1 /*
2 * Copyright © 2008-2015 Intel Corporation
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 (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24 #include "i915_drv.h"
25 #include "intel_display_types.h"
26 #include "intel_dp.h"
27 #include "intel_dp_link_training.h"
28
intel_dp_reset_lttpr_common_caps(struct intel_dp * intel_dp)29 static void intel_dp_reset_lttpr_common_caps(struct intel_dp *intel_dp)
30 {
31 memset(intel_dp->lttpr_common_caps, 0, sizeof(intel_dp->lttpr_common_caps));
32 }
33
intel_dp_reset_lttpr_count(struct intel_dp * intel_dp)34 static void intel_dp_reset_lttpr_count(struct intel_dp *intel_dp)
35 {
36 intel_dp->lttpr_common_caps[DP_PHY_REPEATER_CNT -
37 DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV] = 0;
38 }
39
intel_dp_lttpr_phy_caps(struct intel_dp * intel_dp,enum drm_dp_phy dp_phy)40 static u8 *intel_dp_lttpr_phy_caps(struct intel_dp *intel_dp,
41 enum drm_dp_phy dp_phy)
42 {
43 return intel_dp->lttpr_phy_caps[dp_phy - DP_PHY_LTTPR1];
44 }
45
intel_dp_read_lttpr_phy_caps(struct intel_dp * intel_dp,const u8 dpcd[DP_RECEIVER_CAP_SIZE],enum drm_dp_phy dp_phy)46 static void intel_dp_read_lttpr_phy_caps(struct intel_dp *intel_dp,
47 const u8 dpcd[DP_RECEIVER_CAP_SIZE],
48 enum drm_dp_phy dp_phy)
49 {
50 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
51 u8 *phy_caps = intel_dp_lttpr_phy_caps(intel_dp, dp_phy);
52
53 if (drm_dp_read_lttpr_phy_caps(&intel_dp->aux, dpcd, dp_phy, phy_caps) < 0) {
54 drm_dbg_kms(&dp_to_i915(intel_dp)->drm,
55 "[ENCODER:%d:%s][%s] failed to read the PHY caps\n",
56 encoder->base.base.id, encoder->base.name,
57 drm_dp_phy_name(dp_phy));
58 return;
59 }
60
61 drm_dbg_kms(&dp_to_i915(intel_dp)->drm,
62 "[ENCODER:%d:%s][%s] PHY capabilities: %*ph\n",
63 encoder->base.base.id, encoder->base.name,
64 drm_dp_phy_name(dp_phy),
65 (int)sizeof(intel_dp->lttpr_phy_caps[0]),
66 phy_caps);
67 }
68
intel_dp_read_lttpr_common_caps(struct intel_dp * intel_dp,const u8 dpcd[DP_RECEIVER_CAP_SIZE])69 static bool intel_dp_read_lttpr_common_caps(struct intel_dp *intel_dp,
70 const u8 dpcd[DP_RECEIVER_CAP_SIZE])
71 {
72 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
73 int ret;
74
75 ret = drm_dp_read_lttpr_common_caps(&intel_dp->aux, dpcd,
76 intel_dp->lttpr_common_caps);
77 if (ret < 0)
78 goto reset_caps;
79
80 drm_dbg_kms(&dp_to_i915(intel_dp)->drm,
81 "[ENCODER:%d:%s] LTTPR common capabilities: %*ph\n",
82 encoder->base.base.id, encoder->base.name,
83 (int)sizeof(intel_dp->lttpr_common_caps),
84 intel_dp->lttpr_common_caps);
85
86 /* The minimum value of LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV is 1.4 */
87 if (intel_dp->lttpr_common_caps[0] < 0x14)
88 goto reset_caps;
89
90 return true;
91
92 reset_caps:
93 intel_dp_reset_lttpr_common_caps(intel_dp);
94 return false;
95 }
96
97 static bool
intel_dp_set_lttpr_transparent_mode(struct intel_dp * intel_dp,bool enable)98 intel_dp_set_lttpr_transparent_mode(struct intel_dp *intel_dp, bool enable)
99 {
100 u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT :
101 DP_PHY_REPEATER_MODE_NON_TRANSPARENT;
102
103 return drm_dp_dpcd_write(&intel_dp->aux, DP_PHY_REPEATER_MODE, &val, 1) == 1;
104 }
105
intel_dp_init_lttpr(struct intel_dp * intel_dp,const u8 dpcd[DP_RECEIVER_CAP_SIZE])106 static int intel_dp_init_lttpr(struct intel_dp *intel_dp, const u8 dpcd[DP_RECEIVER_CAP_SIZE])
107 {
108 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
109 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
110 int lttpr_count;
111 int i;
112
113 if (!intel_dp_read_lttpr_common_caps(intel_dp, dpcd))
114 return 0;
115
116 lttpr_count = drm_dp_lttpr_count(intel_dp->lttpr_common_caps);
117 /*
118 * Prevent setting LTTPR transparent mode explicitly if no LTTPRs are
119 * detected as this breaks link training at least on the Dell WD19TB
120 * dock.
