 	}
224 
225 	return result;
226 }
227 
228 static enum signal_type decide_signal_from_strap_and_dongle_type(enum display_dongle_type dongle_type,
229 								 struct audio_support *audio_support)
230 {
231 	enum signal_type signal = SIGNAL_TYPE_NONE;
232 
233 	switch (dongle_type) {
234 	case DISPLAY_DONGLE_DP_HDMI_DONGLE:
235 		if (audio_support->hdmi_audio_on_dongle)
236 			signal = SIGNAL_TYPE_HDMI_TYPE_A;
237 		else
238 			signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
239 		break;
240 	case DISPLAY_DONGLE_DP_DVI_DONGLE:
241 		signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
242 		break;
243 	case DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE:
244 		if (audio_support->hdmi_audio_native)
245 			signal =  SIGNAL_TYPE_HDMI_TYPE_A;
246 		else
247 			signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
248 		break;
249 	default:
250 		signal = SIGNAL_TYPE_NONE;
251 		break;
252 	}
253 
254 	return signal;
255 }
256 
257 static void read_scdc_caps(struct ddc_service *ddc_service,
258 		struct dc_sink *sink)
259 {
260 	uint8_t slave_address = HDMI_SCDC_ADDRESS;
261 	uint8_t offset = HDMI_SCDC_MANUFACTURER_OUI;
262 
263 	link_query_ddc_data(ddc_service, slave_address, &offset,
264 			sizeof(offset), sink->scdc_caps.manufacturer_OUI.byte,
265 			sizeof(sink->scdc_caps.manufacturer_OUI.byte));
266 
267 	offset = HDMI_SCDC_DEVICE_ID;
268 
269 	link_query_ddc_data(ddc_service, slave_address, &offset,
270 			sizeof(offset), &(sink->scdc_caps.device_id.byte),
271 			sizeof(sink->scdc_caps.device_id.byte));
272 }
273 
274 static bool i2c_read(
275 	struct ddc_service *ddc,
276 	uint32_t address,
277 	uint8_t *buffer,
278 	uint32_t len)
279 {
280 	uint8_t offs_data = 0;
281 	struct i2c_payload payloads[2] = {
282 		{
283 		.write = true,
284 		.address = address,
285 		.length = 1,
286 		.data = &offs_data },
287 		{
288 		.write = false,
289 		.address = address,
290 		.length = len,
291 		.data = buffer } };
292 
293 	struct i2c_command command = {
294 		.payloads = payloads,
295 		.number_of_payloads = 2,
296 		.engine = DDC_I2C_COMMAND_ENGINE,
297 		.speed = ddc->ctx->dc->caps.i2c_speed_in_khz };
298 
299 	return dm_helpers_submit_i2c(
300 			ddc->ctx,
301 			ddc->link,
302 			&command);
303 }
304 
305 enum {
306 	DP_SINK_CAP_SIZE =
307 		DP_EDP_CONFIGURATION_CAP - DP_DPCD_REV + 1
308 };
309 
310 static void query_dp_dual_mode_adaptor(
311 	struct ddc_service *ddc,
312 	struct display_sink_capability *sink_cap)
313 {
314 	uint8_t i;
315 	bool is_valid_hdmi_signature;
316 	enum display_dongle_type *dongle = &sink_cap->dongle_type;
317 	uint8_t type2_dongle_buf[DP_ADAPTOR_TYPE2_SIZE];
318 	bool is_type2_dongle = false;
319 	int retry_count = 2;
320 	struct dp_hdmi_dongle_signature_data *dongle_signature;
321 
322 	/* Assume we have no valid DP passive dongle connected */
323 	*dongle = DISPLAY_DONGLE_NONE;
324 	sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_HDMI_SAFE_MAX_TMDS_CLK;
325 
326 	/* Read DP-HDMI dongle I2c (no response interpreted as DP-DVI dongle)*/
327 	if (!i2c_read(
328 		ddc,
329 		DP_HDMI_DONGLE_ADDRESS,
330 		type2_dongle_buf,
331 		sizeof(type2_dongle_buf))) {
332 		/* Passive HDMI dongles can sometimes fail here without retrying*/
333 		while (retry_count > 0) {
334 			if (i2c_read(ddc,
335 				DP_HDMI_DONGLE_ADDRESS,
336 				type2_dongle_buf,
337 				sizeof(type2_dongle_buf)))
338 				break;
339 			retry_count--;
340 		}
341 		if (retry_count == 0) {
342 			*dongle = DISPLAY_DONGLE_DP_DVI_DONGLE;
343 			sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_DVI_MAX_TMDS_CLK;
344 
345 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf, sizeof(type2_dongle_buf),
346 					"DP-DVI passive dongle %dMhz: ",
347 					DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000);
348 			return;
349 		}
350 	}
351 
352 	/* Check if Type 2 dongle.*/
353 	if (type2_dongle_buf[DP_ADAPTOR_TYPE2_REG_ID] == DP_ADAPTOR_TYPE2_ID)
354 		is_type2_dongle = true;
355 
356 	dongle_signature =
357 		(struct dp_hdmi_dongle_signature_data *)type2_dongle_buf;
358 
359 	is_valid_hdmi_signature = true;
360 
361 	/* Check EOT */
362 	if (dongle_signature->eot != DP_HDMI_DONGLE_SIGNATURE_EOT) {
363 		is_valid_hdmi_signature = false;
364 	}
365 
366 	/* Check signature */
367 	for (i = 0; i < sizeof(dongle_signature->id); ++i) {
368 		/* If its not the right signature,
369 		 * skip mismatch in subversion byte.*/
370 		if (dongle_signature->id[i] !=
371 			dp_hdmi_dongle_signature_str[i] && i != 3) {
372 
373 			if (is_type2_dongle) {
374 				is_valid_hdmi_signature = false;
375 				break;
376 			}
377 
378 		}
379 	}
380 
381 	if (is_type2_dongle) {
382 		uint32_t max_tmds_clk =
383 			type2_dongle_buf[DP_ADAPTOR_TYPE2_REG_MAX_TMDS_CLK];
384 
385 		max_tmds_clk = max_tmds_clk * 2 + max_tmds_clk / 2;
386 
387 		if (0 == max_tmds_clk ||
388 				max_tmds_clk < DP_ADAPTOR_TYPE2_MIN_TMDS_CLK ||
389 				max_tmds_clk > DP_ADAPTOR_TYPE2_MAX_TMDS_CLK) {
390 			*dongle = DISPLAY_DONGLE_DP_DVI_DONGLE;
391 
