xref: /linux/drivers/gpu/drm/amd/display/dc/link/link_detection.c (revision 54743ca151a0050e0e9fd89a562392ddbaef4330)
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 "protocols/link_dp_dpia_bw.h"
45 #include "accessories/link_dp_trace.h"
46 
47 #include "link_enc_cfg.h"
48 #include "dm_helpers.h"
49 #include "clk_mgr.h"
50 
51  // Offset DPCD 050Eh == 0x5A
52 #define MST_HUB_ID_0x5A  0x5A
53 
54 #define DC_LOGGER \
55 	link->ctx->logger
56 #define DC_LOGGER_INIT(logger)
57 
58 #define LINK_INFO(...) \
59 	DC_LOG_HW_HOTPLUG(  \
60 		__VA_ARGS__)
61 /*
62  * Some receivers fail to train on first try and are good
63  * on subsequent tries. 2 retries should be plenty. If we
64  * don't have a successful training then we don't expect to
65  * ever get one.
66  */
67 #define LINK_TRAINING_MAX_VERIFY_RETRY 2
68 
69 static const u8 DP_SINK_BRANCH_DEV_NAME_7580[] = "7580\x80u";
70 
71 static const u8 dp_hdmi_dongle_signature_str[] = "DP-HDMI ADAPTOR";
72 
73 static enum ddc_transaction_type get_ddc_transaction_type(enum signal_type sink_signal)
74 {
75 	enum ddc_transaction_type transaction_type = DDC_TRANSACTION_TYPE_NONE;
76 
77 	switch (sink_signal) {
78 	case SIGNAL_TYPE_DVI_SINGLE_LINK:
79 	case SIGNAL_TYPE_DVI_DUAL_LINK:
80 	case SIGNAL_TYPE_HDMI_TYPE_A:
81 	case SIGNAL_TYPE_LVDS:
82 	case SIGNAL_TYPE_RGB:
83 		transaction_type = DDC_TRANSACTION_TYPE_I2C;
84 		break;
85 
86 	case SIGNAL_TYPE_DISPLAY_PORT:
87 	case SIGNAL_TYPE_EDP:
88 		transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
89 		break;
90 
91 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
92 		/* MST does not use I2COverAux, but there is the
93 		 * SPECIAL use case for "immediate dwnstrm device
94 		 * access" (EPR#370830).
95 		 */
96 		transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
97 		break;
98 
99 	default:
100 		break;
101 	}
102 
103 	return transaction_type;
104 }
105 
106 static enum signal_type get_basic_signal_type(struct graphics_object_id encoder,
107 					      struct graphics_object_id downstream)
108 {
109 	if (downstream.type == OBJECT_TYPE_CONNECTOR) {
110 		switch (downstream.id) {
111 		case CONNECTOR_ID_SINGLE_LINK_DVII:
112 			switch (encoder.id) {
113 			case ENCODER_ID_INTERNAL_DAC1:
114 			case ENCODER_ID_INTERNAL_KLDSCP_DAC1:
115 			case ENCODER_ID_INTERNAL_DAC2:
116 			case ENCODER_ID_INTERNAL_KLDSCP_DAC2:
117 				return SIGNAL_TYPE_RGB;
118 			default:
119 				return SIGNAL_TYPE_DVI_SINGLE_LINK;
120 			}
121 		break;
122 		case CONNECTOR_ID_DUAL_LINK_DVII:
123 		{
124 			switch (encoder.id) {
125 			case ENCODER_ID_INTERNAL_DAC1:
126 			case ENCODER_ID_INTERNAL_KLDSCP_DAC1:
127 			case ENCODER_ID_INTERNAL_DAC2:
128 			case ENCODER_ID_INTERNAL_KLDSCP_DAC2:
129 				return SIGNAL_TYPE_RGB;
130 			default:
131 				return SIGNAL_TYPE_DVI_DUAL_LINK;
132 			}
133 		}
134 		break;
135 		case CONNECTOR_ID_SINGLE_LINK_DVID:
136 			return SIGNAL_TYPE_DVI_SINGLE_LINK;
137 		case CONNECTOR_ID_DUAL_LINK_DVID:
138 			return SIGNAL_TYPE_DVI_DUAL_LINK;
139 		case CONNECTOR_ID_VGA:
140 			return SIGNAL_TYPE_RGB;
141 		case CONNECTOR_ID_HDMI_TYPE_A:
142 			return SIGNAL_TYPE_HDMI_TYPE_A;
143 		case CONNECTOR_ID_LVDS:
144 			return SIGNAL_TYPE_LVDS;
145 		case CONNECTOR_ID_DISPLAY_PORT:
146 		case CONNECTOR_ID_USBC:
147 			return SIGNAL_TYPE_DISPLAY_PORT;
148 		case CONNECTOR_ID_EDP:
149 			return SIGNAL_TYPE_EDP;
150 		default:
151 			return SIGNAL_TYPE_NONE;
152 		}
153 	} else if (downstream.type == OBJECT_TYPE_ENCODER) {
154 		switch (downstream.id) {
155 		case ENCODER_ID_EXTERNAL_NUTMEG:
156 		case ENCODER_ID_EXTERNAL_TRAVIS:
157 			return SIGNAL_TYPE_DISPLAY_PORT;
158 		default:
159 			return SIGNAL_TYPE_NONE;
160 		}
161 	}
162 
163 	return SIGNAL_TYPE_NONE;
164 }
165 
166 /*
167  * @brief
168  * Detect output sink type
169  */
170 static enum signal_type link_detect_sink_signal_type(struct dc_link *link,
171 					 enum dc_detect_reason reason)
172 {
173 	enum signal_type result;
174 	struct graphics_object_id enc_id;
175 
176 	if (link->is_dig_mapping_flexible)
177 		enc_id = (struct graphics_object_id){.id = ENCODER_ID_UNKNOWN};
178 	else
179 		enc_id = link->link_enc->id;
180 	result = get_basic_signal_type(enc_id, link->link_id);
181 
182 	/* Use basic signal type for link without physical connector. */
183 	if (link->ep_type != DISPLAY_ENDPOINT_PHY)
184 		return result;
185 
186 	/* Internal digital encoder will detect only dongles
187 	 * that require digital signal
188 	 */
189 
190 	/* Detection mechanism is different
191 	 * for different native connectors.
