xref: /openbmc/linux/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c (revision 6f6249a599e52e1a5f0b632f8edff733cfa76450)
1 /*
2  * Copyright 2012-15 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 #include <drm/display/drm_dp_helper.h>
27 #include <drm/display/drm_dp_mst_helper.h>
28 #include <drm/drm_atomic.h>
29 #include <drm/drm_atomic_helper.h>
30 #include "dm_services.h"
31 #include "amdgpu.h"
32 #include "amdgpu_dm.h"
33 #include "amdgpu_dm_mst_types.h"
34 #include "amdgpu_dm_hdcp.h"
35 
36 #include "dc.h"
37 #include "dm_helpers.h"
38 
39 #include "ddc_service_types.h"
40 #include "dpcd_defs.h"
41 
42 #include "dmub_cmd.h"
43 #if defined(CONFIG_DEBUG_FS)
44 #include "amdgpu_dm_debugfs.h"
45 #endif
46 
47 #include "dc/dcn20/dcn20_resource.h"
48 
49 #define PEAK_FACTOR_X1000 1006
50 
51 /*
52  * This function handles both native AUX and I2C-Over-AUX transactions.
53  */
dm_dp_aux_transfer(struct drm_dp_aux * aux,struct drm_dp_aux_msg * msg)54 static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
55 				  struct drm_dp_aux_msg *msg)
56 {
57 	ssize_t result = 0;
58 	struct aux_payload payload;
59 	enum aux_return_code_type operation_result;
60 	struct amdgpu_device *adev;
61 	struct ddc_service *ddc;
62 	uint8_t copy[16];
63 
64 	if (WARN_ON(msg->size > 16))
65 		return -E2BIG;
66 
67 	payload.address = msg->address;
68 	payload.data = msg->buffer;
69 	payload.length = msg->size;
70 	payload.reply = &msg->reply;
71 	payload.i2c_over_aux = (msg->request & DP_AUX_NATIVE_WRITE) == 0;
72 	payload.write = (msg->request & DP_AUX_I2C_READ) == 0;
73 	payload.mot = (msg->request & DP_AUX_I2C_MOT) != 0;
74 	payload.write_status_update =
75 			(msg->request & DP_AUX_I2C_WRITE_STATUS_UPDATE) != 0;
76 	payload.defer_delay = 0;
77 
78 	if (payload.write) {
79 		memcpy(copy, msg->buffer, msg->size);
80 		payload.data = copy;
81 	}
82 
83 	result = dc_link_aux_transfer_raw(TO_DM_AUX(aux)->ddc_service, &payload,
84 				      &operation_result);
85 
86 	/*
87 	 * w/a on certain intel platform where hpd is unexpected to pull low during
88 	 * 1st sideband message transaction by return AUX_RET_ERROR_HPD_DISCON
89 	 * aux transaction is succuess in such case, therefore bypass the error
90 	 */
91 	ddc = TO_DM_AUX(aux)->ddc_service;
92 	adev = ddc->ctx->driver_context;
93 	if (adev->dm.aux_hpd_discon_quirk) {
94 		if (msg->address == DP_SIDEBAND_MSG_DOWN_REQ_BASE &&
95 			operation_result == AUX_RET_ERROR_HPD_DISCON) {
96 			result = msg->size;
97 			operation_result = AUX_RET_SUCCESS;
98 		}
99 	}
100 
101 	/*
102 	 * result equals to 0 includes the cases of AUX_DEFER/I2C_DEFER
103 	 */
104 	if (payload.write && result >= 0) {
105 		if (result) {
106 			/*one byte indicating partially written bytes*/
107 			drm_dbg_dp(adev_to_drm(adev), "amdgpu: AUX partially written\n");
108 			result = payload.data[0];
109 		} else if (!payload.reply[0])
110 			/*I2C_ACK|AUX_ACK*/
111 			result = msg->size;
112 	}
113 
114 	if (result < 0) {
115 		switch (operation_result) {
116 		case AUX_RET_SUCCESS:
117 			break;
118 		case AUX_RET_ERROR_HPD_DISCON:
119 		case AUX_RET_ERROR_UNKNOWN:
120 		case AUX_RET_ERROR_INVALID_OPERATION:
121 		case AUX_RET_ERROR_PROTOCOL_ERROR:
122 			result = -EIO;
123 			break;
124 		case AUX_RET_ERROR_INVALID_REPLY:
125 		case AUX_RET_ERROR_ENGINE_ACQUIRE:
126 			result = -EBUSY;
127 			break;
128 		case AUX_RET_ERROR_TIMEOUT:
129 			result = -ETIMEDOUT;
130 			break;
131 		}
132 
133 		drm_dbg_dp(adev_to_drm(adev), "amdgpu: DP AUX transfer fail:%d\n", operation_result);
134 	}
135 
136 	if (payload.reply[0])
137 		drm_dbg_dp(adev_to_drm(adev), "amdgpu: AUX reply command not ACK: 0x%02x.",
138 			payload.reply[0]);
139 
140 	return result;
141 }
142 
143 static void
dm_dp_mst_connector_destroy(struct drm_connector * connector)144 dm_dp_mst_connector_destroy(struct drm_connector *connector)
145 {
146 	struct amdgpu_dm_connector *aconnector =
147 		to_amdgpu_dm_connector(connector);
148 
149 	if (aconnector->dc_sink) {
150 		dc_link_remove_remote_sink(aconnector->dc_link,
151 					   aconnector->dc_sink);
152 		dc_sink_release(aconnector->dc_sink);
153 	}
154 
155 	kfree(aconnector->edid);
156 
157 	drm_connector_cleanup(connector);
158 	drm_dp_mst_put_port_malloc(aconnector->mst_output_port);
159 	kfree(aconnector);
160 }
161 
162 static int
amdgpu_dm_mst_connector_late_register(struct drm_connector * connector)163 amdgpu_dm_mst_connector_late_register(struct drm_connector *connector)
164 {
165 	struct amdgpu_dm_connector *amdgpu_dm_connector =
166 		to_amdgpu_dm_connector(connector);
167 	int r;
168 
169 	r = drm_dp_mst_connector_late_register(connector,
170 					       amdgpu_dm_connector->mst_output_port);
171 	if (r < 0)
172 		return r;
173 
174 #if defined(CONFIG_DEBUG_FS)
175 	connector_debugfs_init(amdgpu_dm_connector);
176 #endif
177 
178 	return 0;
179 }
180 
181 static void
amdgpu_dm_mst_connector_early_unregister(struct drm_connector * connector)182 amdgpu_dm_mst_connector_early_unregister(struct drm_connector *connector)
183 {
184 	struct amdgpu_dm_connector *aconnector =
185 		to_amdgpu_dm_connector(connector);
186 	struct drm_dp_mst_port *port = aconnector->mst_output_port;
187 	struct amdgpu_dm_connector *root = aconnector->mst_root;
188 	struct dc_link *dc_link = aconnector->dc_link;
189 	struct dc_sink *dc_sink = aconnector->dc_sink;
190 
191 	drm_dp_mst_connector_early_unregister(connector, port);
192 
193 	/*
194 	 * Release dc_sink for connector which its attached port is
195 	 * no longer in the mst topology
196 	 */
197 	drm_modeset_lock(&root->mst_mgr.base.lock, NULL);
198 	if (dc_sink) {
199 		if (dc_link->sink_count)
200 			dc_link_remove_remote_sink(dc_link, dc_sink);
201 
202 		DC_LOG_MST("DM_MST: remove remote sink 0x%p, %d remaining\n",
203 			dc_sink, dc_link->sink_count);
204 
205 		dc_sink_release(dc_sink);
206 		aconnector->dc_sink = NULL;
207 		aconnector->edid = NULL;
208 		aconnector->dsc_aux = NULL;
209 		port->passthrough_aux = NULL;
210 	}
211 
212 	aconnector->mst_status = MST_STATUS_DEFAULT;
213 	drm_modeset_unlock(&root->mst_mgr.base.lock);
214 }
215 
216 static const struct drm_connector_funcs dm_dp_mst_connector_funcs = {
217 	.fill_modes = drm_helper_probe_single_connector_modes,
218 	.destroy = dm_dp_mst_connector_destroy,
219 	.reset = amdgpu_dm_connector_funcs_reset,
220 	.atomic_duplicate_state = amdgpu_dm_connector_atomic_duplicate_state,
221 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
222 	.atomic_set_property = amdgpu_dm_connector_atomic_set_property,
223 	.atomic_get_property = amdgpu_dm_connector_atomic_get_property,
224 	.late_register = amdgpu_dm_mst_connector_late_register,
225 	.early_unregister = amdgpu_dm_mst_connector_early_unregister,
226 };
227 
needs_dsc_aux_workaround(struct dc_link * link)228 bool needs_dsc_aux_workaround(struct dc_link *link)
229 {
230 	if (link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_90CC24 &&
231 	    (link->dpcd_caps.dpcd_rev.raw == DPCD_REV_14 || link->dpcd_caps.dpcd_rev.raw == DPCD_REV_12) &&
232 	    link->dpcd_caps.sink_count.bits.SINK_COUNT >= 2)
233 		return true;
234 
235 	return false;
236 }
237 
is_synaptics_cascaded_panamera(struct dc_link * link,struct drm_dp_mst_port * port)238 static bool is_synaptics_cascaded_panamera(struct dc_link *link, struct drm_dp_mst_port *port)
239 {
240 	u8 branch_vendor_data[4] = { 0 }; // Vendor data 0x50C ~ 0x50F
241 
242 	if (drm_dp_dpcd_read(port->mgr->aux, DP_BRANCH_VENDOR_SPECIFIC_START, &branch_vendor_data, 4) == 4) {
243 		if (link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_90CC24 &&
244 				IS_SYNAPTICS_CASCADED_PANAMERA(link->dpcd_caps.branch_dev_name, branch_vendor_data)) {
245 			DRM_INFO("Synaptics Cascaded MST hub\n");
246 			return true;
247 		}
248 	}
249 
250 	return false;
251 }
252 
validate_dsc_caps_on_connector(struct amdgpu_dm_connector * aconnector)253 static bool validate_dsc_caps_on_connector(struct amdgpu_dm_connector *aconnector)
254 {
255 	struct dc_sink *dc_sink = aconnector->dc_sink;
256 	struct drm_dp_mst_port *port = aconnector->mst_output_port;
257 	u8 dsc_caps[16] = { 0 };
258 	u8 dsc_branch_dec_caps_raw[3] = { 0 };	// DSC branch decoder caps 0xA0 ~ 0xA2
259 	u8 *dsc_branch_dec_caps = NULL;