392 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
393 					sizeof(type2_dongle_buf),
394 					"DP-DVI passive dongle %dMhz: ",
395 					DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000);
396 		} else {
397 			if (is_valid_hdmi_signature == true) {
398 				*dongle = DISPLAY_DONGLE_DP_HDMI_DONGLE;
399 
400 				CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
401 						sizeof(type2_dongle_buf),
402 						"Type 2 DP-HDMI passive dongle %dMhz: ",
403 						max_tmds_clk);
404 			} else {
405 				*dongle = DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE;
406 
407 				CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
408 						sizeof(type2_dongle_buf),
409 						"Type 2 DP-HDMI passive dongle (no signature) %dMhz: ",
410 						max_tmds_clk);
411 
412 			}
413 
414 			/* Multiply by 1000 to convert to kHz. */
415 			sink_cap->max_hdmi_pixel_clock =
416 				max_tmds_clk * 1000;
417 		}
418 		sink_cap->is_dongle_type_one = false;
419 
420 	} else {
421 		if (is_valid_hdmi_signature == true) {
422 			*dongle = DISPLAY_DONGLE_DP_HDMI_DONGLE;
423 
424 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
425 					sizeof(type2_dongle_buf),
426 					"Type 1 DP-HDMI passive dongle %dMhz: ",
427 					sink_cap->max_hdmi_pixel_clock / 1000);
428 		} else {
429 			*dongle = DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE;
430 
431 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
432 					sizeof(type2_dongle_buf),
433 					"Type 1 DP-HDMI passive dongle (no signature) %dMhz: ",
434 					sink_cap->max_hdmi_pixel_clock / 1000);
435 		}
436 		sink_cap->is_dongle_type_one = true;
437 	}
438 
439 	return;
440 }
441 
442 static enum signal_type dp_passive_dongle_detection(struct ddc_service *ddc,
443 						    struct display_sink_capability *sink_cap,
444 						    struct audio_support *audio_support)
445 {
446 	query_dp_dual_mode_adaptor(ddc, sink_cap);
447 
448 	return decide_signal_from_strap_and_dongle_type(sink_cap->dongle_type,
449 							audio_support);
450 }
451 
452 static void link_disconnect_sink(struct dc_link *link)
453 {
454 	if (link->local_sink) {
455 		dc_sink_release(link->local_sink);
456 		link->local_sink = NULL;
457 	}
458 
459 	link->dpcd_sink_count = 0;
460 	//link->dpcd_caps.dpcd_rev.raw = 0;
461 }
462 
463 static void link_disconnect_remap(struct dc_sink *prev_sink, struct dc_link *link)
464 {
465 	dc_sink_release(link->local_sink);
466 	link->local_sink = prev_sink;
467 }
468 
469 #if defined(CONFIG_DRM_AMD_DC_HDCP)
470 static void query_hdcp_capability(enum signal_type signal, struct dc_link *link)
471 {
472 	struct hdcp_protection_message msg22;
473 	struct hdcp_protection_message msg14;
474 
475 	memset(&msg22, 0, sizeof(struct hdcp_protection_message));
476 	memset(&msg14, 0, sizeof(struct hdcp_protection_message));
477 	memset(link->hdcp_caps.rx_caps.raw, 0,
478 		sizeof(link->hdcp_caps.rx_caps.raw));
479 
480 	if ((link->connector_signal == SIGNAL_TYPE_DISPLAY_PORT &&
481 			link->ddc->transaction_type ==
482 			DDC_TRANSACTION_TYPE_I2C_OVER_AUX) ||
483 			link->connector_signal == SIGNAL_TYPE_EDP) {
484 		msg22.data = link->hdcp_caps.rx_caps.raw;
485 		msg22.length = sizeof(link->hdcp_caps.rx_caps.raw);
486 		msg22.msg_id = HDCP_MESSAGE_ID_RX_CAPS;
487 	} else {
488 		msg22.data = &link->hdcp_caps.rx_caps.fields.version;
489 		msg22.length = sizeof(link->hdcp_caps.rx_caps.fields.version);
490 		msg22.msg_id = HDCP_MESSAGE_ID_HDCP2VERSION;
491 	}
492 	msg22.version = HDCP_VERSION_22;
493 	msg22.link = HDCP_LINK_PRIMARY;
494 	msg22.max_retries = 5;
495 	dc_process_hdcp_msg(signal, link, &msg22);
496 
497 	if (signal == SIGNAL_TYPE_DISPLAY_PORT || signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
498 		enum hdcp_message_status status = HDCP_MESSAGE_UNSUPPORTED;
499 
500 		msg14.data = &link->hdcp_caps.bcaps.raw;
501 		msg14.length = sizeof(link->hdcp_caps.bcaps.raw);
502 		msg14.msg_id = HDCP_MESSAGE_ID_READ_BCAPS;
503 		msg14.version = HDCP_VERSION_14;
504 		msg14.link = HDCP_LINK_PRIMARY;
505 		msg14.max_retries = 5;
506 
507 		status = dc_process_hdcp_msg(signal, link, &msg14);
508 	}
509 
510 }
511 #endif // CONFIG_DRM_AMD_DC_HDCP
512 static void read_current_link_settings_on_detect(struct dc_link *link)
513 {
514 	union lane_count_set lane_count_set = {0};
515 	uint8_t link_bw_set;
516 	uint8_t link_rate_set;
517 	uint32_t read_dpcd_retry_cnt = 10;
518 	enum dc_status status = DC_ERROR_UNEXPECTED;
519 	int i;
520 	union max_down_spread max_down_spread = {0};
521 
522 	// Read DPCD 00101h to find out the number of lanes currently set
523 	for (i = 0; i < read_dpcd_retry_cnt; i++) {
524 		status = core_link_read_dpcd(link,
525 					     DP_LANE_COUNT_SET,
526 					     &lane_count_set.raw,
527 					     sizeof(lane_count_set));
528 		/* First DPCD read after VDD ON can fail if the particular board
529 		 * does not have HPD pin wired correctly. So if DPCD read fails,
530 		 * which it should never happen, retry a few times. Target worst
531 		 * case scenario of 80 ms.