192 	 * LVDS connector supports only LVDS signal;
193 	 * PCIE is a bus slot, the actual connector needs to be detected first;
194 	 * eDP connector supports only eDP signal;
195 	 * HDMI should check straps for audio
196 	 */
197 
198 	/* PCIE detects the actual connector on add-on board */
199 	if (link->link_id.id == CONNECTOR_ID_PCIE) {
200 		/* ZAZTODO implement PCIE add-on card detection */
201 	}
202 
203 	switch (link->link_id.id) {
204 	case CONNECTOR_ID_HDMI_TYPE_A: {
205 		/* check audio support:
206 		 * if native HDMI is not supported, switch to DVI
207 		 */
208 		struct audio_support *aud_support =
209 					&link->dc->res_pool->audio_support;
210 
211 		if (!aud_support->hdmi_audio_native)
212 			if (link->link_id.id == CONNECTOR_ID_HDMI_TYPE_A)
213 				result = SIGNAL_TYPE_DVI_SINGLE_LINK;
214 	}
215 	break;
216 	case CONNECTOR_ID_DISPLAY_PORT:
217 	case CONNECTOR_ID_USBC: {
218 		/* DP HPD short pulse. Passive DP dongle will not
219 		 * have short pulse
220 		 */
221 		if (reason != DETECT_REASON_HPDRX) {
222 			/* Check whether DP signal detected: if not -
223 			 * we assume signal is DVI; it could be corrected
224 			 * to HDMI after dongle detection
225 			 */
226 			if (!dm_helpers_is_dp_sink_present(link))
227 				result = SIGNAL_TYPE_DVI_SINGLE_LINK;
228 		}
229 	}
230 	break;
231 	default:
232 	break;
233 	}
234 
235 	return result;
236 }
237 
238 static enum signal_type decide_signal_from_strap_and_dongle_type(enum display_dongle_type dongle_type,
239 								 struct audio_support *audio_support)
240 {
241 	enum signal_type signal = SIGNAL_TYPE_NONE;
242 
243 	switch (dongle_type) {
244 	case DISPLAY_DONGLE_DP_HDMI_DONGLE:
245 		if (audio_support->hdmi_audio_on_dongle)
246 			signal = SIGNAL_TYPE_HDMI_TYPE_A;
247 		else
248 			signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
249 		break;
250 	case DISPLAY_DONGLE_DP_DVI_DONGLE:
251 		signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
252 		break;
253 	case DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE:
254 		if (audio_support->hdmi_audio_native)
255 			signal =  SIGNAL_TYPE_HDMI_TYPE_A;
256 		else
257 			signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
258 		break;
259 	default:
260 		signal = SIGNAL_TYPE_NONE;
261 		break;
262 	}
263 
264 	return signal;
265 }
266 
267 static void read_scdc_caps(struct ddc_service *ddc_service,
268 		struct dc_sink *sink)
269 {
270 	uint8_t slave_address = HDMI_SCDC_ADDRESS;
271 	uint8_t offset = HDMI_SCDC_MANUFACTURER_OUI;
272 
273 	link_query_ddc_data(ddc_service, slave_address, &offset,
274 			sizeof(offset), sink->scdc_caps.manufacturer_OUI.byte,
275 			sizeof(sink->scdc_caps.manufacturer_OUI.byte));
276 
277 	offset = HDMI_SCDC_DEVICE_ID;
278 
279 	link_query_ddc_data(ddc_service, slave_address, &offset,
280 			sizeof(offset), &(sink->scdc_caps.device_id.byte),
281 			sizeof(sink->scdc_caps.device_id.byte));
282 }
283 
284 static bool i2c_read(
285 	struct ddc_service *ddc,
286 	uint32_t address,
287 	uint8_t *buffer,
288 	uint32_t len)
289 {
290 	uint8_t offs_data = 0;
291 	struct i2c_payload payloads[2] = {
292 		{
293 		.write = true,
294 		.address = address,
295 		.length = 1,
296 		.data = &offs_data },
297 		{
298 		.write = false,
299 		.address = address,
300 		.length = len,
301 		.data = buffer } };
302 
303 	struct i2c_command command = {
304 		.payloads = payloads,
305 		.number_of_payloads = 2,
306 		.engine = DDC_I2C_COMMAND_ENGINE,
307 		.speed = ddc->ctx->dc->caps.i2c_speed_in_khz };
308 
309 	return dm_helpers_submit_i2c(
310 			ddc->ctx,
311 			ddc->link,
312 			&command);
313 }
314 
315 enum {
316 	DP_SINK_CAP_SIZE =
317 		DP_EDP_CONFIGURATION_CAP - DP_DPCD_REV + 1
318 };
319 
320 static void query_dp_dual_mode_adaptor(
321 	struct ddc_service *ddc,
322 	struct display_sink_capability *sink_cap)
323 {
324 	uint8_t i;
325 	bool is_valid_hdmi_signature;
326 	enum display_dongle_type *dongle = &sink_cap->dongle_type;
327 	uint8_t type2_dongle_buf[DP_ADAPTOR_TYPE2_SIZE];
328 	bool is_type2_dongle = false;
329 	int retry_count = 2;
330 	struct dp_hdmi_dongle_signature_data *dongle_signature;
331 	struct dc_link *link = ddc->link;
332 
333 	/* Assume we have no valid DP passive dongle connected */
334 	*dongle = DISPLAY_DONGLE_NONE;
335 	sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_HDMI_SAFE_MAX_TMDS_CLK;
336 
337 	/* Read DP-HDMI dongle I2c (no response interpreted as DP-DVI dongle)*/
338 	if (!i2c_read(
339 		ddc,
340 		DP_HDMI_DONGLE_ADDRESS,
341 		type2_dongle_buf,
342 		sizeof(type2_dongle_buf))) {
343 		/* Passive HDMI dongles can sometimes fail here without retrying*/
344 		while (retry_count > 0) {
345 			if (i2c_read(ddc,
346 				DP_HDMI_DONGLE_ADDRESS,
347 				type2_dongle_buf,
348 				sizeof(type2_dongle_buf)))
349 				break;
350 			retry_count--;
351 		}
352 		if (retry_count == 0) {
353 			*dongle = DISPLAY_DONGLE_DP_DVI_DONGLE;
354 			sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_DVI_MAX_TMDS_CLK;
355 
356 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf, sizeof(type2_dongle_buf),
357 					"DP-DVI passive dongle %dMhz: ",
358 					DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000);
359 			return;
360 		}
361 	}
362 
363 	/* Check if Type 2 dongle.*/
364 	if (type2_dongle_buf[DP_ADAPTOR_TYPE2_REG_ID] == DP_ADAPTOR_TYPE2_ID)
365 		is_type2_dongle = true;
366 
367 	dongle_signature =
368 		(struct dp_hdmi_dongle_signature_data *)type2_dongle_buf;
369 
370 	is_valid_hdmi_signature = true;
371 
372 	/* Check EOT */
373 	if (dongle_signature->eot != DP_HDMI_DONGLE_SIGNATURE_EOT) {
374 		is_valid_hdmi_signature = false;
375 	}
376 
377 	/* Check signature */
378 	for (i = 0; i < sizeof(dongle_signature->id); ++i) {
379 		/* If its not the right signature,
380 		 * skip mismatch in subversion byte.*/
381 		if (dongle_signature->id[i] !=
382 			dp_hdmi_dongle_signature_str[i] && i != 3) {
383 
384 			if (is_type2_dongle) {
385 				is_valid_hdmi_signature = false;
386 				break;
387 			}
388 
389 		}
390 	}
391 
392 	if (is_type2_dongle) {
393 		uint32_t max_tmds_clk =
394 			type2_dongle_buf[DP_ADAPTOR_TYPE2_REG_MAX_TMDS_CLK];
395 
396 		max_tmds_clk = max_tmds_clk * 2 + max_tmds_clk / 2;
397 
398 		if (0 == max_tmds_clk ||
399 				max_tmds_clk < DP_ADAPTOR_TYPE2_MIN_TMDS_CLK ||
400 				max_tmds_clk > DP_ADAPTOR_TYPE2_MAX_TMDS_CLK) {
401 			*dongle = DISPLAY_DONGLE_DP_DVI_DONGLE;