121 */
122 if (lttpr_count == 0)
123 return 0;
124
125 /*
126 * See DP Standard v2.0 3.6.6.1. about the explicit disabling of
127 * non-transparent mode and the disable->enable non-transparent mode
128 * sequence.
129 */
130 intel_dp_set_lttpr_transparent_mode(intel_dp, true);
131
132 /*
133 * In case of unsupported number of LTTPRs or failing to switch to
134 * non-transparent mode fall-back to transparent link training mode,
135 * still taking into account any LTTPR common lane- rate/count limits.
136 */
137 if (lttpr_count < 0)
138 return 0;
139
140 if (!intel_dp_set_lttpr_transparent_mode(intel_dp, false)) {
141 drm_dbg_kms(&i915->drm,
142 "[ENCODER:%d:%s] Switching to LTTPR non-transparent LT mode failed, fall-back to transparent mode\n",
143 encoder->base.base.id, encoder->base.name);
144
145 intel_dp_set_lttpr_transparent_mode(intel_dp, true);
146 intel_dp_reset_lttpr_count(intel_dp);
147
148 return 0;
149 }
150
151 for (i = 0; i < lttpr_count; i++)
152 intel_dp_read_lttpr_phy_caps(intel_dp, dpcd, DP_PHY_LTTPR(i));
153
154 return lttpr_count;
155 }
156
157 /**
158 * intel_dp_init_lttpr_and_dprx_caps - detect LTTPR and DPRX caps, init the LTTPR link training mode
159 * @intel_dp: Intel DP struct
160 *
161 * Read the LTTPR common and DPRX capabilities and switch to non-transparent
162 * link training mode if any is detected and read the PHY capabilities for all
163 * detected LTTPRs. In case of an LTTPR detection error or if the number of
164 * LTTPRs is more than is supported (8), fall back to the no-LTTPR,
165 * transparent mode link training mode.
166 *
167 * Returns:
168 * >0 if LTTPRs were detected and the non-transparent LT mode was set. The
169 * DPRX capabilities are read out.
170 * 0 if no LTTPRs or more than 8 LTTPRs were detected or in case of a
171 * detection failure and the transparent LT mode was set. The DPRX
172 * capabilities are read out.
173 * <0 Reading out the DPRX capabilities failed.
174 */
intel_dp_init_lttpr_and_dprx_caps(struct intel_dp * intel_dp)175 int intel_dp_init_lttpr_and_dprx_caps(struct intel_dp *intel_dp)
176 {
177 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
178 int lttpr_count = 0;
179
180 /*
181 * Detecting LTTPRs must be avoided on platforms with an AUX timeout
182 * period < 3.2ms. (see DP Standard v2.0, 2.11.2, 3.6.6.1).
183 */
184 if (!intel_dp_is_edp(intel_dp) &&
185 (DISPLAY_VER(i915) >= 10 && !IS_GEMINILAKE(i915))) {
186 u8 dpcd[DP_RECEIVER_CAP_SIZE];
187
188 if (drm_dp_dpcd_probe(&intel_dp->aux, DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV))
189 return -EIO;
190
191 if (drm_dp_read_dpcd_caps(&intel_dp->aux, dpcd))
192 return -EIO;
193
194 lttpr_count = intel_dp_init_lttpr(intel_dp, dpcd);
195 }
196
197 /*
198 * The DPTX shall read the DPRX caps after LTTPR detection, so re-read
199 * it here.