260 
261 	aconnector->dsc_aux = drm_dp_mst_dsc_aux_for_port(port);
262 
263 	/*
264 	 * drm_dp_mst_dsc_aux_for_port() will return NULL for certain configs
265 	 * because it only check the dsc/fec caps of the "port variable" and not the dock
266 	 *
267 	 * This case will return NULL: DSC capabe MST dock connected to a non fec/dsc capable display
268 	 *
269 	 * Workaround: explicitly check the use case above and use the mst dock's aux as dsc_aux
270 	 *
271 	 */
272 	if (!aconnector->dsc_aux && !port->parent->port_parent &&
273 	    needs_dsc_aux_workaround(aconnector->dc_link))
274 		aconnector->dsc_aux = &aconnector->mst_root->dm_dp_aux.aux;
275 
276 	/* synaptics cascaded MST hub case */
277 	if (is_synaptics_cascaded_panamera(aconnector->dc_link, port))
278 		aconnector->dsc_aux = port->mgr->aux;
279 
280 	if (!aconnector->dsc_aux)
281 		return false;
282 
283 	if (drm_dp_dpcd_read(aconnector->dsc_aux, DP_DSC_SUPPORT, dsc_caps, 16) < 0)
284 		return false;
285 
286 	if (drm_dp_dpcd_read(aconnector->dsc_aux,
287 			DP_DSC_BRANCH_OVERALL_THROUGHPUT_0, dsc_branch_dec_caps_raw, 3) == 3)
288 		dsc_branch_dec_caps = dsc_branch_dec_caps_raw;
289 
290 	if (!dc_dsc_parse_dsc_dpcd(aconnector->dc_link->ctx->dc,
291 				  dsc_caps, dsc_branch_dec_caps,
292 				  &dc_sink->dsc_caps.dsc_dec_caps))
293 		return false;
294 
295 	return true;
296 }
297 
retrieve_downstream_port_device(struct amdgpu_dm_connector * aconnector)298 static bool retrieve_downstream_port_device(struct amdgpu_dm_connector *aconnector)
299 {
300 	union dp_downstream_port_present ds_port_present;
301 
302 	if (!aconnector->dsc_aux)
303 		return false;
304 
305 	if (drm_dp_dpcd_read(aconnector->dsc_aux, DP_DOWNSTREAMPORT_PRESENT, &ds_port_present, 1) < 0) {
306 		DRM_INFO("Failed to read downstream_port_present 0x05 from DFP of branch device\n");
307 		return false;
308 	}
309 
310 	aconnector->mst_downstream_port_present = ds_port_present;
311 	DRM_INFO("Downstream port present %d, type %d\n",
312 			ds_port_present.fields.PORT_PRESENT, ds_port_present.fields.PORT_TYPE);
313 
314 	return true;
315 }
316 
dm_dp_mst_get_modes(struct drm_connector * connector)317 static int dm_dp_mst_get_modes(struct drm_connector *connector)
318 {
319 	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
320 	int ret = 0;
321 
322 	if (!aconnector)
323 		return drm_add_edid_modes(connector, NULL);
324 
325 	if (!aconnector->edid) {
326 		struct edid *edid;
327 
328 		edid = drm_dp_mst_get_edid(connector, &aconnector->mst_root->mst_mgr, aconnector->mst_output_port);
329 
330 		if (!edid) {
331 			amdgpu_dm_set_mst_status(&aconnector->mst_status,
332 			MST_REMOTE_EDID, false);
333 
334 			drm_connector_update_edid_property(
335 				&aconnector->base,
336 				NULL);
337 
338 			DRM_DEBUG_KMS("Can't get EDID of %s. Add default remote sink.", connector->name);
339 			if (!aconnector->dc_sink) {
340 				struct dc_sink *dc_sink;
341 				struct dc_sink_init_data init_params = {
342 					.link = aconnector->dc_link,
343 					.sink_signal = SIGNAL_TYPE_DISPLAY_PORT_MST };
344 
345 				dc_sink = dc_link_add_remote_sink(
346 					aconnector->dc_link,
347 					NULL,
348 					0,
349 					&init_params);
350 
351 				if (!dc_sink) {
352 					DRM_ERROR("Unable to add a remote sink\n");
353 					return 0;
354 				}
355 
356 				DC_LOG_MST("DM_MST: add remote sink 0x%p, %d remaining\n",
357 					dc_sink, aconnector->dc_link->sink_count);
358 
359 				dc_sink->priv = aconnector;
360 				aconnector->dc_sink = dc_sink;
361 			}
362 
363 			return ret;
364 		}
365 
366 		aconnector->edid = edid;
367 		amdgpu_dm_set_mst_status(&aconnector->mst_status,
368 			MST_REMOTE_EDID, true);
369 	}
370 
371 	if (aconnector->dc_sink && aconnector->dc_sink->sink_signal == SIGNAL_TYPE_VIRTUAL) {
372 		dc_sink_release(aconnector->dc_sink);
373 		aconnector->dc_sink = NULL;
374 	}
375 
376 	if (!aconnector->dc_sink) {
377 		struct dc_sink *dc_sink;
378 		struct dc_sink_init_data init_params = {
379 				.link = aconnector->dc_link,
380 				.sink_signal = SIGNAL_TYPE_DISPLAY_PORT_MST };
381 		dc_sink = dc_link_add_remote_sink(
382 			aconnector->dc_link,
383 			(uint8_t *)aconnector->edid,
384 			(aconnector->edid->extensions + 1) * EDID_LENGTH,
385 			&init_params);
386 
387 		if (!dc_sink) {
388 			DRM_ERROR("Unable to add a remote sink\n");
389 			return 0;
390 		}
391 
392 		DC_LOG_MST("DM_MST: add remote sink 0x%p, %d remaining\n",
393 			dc_sink, aconnector->dc_link->sink_count);
394 
395 		dc_sink->priv = aconnector;
396 		/* dc_link_add_remote_sink returns a new reference */
397 		aconnector->dc_sink = dc_sink;
398 
399 		/* when display is unplugged from mst hub, connctor will be
400 		 * destroyed within dm_dp_mst_connector_destroy. connector
401 		 * hdcp perperties, like type, undesired, desired, enabled,
402 		 * will be lost. So, save hdcp properties into hdcp_work within
403 		 * amdgpu_dm_atomic_commit_tail. if the same display is
404 		 * plugged back with same display index, its hdcp properties
405 		 * will be retrieved from hdcp_work within dm_dp_mst_get_modes
406 		 */
407 		if (aconnector->dc_sink && connector->state) {
408 			struct drm_device *dev = connector->dev;
409 			struct amdgpu_device *adev = drm_to_adev(dev);
410 
411 			if (adev->dm.hdcp_workqueue) {
412 				struct hdcp_workqueue *hdcp_work = adev->dm.hdcp_workqueue;
413 				struct hdcp_workqueue *hdcp_w =
414 					&hdcp_work[aconnector->dc_link->link_index];
415 
416 				connector->state->hdcp_content_type =
417 				hdcp_w->hdcp_content_type[connector->index];
418 				connector->state->content_protection =
419 				hdcp_w->content_protection[connector->index];
420 			}
421 		}
422 
423 		if (aconnector->dc_sink) {
424 			amdgpu_dm_update_freesync_caps(
425 					connector, aconnector->edid);
426 
427 			if (!validate_dsc_caps_on_connector(aconnector))
428 				memset(&aconnector->dc_sink->dsc_caps,
429 				       0, sizeof(aconnector->dc_sink->dsc_caps));
430 
431 			if (!retrieve_downstream_port_device(aconnector))
432 				memset(&aconnector->mst_downstream_port_present,
433 					0, sizeof(aconnector->mst_downstream_port_present));
434 		}
435 	}
436 
437 	drm_connector_update_edid_property(
438 					&aconnector->base, aconnector->edid);
439 
440 	ret = drm_add_edid_modes(connector, aconnector->edid);
441 
442 	return ret;
443 }
444 
445 static struct drm_encoder *
dm_mst_atomic_best_encoder(struct drm_connector * connector,struct drm_atomic_state * state)446 dm_mst_atomic_best_encoder(struct drm_connector *connector,
447 			   struct drm_atomic_state *state)
448 {
449 	struct drm_connector_state *connector_state = drm_atomic_get_new_connector_state(state,
450 											 connector);
451 	struct drm_device *dev = connector->dev;
452 	struct amdgpu_device *adev = drm_to_adev(dev);
453 	struct amdgpu_crtc *acrtc = to_amdgpu_crtc(connector_state->crtc);
454 
455 	return &adev->dm.mst_encoders[acrtc->crtc_id].base;
456 }
457 
458 static int
dm_dp_mst_detect(struct drm_connector * connector,struct drm_modeset_acquire_ctx * ctx,bool force)459 dm_dp_mst_detect(struct drm_connector *connector,
460 		 struct drm_modeset_acquire_ctx *ctx, bool force)
461 {
462 	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
463 	struct amdgpu_dm_connector *master = aconnector->mst_root;
464 	struct drm_dp_mst_port *port = aconnector->mst_output_port;
465 	int connection_status;
466 
467 	if (drm_connector_is_unregistered(connector))
468 		return connector_status_disconnected;
469 
470 	connection_status = drm_dp_mst_detect_port(connector, ctx, &master->mst_mgr,
471 							aconnector->mst_output_port);
472 
473 	if (port->pdt != DP_PEER_DEVICE_NONE && !port->dpcd_rev) {
474 		uint8_t dpcd_rev;
475 		int ret;
476 
477 		ret = drm_dp_dpcd_readb(&port->aux, DP_DP13_DPCD_REV, &dpcd_rev);
478 
479 		if (ret == 1) {
480 			port->dpcd_rev = dpcd_rev;
481 
482 			/* Could be DP1.2 DP Rx case*/
483 			if (!dpcd_rev) {
484 				ret = drm_dp_dpcd_readb(&port->aux, DP_DPCD_REV, &dpcd_rev);
485 
486 				if (ret == 1)
487 					port->dpcd_rev = dpcd_rev;
488 			}
489 
490 			if (!dpcd_rev)
491 				DRM_DEBUG_KMS("Can't decide DPCD revision number!");
492 		}
493 
494 		/*
495 		 * Could be legacy sink, logical port etc on DP1.2.