532 		 */
533 		if (status == DC_OK) {
534 			link->cur_link_settings.lane_count =
535 					lane_count_set.bits.LANE_COUNT_SET;
536 			break;
537 		}
538 
539 		msleep(8);
540 	}
541 
542 	// Read DPCD 00100h to find if standard link rates are set
543 	core_link_read_dpcd(link, DP_LINK_BW_SET,
544 			    &link_bw_set, sizeof(link_bw_set));
545 
546 	if (link_bw_set == 0) {
547 		if (link->connector_signal == SIGNAL_TYPE_EDP) {
548 			/* If standard link rates are not being used,
549 			 * Read DPCD 00115h to find the edp link rate set used
550 			 */
551 			core_link_read_dpcd(link, DP_LINK_RATE_SET,
552 					    &link_rate_set, sizeof(link_rate_set));
553 
554 			// edp_supported_link_rates_count = 0 for DP
555 			if (link_rate_set < link->dpcd_caps.edp_supported_link_rates_count) {
556 				link->cur_link_settings.link_rate =
557 					link->dpcd_caps.edp_supported_link_rates[link_rate_set];
558 				link->cur_link_settings.link_rate_set = link_rate_set;
559 				link->cur_link_settings.use_link_rate_set = true;
560 			}
561 		} else {
562 			// Link Rate not found. Seamless boot may not work.
563 			ASSERT(false);
564 		}
565 	} else {
566 		link->cur_link_settings.link_rate = link_bw_set;
567 		link->cur_link_settings.use_link_rate_set = false;
568 	}
569 	// Read DPCD 00003h to find the max down spread.
570 	core_link_read_dpcd(link, DP_MAX_DOWNSPREAD,
571 			    &max_down_spread.raw, sizeof(max_down_spread));
572 	link->cur_link_settings.link_spread =
573 		max_down_spread.bits.MAX_DOWN_SPREAD ?
574 		LINK_SPREAD_05_DOWNSPREAD_30KHZ : LINK_SPREAD_DISABLED;
575 }
576 
577 static bool detect_dp(struct dc_link *link,
578 		      struct display_sink_capability *sink_caps,
579 		      enum dc_detect_reason reason)
580 {
581 	struct audio_support *audio_support = &link->dc->res_pool->audio_support;
582 
583 	sink_caps->signal = link_detect_sink_signal_type(link, reason);
584 	sink_caps->transaction_type =
585 		get_ddc_transaction_type(sink_caps->signal);
586 
587 	if (sink_caps->transaction_type == DDC_TRANSACTION_TYPE_I2C_OVER_AUX) {
588 		sink_caps->signal = SIGNAL_TYPE_DISPLAY_PORT;
589 		if (!detect_dp_sink_caps(link))
590 			return false;
591 
592 		if (is_dp_branch_device(link))
593 			/* DP SST branch */
594 			link->type = dc_connection_sst_branch;
595 	} else {
596 		/* DP passive dongles */
597 		sink_caps->signal = dp_passive_dongle_detection(link->ddc,
598 								sink_caps,
599 								audio_support);
600 		link->dpcd_caps.dongle_type = sink_caps->dongle_type;
601 		link->dpcd_caps.is_dongle_type_one = sink_caps->is_dongle_type_one;
602 		link->dpcd_caps.dpcd_rev.raw = 0;
603 	}
604 
605 	return true;
606 }
607 
608 static bool is_same_edid(struct dc_edid *old_edid, struct dc_edid *new_edid)
609 {
610 	if (old_edid->length != new_edid->length)
611 		return false;
612 
613 	if (new_edid->length == 0)
614 		return false;
615 
616 	return (memcmp(old_edid->raw_edid,
617 		       new_edid->raw_edid, new_edid->length) == 0);
618 }
619 
620 static bool wait_for_entering_dp_alt_mode(struct dc_link *link)
621 {
622 
623 	/**
624 	 * something is terribly wrong if time out is > 200ms. (5Hz)
625 	 * 500 microseconds * 400 tries us 200 ms
626 	 **/
627 	unsigned int sleep_time_in_microseconds = 500;
628 	unsigned int tries_allowed = 400;
629 	bool is_in_alt_mode;
630 	unsigned long long enter_timestamp;
631 	unsigned long long finish_timestamp;
632 	unsigned long long time_taken_in_ns;
633 	int tries_taken;
634 
635 	DC_LOGGER_INIT(link->ctx->logger);
636 
637 	/**
638 	 * this function will only exist if we are on dcn21 (is_in_alt_mode is a
639 	 *  function pointer, so checking to see if it is equal to 0 is the same
640 	 *  as checking to see if it is null
641 	 **/
642 	if (!link->link_enc->funcs->is_in_alt_mode)
643 		return true;
644 
645 	is_in_alt_mode = link->link_enc->funcs->is_in_alt_mode(link->link_enc);
646 	DC_LOG_DC("DP Alt mode state on HPD: %d\n", is_in_alt_mode);
647 
648 	if (is_in_alt_mode)
649 		return true;
650 
651 	enter_timestamp = dm_get_timestamp(link->ctx);
652 
653 	for (tries_taken = 0; tries_taken < tries_allowed; tries_taken++) {
654 		udelay(sleep_time_in_microseconds);
655 		/* ask the link if alt mode is enabled, if so return ok */
656 		if (link->link_enc->funcs->is_in_alt_mode(link->link_enc)) {
657 			finish_timestamp = dm_get_timestamp(link->ctx);
658 			time_taken_in_ns =
659 				dm_get_elapse_time_in_ns(link->ctx,
660 							 finish_timestamp,