200 */
201 if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd)) {
202 intel_dp_reset_lttpr_common_caps(intel_dp);
203 return -EIO;
204 }
205
206 return lttpr_count;
207 }
208
dp_voltage_max(u8 preemph)209 static u8 dp_voltage_max(u8 preemph)
210 {
211 switch (preemph & DP_TRAIN_PRE_EMPHASIS_MASK) {
212 case DP_TRAIN_PRE_EMPH_LEVEL_0:
213 return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
214 case DP_TRAIN_PRE_EMPH_LEVEL_1:
215 return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
216 case DP_TRAIN_PRE_EMPH_LEVEL_2:
217 return DP_TRAIN_VOLTAGE_SWING_LEVEL_1;
218 case DP_TRAIN_PRE_EMPH_LEVEL_3:
219 default:
220 return DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
221 }
222 }
223
intel_dp_lttpr_voltage_max(struct intel_dp * intel_dp,enum drm_dp_phy dp_phy)224 static u8 intel_dp_lttpr_voltage_max(struct intel_dp *intel_dp,
225 enum drm_dp_phy dp_phy)
226 {
227 const u8 *phy_caps = intel_dp_lttpr_phy_caps(intel_dp, dp_phy);
228
229 if (drm_dp_lttpr_voltage_swing_level_3_supported(phy_caps))
230 return DP_TRAIN_VOLTAGE_SWING_LEVEL_3;
231 else
232 return DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
233 }
234
intel_dp_lttpr_preemph_max(struct intel_dp * intel_dp,enum drm_dp_phy dp_phy)235 static u8 intel_dp_lttpr_preemph_max(struct intel_dp *intel_dp,
236 enum drm_dp_phy dp_phy)
237 {
238 const u8 *phy_caps = intel_dp_lttpr_phy_caps(intel_dp, dp_phy);
239
240 if (drm_dp_lttpr_pre_emphasis_level_3_supported(phy_caps))
241 return DP_TRAIN_PRE_EMPH_LEVEL_3;
242 else
243 return DP_TRAIN_PRE_EMPH_LEVEL_2;
244 }
245
246 static bool
intel_dp_phy_is_downstream_of_source(struct intel_dp * intel_dp,enum drm_dp_phy dp_phy)247 intel_dp_phy_is_downstream_of_source(struct intel_dp *intel_dp,
248 enum drm_dp_phy dp_phy)
249 {
250 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
251 int lttpr_count = drm_dp_lttpr_count(intel_dp->lttpr_common_caps);
252
253 drm_WARN_ON_ONCE(&i915->drm, lttpr_count <= 0 && dp_phy != DP_PHY_DPRX);
254
255 return lttpr_count <= 0 || dp_phy == DP_PHY_LTTPR(lttpr_count - 1);
256 }
257
intel_dp_phy_voltage_max(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy)258 static u8 intel_dp_phy_voltage_max(struct intel_dp *intel_dp,
259 const struct intel_crtc_state *crtc_state,
260 enum drm_dp_phy dp_phy)
261 {
262 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
263 u8 voltage_max;
264
265 /*
266 * Get voltage_max from the DPTX_PHY (source or LTTPR) upstream from
267 * the DPRX_PHY we train.
268 */
269 if (intel_dp_phy_is_downstream_of_source(intel_dp, dp_phy))
270 voltage_max = intel_dp->voltage_max(intel_dp, crtc_state);
271 else
272 voltage_max = intel_dp_lttpr_voltage_max(intel_dp, dp_phy + 1);
273
274 drm_WARN_ON_ONCE(&i915->drm,
275 voltage_max != DP_TRAIN_VOLTAGE_SWING_LEVEL_2 &&
276 voltage_max != DP_TRAIN_VOLTAGE_SWING_LEVEL_3);
277
278 return voltage_max;
279 }
280
intel_dp_phy_preemph_max(struct intel_dp * intel_dp,enum drm_dp_phy dp_phy)281 static u8 intel_dp_phy_preemph_max(struct intel_dp *intel_dp,
282 enum drm_dp_phy dp_phy)
283 {
284 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
285 u8 preemph_max;
286
287 /*
288 * Get preemph_max from the DPTX_PHY (source or LTTPR) upstream from
289 * the DPRX_PHY we train.