496 		 * Will get Nack under these cases when issue remote
497 		 * DPCD read.
498 		 */
499 		if (ret != 1)
500 			DRM_DEBUG_KMS("Can't access DPCD");
501 	} else if (port->pdt == DP_PEER_DEVICE_NONE) {
502 		port->dpcd_rev = 0;
503 	}
504 
505 	/*
506 	 * Release dc_sink for connector which unplug event is notified by CSN msg
507 	 */
508 	if (connection_status == connector_status_disconnected && aconnector->dc_sink) {
509 		if (aconnector->dc_link->sink_count)
510 			dc_link_remove_remote_sink(aconnector->dc_link, aconnector->dc_sink);
511 
512 		DC_LOG_MST("DM_MST: remove remote sink 0x%p, %d remaining\n",
513 			aconnector->dc_link, aconnector->dc_link->sink_count);
514 
515 		dc_sink_release(aconnector->dc_sink);
516 		aconnector->dc_sink = NULL;
517 		aconnector->edid = NULL;
518 		aconnector->dsc_aux = NULL;
519 		port->passthrough_aux = NULL;
520 
521 		amdgpu_dm_set_mst_status(&aconnector->mst_status,
522 			MST_REMOTE_EDID | MST_ALLOCATE_NEW_PAYLOAD | MST_CLEAR_ALLOCATED_PAYLOAD,
523 			false);
524 	}
525 
526 	return connection_status;
527 }
528 
dm_dp_mst_atomic_check(struct drm_connector * connector,struct drm_atomic_state * state)529 static int dm_dp_mst_atomic_check(struct drm_connector *connector,
530 				  struct drm_atomic_state *state)
531 {
532 	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
533 	struct drm_dp_mst_topology_mgr *mst_mgr = &aconnector->mst_root->mst_mgr;
534 	struct drm_dp_mst_port *mst_port = aconnector->mst_output_port;
535 
536 	return drm_dp_atomic_release_time_slots(state, mst_mgr, mst_port);
537 }
538 
539 static const struct drm_connector_helper_funcs dm_dp_mst_connector_helper_funcs = {
540 	.get_modes = dm_dp_mst_get_modes,
541 	.mode_valid = amdgpu_dm_connector_mode_valid,
542 	.atomic_best_encoder = dm_mst_atomic_best_encoder,
543 	.detect_ctx = dm_dp_mst_detect,
544 	.atomic_check = dm_dp_mst_atomic_check,
545 };
546 
amdgpu_dm_encoder_destroy(struct drm_encoder * encoder)547 static void amdgpu_dm_encoder_destroy(struct drm_encoder *encoder)
548 {
549 	drm_encoder_cleanup(encoder);
550 }
551 
552 static const struct drm_encoder_funcs amdgpu_dm_encoder_funcs = {
553 	.destroy = amdgpu_dm_encoder_destroy,
554 };
555 
556 void
dm_dp_create_fake_mst_encoders(struct amdgpu_device * adev)557 dm_dp_create_fake_mst_encoders(struct amdgpu_device *adev)
558 {
559 	struct drm_device *dev = adev_to_drm(adev);
560 	int i;
561 
562 	for (i = 0; i < adev->dm.display_indexes_num; i++) {
563 		struct amdgpu_encoder *amdgpu_encoder = &adev->dm.mst_encoders[i];
564 		struct drm_encoder *encoder = &amdgpu_encoder->base;
565 
566 		encoder->possible_crtcs = amdgpu_dm_get_encoder_crtc_mask(adev);
567 
568 		drm_encoder_init(
569 			dev,
570 			&amdgpu_encoder->base,
571 			&amdgpu_dm_encoder_funcs,
572 			DRM_MODE_ENCODER_DPMST,
573 			NULL);
574 
575 		drm_encoder_helper_add(encoder, &amdgpu_dm_encoder_helper_funcs);
576 	}
577 }
578 
579 static struct drm_connector *
dm_dp_add_mst_connector(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,const char * pathprop)580 dm_dp_add_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
581 			struct drm_dp_mst_port *port,
582 			const char *pathprop)
583 {
584 	struct amdgpu_dm_connector *master = container_of(mgr, struct amdgpu_dm_connector, mst_mgr);
585 	struct drm_device *dev = master->base.dev;
586 	struct amdgpu_device *adev = drm_to_adev(dev);
587 	struct amdgpu_dm_connector *aconnector;
588 	struct drm_connector *connector;
589 	int i;
590 
591 	aconnector = kzalloc(sizeof(*aconnector), GFP_KERNEL);
592 	if (!aconnector)
593 		return NULL;
594 
595 	connector = &aconnector->base;
596 	aconnector->mst_output_port = port;
597 	aconnector->mst_root = master;
598 	amdgpu_dm_set_mst_status(&aconnector->mst_status,
599 			MST_PROBE, true);
600 
601 	if (drm_connector_init(
602 		dev,
603 		connector,
604 		&dm_dp_mst_connector_funcs,
605 		DRM_MODE_CONNECTOR_DisplayPort)) {
606 		kfree(aconnector);
607 		return NULL;
608 	}
609 	drm_connector_helper_add(connector, &dm_dp_mst_connector_helper_funcs);
610 
611 	amdgpu_dm_connector_init_helper(
612 		&adev->dm,
613 		aconnector,
614 		DRM_MODE_CONNECTOR_DisplayPort,
615 		master->dc_link,
616 		master->connector_id);
617 
618 	for (i = 0; i < adev->dm.display_indexes_num; i++) {
619 		drm_connector_attach_encoder(&aconnector->base,
620 					     &adev->dm.mst_encoders[i].base);
621 	}
622 
623 	connector->max_bpc_property = master->base.max_bpc_property;
624 	if (connector->max_bpc_property)
625 		drm_connector_attach_max_bpc_property(connector, 8, 16);
626 
627 	connector->vrr_capable_property = master->base.vrr_capable_property;
628 	if (connector->vrr_capable_property)
629 		drm_connector_attach_vrr_capable_property(connector);
630 
631 	drm_object_attach_property(
632 		&connector->base,
633 		dev->mode_config.path_property,
634 		0);
635 	drm_object_attach_property(
636 		&connector->base,
637 		dev->mode_config.tile_property,
638 		0);
639 	connector->colorspace_property = master->base.colorspace_property;
640 	if (connector->colorspace_property)
641 		drm_connector_attach_colorspace_property(connector);
642 
643 	drm_connector_set_path_property(connector, pathprop);
644 
645 	/*
646 	 * Initialize connector state before adding the connectror to drm and
647 	 * framebuffer lists
648 	 */
649 	amdgpu_dm_connector_funcs_reset(connector);
650 
651 	drm_dp_mst_get_port_malloc(port);
652 
653 	return connector;
654 }
655 
dm_handle_mst_sideband_msg_ready_event(struct drm_dp_mst_topology_mgr * mgr,enum mst_msg_ready_type msg_rdy_type)656 void dm_handle_mst_sideband_msg_ready_event(
657 	struct drm_dp_mst_topology_mgr *mgr,
658 	enum mst_msg_ready_type msg_rdy_type)
659 {
660 	uint8_t esi[DP_PSR_ERROR_STATUS - DP_SINK_COUNT_ESI] = { 0 };
661 	uint8_t dret;
662 	bool new_irq_handled = false;
663 	int dpcd_addr;
664 	uint8_t dpcd_bytes_to_read;
665 	const uint8_t max_process_count = 30;
666 	uint8_t process_count = 0;
667 	u8 retry;
668 	struct amdgpu_dm_connector *aconnector =
669 			container_of(mgr, struct amdgpu_dm_connector, mst_mgr);
670 
671 
672 	const struct dc_link_status *link_status = dc_link_get_status(aconnector->dc_link);
673 
674 	if (link_status->dpcd_caps->dpcd_rev.raw < 0x12) {
675 		dpcd_bytes_to_read = DP_LANE0_1_STATUS - DP_SINK_COUNT;
676 		/* DPCD 0x200 - 0x201 for downstream IRQ */
677 		dpcd_addr = DP_SINK_COUNT;
678 	} else {
679 		dpcd_bytes_to_read = DP_PSR_ERROR_STATUS - DP_SINK_COUNT_ESI;
680 		/* DPCD 0x2002 - 0x2005 for downstream IRQ */
681 		dpcd_addr = DP_SINK_COUNT_ESI;
682 	}
683 
684 	mutex_lock(&aconnector->handle_mst_msg_ready);
685 
686 	while (process_count < max_process_count) {
687 		u8 ack[DP_PSR_ERROR_STATUS - DP_SINK_COUNT_ESI] = {};
688 
689 		process_count++;
690 
691 		dret = drm_dp_dpcd_read(
692 			&aconnector->dm_dp_aux.aux,
693 			dpcd_addr,
694 			esi,
695 			dpcd_bytes_to_read);
696 
697 		if (dret != dpcd_bytes_to_read) {