402 
403 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
404 					sizeof(type2_dongle_buf),
405 					"DP-DVI passive dongle %dMhz: ",
406 					DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000);
407 		} else {
408 			if (is_valid_hdmi_signature == true) {
409 				*dongle = DISPLAY_DONGLE_DP_HDMI_DONGLE;
410 
411 				CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
412 						sizeof(type2_dongle_buf),
413 						"Type 2 DP-HDMI passive dongle %dMhz: ",
414 						max_tmds_clk);
415 			} else {
416 				*dongle = DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE;
417 
418 				CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
419 						sizeof(type2_dongle_buf),
420 						"Type 2 DP-HDMI passive dongle (no signature) %dMhz: ",
421 						max_tmds_clk);
422 
423 			}
424 
425 			/* Multiply by 1000 to convert to kHz. */
426 			sink_cap->max_hdmi_pixel_clock =
427 				max_tmds_clk * 1000;
428 		}
429 		sink_cap->is_dongle_type_one = false;
430 
431 	} else {
432 		if (is_valid_hdmi_signature == true) {
433 			*dongle = DISPLAY_DONGLE_DP_HDMI_DONGLE;
434 
435 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
436 					sizeof(type2_dongle_buf),
437 					"Type 1 DP-HDMI passive dongle %dMhz: ",
438 					sink_cap->max_hdmi_pixel_clock / 1000);
439 		} else {
440 			*dongle = DISPLAY_DONGLE_DP_HDMI_MISMATCHED_DONGLE;
441 
442 			CONN_DATA_DETECT(ddc->link, type2_dongle_buf,
443 					sizeof(type2_dongle_buf),
444 					"Type 1 DP-HDMI passive dongle (no signature) %dMhz: ",
445 					sink_cap->max_hdmi_pixel_clock / 1000);
446 		}
447 		sink_cap->is_dongle_type_one = true;
448 	}
449 
450 	return;
451 }
452 
453 static enum signal_type dp_passive_dongle_detection(struct ddc_service *ddc,
454 						    struct display_sink_capability *sink_cap,
455 						    struct audio_support *audio_support)
456 {
457 	query_dp_dual_mode_adaptor(ddc, sink_cap);
458 
459 	return decide_signal_from_strap_and_dongle_type(sink_cap->dongle_type,
460 							audio_support);
461 }
462 
463 static void link_disconnect_sink(struct dc_link *link)
464 {
465 	if (link->local_sink) {
466 		dc_sink_release(link->local_sink);
467 		link->local_sink = NULL;
468 	}
469 
470 	link->dpcd_sink_count = 0;
471 	//link->dpcd_caps.dpcd_rev.raw = 0;
472 }
473 
474 static void link_disconnect_remap(struct dc_sink *prev_sink, struct dc_link *link)
475 {
476 	dc_sink_release(link->local_sink);
477 	link->local_sink = prev_sink;
478 }
479 
480 static void query_hdcp_capability(enum signal_type signal, struct dc_link *link)
481 {
482 	struct hdcp_protection_message msg22;
483 	struct hdcp_protection_message msg14;
484 
485 	memset(&msg22, 0, sizeof(struct hdcp_protection_message));
486 	memset(&msg14, 0, sizeof(struct hdcp_protection_message));
487 	memset(link->hdcp_caps.rx_caps.raw, 0,
488 		sizeof(link->hdcp_caps.rx_caps.raw));
489 
490 	if ((link->connector_signal == SIGNAL_TYPE_DISPLAY_PORT &&
491 			link->ddc->transaction_type ==
492 			DDC_TRANSACTION_TYPE_I2C_OVER_AUX) ||
493 			link->connector_signal == SIGNAL_TYPE_EDP) {
494 		msg22.data = link->hdcp_caps.rx_caps.raw;
495 		msg22.length = sizeof(link->hdcp_caps.rx_caps.raw);
496 		msg22.msg_id = HDCP_MESSAGE_ID_RX_CAPS;
497 	} else {
498 		msg22.data = &link->hdcp_caps.rx_caps.fields.version;
499 		msg22.length = sizeof(link->hdcp_caps.rx_caps.fields.version);
500 		msg22.msg_id = HDCP_MESSAGE_ID_HDCP2VERSION;
501 	}
502 	msg22.version = HDCP_VERSION_22;
503 	msg22.link = HDCP_LINK_PRIMARY;
504 	msg22.max_retries = 5;
505 	dc_process_hdcp_msg(signal, link, &msg22);
506 
507 	if (signal == SIGNAL_TYPE_DISPLAY_PORT || signal == SIGNAL_TYPE_DISPLAY_PORT_MST) {
508 		msg14.data = &link->hdcp_caps.bcaps.raw;
509 		msg14.length = sizeof(link->hdcp_caps.bcaps.raw);
510 		msg14.msg_id = HDCP_MESSAGE_ID_READ_BCAPS;
511 		msg14.version = HDCP_VERSION_14;
512 		msg14.link = HDCP_LINK_PRIMARY;
513 		msg14.max_retries = 5;
514 
515 		dc_process_hdcp_msg(signal, link, &msg14);
516 	}
517 
518 }
519 static void read_current_link_settings_on_detect(struct dc_link *link)
520 {
521 	union lane_count_set lane_count_set = {0};
522 	uint8_t link_bw_set = 0;
523 	uint8_t link_rate_set = 0;
524 	uint32_t read_dpcd_retry_cnt = 10;
525 	enum dc_status status = DC_ERROR_UNEXPECTED;
526 	int i;
527 	union max_down_spread max_down_spread = {0};
528 
529 	// Read DPCD 00101h to find out the number of lanes currently set
530 	for (i = 0; i < read_dpcd_retry_cnt; i++) {
531 		status = core_link_read_dpcd(link,
532 					     DP_LANE_COUNT_SET,
533 					     &lane_count_set.raw,
534 					     sizeof(lane_count_set));
535 		/* First DPCD read after VDD ON can fail if the particular board
536 		 * does not have HPD pin wired correctly. So if DPCD read fails,
537 		 * which it should never happen, retry a few times. Target worst
538 		 * case scenario of 80 ms.
539 		 */
540 		if (status == DC_OK) {
541 			link->cur_link_settings.lane_count =
542 					lane_count_set.bits.LANE_COUNT_SET;
543 			break;
544 		}
545 
546 		msleep(8);
547 	}
548 
549 	// Read DPCD 00100h to find if standard link rates are set
550 	core_link_read_dpcd(link, DP_LINK_BW_SET,
551 			    &link_bw_set, sizeof(link_bw_set));
552 
553 	if (link_bw_set == 0) {
554 		if (link->connector_signal == SIGNAL_TYPE_EDP) {
555 			/* If standard link rates are not being used,
556 			 * Read DPCD 00115h to find the edp link rate set used
557 			 */
558 			core_link_read_dpcd(link, DP_LINK_RATE_SET,
559 					    &link_rate_set, sizeof(link_rate_set));
560 
561 			// edp_supported_link_rates_count = 0 for DP
562 			if (link_rate_set < link->dpcd_caps.edp_supported_link_rates_count) {
563 				link->cur_link_settings.link_rate =
564 					link->dpcd_caps.edp_supported_link_rates[link_rate_set];
565 				link->cur_link_settings.link_rate_set = link_rate_set;
566 				link->cur_link_settings.use_link_rate_set = true;
567 			}
568 		} else {
569 			// Link Rate not found. Seamless boot may not work.
570 			ASSERT(false);
571 		}
572 	} else {
573 		link->cur_link_settings.link_rate = link_bw_set;
574 		link->cur_link_settings.use_link_rate_set = false;
575 	}
576 	// Read DPCD 00003h to find the max down spread.
577 	core_link_read_dpcd(link, DP_MAX_DOWNSPREAD,
578 			    &max_down_spread.raw, sizeof(max_down_spread));
579 	link->cur_link_settings.link_spread =
580 		max_down_spread.bits.MAX_DOWN_SPREAD ?