661 							 enter_timestamp);
662 			DC_LOG_WARNING("Alt mode entered finished after %llu ms\n",
663 				       div_u64(time_taken_in_ns, 1000000));
664 			return true;
665 		}
666 	}
667 	finish_timestamp = dm_get_timestamp(link->ctx);
668 	time_taken_in_ns = dm_get_elapse_time_in_ns(link->ctx, finish_timestamp,
669 						    enter_timestamp);
670 	DC_LOG_WARNING("Alt mode has timed out after %llu ms\n",
671 			div_u64(time_taken_in_ns, 1000000));
672 	return false;
673 }
674 
675 static void apply_dpia_mst_dsc_always_on_wa(struct dc_link *link)
676 {
677 	/* Apply work around for tunneled MST on certain USB4 docks. Always use DSC if dock
678 	 * reports DSC support.
679 	 */
680 	if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA &&
681 			link->type == dc_connection_mst_branch &&
682 			link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_90CC24 &&
683 			link->dpcd_caps.branch_hw_revision == DP_BRANCH_HW_REV_20 &&
684 			link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_SUPPORT &&
685 			!link->dc->debug.dpia_debug.bits.disable_mst_dsc_work_around)
686 		link->wa_flags.dpia_mst_dsc_always_on = true;
687 }
688 
689 static void revert_dpia_mst_dsc_always_on_wa(struct dc_link *link)
690 {
691 	/* Disable work around which keeps DSC on for tunneled MST on certain USB4 docks. */
692 	if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
693 		link->wa_flags.dpia_mst_dsc_always_on = false;
694 }
695 
696 static bool discover_dp_mst_topology(struct dc_link *link, enum dc_detect_reason reason)
697 {
698 	DC_LOGGER_INIT(link->ctx->logger);
699 
700 	LINK_INFO("link=%d, mst branch is now Connected\n",
701 		  link->link_index);
702 
703 	link->type = dc_connection_mst_branch;
704 	apply_dpia_mst_dsc_always_on_wa(link);
705 
706 	dm_helpers_dp_update_branch_info(link->ctx, link);
707 	if (dm_helpers_dp_mst_start_top_mgr(link->ctx,
708 			link, (reason == DETECT_REASON_BOOT || reason == DETECT_REASON_RESUMEFROMS3S4))) {
709 		link_disconnect_sink(link);
710 	} else {
711 		link->type = dc_connection_sst_branch;
712 	}
713 
714 	return link->type == dc_connection_mst_branch;
715 }
716 
717 bool link_reset_cur_dp_mst_topology(struct dc_link *link)
718 {
719 	DC_LOGGER_INIT(link->ctx->logger);
720 
721 	LINK_INFO("link=%d, mst branch is now Disconnected\n",
722 		  link->link_index);
723 
724 	revert_dpia_mst_dsc_always_on_wa(link);
725 	return dm_helpers_dp_mst_stop_top_mgr(link->ctx, link);
726 }
727 
728 static bool should_prepare_phy_clocks_for_link_verification(const struct dc *dc,
729 		enum dc_detect_reason reason)
730 {
731 	int i;
732 	bool can_apply_seamless_boot = false;
733 
734 	for (i = 0; i < dc->current_state->stream_count; i++) {
735 		if (dc->current_state->streams[i]->apply_seamless_boot_optimization) {
736 			can_apply_seamless_boot = true;
737 			break;
738 		}
739 	}
740 
741 	return !can_apply_seamless_boot && reason != DETECT_REASON_BOOT;
742 }
743 
744 static void prepare_phy_clocks_for_destructive_link_verification(const struct dc *dc)
745 {
746 	dc_z10_restore(dc);
747 	clk_mgr_exit_optimized_pwr_state(dc, dc->clk_mgr);
748 }
749 
750 static void restore_phy_clocks_for_destructive_link_verification(const struct dc *dc)
751 {
752 	clk_mgr_optimize_pwr_state(dc, dc->clk_mgr);
753 }
754 
755 static void verify_link_capability_destructive(struct dc_link *link,
756 		struct dc_sink *sink,
757 		enum dc_detect_reason reason)
758 {
759 	bool should_prepare_phy_clocks =
760 			should_prepare_phy_clocks_for_link_verification(link->dc, reason);
761 
762 	if (should_prepare_phy_clocks)
763 		prepare_phy_clocks_for_destructive_link_verification(link->dc);
764 
765 	if (dc_is_dp_signal(link->local_sink->sink_signal)) {
766 		struct dc_link_settings known_limit_link_setting =
767 				dp_get_max_link_cap(link);
768 		link_set_all_streams_dpms_off_for_link(link);
769 		dp_verify_link_cap_with_retries(
770 				link, &known_limit_link_setting,
771 				LINK_TRAINING_MAX_VERIFY_RETRY);
772 	} else {
773 		ASSERT(0);
774 	}
775 
776 	if (should_prepare_phy_clocks)
777 		restore_phy_clocks_for_destructive_link_verification(link->dc);
778 }
779 
780 static void verify_link_capability_non_destructive(struct dc_link *link)
781 {
782 	if (dc_is_dp_signal(link->local_sink->sink_signal)) {
783 		if (dc_is_embedded_signal(link->local_sink->sink_signal) ||
784 				link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
785 			/* TODO - should we check link encoder's max link caps here?