290 */
291 if (intel_dp_phy_is_downstream_of_source(intel_dp, dp_phy))
292 preemph_max = intel_dp->preemph_max(intel_dp);
293 else
294 preemph_max = intel_dp_lttpr_preemph_max(intel_dp, dp_phy + 1);
295
296 drm_WARN_ON_ONCE(&i915->drm,
297 preemph_max != DP_TRAIN_PRE_EMPH_LEVEL_2 &&
298 preemph_max != DP_TRAIN_PRE_EMPH_LEVEL_3);
299
300 return preemph_max;
301 }
302
has_per_lane_signal_levels(struct intel_dp * intel_dp,enum drm_dp_phy dp_phy)303 static bool has_per_lane_signal_levels(struct intel_dp *intel_dp,
304 enum drm_dp_phy dp_phy)
305 {
306 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
307
308 return !intel_dp_phy_is_downstream_of_source(intel_dp, dp_phy) ||
309 DISPLAY_VER(i915) >= 11;
310 }
311
312 /* 128b/132b */
intel_dp_get_lane_adjust_tx_ffe_preset(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy,const u8 link_status[DP_LINK_STATUS_SIZE],int lane)313 static u8 intel_dp_get_lane_adjust_tx_ffe_preset(struct intel_dp *intel_dp,
314 const struct intel_crtc_state *crtc_state,
315 enum drm_dp_phy dp_phy,
316 const u8 link_status[DP_LINK_STATUS_SIZE],
317 int lane)
318 {
319 u8 tx_ffe = 0;
320
321 if (has_per_lane_signal_levels(intel_dp, dp_phy)) {
322 lane = min(lane, crtc_state->lane_count - 1);
323 tx_ffe = drm_dp_get_adjust_tx_ffe_preset(link_status, lane);
324 } else {
325 for (lane = 0; lane < crtc_state->lane_count; lane++)
326 tx_ffe = max(tx_ffe, drm_dp_get_adjust_tx_ffe_preset(link_status, lane));
327 }
328
329 return tx_ffe;
330 }
331
332 /* 8b/10b */
intel_dp_get_lane_adjust_vswing_preemph(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy,const u8 link_status[DP_LINK_STATUS_SIZE],int lane)333 static u8 intel_dp_get_lane_adjust_vswing_preemph(struct intel_dp *intel_dp,
334 const struct intel_crtc_state *crtc_state,
335 enum drm_dp_phy dp_phy,
336 const u8 link_status[DP_LINK_STATUS_SIZE],
337 int lane)
338 {
339 u8 v = 0;
340 u8 p = 0;
341 u8 voltage_max;
342 u8 preemph_max;
343
344 if (has_per_lane_signal_levels(intel_dp, dp_phy)) {
345 lane = min(lane, crtc_state->lane_count - 1);
346
347 v = drm_dp_get_adjust_request_voltage(link_status, lane);
348 p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane);
349 } else {
350 for (lane = 0; lane < crtc_state->lane_count; lane++) {
351 v = max(v, drm_dp_get_adjust_request_voltage(link_status, lane));
352 p = max(p, drm_dp_get_adjust_request_pre_emphasis(link_status, lane));
353 }
354 }
355
356 preemph_max = intel_dp_phy_preemph_max(intel_dp, dp_phy);
357 if (p >= preemph_max)
358 p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED;
359
360 v = min(v, dp_voltage_max(p));
361
362 voltage_max = intel_dp_phy_voltage_max(intel_dp, crtc_state, dp_phy);
363 if (v >= voltage_max)
364 v = voltage_max | DP_TRAIN_MAX_SWING_REACHED;
365
366 return v | p;
367 }
368
intel_dp_get_lane_adjust_train(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy,const u8 link_status[DP_LINK_STATUS_SIZE],int lane)369 static u8 intel_dp_get_lane_adjust_train(struct intel_dp *intel_dp,
370 const struct intel_crtc_state *crtc_state,