581 		LINK_SPREAD_05_DOWNSPREAD_30KHZ : LINK_SPREAD_DISABLED;
582 }
583 
584 static bool detect_dp(struct dc_link *link,
585 		      struct display_sink_capability *sink_caps,
586 		      enum dc_detect_reason reason)
587 {
588 	struct audio_support *audio_support = &link->dc->res_pool->audio_support;
589 
590 	sink_caps->signal = link_detect_sink_signal_type(link, reason);
591 	sink_caps->transaction_type =
592 		get_ddc_transaction_type(sink_caps->signal);
593 
594 	if (sink_caps->transaction_type == DDC_TRANSACTION_TYPE_I2C_OVER_AUX) {
595 		sink_caps->signal = SIGNAL_TYPE_DISPLAY_PORT;
596 		if (!detect_dp_sink_caps(link))
597 			return false;
598 
599 		if (is_dp_branch_device(link))
600 			/* DP SST branch */
601 			link->type = dc_connection_sst_branch;
602 	} else {
603 		if (link->dc->debug.disable_dp_plus_plus_wa &&
604 				link->link_enc->features.flags.bits.IS_UHBR20_CAPABLE)
605 			return false;
606 
607 		/* DP passive dongles */
608 		sink_caps->signal = dp_passive_dongle_detection(link->ddc,
609 								sink_caps,
610 								audio_support);
611 		link->dpcd_caps.dongle_type = sink_caps->dongle_type;
612 		link->dpcd_caps.is_dongle_type_one = sink_caps->is_dongle_type_one;
613 		link->dpcd_caps.dpcd_rev.raw = 0;
614 	}
615 
616 	return true;
617 }
618 
619 static bool is_same_edid(struct dc_edid *old_edid, struct dc_edid *new_edid)
620 {
621 	if (old_edid->length != new_edid->length)
622 		return false;
623 
624 	if (new_edid->length == 0)
625 		return false;
626 
627 	return (memcmp(old_edid->raw_edid,
628 		       new_edid->raw_edid, new_edid->length) == 0);
629 }
630 
631 static bool wait_for_entering_dp_alt_mode(struct dc_link *link)
632 {
633 
634 	/**
635 	 * something is terribly wrong if time out is > 200ms. (5Hz)
636 	 * 500 microseconds * 400 tries us 200 ms
637 	 **/
638 	unsigned int sleep_time_in_microseconds = 500;
639 	unsigned int tries_allowed = 400;
640 	bool is_in_alt_mode;
641 	unsigned long long enter_timestamp;
642 	unsigned long long finish_timestamp;
643 	unsigned long long time_taken_in_ns;
644 	int tries_taken;
645 
646 	DC_LOGGER_INIT(link->ctx->logger);
647 
648 	/**
649 	 * this function will only exist if we are on dcn21 (is_in_alt_mode is a
650 	 *  function pointer, so checking to see if it is equal to 0 is the same
651 	 *  as checking to see if it is null
652 	 **/
653 	if (!link->link_enc->funcs->is_in_alt_mode)
654 		return true;
655 
656 	is_in_alt_mode = link->link_enc->funcs->is_in_alt_mode(link->link_enc);
657 	DC_LOG_DC("DP Alt mode state on HPD: %d\n", is_in_alt_mode);
658 
659 	if (is_in_alt_mode)
660 		return true;
661 
662 	enter_timestamp = dm_get_timestamp(link->ctx);
663 
664 	for (tries_taken = 0; tries_taken < tries_allowed; tries_taken++) {
665 		udelay(sleep_time_in_microseconds);
666 		/* ask the link if alt mode is enabled, if so return ok */
667 		if (link->link_enc->funcs->is_in_alt_mode(link->link_enc)) {
668 			finish_timestamp = dm_get_timestamp(link->ctx);
669 			time_taken_in_ns =
670 				dm_get_elapse_time_in_ns(link->ctx,
671 							 finish_timestamp,
672 							 enter_timestamp);
673 			DC_LOG_WARNING("Alt mode entered finished after %llu ms\n",
674 				       div_u64(time_taken_in_ns, 1000000));
675 			return true;
676 		}
677 	}
678 	finish_timestamp = dm_get_timestamp(link->ctx);
679 	time_taken_in_ns = dm_get_elapse_time_in_ns(link->ctx, finish_timestamp,
680 						    enter_timestamp);
681 	DC_LOG_WARNING("Alt mode has timed out after %llu ms\n",
682 			div_u64(time_taken_in_ns, 1000000));
683 	return false;
684 }
685 
686 static void apply_dpia_mst_dsc_always_on_wa(struct dc_link *link)
687 {
688 	/* Apply work around for tunneled MST on certain USB4 docks. Always use DSC if dock
689 	 * reports DSC support.
690 	 */
691 	if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA &&
692 			link->type == dc_connection_mst_branch &&
693 			link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_90CC24 &&
694 			link->dpcd_caps.branch_hw_revision == DP_BRANCH_HW_REV_20 &&
695 			link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_SUPPORT &&
696 			!link->dc->debug.dpia_debug.bits.disable_mst_dsc_work_around)
697 		link->wa_flags.dpia_mst_dsc_always_on = true;
698 
699 	if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA &&
700 		link->type == dc_connection_mst_branch &&
701 		link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_90CC24 &&
702 		link->dpcd_caps.branch_vendor_specific_data[2] == MST_HUB_ID_0x5A &&
703 		link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_SUPPORT &&
704 		!link->dc->debug.dpia_debug.bits.disable_mst_dsc_work_around) {
705 			link->wa_flags.dpia_mst_dsc_always_on = true;
706 	}
707 }
708 
709 static void revert_dpia_mst_dsc_always_on_wa(struct dc_link *link)
710 {
711 	/* Disable work around which keeps DSC on for tunneled MST on certain USB4 docks. */
712 	if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
713 		link->wa_flags.dpia_mst_dsc_always_on = false;
714 }
715 
716 static bool discover_dp_mst_topology(struct dc_link *link, enum dc_detect_reason reason)
717 {
718 	DC_LOGGER_INIT(link->ctx->logger);
719 
720 	LINK_INFO("link=%d, mst branch is now Connected\n",
721 		  link->link_index);
722 
723 	link->type = dc_connection_mst_branch;
724 	apply_dpia_mst_dsc_always_on_wa(link);
725 
726 	dm_helpers_dp_update_branch_info(link->ctx, link);
727 	if (dm_helpers_dp_mst_start_top_mgr(link->ctx,
728 			link, (reason == DETECT_REASON_BOOT || reason == DETECT_REASON_RESUMEFROMS3S4))) {
729 		link_disconnect_sink(link);
730 	} else {
731 		link->type = dc_connection_sst_branch;
732 	}
733 
734 	return link->type == dc_connection_mst_branch;
735 }
736 
737 bool link_reset_cur_dp_mst_topology(struct dc_link *link)
738 {
739 	DC_LOGGER_INIT(link->ctx->logger);
740 
741 	LINK_INFO("link=%d, mst branch is now Disconnected\n",
742 		  link->link_index);
743 
744 	revert_dpia_mst_dsc_always_on_wa(link);
745 	return dm_helpers_dp_mst_stop_top_mgr(link->ctx, link);
746 }
747 
748 static bool should_prepare_phy_clocks_for_link_verification(const struct dc *dc,
749 		enum dc_detect_reason reason)
750 {
751 	int i;
752 	bool can_apply_seamless_boot = false;
753 
754 	for (i = 0; i < dc->current_state->stream_count; i++) {
755 		if (dc->current_state->streams[i]->apply_seamless_boot_optimization) {
756 			can_apply_seamless_boot = true;
757 			break;
758 		}
759 	}
760 
761 	return !can_apply_seamless_boot && reason != DETECT_REASON_BOOT;
762 }
763 
764 static void prepare_phy_clocks_for_destructive_link_verification(const struct dc *dc)
765 {
766 	dc_z10_restore(dc);
767 	clk_mgr_exit_optimized_pwr_state(dc, dc->clk_mgr);
768 }
769 
770 static void restore_phy_clocks_for_destructive_link_verification(const struct dc *dc)
771 {
772 	clk_mgr_optimize_pwr_state(dc, dc->clk_mgr);
773 }
774 
775 static void verify_link_capability_destructive(struct dc_link *link,
776 		struct dc_sink *sink,
777 		enum dc_detect_reason reason)
778 {
779 	bool should_prepare_phy_clocks =
780 			should_prepare_phy_clocks_for_link_verification(link->dc, reason);
781 
782 	if (should_prepare_phy_clocks)
783 		prepare_phy_clocks_for_destructive_link_verification(link->dc);
784 
785 	if (dc_is_dp_signal(link->local_sink->sink_signal)) {
786 		struct dc_link_settings known_limit_link_setting =
787 				dp_get_max_link_cap(link);
788 		link_set_all_streams_dpms_off_for_link(link);
789 		dp_verify_link_cap_with_retries(
790 				link, &known_limit_link_setting,
791 				LINK_TRAINING_MAX_VERIFY_RETRY);
792 	} else {
793 		ASSERT(0);
794 	}
795 
796 	if (should_prepare_phy_clocks)
797 		restore_phy_clocks_for_destructive_link_verification(link->dc);
798 }
799 
800 static void verify_link_capability_non_destructive(struct dc_link *link)
801 {
802 	if (dc_is_dp_signal(link->local_sink->sink_signal)) {
803 		if (dc_is_embedded_signal(link->local_sink->sink_signal) ||
804 				link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
805 			/* TODO - should we check link encoder's max link caps here?