786 			 * How do we know which link encoder to check from?
787 			 */
788 			link->verified_link_cap = link->reported_link_cap;
789 		else
790 			link->verified_link_cap = dp_get_max_link_cap(link);
791 	}
792 }
793 
794 static bool should_verify_link_capability_destructively(struct dc_link *link,
795 		enum dc_detect_reason reason)
796 {
797 	bool destrictive = false;
798 	struct dc_link_settings max_link_cap;
799 	bool is_link_enc_unavailable = link->link_enc &&
800 			link->dc->res_pool->funcs->link_encs_assign &&
801 			!link_enc_cfg_is_link_enc_avail(
802 					link->ctx->dc,
803 					link->link_enc->preferred_engine,
804 					link);
805 
806 	if (dc_is_dp_signal(link->local_sink->sink_signal)) {
807 		max_link_cap = dp_get_max_link_cap(link);
808 		destrictive = true;
809 
810 		if (link->dc->debug.skip_detection_link_training ||
811 				dc_is_embedded_signal(link->local_sink->sink_signal) ||
812 				link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA) {
813 			destrictive = false;
814 		} else if (link_dp_get_encoding_format(&max_link_cap) ==
815 				DP_8b_10b_ENCODING) {
816 			if (link->dpcd_caps.is_mst_capable ||
817 					is_link_enc_unavailable) {
818 				destrictive = false;
819 			}
820 		}
821 	}
822 
823 	return destrictive;
824 }
825 
826 static void verify_link_capability(struct dc_link *link, struct dc_sink *sink,
827 		enum dc_detect_reason reason)
828 {
829 	if (should_verify_link_capability_destructively(link, reason))
830 		verify_link_capability_destructive(link, sink, reason);
831 	else
832 		verify_link_capability_non_destructive(link);
833 }
834 
835 /**
836  * detect_link_and_local_sink() - Detect if a sink is attached to a given link
837  *
838  * link->local_sink is created or destroyed as needed.
839  *
840  * This does not create remote sinks.
841  */
842 static bool detect_link_and_local_sink(struct dc_link *link,
843 				  enum dc_detect_reason reason)
844 {
845 	struct dc_sink_init_data sink_init_data = { 0 };
846 	struct display_sink_capability sink_caps = { 0 };
847 	uint32_t i;
848 	bool converter_disable_audio = false;
849 	struct audio_support *aud_support = &link->dc->res_pool->audio_support;
850 	bool same_edid = false;
851 	enum dc_edid_status edid_status;
852 	struct dc_context *dc_ctx = link->ctx;
853 	struct dc *dc = dc_ctx->dc;
854 	struct dc_sink *sink = NULL;
855 	struct dc_sink *prev_sink = NULL;
856 	struct dpcd_caps prev_dpcd_caps;
857 	enum dc_connection_type new_connection_type = dc_connection_none;
858 	enum dc_connection_type pre_connection_type = link->type;
859 	const uint32_t post_oui_delay = 30; // 30ms
860 
861 	DC_LOGGER_INIT(link->ctx->logger);
862 
863 	if (dc_is_virtual_signal(link->connector_signal))
864 		return false;
865 
866 	if (((link->connector_signal == SIGNAL_TYPE_LVDS ||
867 		link->connector_signal == SIGNAL_TYPE_EDP) &&
868 		(!link->dc->config.allow_edp_hotplug_detection)) &&
869 		link->local_sink) {
870 		// need to re-write OUI and brightness in resume case
871 		if (link->connector_signal == SIGNAL_TYPE_EDP &&
872 			(link->dpcd_sink_ext_caps.bits.oled == 1)) {
873 			dpcd_set_source_specific_data(link);
874 			msleep(post_oui_delay);
875 			set_default_brightness_aux(link);
876 			//TODO: use cached
877 		}
878 
879 		return true;
880 	}
881 
882 	if (!dc_link_detect_connection_type(link, &new_connection_type)) {
883 		BREAK_TO_DEBUGGER();
884 		return false;
885 	}
886 
887 	prev_sink = link->local_sink;
888 	if (prev_sink) {
889 		dc_sink_retain(prev_sink);
890 		memcpy(&prev_dpcd_caps, &link->dpcd_caps, sizeof(struct dpcd_caps));
891 	}
892 
893 	link_disconnect_sink(link);
894 	if (new_connection_type != dc_connection_none) {
895 		link->type = new_connection_type;
896 		link->link_state_valid = false;
897 
898 		/* From Disconnected-to-Connected. */
899 		switch (link->connector_signal) {
900 		case SIGNAL_TYPE_HDMI_TYPE_A: {
901 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
902 			if (aud_support->hdmi_audio_native)
903 				sink_caps.signal = SIGNAL_TYPE_HDMI_TYPE_A;
904 			else
905 				sink_caps.signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
906 			break;
907 		}
908 
909 		case SIGNAL_TYPE_DVI_SINGLE_LINK: {
910 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
911 			sink_caps.signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
912 			break;
913 		}
914 
915 		case SIGNAL_TYPE_DVI_DUAL_LINK: {