371 enum drm_dp_phy dp_phy,
372 const u8 link_status[DP_LINK_STATUS_SIZE],
373 int lane)
374 {
375 if (intel_dp_is_uhbr(crtc_state))
376 return intel_dp_get_lane_adjust_tx_ffe_preset(intel_dp, crtc_state,
377 dp_phy, link_status, lane);
378 else
379 return intel_dp_get_lane_adjust_vswing_preemph(intel_dp, crtc_state,
380 dp_phy, link_status, lane);
381 }
382
383 #define TRAIN_REQ_FMT "%d/%d/%d/%d"
384 #define _TRAIN_REQ_VSWING_ARGS(link_status, lane) \
385 (drm_dp_get_adjust_request_voltage((link_status), (lane)) >> DP_TRAIN_VOLTAGE_SWING_SHIFT)
386 #define TRAIN_REQ_VSWING_ARGS(link_status) \
387 _TRAIN_REQ_VSWING_ARGS(link_status, 0), \
388 _TRAIN_REQ_VSWING_ARGS(link_status, 1), \
389 _TRAIN_REQ_VSWING_ARGS(link_status, 2), \
390 _TRAIN_REQ_VSWING_ARGS(link_status, 3)
391 #define _TRAIN_REQ_PREEMPH_ARGS(link_status, lane) \
392 (drm_dp_get_adjust_request_pre_emphasis((link_status), (lane)) >> DP_TRAIN_PRE_EMPHASIS_SHIFT)
393 #define TRAIN_REQ_PREEMPH_ARGS(link_status) \
394 _TRAIN_REQ_PREEMPH_ARGS(link_status, 0), \
395 _TRAIN_REQ_PREEMPH_ARGS(link_status, 1), \
396 _TRAIN_REQ_PREEMPH_ARGS(link_status, 2), \
397 _TRAIN_REQ_PREEMPH_ARGS(link_status, 3)
398 #define _TRAIN_REQ_TX_FFE_ARGS(link_status, lane) \
399 drm_dp_get_adjust_tx_ffe_preset((link_status), (lane))
400 #define TRAIN_REQ_TX_FFE_ARGS(link_status) \
401 _TRAIN_REQ_TX_FFE_ARGS(link_status, 0), \
402 _TRAIN_REQ_TX_FFE_ARGS(link_status, 1), \
403 _TRAIN_REQ_TX_FFE_ARGS(link_status, 2), \
404 _TRAIN_REQ_TX_FFE_ARGS(link_status, 3)
405
406 void
intel_dp_get_adjust_train(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy,const u8 link_status[DP_LINK_STATUS_SIZE])407 intel_dp_get_adjust_train(struct intel_dp *intel_dp,
408 const struct intel_crtc_state *crtc_state,
409 enum drm_dp_phy dp_phy,
410 const u8 link_status[DP_LINK_STATUS_SIZE])
411 {
412 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
413 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
414 int lane;
415
416 if (intel_dp_is_uhbr(crtc_state)) {
417 drm_dbg_kms(&i915->drm, "[ENCODER:%d:%s][%s] 128b/132b, lanes: %d, "
418 "TX FFE request: " TRAIN_REQ_FMT "\n",
419 encoder->base.base.id, encoder->base.name,
420 drm_dp_phy_name(dp_phy),
421 crtc_state->lane_count,
422 TRAIN_REQ_TX_FFE_ARGS(link_status));
423 } else {
424 drm_dbg_kms(&i915->drm, "[ENCODER:%d:%s][%s] 8b/10b, lanes: %d, "
425 "vswing request: " TRAIN_REQ_FMT ", "
426 "pre-emphasis request: " TRAIN_REQ_FMT "\n",
427 encoder->base.base.id, encoder->base.name,
428 drm_dp_phy_name(dp_phy),
429 crtc_state->lane_count,
430 TRAIN_REQ_VSWING_ARGS(link_status),
431 TRAIN_REQ_PREEMPH_ARGS(link_status));
432 }
433
434 for (lane = 0; lane < 4; lane++)
435 intel_dp->train_set[lane] =
436 intel_dp_get_lane_adjust_train(intel_dp, crtc_state,
437 dp_phy, link_status, lane);
438 }
439
intel_dp_training_pattern_set_reg(struct intel_dp * intel_dp,enum drm_dp_phy dp_phy)440 static int intel_dp_training_pattern_set_reg(struct intel_dp *intel_dp,
441 enum drm_dp_phy dp_phy)
442 {
443 return dp_phy == DP_PHY_DPRX ?