806 			 * How do we know which link encoder to check from?
807 			 */
808 			link->verified_link_cap = link->reported_link_cap;
809 		else
810 			link->verified_link_cap = dp_get_max_link_cap(link);
811 	}
812 }
813 
814 static bool should_verify_link_capability_destructively(struct dc_link *link,
815 		enum dc_detect_reason reason)
816 {
817 	bool destrictive = false;
818 	struct dc_link_settings max_link_cap;
819 	bool is_link_enc_unavailable = false;
820 
821 	if (!link->dc->config.unify_link_enc_assignment)
822 		is_link_enc_unavailable = link->link_enc &&
823 			link->dc->res_pool->funcs->link_encs_assign &&
824 			!link_enc_cfg_is_link_enc_avail(
825 					link->ctx->dc,
826 					link->link_enc->preferred_engine,
827 					link);
828 
829 	if (dc_is_dp_signal(link->local_sink->sink_signal)) {
830 		max_link_cap = dp_get_max_link_cap(link);
831 		destrictive = true;
832 
833 		if (link->dc->debug.skip_detection_link_training ||
834 				dc_is_embedded_signal(link->local_sink->sink_signal) ||
835 				(link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA &&
836 				!link->dc->config.enable_dpia_pre_training)) {
837 			destrictive = false;
838 		} else if (link_dp_get_encoding_format(&max_link_cap) ==
839 				DP_8b_10b_ENCODING) {
840 			if (link->dpcd_caps.is_mst_capable ||
841 					is_link_enc_unavailable) {
842 				destrictive = false;
843 			}
844 		}
845 	}
846 
847 	return destrictive;
848 }
849 
850 static void verify_link_capability(struct dc_link *link, struct dc_sink *sink,
851 		enum dc_detect_reason reason)
852 {
853 	if (should_verify_link_capability_destructively(link, reason))
854 		verify_link_capability_destructive(link, sink, reason);
855 	else
856 		verify_link_capability_non_destructive(link);
857 }
858 
859 /*
860  * detect_link_and_local_sink() - Detect if a sink is attached to a given link
861  *
862  * link->local_sink is created or destroyed as needed.
863  *
864  * This does not create remote sinks.
865  */
866 static bool detect_link_and_local_sink(struct dc_link *link,
867 				  enum dc_detect_reason reason)
868 {
869 	struct dc_sink_init_data sink_init_data = { 0 };
870 	struct display_sink_capability sink_caps = { 0 };
871 	uint32_t i;
872 	bool converter_disable_audio = false;
873 	struct audio_support *aud_support = &link->dc->res_pool->audio_support;
874 	bool same_edid = false;
875 	enum dc_edid_status edid_status;
876 	struct dc_context *dc_ctx = link->ctx;
877 	struct dc *dc = dc_ctx->dc;
878 	struct dc_sink *sink = NULL;
879 	struct dc_sink *prev_sink = NULL;
880 	struct dpcd_caps prev_dpcd_caps;
881 	enum dc_connection_type new_connection_type = dc_connection_none;
882 	const uint32_t post_oui_delay = 30; // 30ms
883 
884 	DC_LOGGER_INIT(link->ctx->logger);
885 
886 	if (dc_is_virtual_signal(link->connector_signal))
887 		return false;
888 
889 	if (((link->connector_signal == SIGNAL_TYPE_LVDS ||
890 		link->connector_signal == SIGNAL_TYPE_EDP) &&
891 		(!link->dc->config.allow_edp_hotplug_detection)) &&
892 		link->local_sink) {
893 		// need to re-write OUI and brightness in resume case
894 		if (link->connector_signal == SIGNAL_TYPE_EDP &&
895 			(link->dpcd_sink_ext_caps.bits.oled == 1)) {
896 			dpcd_set_source_specific_data(link);
897 			msleep(post_oui_delay);
898 			set_default_brightness_aux(link);
899 		}
900 
901 		return true;
902 	}
903 
904 	if (!link_detect_connection_type(link, &new_connection_type)) {
905 		BREAK_TO_DEBUGGER();
906 		return false;
907 	}
908 
909 	prev_sink = link->local_sink;
910 	if (prev_sink) {
911 		dc_sink_retain(prev_sink);
912 		memcpy(&prev_dpcd_caps, &link->dpcd_caps, sizeof(struct dpcd_caps));
913 	}
914 
915 	link_disconnect_sink(link);
916 	if (new_connection_type != dc_connection_none) {
917 		link->type = new_connection_type;
918 		link->link_state_valid = false;
919 
920 		/* From Disconnected-to-Connected. */
921 		switch (link->connector_signal) {
922 		case SIGNAL_TYPE_HDMI_TYPE_A: {
923 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
924 			if (aud_support->hdmi_audio_native)
925 				sink_caps.signal = SIGNAL_TYPE_HDMI_TYPE_A;
926 			else
927 				sink_caps.signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
928 			break;
929 		}
930 
931 		case SIGNAL_TYPE_DVI_SINGLE_LINK: {
932 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
933 			sink_caps.signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
934 			break;
935 		}
936 
937 		case SIGNAL_TYPE_DVI_DUAL_LINK: {
938 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
939 			sink_caps.signal = SIGNAL_TYPE_DVI_DUAL_LINK;
940 			break;
941 		}
942 
943 		case SIGNAL_TYPE_LVDS: {
944 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C;
945 			sink_caps.signal = SIGNAL_TYPE_LVDS;
946 			break;
947 		}
948 
949 		case SIGNAL_TYPE_EDP: {
950 			detect_edp_sink_caps(link);
951 			read_current_link_settings_on_detect(link);
952 
953 			/* Disable power sequence on MIPI panel + converter
954 			 */
955 			if (dc->config.enable_mipi_converter_optimization &&
956 				dc_ctx->dce_version == DCN_VERSION_3_01 &&
957 				link->dpcd_caps.sink_dev_id == DP_BRANCH_DEVICE_ID_0022B9 &&
958 				memcmp(&link->dpcd_caps.branch_dev_name, DP_SINK_BRANCH_DEV_NAME_7580,
959 					sizeof(link->dpcd_caps.branch_dev_name)) == 0) {
960 				dc->config.edp_no_power_sequencing = true;
961 
962 				if (!link->dpcd_caps.set_power_state_capable_edp)
963 					link->wa_flags.dp_keep_receiver_powered = true;
964 			}
965 