916 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
917 			sink_caps.signal = SIGNAL_TYPE_DVI_DUAL_LINK;
918 			break;
919 		}
920 
921 		case SIGNAL_TYPE_LVDS: {
922 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
923 			sink_caps.signal = SIGNAL_TYPE_LVDS;
924 			break;
925 		}
926 
927 		case SIGNAL_TYPE_EDP: {
928 			detect_edp_sink_caps(link);
929 			read_current_link_settings_on_detect(link);
930 
931 			/* Disable power sequence on MIPI panel + converter
932 			 */
933 			if (dc->config.enable_mipi_converter_optimization &&
934 				dc_ctx->dce_version == DCN_VERSION_3_01 &&
935 				link->dpcd_caps.sink_dev_id == DP_BRANCH_DEVICE_ID_0022B9 &&
936 				memcmp(&link->dpcd_caps.branch_dev_name, DP_SINK_BRANCH_DEV_NAME_7580,
937 					sizeof(link->dpcd_caps.branch_dev_name)) == 0) {
938 				dc->config.edp_no_power_sequencing = true;
939 
940 				if (!link->dpcd_caps.set_power_state_capable_edp)
941 					link->wa_flags.dp_keep_receiver_powered = true;
942 			}
943 
944 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
945 			sink_caps.signal = SIGNAL_TYPE_EDP;
946 			break;
947 		}
948 
949 		case SIGNAL_TYPE_DISPLAY_PORT: {
950 
951 			/* wa HPD high coming too early*/
952 			if (link->ep_type == DISPLAY_ENDPOINT_PHY &&
953 			    link->link_enc->features.flags.bits.DP_IS_USB_C == 1) {
954 
955 				/* if alt mode times out, return false */
956 				if (!wait_for_entering_dp_alt_mode(link))
957 					return false;
958 			}
959 
960 			if (!detect_dp(link, &sink_caps, reason)) {
961 				link->type = pre_connection_type;
962 
963 				if (prev_sink)
964 					dc_sink_release(prev_sink);
965 				return false;
966 			}
967 
968 			/* Active SST downstream branch device unplug*/
969 			if (link->type == dc_connection_sst_branch &&
970 			    link->dpcd_caps.sink_count.bits.SINK_COUNT == 0) {
971 				if (prev_sink)
972 					/* Downstream unplug */
973 					dc_sink_release(prev_sink);
974 				return true;
975 			}
976 
977 			/* disable audio for non DP to HDMI active sst converter */
978 			if (link->type == dc_connection_sst_branch &&
979 					is_dp_active_dongle(link) &&
980 					(link->dpcd_caps.dongle_type !=
981 							DISPLAY_DONGLE_DP_HDMI_CONVERTER))
982 				converter_disable_audio = true;
983 			break;
984 		}
985 
986 		default:
987 			DC_ERROR("Invalid connector type! signal:%d\n",
988 				 link->connector_signal);
989 			if (prev_sink)
990 				dc_sink_release(prev_sink);
991 			return false;
992 		} /* switch() */
993 
994 		if (link->dpcd_caps.sink_count.bits.SINK_COUNT)
995 			link->dpcd_sink_count =
996 				link->dpcd_caps.sink_count.bits.SINK_COUNT;
997 		else
998 			link->dpcd_sink_count = 1;
999 
1000 		set_ddc_transaction_type(link->ddc,
1001 						     sink_caps.transaction_type);
1002 
1003 		link->aux_mode =
1004 			link_is_in_aux_transaction_mode(link->ddc);
1005 
1006 		sink_init_data.link = link;
1007 		sink_init_data.sink_signal = sink_caps.signal;
1008 
1009 		sink = dc_sink_create(&sink_init_data);
1010 		if (!sink) {
1011 			DC_ERROR("Failed to create sink!\n");
1012 			if (prev_sink)
1013 				dc_sink_release(prev_sink);
1014 			return false;
1015 		}
1016 
1017 		sink->link->dongle_max_pix_clk = sink_caps.max_hdmi_pixel_clock;
1018 		sink->converter_disable_audio = converter_disable_audio;
1019 
1020 		/* dc_sink_create returns a new reference */
1021 		link->local_sink = sink;
1022 
1023 		edid_status = dm_helpers_read_local_edid(link->ctx,
1024 							 link, sink);
1025 
1026 		switch (edid_status) {
1027 		case EDID_BAD_CHECKSUM:
1028 			DC_LOG_ERROR("EDID checksum invalid.\n");
1029 			break;
1030 		case EDID_PARTIAL_VALID:
1031 			DC_LOG_ERROR("Partial EDID valid, abandon invalid blocks.\n");
1032 			break;
1033 		case EDID_NO_RESPONSE:
1034 			DC_LOG_ERROR("No EDID read.\n");
1035 			/*
1036 			 * Abort detection for non-DP connectors if we have
1037 			 * no EDID
1038 			 *
1039 			 * DP needs to report as connected if HDP is high
1040 			 * even if we have no EDID in order to go to
1041 			 * fail-safe mode
1042 			 */
1043 			if (dc_is_hdmi_signal(link->connector_signal) ||
1044 			    dc_is_dvi_signal(link->connector_signal)) {
1045 				if (prev_sink)
1046 					dc_sink_release(prev_sink);
1047 
1048 				return false;
1049 			}
1050 
1051 			if (link->type == dc_connection_sst_branch &&
1052 					link->dpcd_caps.dongle_type ==
1053 						DISPLAY_DONGLE_DP_VGA_CONVERTER &&