444 DP_TRAINING_PATTERN_SET :
445 DP_TRAINING_PATTERN_SET_PHY_REPEATER(dp_phy);
446 }
447
448 static bool
intel_dp_set_link_train(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy,u8 dp_train_pat)449 intel_dp_set_link_train(struct intel_dp *intel_dp,
450 const struct intel_crtc_state *crtc_state,
451 enum drm_dp_phy dp_phy,
452 u8 dp_train_pat)
453 {
454 int reg = intel_dp_training_pattern_set_reg(intel_dp, dp_phy);
455 u8 buf[sizeof(intel_dp->train_set) + 1];
456 int len;
457
458 intel_dp_program_link_training_pattern(intel_dp, crtc_state,
459 dp_phy, dp_train_pat);
460
461 buf[0] = dp_train_pat;
462 /* DP_TRAINING_LANEx_SET follow DP_TRAINING_PATTERN_SET */
463 memcpy(buf + 1, intel_dp->train_set, crtc_state->lane_count);
464 len = crtc_state->lane_count + 1;
465
466 return drm_dp_dpcd_write(&intel_dp->aux, reg, buf, len) == len;
467 }
468
dp_training_pattern_name(u8 train_pat)469 static char dp_training_pattern_name(u8 train_pat)
470 {
471 switch (train_pat) {
472 case DP_TRAINING_PATTERN_1:
473 case DP_TRAINING_PATTERN_2:
474 case DP_TRAINING_PATTERN_3:
475 return '0' + train_pat;
476 case DP_TRAINING_PATTERN_4:
477 return '4';
478 default:
479 MISSING_CASE(train_pat);
480 return '?';
481 }
482 }
483
484 void
intel_dp_program_link_training_pattern(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy,u8 dp_train_pat)485 intel_dp_program_link_training_pattern(struct intel_dp *intel_dp,
486 const struct intel_crtc_state *crtc_state,
487 enum drm_dp_phy dp_phy,
488 u8 dp_train_pat)
489 {
490 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
491 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
492 u8 train_pat = intel_dp_training_pattern_symbol(dp_train_pat);
493
494 if (train_pat != DP_TRAINING_PATTERN_DISABLE)
495 drm_dbg_kms(&i915->drm,
496 "[ENCODER:%d:%s][%s] Using DP training pattern TPS%c\n",
497 encoder->base.base.id, encoder->base.name,
498 drm_dp_phy_name(dp_phy),
499 dp_training_pattern_name(train_pat));
500
501 intel_dp->set_link_train(intel_dp, crtc_state, dp_train_pat);
502 }
503
504 #define TRAIN_SET_FMT "%d%s/%d%s/%d%s/%d%s"
505 #define _TRAIN_SET_VSWING_ARGS(train_set) \
506 ((train_set) & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT, \
507 (train_set) & DP_TRAIN_MAX_SWING_REACHED ? "(max)" : ""
508 #define TRAIN_SET_VSWING_ARGS(train_set) \
509 _TRAIN_SET_VSWING_ARGS((train_set)[0]), \
510 _TRAIN_SET_VSWING_ARGS((train_set)[1]), \
511 _TRAIN_SET_VSWING_ARGS((train_set)[2]), \
512 _TRAIN_SET_VSWING_ARGS((train_set)[3])
513 #define _TRAIN_SET_PREEMPH_ARGS(train_set) \
514 ((train_set) & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT, \
515 (train_set) & DP_TRAIN_MAX_PRE_EMPHASIS_REACHED ? "(max)" : ""
516 #define TRAIN_SET_PREEMPH_ARGS(train_set) \
517 _TRAIN_SET_PREEMPH_ARGS((train_set)[0]), \
518 _TRAIN_SET_PREEMPH_ARGS((train_set)[1]), \
519 _TRAIN_SET_PREEMPH_ARGS((train_set)[2]), \
520 _TRAIN_SET_PREEMPH_ARGS((train_set)[3])
521 #define _TRAIN_SET_TX_FFE_ARGS(train_set) \
522 ((train_set) & DP_TX_FFE_PRESET_VALUE_MASK), ""
523 #define TRAIN_SET_TX_FFE_ARGS(train_set) \
524 _TRAIN_SET_TX_FFE_ARGS((train_set)[0]), \
525 _TRAIN_SET_TX_FFE_ARGS((train_set)[1]), \
526 _TRAIN_SET_TX_FFE_ARGS((train_set)[2]), \
527 _TRAIN_SET_TX_FFE_ARGS((train_set)[3])
528
intel_dp_set_signal_levels(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy)529 void intel_dp_set_signal_levels(struct intel_dp *intel_dp,
530 const struct intel_crtc_state *crtc_state,
531 enum drm_dp_phy dp_phy)
532 {
533 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
534 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
535
536 if (intel_dp_is_uhbr(crtc_state)) {
537 drm_dbg_kms(&i915->drm, "[ENCODER:%d:%s][%s] 128b/132b, lanes: %d, "
538 "TX FFE presets: " TRAIN_SET_FMT "\n",
539 encoder->base.base.id, encoder->base.name,
540 drm_dp_phy_name(dp_phy),
541 crtc_state->lane_count,
542 TRAIN_SET_TX_FFE_ARGS(intel_dp->train_set));
543 } else {
544 drm_dbg_kms(&i915->drm, "[ENCODER:%d:%s][%s] 8b/10b, lanes: %d, "
545 "vswing levels: " TRAIN_SET_FMT ", "
546 "pre-emphasis levels: " TRAIN_SET_FMT "\n",
547 encoder->base.base.id, encoder->base.name,
548 drm_dp_phy_name(dp_phy),
549 crtc_state->lane_count,
550 TRAIN_SET_VSWING_ARGS(intel_dp->train_set),
551 TRAIN_SET_PREEMPH_ARGS(intel_dp->train_set));
552 }
553
554 if (intel_dp_phy_is_downstream_of_source(intel_dp, dp_phy))
555 encoder->set_signal_levels(encoder, crtc_state);
556 }
557
558 static bool
intel_dp_reset_link_train(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy,u8 dp_train_pat)559 intel_dp_reset_link_train(struct intel_dp *intel_dp,
560 const struct intel_crtc_state *crtc_state,
561 enum drm_dp_phy dp_phy,
562 u8 dp_train_pat)
563 {
564 memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set));
565 intel_dp_set_signal_levels(intel_dp, crtc_state, dp_phy);
566 return intel_dp_set_link_train(intel_dp, crtc_state, dp_phy, dp_train_pat);
567 }
568
569 static bool
intel_dp_update_link_train(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy)570 intel_dp_update_link_train(struct intel_dp *intel_dp,
571 const struct intel_crtc_state *crtc_state,
572 enum drm_dp_phy dp_phy)
573 {
574 int reg = dp_phy == DP_PHY_DPRX ?