966 			sink_caps.transaction_type = DDC_TRANSACTION_TYPE_I2C_OVER_AUX;
967 			sink_caps.signal = SIGNAL_TYPE_EDP;
968 			break;
969 		}
970 
971 		case SIGNAL_TYPE_DISPLAY_PORT: {
972 
973 			/* wa HPD high coming too early*/
974 			if (link->ep_type == DISPLAY_ENDPOINT_PHY &&
975 			    link->link_enc->features.flags.bits.DP_IS_USB_C == 1) {
976 
977 				/* if alt mode times out, return false */
978 				if (!wait_for_entering_dp_alt_mode(link))
979 					return false;
980 			}
981 
982 			if (!detect_dp(link, &sink_caps, reason)) {
983 
984 				if (prev_sink)
985 					dc_sink_release(prev_sink);
986 				return false;
987 			}
988 
989 			/* Active SST downstream branch device unplug*/
990 			if (link->type == dc_connection_sst_branch &&
991 			    link->dpcd_caps.sink_count.bits.SINK_COUNT == 0) {
992 				if (prev_sink)
993 					/* Downstream unplug */
994 					dc_sink_release(prev_sink);
995 				return true;
996 			}
997 
998 			/* disable audio for non DP to HDMI active sst converter */
999 			if (link->type == dc_connection_sst_branch &&
1000 					is_dp_active_dongle(link) &&
1001 					(link->dpcd_caps.dongle_type !=
1002 							DISPLAY_DONGLE_DP_HDMI_CONVERTER))
1003 				converter_disable_audio = true;
1004 
1005 			/* limited link rate to HBR3 for DPIA until we implement USB4 V2 */
1006 			if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA &&
1007 					link->reported_link_cap.link_rate > LINK_RATE_HIGH3)
1008 				link->reported_link_cap.link_rate = LINK_RATE_HIGH3;
1009 
1010 			/*
1011 			 * If this is DP over USB4 link then we need to:
1012 			 * - Enable BW ALLOC support on DPtx if applicable
1013 			 */
1014 			if (dc->config.usb4_bw_alloc_support) {
1015 				if (link_dp_dpia_set_dptx_usb4_bw_alloc_support(link)) {
1016 					/* update with non reduced link cap if bw allocation mode is supported */
1017 					if (link->dpia_bw_alloc_config.nrd_max_link_rate &&
1018 						link->dpia_bw_alloc_config.nrd_max_lane_count) {
1019 						link->reported_link_cap.link_rate =
1020 							link->dpia_bw_alloc_config.nrd_max_link_rate;
1021 						link->reported_link_cap.lane_count =
1022 							link->dpia_bw_alloc_config.nrd_max_lane_count;
1023 					}
1024 				}
1025 			}
1026 			break;
1027 		}
1028 
1029 		default:
1030 			DC_ERROR("Invalid connector type! signal:%d\n",
1031 				 link->connector_signal);
1032 			if (prev_sink)
1033 				dc_sink_release(prev_sink);
1034 			return false;
1035 		} /* switch() */
1036 
1037 		if (link->dpcd_caps.sink_count.bits.SINK_COUNT)
1038 			link->dpcd_sink_count =
1039 				link->dpcd_caps.sink_count.bits.SINK_COUNT;
1040 		else
1041 			link->dpcd_sink_count = 1;
1042 
1043 		set_ddc_transaction_type(link->ddc,
1044 						     sink_caps.transaction_type);
1045 
1046 		link->aux_mode =
1047 			link_is_in_aux_transaction_mode(link->ddc);
1048 
1049 		sink_init_data.link = link;
1050 		sink_init_data.sink_signal = sink_caps.signal;
1051 
1052 		sink = dc_sink_create(&sink_init_data);
1053 		if (!sink) {
1054 			DC_ERROR("Failed to create sink!\n");
1055 			if (prev_sink)
1056 				dc_sink_release(prev_sink);
1057 			return false;
1058 		}
1059 
1060 		sink->link->dongle_max_pix_clk = sink_caps.max_hdmi_pixel_clock;
1061 		sink->converter_disable_audio = converter_disable_audio;
1062 
1063 		/* dc_sink_create returns a new reference */
1064 		link->local_sink = sink;
1065 
1066 		edid_status = dm_helpers_read_local_edid(link->ctx,
1067 							 link, sink);
1068 
1069 		switch (edid_status) {
1070 		case EDID_BAD_CHECKSUM:
1071 			DC_LOG_ERROR("EDID checksum invalid.\n");
1072 			break;
1073 		case EDID_PARTIAL_VALID:
1074 			DC_LOG_ERROR("Partial EDID valid, abandon invalid blocks.\n");
1075 			break;
1076 		case EDID_NO_RESPONSE:
1077 			DC_LOG_ERROR("No EDID read.\n");
1078 			/*
1079 			 * Abort detection for non-DP connectors if we have
1080 			 * no EDID
1081 			 *
1082 			 * DP needs to report as connected if HDP is high
1083 			 * even if we have no EDID in order to go to
1084 			 * fail-safe mode
1085 			 */
1086 			if (dc_is_hdmi_signal(link->connector_signal) ||
1087 			    dc_is_dvi_signal(link->connector_signal)) {
1088 				if (prev_sink)
1089 					dc_sink_release(prev_sink);
1090 
1091 				return false;
1092 			}
1093 
1094 			if (link->type == dc_connection_sst_branch &&
1095 					link->dpcd_caps.dongle_type ==
1096 						DISPLAY_DONGLE_DP_VGA_CONVERTER &&
1097 					reason == DETECT_REASON_HPDRX) {
1098 				/* Abort detection for DP-VGA adapters when EDID
1099 				 * can't be read and detection reason is VGA-side
1100 				 * hotplug
1101 				 */
1102 				if (prev_sink)
1103 					dc_sink_release(prev_sink);
1104 				link_disconnect_sink(link);
1105 
1106 				return true;
1107 			}
1108 
1109 			break;
1110 		default:
1111 			break;
1112 		}
1113 
1114 		// Check if edid is the same
1115 		if ((prev_sink) &&
1116 		    (edid_status == EDID_THE_SAME || edid_status == EDID_OK))
1117 			same_edid = is_same_edid(&prev_sink->dc_edid,
1118 						 &sink->dc_edid);
1119 
1120 		if (sink->edid_caps.panel_patch.skip_scdc_overwrite)
1121 			link->ctx->dc->debug.hdmi20_disable = true;
1122 
1123 		if (sink->edid_caps.panel_patch.remove_sink_ext_caps)
1124 			link->dpcd_sink_ext_caps.raw = 0;
1125 
1126 		if (dc_is_hdmi_signal(link->connector_signal))
1127 			read_scdc_caps(link->ddc, link->local_sink);
1128 
1129 		if (link->connector_signal == SIGNAL_TYPE_DISPLAY_PORT &&
1130 		    sink_caps.transaction_type ==
1131 		    DDC_TRANSACTION_TYPE_I2C_OVER_AUX) {
1132 			/*