698 			DRM_DEBUG_KMS("DPCD read and acked number is not as expected!");
699 			break;
700 		}
701 
702 		DRM_DEBUG_DRIVER("ESI %02x %02x %02x\n", esi[0], esi[1], esi[2]);
703 
704 		switch (msg_rdy_type) {
705 		case DOWN_REP_MSG_RDY_EVENT:
706 			/* Only handle DOWN_REP_MSG_RDY case*/
707 			esi[1] &= DP_DOWN_REP_MSG_RDY;
708 			break;
709 		case UP_REQ_MSG_RDY_EVENT:
710 			/* Only handle UP_REQ_MSG_RDY case*/
711 			esi[1] &= DP_UP_REQ_MSG_RDY;
712 			break;
713 		default:
714 			/* Handle both cases*/
715 			esi[1] &= (DP_DOWN_REP_MSG_RDY | DP_UP_REQ_MSG_RDY);
716 			break;
717 		}
718 
719 		if (!esi[1])
720 			break;
721 
722 		/* handle MST irq */
723 		if (aconnector->mst_mgr.mst_state)
724 			drm_dp_mst_hpd_irq_handle_event(&aconnector->mst_mgr,
725 						 esi,
726 						 ack,
727 						 &new_irq_handled);
728 
729 		if (new_irq_handled) {
730 			/* ACK at DPCD to notify down stream */
731 			for (retry = 0; retry < 3; retry++) {
732 				ssize_t wret;
733 
734 				wret = drm_dp_dpcd_writeb(&aconnector->dm_dp_aux.aux,
735 							  dpcd_addr + 1,
736 							  ack[1]);
737 				if (wret == 1)
738 					break;
739 			}
740 
741 			if (retry == 3) {
742 				DRM_ERROR("Failed to ack MST event.\n");
743 				break;
744 			}
745 
746 			drm_dp_mst_hpd_irq_send_new_request(&aconnector->mst_mgr);
747 
748 			new_irq_handled = false;
749 		} else {
750 			break;
751 		}
752 	}
753 
754 	mutex_unlock(&aconnector->handle_mst_msg_ready);
755 
756 	if (process_count == max_process_count)
757 		DRM_DEBUG_DRIVER("Loop exceeded max iterations\n");
758 }
759 
dm_handle_mst_down_rep_msg_ready(struct drm_dp_mst_topology_mgr * mgr)760 static void dm_handle_mst_down_rep_msg_ready(struct drm_dp_mst_topology_mgr *mgr)
761 {
762 	dm_handle_mst_sideband_msg_ready_event(mgr, DOWN_REP_MSG_RDY_EVENT);
763 }
764 
765 static const struct drm_dp_mst_topology_cbs dm_mst_cbs = {
766 	.add_connector = dm_dp_add_mst_connector,
767 	.poll_hpd_irq = dm_handle_mst_down_rep_msg_ready,
768 };
769 
amdgpu_dm_initialize_dp_connector(struct amdgpu_display_manager * dm,struct amdgpu_dm_connector * aconnector,int link_index)770 void amdgpu_dm_initialize_dp_connector(struct amdgpu_display_manager *dm,
771 				       struct amdgpu_dm_connector *aconnector,
772 				       int link_index)
773 {
774 	struct dc_link_settings max_link_enc_cap = {0};
775 
776 	aconnector->dm_dp_aux.aux.name =
777 		kasprintf(GFP_KERNEL, "AMDGPU DM aux hw bus %d",
778 			  link_index);
779 	aconnector->dm_dp_aux.aux.transfer = dm_dp_aux_transfer;
780 	aconnector->dm_dp_aux.aux.drm_dev = dm->ddev;
781 	aconnector->dm_dp_aux.ddc_service = aconnector->dc_link->ddc;
782 
783 	drm_dp_aux_init(&aconnector->dm_dp_aux.aux);
784 	drm_dp_cec_register_connector(&aconnector->dm_dp_aux.aux,
785 				      &aconnector->base);
786 
787 	if (aconnector->base.connector_type == DRM_MODE_CONNECTOR_eDP)
788 		return;
789 
790 	dc_link_dp_get_max_link_enc_cap(aconnector->dc_link, &max_link_enc_cap);
791 	aconnector->mst_mgr.cbs = &dm_mst_cbs;
792 	drm_dp_mst_topology_mgr_init(&aconnector->mst_mgr, adev_to_drm(dm->adev),
793 				     &aconnector->dm_dp_aux.aux, 16, 4, aconnector->connector_id);
794 
795 	drm_connector_attach_dp_subconnector_property(&aconnector->base);
796 }
797 
dm_mst_get_pbn_divider(struct dc_link * link)798 int dm_mst_get_pbn_divider(struct dc_link *link)
799 {
800 	if (!link)
801 		return 0;
802 
803 	return dc_link_bandwidth_kbps(link,
804 			dc_link_get_link_cap(link)) / (8 * 1000 * 54);
805 }
806 
807 struct dsc_mst_fairness_params {
808 	struct dc_crtc_timing *timing;
809 	struct dc_sink *sink;
810 	struct dc_dsc_bw_range bw_range;
811 	bool compression_possible;
812 	struct drm_dp_mst_port *port;
813 	enum dsc_clock_force_state clock_force_enable;
814 	uint32_t num_slices_h;
815 	uint32_t num_slices_v;
816 	uint32_t bpp_overwrite;
817 	struct amdgpu_dm_connector *aconnector;
818 };
819 
get_fec_overhead_multiplier(struct dc_link * dc_link)820 static uint16_t get_fec_overhead_multiplier(struct dc_link *dc_link)
821 {
822 	u8 link_coding_cap;
823 	uint16_t fec_overhead_multiplier_x1000 = PBN_FEC_OVERHEAD_MULTIPLIER_8B_10B;
824 
825 	link_coding_cap = dc_link_dp_mst_decide_link_encoding_format(dc_link);
826 	if (link_coding_cap == DP_128b_132b_ENCODING)
827 		fec_overhead_multiplier_x1000 = PBN_FEC_OVERHEAD_MULTIPLIER_128B_132B;
828 
829 	return fec_overhead_multiplier_x1000;
830 }
831 
kbps_to_peak_pbn(int kbps,uint16_t fec_overhead_multiplier_x1000)832 static int kbps_to_peak_pbn(int kbps, uint16_t fec_overhead_multiplier_x1000)
833 {
834 	u64 peak_kbps = kbps;
835 
836 	peak_kbps *= 1006;
837 	peak_kbps *= fec_overhead_multiplier_x1000;
838 	peak_kbps = div_u64(peak_kbps, 1000 * 1000);
839 	return (int) DIV64_U64_ROUND_UP(peak_kbps * 64, (54 * 8 * 1000));
840 }
841 
set_dsc_configs_from_fairness_vars(struct dsc_mst_fairness_params * params,struct dsc_mst_fairness_vars * vars,int count,int k)842 static void set_dsc_configs_from_fairness_vars(struct dsc_mst_fairness_params *params,
843 		struct dsc_mst_fairness_vars *vars,
844 		int count,
845 		int k)
846 {
847 	struct drm_connector *drm_connector;
848 	int i;
849 	struct dc_dsc_config_options dsc_options = {0};
850 
851 	for (i = 0; i < count; i++) {
852 		drm_connector = &params[i].aconnector->base;
853 
854 		dc_dsc_get_default_config_option(params[i].sink->ctx->dc, &dsc_options);
855 		dsc_options.max_target_bpp_limit_override_x16 = drm_connector->display_info.max_dsc_bpp * 16;
856 
857 		memset(&params[i].timing->dsc_cfg, 0, sizeof(params[i].timing->dsc_cfg));
858 		if (vars[i + k].dsc_enabled && dc_dsc_compute_config(
859 					params[i].sink->ctx->dc->res_pool->dscs[0],
860 					&params[i].sink->dsc_caps.dsc_dec_caps,
861 					&dsc_options,
862 					0,
863 					params[i].timing,
864 					dc_link_get_highest_encoding_format(params[i].aconnector->dc_link),
865 					&params[i].timing->dsc_cfg)) {
866 			params[i].timing->flags.DSC = 1;
867 
868 			if (params[i].bpp_overwrite)
869 				params[i].timing->dsc_cfg.bits_per_pixel = params[i].bpp_overwrite;
870 			else
871 				params[i].timing->dsc_cfg.bits_per_pixel = vars[i + k].bpp_x16;
872 
873 			if (params[i].num_slices_h)
874 				params[i].timing->dsc_cfg.num_slices_h = params[i].num_slices_h;
875 
876 			if (params[i].num_slices_v)
877 				params[i].timing->dsc_cfg.num_slices_v = params[i].num_slices_v;
878 		} else {
879 			params[i].timing->flags.DSC = 0;
880 		}
881 		params[i].timing->dsc_cfg.mst_pbn = vars[i + k].pbn;
882 	}
883 
884 	for (i = 0; i < count; i++) {
885 		if (params[i].sink) {
886 			if (params[i].sink->sink_signal != SIGNAL_TYPE_VIRTUAL &&
887 				params[i].sink->sink_signal != SIGNAL_TYPE_NONE)
888 				DRM_DEBUG_DRIVER("%s i=%d dispname=%s\n", __func__, i,
889 					params[i].sink->edid_caps.display_name);
890 		}
891 
892 		DRM_DEBUG_DRIVER("dsc=%d bits_per_pixel=%d pbn=%d\n",
893 			params[i].timing->flags.DSC,
894 			params[i].timing->dsc_cfg.bits_per_pixel,