1054 					reason == DETECT_REASON_HPDRX) {
1055 				/* Abort detection for DP-VGA adapters when EDID
1056 				 * can't be read and detection reason is VGA-side
1057 				 * hotplug
1058 				 */
1059 				if (prev_sink)
1060 					dc_sink_release(prev_sink);
1061 				link_disconnect_sink(link);
1062 
1063 				return true;
1064 			}
1065 
1066 			break;
1067 		default:
1068 			break;
1069 		}
1070 
1071 		// Check if edid is the same
1072 		if ((prev_sink) &&
1073 		    (edid_status == EDID_THE_SAME || edid_status == EDID_OK))
1074 			same_edid = is_same_edid(&prev_sink->dc_edid,
1075 						 &sink->dc_edid);
1076 
1077 		if (sink->edid_caps.panel_patch.skip_scdc_overwrite)
1078 			link->ctx->dc->debug.hdmi20_disable = true;
1079 
1080 		if (dc_is_hdmi_signal(link->connector_signal))
1081 			read_scdc_caps(link->ddc, link->local_sink);
1082 
1083 		if (link->connector_signal == SIGNAL_TYPE_DISPLAY_PORT &&
1084 		    sink_caps.transaction_type ==
1085 		    DDC_TRANSACTION_TYPE_I2C_OVER_AUX) {
1086 			/*
1087 			 * TODO debug why certain monitors don't like
1088 			 *  two link trainings
1089 			 */
1090 #if defined(CONFIG_DRM_AMD_DC_HDCP)
1091 			query_hdcp_capability(sink->sink_signal, link);
1092 #endif
1093 		} else {
1094 			// If edid is the same, then discard new sink and revert back to original sink
1095 			if (same_edid) {
1096 				link_disconnect_remap(prev_sink, link);
1097 				sink = prev_sink;
1098 				prev_sink = NULL;
1099 			}
1100 #if defined(CONFIG_DRM_AMD_DC_HDCP)
1101 			query_hdcp_capability(sink->sink_signal, link);
1102 #endif
1103 		}
1104 
1105 		/* HDMI-DVI Dongle */
1106 		if (sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A &&
1107 		    !sink->edid_caps.edid_hdmi)
1108 			sink->sink_signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
1109 
1110 		if (link->local_sink && dc_is_dp_signal(sink_caps.signal))
1111 			dp_trace_init(link);
1112 
1113 		/* Connectivity log: detection */
1114 		for (i = 0; i < sink->dc_edid.length / DC_EDID_BLOCK_SIZE; i++) {
1115 			CONN_DATA_DETECT(link,
1116 					 &sink->dc_edid.raw_edid[i * DC_EDID_BLOCK_SIZE],
1117 					 DC_EDID_BLOCK_SIZE,
1118 					 "%s: [Block %d] ", sink->edid_caps.display_name, i);
1119 		}
1120 
1121 		DC_LOG_DETECTION_EDID_PARSER("%s: "
1122 			"manufacturer_id = %X, "
1123 			"product_id = %X, "
1124 			"serial_number = %X, "
1125 			"manufacture_week = %d, "
1126 			"manufacture_year = %d, "
1127 			"display_name = %s, "
1128 			"speaker_flag = %d, "
1129 			"audio_mode_count = %d\n",
1130 			__func__,
1131 			sink->edid_caps.manufacturer_id,
1132 			sink->edid_caps.product_id,
1133 			sink->edid_caps.serial_number,
1134 			sink->edid_caps.manufacture_week,
1135 			sink->edid_caps.manufacture_year,
1136 			sink->edid_caps.display_name,
1137 			sink->edid_caps.speaker_flags,
1138 			sink->edid_caps.audio_mode_count);
1139 
1140 		for (i = 0; i < sink->edid_caps.audio_mode_count; i++) {
1141 			DC_LOG_DETECTION_EDID_PARSER("%s: mode number = %d, "
1142 				"format_code = %d, "
1143 				"channel_count = %d, "
1144 				"sample_rate = %d, "
1145 				"sample_size = %d\n",
1146 				__func__,
1147 				i,
1148 				sink->edid_caps.audio_modes[i].format_code,
1149 				sink->edid_caps.audio_modes[i].channel_count,
1150 				sink->edid_caps.audio_modes[i].sample_rate,
1151 				sink->edid_caps.audio_modes[i].sample_size);
1152 		}
1153 
1154 		if (link->connector_signal == SIGNAL_TYPE_EDP) {
1155 			// Init dc_panel_config by HW config
1156 			if (dc_ctx->dc->res_pool->funcs->get_panel_config_defaults)
1157 				dc_ctx->dc->res_pool->funcs->get_panel_config_defaults(&link->panel_config);
1158 			// Pickup base DM settings
1159 			dm_helpers_init_panel_settings(dc_ctx, &link->panel_config, sink);
1160 			// Override dc_panel_config if system has specific settings
1161 			dm_helpers_override_panel_settings(dc_ctx, &link->panel_config);
1162 		}
1163 
1164 	} else {
1165 		/* From Connected-to-Disconnected. */
1166 		link->type = dc_connection_none;
1167 		sink_caps.signal = SIGNAL_TYPE_NONE;
1168 #if defined(CONFIG_DRM_AMD_DC_HDCP)
1169 		memset(&link->hdcp_caps, 0, sizeof(struct hdcp_caps));
1170 #endif
1171 		/* When we unplug a passive DP-HDMI dongle connection, dongle_max_pix_clk
1172 		 *  is not cleared. If we emulate a DP signal on this connection, it thinks
1173 		 *  the dongle is still there and limits the number of modes we can emulate.