1133 			 * TODO debug why certain monitors don't like
1134 			 *  two link trainings
1135 			 */
1136 			query_hdcp_capability(sink->sink_signal, link);
1137 		} else {
1138 			// If edid is the same, then discard new sink and revert back to original sink
1139 			if (same_edid) {
1140 				link_disconnect_remap(prev_sink, link);
1141 				sink = prev_sink;
1142 				prev_sink = NULL;
1143 			}
1144 			query_hdcp_capability(sink->sink_signal, link);
1145 		}
1146 
1147 		/* HDMI-DVI Dongle */
1148 		if (sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A &&
1149 		    !sink->edid_caps.edid_hdmi)
1150 			sink->sink_signal = SIGNAL_TYPE_DVI_SINGLE_LINK;
1151 
1152 		if (link->local_sink && dc_is_dp_signal(sink_caps.signal))
1153 			dp_trace_init(link);
1154 
1155 		/* Connectivity log: detection */
1156 		for (i = 0; i < sink->dc_edid.length / DC_EDID_BLOCK_SIZE; i++) {
1157 			CONN_DATA_DETECT(link,
1158 					 &sink->dc_edid.raw_edid[i * DC_EDID_BLOCK_SIZE],
1159 					 DC_EDID_BLOCK_SIZE,
1160 					 "%s: [Block %d] ", sink->edid_caps.display_name, i);
1161 		}
1162 
1163 		DC_LOG_DETECTION_EDID_PARSER("%s: "
1164 			"manufacturer_id = %X, "
1165 			"product_id = %X, "
1166 			"serial_number = %X, "
1167 			"manufacture_week = %d, "
1168 			"manufacture_year = %d, "
1169 			"display_name = %s, "
1170 			"speaker_flag = %d, "
1171 			"audio_mode_count = %d\n",
1172 			__func__,
1173 			sink->edid_caps.manufacturer_id,
1174 			sink->edid_caps.product_id,
1175 			sink->edid_caps.serial_number,
1176 			sink->edid_caps.manufacture_week,
1177 			sink->edid_caps.manufacture_year,
1178 			sink->edid_caps.display_name,
1179 			sink->edid_caps.speaker_flags,
1180 			sink->edid_caps.audio_mode_count);
1181 
1182 		for (i = 0; i < sink->edid_caps.audio_mode_count; i++) {
1183 			DC_LOG_DETECTION_EDID_PARSER("%s: mode number = %d, "
1184 				"format_code = %d, "
1185 				"channel_count = %d, "
1186 				"sample_rate = %d, "
1187 				"sample_size = %d\n",
1188 				__func__,
1189 				i,
1190 				sink->edid_caps.audio_modes[i].format_code,
1191 				sink->edid_caps.audio_modes[i].channel_count,
1192 				sink->edid_caps.audio_modes[i].sample_rate,
1193 				sink->edid_caps.audio_modes[i].sample_size);
1194 		}
1195 
1196 		if (link->connector_signal == SIGNAL_TYPE_EDP) {
1197 			// Init dc_panel_config by HW config
1198 			if (dc_ctx->dc->res_pool->funcs->get_panel_config_defaults)
1199 				dc_ctx->dc->res_pool->funcs->get_panel_config_defaults(&link->panel_config);
1200 			// Pickup base DM settings
1201 			dm_helpers_init_panel_settings(dc_ctx, &link->panel_config, sink);
1202 			// Override dc_panel_config if system has specific settings
1203 			dm_helpers_override_panel_settings(dc_ctx, &link->panel_config);
1204 
1205 			//sink only can use supported link rate table, we are foreced to enable it
1206 			if (link->reported_link_cap.link_rate == LINK_RATE_UNKNOWN)
1207 				link->panel_config.ilr.optimize_edp_link_rate = true;
1208 			link->reported_link_cap.link_rate = get_max_edp_link_rate(link);
1209 		}
1210 
1211 	} else {
1212 		/* From Connected-to-Disconnected. */
1213 		link->type = dc_connection_none;
1214 		sink_caps.signal = SIGNAL_TYPE_NONE;
1215 		memset(&link->hdcp_caps, 0, sizeof(struct hdcp_caps));
1216 		/* When we unplug a passive DP-HDMI dongle connection, dongle_max_pix_clk
1217 		 *  is not cleared. If we emulate a DP signal on this connection, it thinks
1218 		 *  the dongle is still there and limits the number of modes we can emulate.
1219 		 *  Clear dongle_max_pix_clk on disconnect to fix this
1220 		 */
1221 		link->dongle_max_pix_clk = 0;
1222 
1223 		dc_link_clear_dprx_states(link);
1224 		dp_trace_reset(link);
1225 	}
1226 
1227 	LINK_INFO("link=%d, dc_sink_in=%p is now %s prev_sink=%p edid same=%d\n",
1228 		  link->link_index, sink,
1229 		  (sink_caps.signal ==
1230 		   SIGNAL_TYPE_NONE ? "Disconnected" : "Connected"),
1231 		  prev_sink, same_edid);
1232 
1233 	if (prev_sink)
1234 		dc_sink_release(prev_sink);
1235 
1236 	return true;
1237 }
1238 
1239 /*
1240  * link_detect_connection_type() - Determine if there is a sink connected
1241  *
1242  * @type: Returned connection type
1243  * Does not detect downstream devices, such as MST sinks
1244  * or display connected through active dongles
1245  */
1246 bool link_detect_connection_type(struct dc_link *link, enum dc_connection_type *type)
1247 {
1248 	uint32_t is_hpd_high = 0;
1249 
1250 	if (link->connector_signal == SIGNAL_TYPE_LVDS) {
1251 		*type = dc_connection_single;
1252 		return true;
1253 	}
1254 
1255 	if (link->connector_signal == SIGNAL_TYPE_EDP) {
1256 		/*in case it is not on*/
1257 		if (!link->dc->config.edp_no_power_sequencing)
1258 			link->dc->hwss.edp_power_control(link, true);
1259 		link->dc->hwss.edp_wait_for_hpd_ready(link, true);
1260 	}
1261 
1262 	/* Link may not have physical HPD pin. */
1263 	if (link->ep_type != DISPLAY_ENDPOINT_PHY) {
1264 		if (link->is_hpd_pending || !dpia_query_hpd_status(link))
1265 			*type = dc_connection_none;
1266 		else
1267 			*type = dc_connection_single;
1268 
1269 		return true;
1270 	}
1271 
1272 
1273 	if (!query_hpd_status(link, &is_hpd_high))
1274 		goto hpd_gpio_failure;
1275 
1276 	if (is_hpd_high) {
1277 		*type = dc_connection_single;
1278 		/* TODO: need to do the actual detection */
1279 	} else {
1280 		*type = dc_connection_none;
1281 		if (link->connector_signal == SIGNAL_TYPE_EDP) {
1282 			/* eDP is not connected, power down it */
1283 			if (!link->dc->config.edp_no_power_sequencing)