895 			vars[i + k].pbn);
896 	}
897 }
898 
bpp_x16_from_pbn(struct dsc_mst_fairness_params param,int pbn)899 static int bpp_x16_from_pbn(struct dsc_mst_fairness_params param, int pbn)
900 {
901 	struct dc_dsc_config dsc_config;
902 	u64 kbps;
903 
904 	struct drm_connector *drm_connector = &param.aconnector->base;
905 	struct dc_dsc_config_options dsc_options = {0};
906 
907 	dc_dsc_get_default_config_option(param.sink->ctx->dc, &dsc_options);
908 	dsc_options.max_target_bpp_limit_override_x16 = drm_connector->display_info.max_dsc_bpp * 16;
909 
910 	kbps = div_u64((u64)pbn * 994 * 8 * 54, 64);
911 	dc_dsc_compute_config(
912 			param.sink->ctx->dc->res_pool->dscs[0],
913 			&param.sink->dsc_caps.dsc_dec_caps,
914 			&dsc_options,
915 			(int) kbps, param.timing,
916 			dc_link_get_highest_encoding_format(param.aconnector->dc_link),
917 			&dsc_config);
918 
919 	return dsc_config.bits_per_pixel;
920 }
921 
increase_dsc_bpp(struct drm_atomic_state * state,struct drm_dp_mst_topology_state * mst_state,struct dc_link * dc_link,struct dsc_mst_fairness_params * params,struct dsc_mst_fairness_vars * vars,int count,int k)922 static int increase_dsc_bpp(struct drm_atomic_state *state,
923 			    struct drm_dp_mst_topology_state *mst_state,
924 			    struct dc_link *dc_link,
925 			    struct dsc_mst_fairness_params *params,
926 			    struct dsc_mst_fairness_vars *vars,
927 			    int count,
928 			    int k)
929 {
930 	int i;
931 	bool bpp_increased[MAX_PIPES];
932 	int initial_slack[MAX_PIPES];
933 	int min_initial_slack;
934 	int next_index;
935 	int remaining_to_increase = 0;
936 	int link_timeslots_used;
937 	int fair_pbn_alloc;
938 	int ret = 0;
939 	uint16_t fec_overhead_multiplier_x1000 = get_fec_overhead_multiplier(dc_link);
940 
941 	for (i = 0; i < count; i++) {
942 		if (vars[i + k].dsc_enabled) {
943 			initial_slack[i] =
944 			kbps_to_peak_pbn(params[i].bw_range.max_kbps, fec_overhead_multiplier_x1000) - vars[i + k].pbn;
945 			bpp_increased[i] = false;
946 			remaining_to_increase += 1;
947 		} else {
948 			initial_slack[i] = 0;
949 			bpp_increased[i] = true;
950 		}
951 	}
952 
953 	while (remaining_to_increase) {
954 		next_index = -1;
955 		min_initial_slack = -1;
956 		for (i = 0; i < count; i++) {
957 			if (!bpp_increased[i]) {
958 				if (min_initial_slack == -1 || min_initial_slack > initial_slack[i]) {
959 					min_initial_slack = initial_slack[i];
960 					next_index = i;
961 				}
962 			}
963 		}
964 
965 		if (next_index == -1)
966 			break;
967 
968 		link_timeslots_used = 0;
969 
970 		for (i = 0; i < count; i++)
971 			link_timeslots_used += DIV_ROUND_UP(vars[i + k].pbn, mst_state->pbn_div);
972 
973 		fair_pbn_alloc =
974 			(63 - link_timeslots_used) / remaining_to_increase * mst_state->pbn_div;
975 
976 		if (initial_slack[next_index] > fair_pbn_alloc) {
977 			vars[next_index].pbn += fair_pbn_alloc;
978 			ret = drm_dp_atomic_find_time_slots(state,
979 							    params[next_index].port->mgr,
980 							    params[next_index].port,
981 							    vars[next_index].pbn);
982 			if (ret < 0)
983 				return ret;
984 
985 			ret = drm_dp_mst_atomic_check(state);
986 			if (ret == 0) {
987 				vars[next_index].bpp_x16 = bpp_x16_from_pbn(params[next_index], vars[next_index].pbn);
988 			} else {
989 				vars[next_index].pbn -= fair_pbn_alloc;
990 				ret = drm_dp_atomic_find_time_slots(state,
991 								    params[next_index].port->mgr,
992 								    params[next_index].port,
993 								    vars[next_index].pbn);
994 				if (ret < 0)
995 					return ret;
996 			}
997 		} else {
998 			vars[next_index].pbn += initial_slack[next_index];
999 			ret = drm_dp_atomic_find_time_slots(state,
1000 							    params[next_index].port->mgr,
1001 							    params[next_index].port,
1002 							    vars[next_index].pbn);
1003 			if (ret < 0)
1004 				return ret;
1005 
1006 			ret = drm_dp_mst_atomic_check(state);
1007 			if (ret == 0) {
1008 				vars[next_index].bpp_x16 = params[next_index].bw_range.max_target_bpp_x16;
1009 			} else {
1010 				vars[next_index].pbn -= initial_slack[next_index];
1011 				ret = drm_dp_atomic_find_time_slots(state,
1012 								    params[next_index].port->mgr,
1013 								    params[next_index].port,
1014 								    vars[next_index].pbn);
1015 				if (ret < 0)
1016 					return ret;
1017 			}
1018 		}
1019 
1020 		bpp_increased[next_index] = true;
1021 		remaining_to_increase--;
1022 	}
1023 	return 0;
1024 }
1025 
try_disable_dsc(struct drm_atomic_state * state,struct dc_link * dc_link,struct dsc_mst_fairness_params * params,struct dsc_mst_fairness_vars * vars,int count,int k)1026 static int try_disable_dsc(struct drm_atomic_state *state,
1027 			   struct dc_link *dc_link,
1028 			   struct dsc_mst_fairness_params *params,
1029 			   struct dsc_mst_fairness_vars *vars,
1030 			   int count,
1031 			   int k)
1032 {
1033 	int i;
1034 	bool tried[MAX_PIPES];
1035 	int kbps_increase[MAX_PIPES];
1036 	int max_kbps_increase;
1037 	int next_index;
1038 	int remaining_to_try = 0;
1039 	int ret;
1040 	uint16_t fec_overhead_multiplier_x1000 = get_fec_overhead_multiplier(dc_link);
1041 
1042 	for (i = 0; i < count; i++) {
1043 		if (vars[i + k].dsc_enabled
1044 				&& vars[i + k].bpp_x16 == params[i].bw_range.max_target_bpp_x16
1045 				&& params[i].clock_force_enable == DSC_CLK_FORCE_DEFAULT) {
1046 			kbps_increase[i] = params[i].bw_range.stream_kbps - params[i].bw_range.max_kbps;
1047 			tried[i] = false;
1048 			remaining_to_try += 1;
1049 		} else {
1050 			kbps_increase[i] = 0;
1051 			tried[i] = true;
1052 		}
1053 	}
1054 
1055 	while (remaining_to_try) {
1056 		next_index = -1;
1057 		max_kbps_increase = -1;
1058 		for (i = 0; i < count; i++) {
1059 			if (!tried[i]) {
1060 				if (max_kbps_increase == -1 || max_kbps_increase < kbps_increase[i]) {
1061 					max_kbps_increase = kbps_increase[i];
1062 					next_index = i;
1063 				}
1064 			}
1065 		}
1066 
1067 		if (next_index == -1)
1068 			break;
1069 
1070 		vars[next_index].pbn = kbps_to_peak_pbn(params[next_index].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
1071 		ret = drm_dp_atomic_find_time_slots(state,
1072 						    params[next_index].port->mgr,
1073 						    params[next_index].port,
1074 						    vars[next_index].pbn);
1075 		if (ret < 0)
1076 			return ret;
1077 
1078 		ret = drm_dp_mst_atomic_check(state);
1079 		if (ret == 0) {
1080 			vars[next_index].dsc_enabled = false;
1081 			vars[next_index].bpp_x16 = 0;
1082 		} else {
1083 			vars[next_index].pbn = kbps_to_peak_pbn(params[next_index].bw_range.max_kbps, fec_overhead_multiplier_x1000);
1084 			ret = drm_dp_atomic_find_time_slots(state,
1085 							    params[next_index].port->mgr,
1086 							    params[next_index].port,
1087 							    vars[next_index].pbn);
1088 			if (ret < 0)
1089 				return ret;
1090 		}
1091 
1092 		tried[next_index] = true;
1093 		remaining_to_try--;
1094 	}
1095 	return 0;
1096 }
1097 