575 DP_TRAINING_LANE0_SET :
576 DP_TRAINING_LANE0_SET_PHY_REPEATER(dp_phy);
577 int ret;
578
579 intel_dp_set_signal_levels(intel_dp, crtc_state, dp_phy);
580
581 ret = drm_dp_dpcd_write(&intel_dp->aux, reg,
582 intel_dp->train_set, crtc_state->lane_count);
583
584 return ret == crtc_state->lane_count;
585 }
586
587 /* 128b/132b */
intel_dp_lane_max_tx_ffe_reached(u8 train_set_lane)588 static bool intel_dp_lane_max_tx_ffe_reached(u8 train_set_lane)
589 {
590 return (train_set_lane & DP_TX_FFE_PRESET_VALUE_MASK) ==
591 DP_TX_FFE_PRESET_VALUE_MASK;
592 }
593
594 /*
595 * 8b/10b
596 *
597 * FIXME: The DP spec is very confusing here, also the Link CTS spec seems to
598 * have self contradicting tests around this area.
599 *
600 * In lieu of better ideas let's just stop when we've reached the max supported
601 * vswing with its max pre-emphasis, which is either 2+1 or 3+0 depending on
602 * whether vswing level 3 is supported or not.
603 */
intel_dp_lane_max_vswing_reached(u8 train_set_lane)604 static bool intel_dp_lane_max_vswing_reached(u8 train_set_lane)
605 {
606 u8 v = (train_set_lane & DP_TRAIN_VOLTAGE_SWING_MASK) >>
607 DP_TRAIN_VOLTAGE_SWING_SHIFT;
608 u8 p = (train_set_lane & DP_TRAIN_PRE_EMPHASIS_MASK) >>
609 DP_TRAIN_PRE_EMPHASIS_SHIFT;
610
611 if ((train_set_lane & DP_TRAIN_MAX_SWING_REACHED) == 0)
612 return false;
613
614 if (v + p != 3)
615 return false;
616
617 return true;
618 }
619
intel_dp_link_max_vswing_reached(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state)620 static bool intel_dp_link_max_vswing_reached(struct intel_dp *intel_dp,
621 const struct intel_crtc_state *crtc_state)
622 {
623 int lane;
624
625 for (lane = 0; lane < crtc_state->lane_count; lane++) {
626 u8 train_set_lane = intel_dp->train_set[lane];
627
628 if (intel_dp_is_uhbr(crtc_state)) {
629 if (!intel_dp_lane_max_tx_ffe_reached(train_set_lane))
630 return false;
631 } else {
632 if (!intel_dp_lane_max_vswing_reached(train_set_lane))
633 return false;
634 }
635 }
636
637 return true;
638 }
639
640 /*
641 * Prepare link training by configuring the link parameters. On DDI platforms
642 * also enable the port here.
643 */
644 static bool
intel_dp_prepare_link_train(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state)645 intel_dp_prepare_link_train(struct intel_dp *intel_dp,
646 const struct intel_crtc_state *crtc_state)
647 {
648 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
649 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
650 u8 link_config[2];
651 u8 link_bw, rate_select;
652
653 if (intel_dp->prepare_link_retrain)
654 intel_dp->prepare_link_retrain(intel_dp, crtc_state);
655
656 intel_dp_compute_rate(intel_dp, crtc_state->port_clock,
657 &link_bw, &rate_select);
658
659 /*
660 * WaEdpLinkRateDataReload
661 *
662 * Parade PS8461E MUX (used on varius TGL+ laptops) needs
663 * to snoop the link rates reported by the sink when we
664 * use LINK_RATE_SET in order to operate in jitter cleaning
665 * mode (as opposed to redriver mode). Unfortunately it
666 * loses track of the snooped link rates when powered down,
667 * so we need to make it re-snoop often. Without this high
668 * link rates are not stable.