1174 		 *  Clear dongle_max_pix_clk on disconnect to fix this
1175 		 */
1176 		link->dongle_max_pix_clk = 0;
1177 
1178 		dc_link_clear_dprx_states(link);
1179 		dp_trace_reset(link);
1180 	}
1181 
1182 	LINK_INFO("link=%d, dc_sink_in=%p is now %s prev_sink=%p edid same=%d\n",
1183 		  link->link_index, sink,
1184 		  (sink_caps.signal ==
1185 		   SIGNAL_TYPE_NONE ? "Disconnected" : "Connected"),
1186 		  prev_sink, same_edid);
1187 
1188 	if (prev_sink)
1189 		dc_sink_release(prev_sink);
1190 
1191 	return true;
1192 }
1193 
1194 /**
1195  * dc_link_detect_connection_type() - Determine if there is a sink connected
1196  *
1197  * @type: Returned connection type
1198  * Does not detect downstream devices, such as MST sinks
1199  * or display connected through active dongles
1200  */
1201 bool link_detect_connection_type(struct dc_link *link, enum dc_connection_type *type)
1202 {
1203 	uint32_t is_hpd_high = 0;
1204 
1205 	if (link->connector_signal == SIGNAL_TYPE_LVDS) {
1206 		*type = dc_connection_single;
1207 		return true;
1208 	}
1209 
1210 	if (link->connector_signal == SIGNAL_TYPE_EDP) {
1211 		/*in case it is not on*/
1212 		if (!link->dc->config.edp_no_power_sequencing)
1213 			link->dc->hwss.edp_power_control(link, true);
1214 		link->dc->hwss.edp_wait_for_hpd_ready(link, true);
1215 	}
1216 
1217 	/* Link may not have physical HPD pin. */
1218 	if (link->ep_type != DISPLAY_ENDPOINT_PHY) {
1219 		if (link->is_hpd_pending || !dc_link_dpia_query_hpd_status(link))
1220 			*type = dc_connection_none;
1221 		else
1222 			*type = dc_connection_single;
1223 
1224 		return true;
1225 	}
1226 
1227 
1228 	if (!query_hpd_status(link, &is_hpd_high))
1229 		goto hpd_gpio_failure;
1230 
1231 	if (is_hpd_high) {
1232 		*type = dc_connection_single;
1233 		/* TODO: need to do the actual detection */
1234 	} else {
1235 		*type = dc_connection_none;
1236 	}
1237 
1238 	return true;
1239 
1240 hpd_gpio_failure:
1241 	return false;
1242 }
1243 
1244 bool link_detect(struct dc_link *link, enum dc_detect_reason reason)
1245 {
1246 	bool is_local_sink_detect_success;
1247 	bool is_delegated_to_mst_top_mgr = false;
1248 	enum dc_connection_type pre_link_type = link->type;
1249 
1250 	DC_LOGGER_INIT(link->ctx->logger);
1251 
1252 	is_local_sink_detect_success = detect_link_and_local_sink(link, reason);
1253 
1254 	if (is_local_sink_detect_success && link->local_sink)
1255 		verify_link_capability(link, link->local_sink, reason);
1256 
1257 	DC_LOG_DC("%s: link_index=%d is_local_sink_detect_success=%d pre_link_type=%d link_type=%d\n", __func__,
1258 				link->link_index, is_local_sink_detect_success, pre_link_type, link->type);
1259 
1260 	if (is_local_sink_detect_success && link->local_sink &&
1261 			dc_is_dp_signal(link->local_sink->sink_signal) &&
1262 			link->dpcd_caps.is_mst_capable)
1263 		is_delegated_to_mst_top_mgr = discover_dp_mst_topology(link, reason);
1264 
1265 	if (is_local_sink_detect_success &&
1266 			pre_link_type == dc_connection_mst_branch &&
1267 			link->type != dc_connection_mst_branch)
1268 		is_delegated_to_mst_top_mgr = link_reset_cur_dp_mst_topology(link);
1269 
1270 	return is_local_sink_detect_success && !is_delegated_to_mst_top_mgr;
1271 }
1272 
1273 void link_clear_dprx_states(struct dc_link *link)
1274 {
1275 	memset(&link->dprx_states, 0, sizeof(link->dprx_states));
1276 }
1277 #if defined(CONFIG_DRM_AMD_DC_HDCP)
1278 
1279 bool link_is_hdcp14(struct dc_link *link, enum signal_type signal)
1280 {
1281 	bool ret = false;
1282 
1283 	switch (signal)	{
1284 	case SIGNAL_TYPE_DISPLAY_PORT:
1285 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
1286 		ret = link->hdcp_caps.bcaps.bits.HDCP_CAPABLE;
1287 		break;
1288 	case SIGNAL_TYPE_DVI_SINGLE_LINK:
1289 	case SIGNAL_TYPE_DVI_DUAL_LINK:
1290 	case SIGNAL_TYPE_HDMI_TYPE_A:
1291 	/* HDMI doesn't tell us its HDCP(1.4) capability, so assume to always be capable,
1292 	 * we can poll for bksv but some displays have an issue with this. Since its so rare
1293 	 * for a display to not be 1.4 capable, this assumtion is ok
1294 	 */
1295 		ret = true;
1296 		break;
1297 	default:
1298 		break;
1299 	}
1300 	return ret;
1301 }
1302 
1303 bool link_is_hdcp22(struct dc_link *link, enum signal_type signal)
1304 {
1305 	bool ret = false;
1306 
1307 	switch (signal)	{
1308 	case SIGNAL_TYPE_DISPLAY_PORT:
1309 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
1310 		ret = (link->hdcp_caps.bcaps.bits.HDCP_CAPABLE &&
1311 				link->hdcp_caps.rx_caps.fields.byte0.hdcp_capable &&
1312 				(link->hdcp_caps.rx_caps.fields.version == 0x2)) ? 1 : 0;
1313 		break;
1314 	case SIGNAL_TYPE_DVI_SINGLE_LINK:
1315 	case SIGNAL_TYPE_DVI_DUAL_LINK:
1316 	case SIGNAL_TYPE_HDMI_TYPE_A:
1317 		ret = (link->hdcp_caps.rx_caps.fields.version == 0x4) ? 1:0;
1318 		break;
1319 	default:
1320 		break;
1321 	}
1322 
1323 	return ret;
1324 }
1325 #endif // CONFIG_DRM_AMD_DC_HDCP
1326 
1327 const struct dc_link_status *link_get_status(const struct dc_link *link)
1328 {
1329 	return &link->link_status;
1330 }
1331 
1332