compute_mst_dsc_configs_for_link(struct drm_atomic_state * state,struct dc_state * dc_state,struct dc_link * dc_link,struct dsc_mst_fairness_vars * vars,struct drm_dp_mst_topology_mgr * mgr,int * link_vars_start_index)1098 static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
1099 					    struct dc_state *dc_state,
1100 					    struct dc_link *dc_link,
1101 					    struct dsc_mst_fairness_vars *vars,
1102 					    struct drm_dp_mst_topology_mgr *mgr,
1103 					    int *link_vars_start_index)
1104 {
1105 	struct dc_stream_state *stream;
1106 	struct dsc_mst_fairness_params params[MAX_PIPES];
1107 	struct amdgpu_dm_connector *aconnector;
1108 	struct drm_dp_mst_topology_state *mst_state = drm_atomic_get_mst_topology_state(state, mgr);
1109 	int count = 0;
1110 	int i, k, ret;
1111 	bool debugfs_overwrite = false;
1112 	uint16_t fec_overhead_multiplier_x1000 = get_fec_overhead_multiplier(dc_link);
1113 
1114 	memset(params, 0, sizeof(params));
1115 
1116 	if (IS_ERR(mst_state))
1117 		return PTR_ERR(mst_state);
1118 
1119 	/* Set up params */
1120 	for (i = 0; i < dc_state->stream_count; i++) {
1121 		struct dc_dsc_policy dsc_policy = {0};
1122 
1123 		stream = dc_state->streams[i];
1124 
1125 		if (stream->link != dc_link)
1126 			continue;
1127 
1128 		aconnector = (struct amdgpu_dm_connector *)stream->dm_stream_context;
1129 		if (!aconnector)
1130 			continue;
1131 
1132 		if (!aconnector->mst_output_port)
1133 			continue;
1134 
1135 		stream->timing.flags.DSC = 0;
1136 
1137 		params[count].timing = &stream->timing;
1138 		params[count].sink = stream->sink;
1139 		params[count].aconnector = aconnector;
1140 		params[count].port = aconnector->mst_output_port;
1141 		params[count].clock_force_enable = aconnector->dsc_settings.dsc_force_enable;
1142 		if (params[count].clock_force_enable == DSC_CLK_FORCE_ENABLE)
1143 			debugfs_overwrite = true;
1144 		params[count].num_slices_h = aconnector->dsc_settings.dsc_num_slices_h;
1145 		params[count].num_slices_v = aconnector->dsc_settings.dsc_num_slices_v;
1146 		params[count].bpp_overwrite = aconnector->dsc_settings.dsc_bits_per_pixel;
1147 		params[count].compression_possible = stream->sink->dsc_caps.dsc_dec_caps.is_dsc_supported;
1148 		dc_dsc_get_policy_for_timing(params[count].timing, 0, &dsc_policy, dc_link_get_highest_encoding_format(stream->link));
1149 		if (!dc_dsc_compute_bandwidth_range(
1150 				stream->sink->ctx->dc->res_pool->dscs[0],
1151 				stream->sink->ctx->dc->debug.dsc_min_slice_height_override,
1152 				dsc_policy.min_target_bpp * 16,
1153 				dsc_policy.max_target_bpp * 16,
1154 				&stream->sink->dsc_caps.dsc_dec_caps,
1155 				&stream->timing,
1156 				dc_link_get_highest_encoding_format(dc_link),
1157 				&params[count].bw_range))
1158 			params[count].bw_range.stream_kbps = dc_bandwidth_in_kbps_from_timing(&stream->timing,
1159 					dc_link_get_highest_encoding_format(dc_link));
1160 
1161 		count++;
1162 	}
1163 
1164 	if (count == 0) {
1165 		ASSERT(0);
1166 		return 0;
1167 	}
1168 
1169 	/* k is start index of vars for current phy link used by mst hub */
1170 	k = *link_vars_start_index;
1171 	/* set vars start index for next mst hub phy link */
1172 	*link_vars_start_index += count;
1173 
1174 	/* Try no compression */
1175 	for (i = 0; i < count; i++) {
1176 		vars[i + k].aconnector = params[i].aconnector;
1177 		vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
1178 		vars[i + k].dsc_enabled = false;
1179 		vars[i + k].bpp_x16 = 0;
1180 		ret = drm_dp_atomic_find_time_slots(state, params[i].port->mgr, params[i].port,
1181 						    vars[i + k].pbn);
1182 		if (ret < 0)
1183 			return ret;
1184 	}
1185 	ret = drm_dp_mst_atomic_check(state);
1186 	if (ret == 0 && !debugfs_overwrite) {
1187 		set_dsc_configs_from_fairness_vars(params, vars, count, k);
1188 		return 0;
1189 	} else if (ret != -ENOSPC) {
1190 		return ret;
1191 	}
1192 
1193 	/* Try max compression */
1194 	for (i = 0; i < count; i++) {
1195 		if (params[i].compression_possible && params[i].clock_force_enable != DSC_CLK_FORCE_DISABLE) {
1196 			vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.min_kbps, fec_overhead_multiplier_x1000);
1197 			vars[i + k].dsc_enabled = true;
1198 			vars[i + k].bpp_x16 = params[i].bw_range.min_target_bpp_x16;
1199 			ret = drm_dp_atomic_find_time_slots(state, params[i].port->mgr,
1200 							    params[i].port, vars[i + k].pbn);
1201 			if (ret < 0)
1202 				return ret;
1203 		} else {
1204 			vars[i + k].pbn = kbps_to_peak_pbn(params[i].bw_range.stream_kbps, fec_overhead_multiplier_x1000);
1205 			vars[i + k].dsc_enabled = false;
1206 			vars[i + k].bpp_x16 = 0;
1207 			ret = drm_dp_atomic_find_time_slots(state, params[i].port->mgr,
1208 							    params[i].port, vars[i + k].pbn);
1209 			if (ret < 0)
1210 				return ret;
1211 		}
1212 	}
1213 	ret = drm_dp_mst_atomic_check(state);
1214 	if (ret != 0)
1215 		return ret;
1216 
1217 	/* Optimize degree of compression */
1218 	ret = increase_dsc_bpp(state, mst_state, dc_link, params, vars, count, k);
1219 	if (ret < 0)
1220 		return ret;
1221 
1222 	ret = try_disable_dsc(state, dc_link, params, vars, count, k);
1223 	if (ret < 0)
1224 		return ret;
1225 
1226 	set_dsc_configs_from_fairness_vars(params, vars, count, k);
1227 
1228 	return 0;
1229 }
1230 
is_dsc_need_re_compute(struct drm_atomic_state * state,struct dc_state * dc_state,struct dc_link * dc_link)1231 static bool is_dsc_need_re_compute(
1232 	struct drm_atomic_state *state,
1233 	struct dc_state *dc_state,
1234 	struct dc_link *dc_link)
1235 {
1236 	int i, j;
1237 	bool is_dsc_need_re_compute = false;
1238 	struct amdgpu_dm_connector *stream_on_link[MAX_PIPES];
1239 	int new_stream_on_link_num = 0;
1240 	struct amdgpu_dm_connector *aconnector;
1241 	struct dc_stream_state *stream;
1242 	const struct dc *dc = dc_link->dc;
1243 
1244 	/* only check phy used by dsc mst branch */
1245 	if (dc_link->type != dc_connection_mst_branch)
1246 		return false;
1247 
1248 	for (i = 0; i < MAX_PIPES; i++)
1249 		stream_on_link[i] = NULL;
1250 
1251 	/* check if there is mode change in new request */
1252 	for (i = 0; i < dc_state->stream_count; i++) {
1253 		struct drm_crtc_state *new_crtc_state;
1254 		struct drm_connector_state *new_conn_state;
1255 
1256 		stream = dc_state->streams[i];
1257 		if (!stream)
1258 			continue;
1259 
1260 		/* check if stream using the same link for mst */
1261 		if (stream->link != dc_link)
1262 			continue;
1263 
1264 		aconnector = (struct amdgpu_dm_connector *) stream->dm_stream_context;
1265 		if (!aconnector)
1266 			continue;
1267 
1268 		/*
1269 		 *	Check if cached virtual MST DSC caps are available and DSC is supported
1270 		 *	this change takes care of newer MST DSC capable devices that report their
1271 		 *	DPCD caps as per specifications in their Virtual DPCD registers.
1272 
1273 		 *	TODO: implement the check for older MST DSC devices that do not conform to
1274 		 *	specifications.