1284 				link->dc->hwss.edp_power_control(link, false);
1285 		}
1286 	}
1287 
1288 	return true;
1289 
1290 hpd_gpio_failure:
1291 	return false;
1292 }
1293 
1294 bool link_detect(struct dc_link *link, enum dc_detect_reason reason)
1295 {
1296 	bool is_local_sink_detect_success;
1297 	bool is_delegated_to_mst_top_mgr = false;
1298 	enum dc_connection_type pre_link_type = link->type;
1299 
1300 	DC_LOGGER_INIT(link->ctx->logger);
1301 
1302 	is_local_sink_detect_success = detect_link_and_local_sink(link, reason);
1303 
1304 	if (is_local_sink_detect_success && link->local_sink)
1305 		verify_link_capability(link, link->local_sink, reason);
1306 
1307 	DC_LOG_DC("%s: link_index=%d is_local_sink_detect_success=%d pre_link_type=%d link_type=%d\n", __func__,
1308 				link->link_index, is_local_sink_detect_success, pre_link_type, link->type);
1309 
1310 	if (is_local_sink_detect_success && link->local_sink &&
1311 			dc_is_dp_signal(link->local_sink->sink_signal) &&
1312 			link->dpcd_caps.is_mst_capable)
1313 		is_delegated_to_mst_top_mgr = discover_dp_mst_topology(link, reason);
1314 
1315 	if (pre_link_type == dc_connection_mst_branch &&
1316 			link->type != dc_connection_mst_branch)
1317 		is_delegated_to_mst_top_mgr = link_reset_cur_dp_mst_topology(link);
1318 
1319 	return is_local_sink_detect_success && !is_delegated_to_mst_top_mgr;
1320 }
1321 
1322 void link_clear_dprx_states(struct dc_link *link)
1323 {
1324 	memset(&link->dprx_states, 0, sizeof(link->dprx_states));
1325 }
1326 
1327 bool link_is_hdcp14(struct dc_link *link, enum signal_type signal)
1328 {
1329 	bool ret = false;
1330 
1331 	switch (signal)	{
1332 	case SIGNAL_TYPE_DISPLAY_PORT:
1333 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
1334 		ret = link->hdcp_caps.bcaps.bits.HDCP_CAPABLE;
1335 		break;
1336 	case SIGNAL_TYPE_DVI_SINGLE_LINK:
1337 	case SIGNAL_TYPE_DVI_DUAL_LINK:
1338 	case SIGNAL_TYPE_HDMI_TYPE_A:
1339 	/* HDMI doesn't tell us its HDCP(1.4) capability, so assume to always be capable,
1340 	 * we can poll for bksv but some displays have an issue with this. Since its so rare
1341 	 * for a display to not be 1.4 capable, this assumtion is ok
1342 	 */
1343 		ret = true;
1344 		break;
1345 	default:
1346 		break;
1347 	}
1348 	return ret;
1349 }
1350 
1351 bool link_is_hdcp22(struct dc_link *link, enum signal_type signal)
1352 {
1353 	bool ret = false;
1354 
1355 	switch (signal)	{
1356 	case SIGNAL_TYPE_DISPLAY_PORT:
1357 	case SIGNAL_TYPE_DISPLAY_PORT_MST:
1358 		ret = (link->hdcp_caps.bcaps.bits.HDCP_CAPABLE &&
1359 				link->hdcp_caps.rx_caps.fields.byte0.hdcp_capable &&
1360 				(link->hdcp_caps.rx_caps.fields.version == 0x2)) ? 1 : 0;
1361 		break;
1362 	case SIGNAL_TYPE_DVI_SINGLE_LINK:
1363 	case SIGNAL_TYPE_DVI_DUAL_LINK:
1364 	case SIGNAL_TYPE_HDMI_TYPE_A:
1365 		ret = (link->hdcp_caps.rx_caps.fields.version == 0x4) ? 1:0;
1366 		break;
1367 	default:
1368 		break;
1369 	}
1370 
1371 	return ret;
1372 }
1373 
1374 const struct dc_link_status *link_get_status(const struct dc_link *link)
1375 {
1376 	return &link->link_status;
1377 }
1378 
1379 
1380 static bool link_add_remote_sink_helper(struct dc_link *dc_link, struct dc_sink *sink)
1381 {
1382 	if (dc_link->sink_count >= MAX_SINKS_PER_LINK) {
1383 		BREAK_TO_DEBUGGER();
1384 		return false;
1385 	}
1386 
1387 	dc_sink_retain(sink);
1388 
1389 	dc_link->remote_sinks[dc_link->sink_count] = sink;
1390 	dc_link->sink_count++;
1391 
1392 	return true;
1393 }
1394 
1395 struct dc_sink *link_add_remote_sink(
1396 		struct dc_link *link,
1397 		const uint8_t *edid,
1398 		int len,
1399 		struct dc_sink_init_data *init_data)
1400 {
1401 	struct dc_sink *dc_sink;
1402 	enum dc_edid_status edid_status;
1403 
1404 	if (len > DC_MAX_EDID_BUFFER_SIZE) {
1405 		dm_error("Max EDID buffer size breached!\n");
1406 		return NULL;
1407 	}
1408 
1409 	if (!init_data) {
1410 		BREAK_TO_DEBUGGER();
1411 		return NULL;
1412 	}
1413 
1414 	if (!init_data->link) {
1415 		BREAK_TO_DEBUGGER();
1416 		return NULL;
1417 	}
1418 
1419 	dc_sink = dc_sink_create(init_data);
1420 
1421 	if (!dc_sink)
1422 		return NULL;
1423 
1424 	memmove(dc_sink->dc_edid.raw_edid, edid, len);
1425 	dc_sink->dc_edid.length = len;
1426 
1427 	if (!link_add_remote_sink_helper(
1428 			link,
1429 			dc_sink))
1430 		goto fail_add_sink;
1431 
1432 	edid_status = dm_helpers_parse_edid_caps(
1433 			link,
1434 			&dc_sink->dc_edid,
1435 			&dc_sink->edid_caps);
1436 
1437 	/*
1438 	 * Treat device as no EDID device if EDID
1439 	 * parsing fails
1440 	 */
1441 	if (edid_status != EDID_OK && edid_status != EDID_PARTIAL_VALID) {
1442 		dc_sink->dc_edid.length = 0;
1443 		dm_error("Bad EDID, status%d!\n", edid_status);
1444 	}
1445 
1446 	return dc_sink;
1447 
1448 fail_add_sink:
1449 	dc_sink_release(dc_sink);
1450 	return NULL;
1451 }
1452 
1453 void link_remove_remote_sink(struct dc_link *link, struct dc_sink *sink)
1454 {
1455 	int i;
1456 
1457 	if (!link->sink_count) {
1458 		BREAK_TO_DEBUGGER();
1459 		return;
1460 	}
1461 
1462 	for (i = 0; i < link->sink_count; i++) {
1463 		if (link->remote_sinks[i] == sink) {
1464 			dc_sink_release(sink);
1465 			link->remote_sinks[i] = NULL;
1466 
1467 			/* shrink array to remove empty place */
1468 			while (i < link->sink_count - 1) {
1469 				link->remote_sinks[i] = link->remote_sinks[i+1];
1470 				i++;
1471 			}
1472 			link->remote_sinks[i] = NULL;
1473 			link->sink_count--;
1474 			return;
1475 		}
1476 	}
1477 }
1478