1275 		*/
1276 		if (!(aconnector->dc_sink->dsc_caps.dsc_dec_caps.is_dsc_supported ||
1277 			aconnector->dc_link->dpcd_caps.dsc_caps.dsc_basic_caps.fields.dsc_support.DSC_PASSTHROUGH_SUPPORT))
1278 			continue;
1279 
1280 		stream_on_link[new_stream_on_link_num] = aconnector;
1281 		new_stream_on_link_num++;
1282 
1283 		new_conn_state = drm_atomic_get_new_connector_state(state, &aconnector->base);
1284 		if (!new_conn_state)
1285 			continue;
1286 
1287 		if (IS_ERR(new_conn_state))
1288 			continue;
1289 
1290 		if (!new_conn_state->crtc)
1291 			continue;
1292 
1293 		new_crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc);
1294 		if (!new_crtc_state)
1295 			continue;
1296 
1297 		if (IS_ERR(new_crtc_state))
1298 			continue;
1299 
1300 		if (new_crtc_state->enable && new_crtc_state->active) {
1301 			if (new_crtc_state->mode_changed || new_crtc_state->active_changed ||
1302 				new_crtc_state->connectors_changed)
1303 				return true;
1304 		}
1305 	}
1306 
1307 	if (new_stream_on_link_num == 0)
1308 		return false;
1309 
1310 	/* check current_state if there stream on link but it is not in
1311 	 * new request state
1312 	 */
1313 	for (i = 0; i < dc->current_state->stream_count; i++) {
1314 		stream = dc->current_state->streams[i];
1315 		/* only check stream on the mst hub */
1316 		if (stream->link != dc_link)
1317 			continue;
1318 
1319 		aconnector = (struct amdgpu_dm_connector *)stream->dm_stream_context;
1320 		if (!aconnector)
1321 			continue;
1322 
1323 		for (j = 0; j < new_stream_on_link_num; j++) {
1324 			if (stream_on_link[j]) {
1325 				if (aconnector == stream_on_link[j])
1326 					break;
1327 			}
1328 		}
1329 
1330 		if (j == new_stream_on_link_num) {
1331 			/* not in new state */
1332 			is_dsc_need_re_compute = true;
1333 			break;
1334 		}
1335 	}
1336 
1337 	return is_dsc_need_re_compute;
1338 }
1339 
compute_mst_dsc_configs_for_state(struct drm_atomic_state * state,struct dc_state * dc_state,struct dsc_mst_fairness_vars * vars)1340 int compute_mst_dsc_configs_for_state(struct drm_atomic_state *state,
1341 				      struct dc_state *dc_state,
1342 				      struct dsc_mst_fairness_vars *vars)
1343 {
1344 	int i, j;
1345 	struct dc_stream_state *stream;
1346 	bool computed_streams[MAX_PIPES];
1347 	struct amdgpu_dm_connector *aconnector;
1348 	struct drm_dp_mst_topology_mgr *mst_mgr;
1349 	struct resource_pool *res_pool;
1350 	int link_vars_start_index = 0;
1351 	int ret = 0;
1352 
1353 	for (i = 0; i < dc_state->stream_count; i++)
1354 		computed_streams[i] = false;
1355 
1356 	for (i = 0; i < dc_state->stream_count; i++) {
1357 		stream = dc_state->streams[i];
1358 		res_pool = stream->ctx->dc->res_pool;
1359 
1360 		if (stream->signal != SIGNAL_TYPE_DISPLAY_PORT_MST)
1361 			continue;
1362 
1363 		aconnector = (struct amdgpu_dm_connector *)stream->dm_stream_context;
1364 
1365 		if (!aconnector || !aconnector->dc_sink || !aconnector->mst_output_port)
1366 			continue;
1367 
1368 		if (!aconnector->dc_sink->dsc_caps.dsc_dec_caps.is_dsc_supported)
1369 			continue;
1370 
1371 		if (computed_streams[i])
1372 			continue;
1373 
1374 		if (res_pool->funcs->remove_stream_from_ctx &&
1375 		    res_pool->funcs->remove_stream_from_ctx(stream->ctx->dc, dc_state, stream) != DC_OK)
1376 			return -EINVAL;
1377 
1378 		if (!is_dsc_need_re_compute(state, dc_state, stream->link))
1379 			continue;
1380 
1381 		mst_mgr = aconnector->mst_output_port->mgr;
1382 		ret = compute_mst_dsc_configs_for_link(state, dc_state, stream->link, vars, mst_mgr,
1383 						       &link_vars_start_index);
1384 		if (ret != 0)
1385 			return ret;
1386 
1387 		for (j = 0; j < dc_state->stream_count; j++) {
1388 			if (dc_state->streams[j]->link == stream->link)
1389 				computed_streams[j] = true;
1390 		}
1391 	}
1392 
1393 	for (i = 0; i < dc_state->stream_count; i++) {
1394 		stream = dc_state->streams[i];
1395 
1396 		if (stream->timing.flags.DSC == 1)
1397 			if (dc_stream_add_dsc_to_resource(stream->ctx->dc, dc_state, stream) != DC_OK)
1398 				return -EINVAL;
1399 	}
1400 
1401 	return ret;
1402 }
1403 
pre_compute_mst_dsc_configs_for_state(struct drm_atomic_state * state,struct dc_state * dc_state,struct dsc_mst_fairness_vars * vars)1404 static int pre_compute_mst_dsc_configs_for_state(struct drm_atomic_state *state,
1405 						 struct dc_state *dc_state,
1406 						 struct dsc_mst_fairness_vars *vars)
1407 {
1408 	int i, j;
1409 	struct dc_stream_state *stream;
1410 	bool computed_streams[MAX_PIPES];
1411 	struct amdgpu_dm_connector *aconnector;
1412 	struct drm_dp_mst_topology_mgr *mst_mgr;
1413 	int link_vars_start_index = 0;
1414 	int ret = 0;
1415 
1416 	for (i = 0; i < dc_state->stream_count; i++)
1417 		computed_streams[i] = false;
1418 
1419 	for (i = 0; i < dc_state->stream_count; i++) {
1420 		stream = dc_state->streams[i];
1421 
1422 		if (stream->signal != SIGNAL_TYPE_DISPLAY_PORT_MST)
1423 			continue;
1424 
1425 		aconnector = (struct amdgpu_dm_connector *)stream->dm_stream_context;
1426 
1427 		if (!aconnector || !aconnector->dc_sink || !aconnector->mst_output_port)
1428 			continue;
1429 
1430 		if (!aconnector->dc_sink->dsc_caps.dsc_dec_caps.is_dsc_supported)
1431 			continue;
1432 
1433 		if (computed_streams[i])
1434 			continue;
1435 
1436 		if (!is_dsc_need_re_compute(state, dc_state, stream->link))
1437 			continue;
1438 
1439 		mst_mgr = aconnector->mst_output_port->mgr;
1440 		ret = compute_mst_dsc_configs_for_link(state, dc_state, stream->link, vars, mst_mgr,
1441 						       &link_vars_start_index);
1442 		if (ret != 0)
1443 			return ret;
1444 
1445 		for (j = 0; j < dc_state->stream_count; j++) {
1446 			if (dc_state->streams[j]->link == stream->link)
1447 				computed_streams[j] = true;
1448 		}
1449 	}
1450 
1451 	return ret;
1452 }
1453 
find_crtc_index_in_state_by_stream(struct drm_atomic_state * state,struct dc_stream_state * stream)1454 static int find_crtc_index_in_state_by_stream(struct drm_atomic_state *state,
1455 					      struct dc_stream_state *stream)
1456 {
1457 	int i;
1458 	struct drm_crtc *crtc;
1459 	struct drm_crtc_state *new_state, *old_state;
1460 
1461 	for_each_oldnew_crtc_in_state(state, crtc, old_state, new_state, i) {
1462 		struct dm_crtc_state *dm_state = to_dm_crtc_state(new_state);
1463 
1464 		if (dm_state->stream == stream)
1465 			return i;
1466 	}
1467 	return -1;
1468 }
1469 
is_link_to_dschub(struct dc_link * dc_link)1470 static bool is_link_to_dschub(struct dc_link *dc_link)
1471 {
1472 	union dpcd_dsc_basic_capabilities *dsc_caps =
1473 			&dc_link->dpcd_caps.dsc_caps.dsc_basic_caps;
1474 
1475 	/* only check phy used by dsc mst branch */
1476 	if (dc_link->type != dc_connection_mst_branch)
1477 		return false;
1478 
1479 	if (!(dsc_caps->fields.dsc_support.DSC_SUPPORT ||
1480 	      dsc_caps->fields.dsc_support.DSC_PASSTHROUGH_SUPPORT))
1481 		return false;
1482 	return true;
1483 }
1484 
is_dsc_precompute_needed(struct drm_atomic_state * state)1485 static bool is_dsc_precompute_needed(struct drm_atomic_state *state)
1486 {
1487 	int i;
1488 	struct drm_crtc *crtc;
1489 	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
1490 	bool ret = false;
1491 
1492 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
1493 		struct dm_crtc_state *dm_crtc_state = to_dm_crtc_state(new_crtc_state);
1494 
1495 		if (!amdgpu_dm_find_first_crtc_matching_connector(state, crtc)) {
1496 			ret =  false;
1497 			break;
1498 		}
1499 		if (dm_crtc_state->stream && dm_crtc_state->stream->link)
1500 			if (is_link_to_dschub(dm_crtc_state->stream->link))
1501 				ret = true;
1502 	}
1503 	return ret;
1504 }
1505 
pre_validate_dsc(struct drm_atomic_state * state,struct dm_atomic_state ** dm_state_ptr,struct dsc_mst_fairness_vars * vars)1506 int pre_validate_dsc(struct drm_atomic_state *state,
1507 		     struct dm_atomic_state **dm_state_ptr,
1508 		     struct dsc_mst_fairness_vars *vars)
1509 {
1510 	int i;
1511 	struct dm_atomic_state *dm_state;
1512 	struct dc_state *local_dc_state = NULL;
1513 	int ret = 0;
1514 
1515 	if (!is_dsc_precompute_needed(state)) {
1516 		DRM_INFO_ONCE("DSC precompute is not needed.\n");
1517 		return 0;
1518 	}
1519 	ret = dm_atomic_get_state(state, dm_state_ptr);
1520 	if (ret != 0) {
1521 		DRM_INFO_ONCE("dm_atomic_get_state() failed\n");
1522 		return ret;
1523 	}
1524 	dm_state = *dm_state_ptr;
1525 
1526 	/*
1527 	 * create local vailable for dc_state. copy content of streams of dm_state->context
1528 	 * to local variable. make sure stream pointer of local variable not the same as stream
1529 	 * from dm_state->context.
1530 	 */
1531 
1532 	local_dc_state = kmemdup(dm_state->context, sizeof(struct dc_state), GFP_KERNEL);
1533 	if (!local_dc_state)
1534 		return -ENOMEM;
1535 
1536 	for (i = 0; i < local_dc_state->stream_count; i++) {
1537 		struct dc_stream_state *stream = dm_state->context->streams[i];
1538 		int ind = find_crtc_index_in_state_by_stream(state, stream);
1539 
1540 		if (ind >= 0) {
1541 			struct amdgpu_dm_connector *aconnector;
1542 			struct drm_connector_state *drm_new_conn_state;
1543 			struct dm_connector_state *dm_new_conn_state;
1544 			struct dm_crtc_state *dm_old_crtc_state;
1545 
1546 			aconnector =
1547 				amdgpu_dm_find_first_crtc_matching_connector(state,
1548 									     state->crtcs[ind].ptr);
1549 			drm_new_conn_state =
1550 				drm_atomic_get_new_connector_state(state,
1551 								   &aconnector->base);
1552 			dm_new_conn_state = to_dm_connector_state(drm_new_conn_state);
1553 			dm_old_crtc_state = to_dm_crtc_state(state->crtcs[ind].old_state);
1554 
1555 			local_dc_state->streams[i] =
1556 				create_validate_stream_for_sink(aconnector,
1557 								&state->crtcs[ind].new_state->mode,
1558 								dm_new_conn_state,
1559 								dm_old_crtc_state->stream);
1560 			if (local_dc_state->streams[i] == NULL) {
1561 				ret = -EINVAL;
1562 				break;
1563 			}
1564 		}
1565 	}
1566 
1567 	if (ret != 0)
1568 		goto clean_exit;
1569 
1570 	ret = pre_compute_mst_dsc_configs_for_state(state, local_dc_state, vars);
1571 	if (ret != 0) {
1572 		DRM_INFO_ONCE("pre_compute_mst_dsc_configs_for_state() failed\n");
1573 		ret = -EINVAL;
1574 		goto clean_exit;
1575 	}
1576 
1577 	/*
1578 	 * compare local_streams -> timing  with dm_state->context,
1579 	 * if the same set crtc_state->mode-change = 0;
1580 	 */
1581 	for (i = 0; i < local_dc_state->stream_count; i++) {
1582 		struct dc_stream_state *stream = dm_state->context->streams[i];
1583 
1584 		if (local_dc_state->streams[i] &&
1585 		    dc_is_timing_changed(stream, local_dc_state->streams[i])) {
1586 			DRM_INFO_ONCE("crtc[%d] needs mode_changed\n", i);
1587 		} else {
1588 			int ind = find_crtc_index_in_state_by_stream(state, stream);
1589 
1590 			if (ind >= 0)
1591 				state->crtcs[ind].new_state->mode_changed = 0;
1592 		}
1593 	}
1594 clean_exit:
1595 	for (i = 0; i < local_dc_state->stream_count; i++) {
1596 		struct dc_stream_state *stream = dm_state->context->streams[i];
1597 
1598 		if (local_dc_state->streams[i] != stream)
1599 			dc_stream_release(local_dc_state->streams[i]);
1600 	}
1601 
1602 	kfree(local_dc_state);
1603 
1604 	return ret;
1605 }
1606 
kbps_from_pbn(unsigned int pbn)1607 static uint32_t kbps_from_pbn(unsigned int pbn)
1608 {
1609 	uint64_t kbps = (uint64_t)pbn;
1610 
1611 	kbps *= (1000000 / PEAK_FACTOR_X1000);
1612 	kbps *= 8;
1613 	kbps *= 54;
1614 	kbps /= 64;
1615 
1616 	return (uint32_t)kbps;
1617 }
1618 
is_dsc_common_config_possible(struct dc_stream_state * stream,struct dc_dsc_bw_range * bw_range)1619 static bool is_dsc_common_config_possible(struct dc_stream_state *stream,
1620 					  struct dc_dsc_bw_range *bw_range)
1621 {
1622 	struct dc_dsc_policy dsc_policy = {0};
1623 
1624 	dc_dsc_get_policy_for_timing(&stream->timing, 0, &dsc_policy, dc_link_get_highest_encoding_format(stream->link));
1625 	dc_dsc_compute_bandwidth_range(stream->sink->ctx->dc->res_pool->dscs[0],
1626 				       stream->sink->ctx->dc->debug.dsc_min_slice_height_override,
1627 				       dsc_policy.min_target_bpp * 16,
1628 				       dsc_policy.max_target_bpp * 16,
1629 				       &stream->sink->dsc_caps.dsc_dec_caps,
1630 				       &stream->timing, dc_link_get_highest_encoding_format(stream->link), bw_range);
1631 
1632 	return bw_range->max_target_bpp_x16 && bw_range->min_target_bpp_x16;
1633 }
1634 
dm_dp_mst_is_port_support_mode(struct amdgpu_dm_connector * aconnector,struct dc_stream_state * stream)1635 enum dc_status dm_dp_mst_is_port_support_mode(
1636 	struct amdgpu_dm_connector *aconnector,
1637 	struct dc_stream_state *stream)
1638 {
1639 	int bpp, pbn, branch_max_throughput_mps = 0;
1640 	struct dc_link_settings cur_link_settings;
1641 	unsigned int end_to_end_bw_in_kbps = 0;
1642 	unsigned int upper_link_bw_in_kbps = 0, down_link_bw_in_kbps = 0;
1643 	unsigned int max_compressed_bw_in_kbps = 0;
1644 	struct dc_dsc_bw_range bw_range = {0};
1645 	uint16_t full_pbn = aconnector->mst_output_port->full_pbn;
1646 
1647 	/*
1648 	 * Consider the case with the depth of the mst topology tree is equal or less than 2
1649 	 * A. When dsc bitstream can be transmitted along the entire path
1650 	 *    1. dsc is possible between source and branch/leaf device (common dsc params is possible), AND
1651 	 *    2. dsc passthrough supported at MST branch, or
1652 	 *    3. dsc decoding supported at leaf MST device
1653 	 *    Use maximum dsc compression as bw constraint
1654 	 * B. When dsc bitstream cannot be transmitted along the entire path
1655 	 *    Use native bw as bw constraint
1656 	 */
1657 	if (is_dsc_common_config_possible(stream, &bw_range) &&
1658 	   (aconnector->mst_output_port->passthrough_aux ||
1659 	    aconnector->dsc_aux == &aconnector->mst_output_port->aux)) {
1660 		cur_link_settings = stream->link->verified_link_cap;
1661 
1662 		upper_link_bw_in_kbps = dc_link_bandwidth_kbps(aconnector->dc_link,
1663 							       &cur_link_settings);
1664 		down_link_bw_in_kbps = kbps_from_pbn(full_pbn);
1665 
1666 		/* pick the bottleneck */
1667 		end_to_end_bw_in_kbps = min(upper_link_bw_in_kbps,
1668 					    down_link_bw_in_kbps);
1669 
1670 		/*
1671 		 * use the maximum dsc compression bandwidth as the required
1672 		 * bandwidth for the mode
1673 		 */
1674 		max_compressed_bw_in_kbps = bw_range.min_kbps;
1675 
1676 		if (end_to_end_bw_in_kbps < max_compressed_bw_in_kbps) {
1677 			DRM_DEBUG_DRIVER("Mode does not fit into DSC pass-through bandwidth validation\n");
1678 			return DC_FAIL_BANDWIDTH_VALIDATE;
1679 		}
1680 	} else {
1681 		/* check if mode could be supported within full_pbn */
1682 		bpp = convert_dc_color_depth_into_bpc(stream->timing.display_color_depth) * 3;
1683 		pbn = drm_dp_calc_pbn_mode(stream->timing.pix_clk_100hz / 10, bpp << 4);
1684 		if (pbn > full_pbn)
1685 			return DC_FAIL_BANDWIDTH_VALIDATE;
1686 	}
1687 
1688 	/* check is mst dsc output bandwidth branch_overall_throughput_0_mps */
1689 	switch (stream->timing.pixel_encoding) {
1690 	case PIXEL_ENCODING_RGB:
1691 	case PIXEL_ENCODING_YCBCR444:
1692 		branch_max_throughput_mps =
1693 			aconnector->dc_sink->dsc_caps.dsc_dec_caps.branch_overall_throughput_0_mps;
1694 		break;
1695 	case PIXEL_ENCODING_YCBCR422:
1696 	case PIXEL_ENCODING_YCBCR420:
1697 		branch_max_throughput_mps =
1698 			aconnector->dc_sink->dsc_caps.dsc_dec_caps.branch_overall_throughput_1_mps;
1699 		break;
1700 	default:
1701 		break;
1702 	}
1703 
1704 	if (branch_max_throughput_mps != 0 &&
1705 		((stream->timing.pix_clk_100hz / 10) >  branch_max_throughput_mps * 1000))
1706 		return DC_FAIL_BANDWIDTH_VALIDATE;
1707 
1708 	return DC_OK;
1709 }
1710