669 */
670 if (!link_bw) {
671 struct intel_connector *connector = intel_dp->attached_connector;
672 __le16 sink_rates[DP_MAX_SUPPORTED_RATES];
673
674 drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] Reloading eDP link rates\n",
675 connector->base.base.id, connector->base.name);
676
677 drm_dp_dpcd_read(&intel_dp->aux, DP_SUPPORTED_LINK_RATES,
678 sink_rates, sizeof(sink_rates));
679 }
680
681 if (link_bw)
682 drm_dbg_kms(&i915->drm,
683 "[ENCODER:%d:%s] Using LINK_BW_SET value %02x\n",
684 encoder->base.base.id, encoder->base.name, link_bw);
685 else
686 drm_dbg_kms(&i915->drm,
687 "[ENCODER:%d:%s] Using LINK_RATE_SET value %02x\n",
688 encoder->base.base.id, encoder->base.name, rate_select);
689
690 /* Write the link configuration data */
691 link_config[0] = link_bw;
692 link_config[1] = crtc_state->lane_count;
693 if (drm_dp_enhanced_frame_cap(intel_dp->dpcd))
694 link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
695 drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_BW_SET, link_config, 2);
696
697 /* eDP 1.4 rate select method. */
698 if (!link_bw)
699 drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_RATE_SET,
700 &rate_select, 1);
701
702 link_config[0] = crtc_state->vrr.enable ? DP_MSA_TIMING_PAR_IGNORE_EN : 0;
703 link_config[1] = intel_dp_is_uhbr(crtc_state) ?
704 DP_SET_ANSI_128B132B : DP_SET_ANSI_8B10B;
705 drm_dp_dpcd_write(&intel_dp->aux, DP_DOWNSPREAD_CTRL, link_config, 2);
706
707 return true;
708 }
709
intel_dp_adjust_request_changed(const struct intel_crtc_state * crtc_state,const u8 old_link_status[DP_LINK_STATUS_SIZE],const u8 new_link_status[DP_LINK_STATUS_SIZE])710 static bool intel_dp_adjust_request_changed(const struct intel_crtc_state *crtc_state,
711 const u8 old_link_status[DP_LINK_STATUS_SIZE],
712 const u8 new_link_status[DP_LINK_STATUS_SIZE])
713 {
714 int lane;
715
716 for (lane = 0; lane < crtc_state->lane_count; lane++) {
717 u8 old, new;
718
719 if (intel_dp_is_uhbr(crtc_state)) {
720 old = drm_dp_get_adjust_tx_ffe_preset(old_link_status, lane);
721 new = drm_dp_get_adjust_tx_ffe_preset(new_link_status, lane);
722 } else {
723 old = drm_dp_get_adjust_request_voltage(old_link_status, lane) |
724 drm_dp_get_adjust_request_pre_emphasis(old_link_status, lane);
725 new = drm_dp_get_adjust_request_voltage(new_link_status, lane) |
726 drm_dp_get_adjust_request_pre_emphasis(new_link_status, lane);
727 }
728
729 if (old != new)
730 return true;
731 }
732
733 return false;
734 }
735
736 void
intel_dp_dump_link_status(struct intel_dp * intel_dp,enum drm_dp_phy dp_phy,const u8 link_status[DP_LINK_STATUS_SIZE])737 intel_dp_dump_link_status(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy,
738 const u8 link_status[DP_LINK_STATUS_SIZE])
739 {
740 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
741 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
742
743 drm_dbg_kms(&i915->drm,
744 "[ENCODER:%d:%s][%s] ln0_1:0x%x ln2_3:0x%x align:0x%x sink:0x%x adj_req0_1:0x%x adj_req2_3:0x%x\n",
745 encoder->base.base.id, encoder->base.name,
746 drm_dp_phy_name(dp_phy),
747 link_status[0], link_status[1], link_status[2],
748 link_status[3], link_status[4], link_status[5]);
749 }
750
751 /*
752 * Perform the link training clock recovery phase on the given DP PHY using
753 * training pattern 1.
754 */
755 static bool
intel_dp_link_training_clock_recovery(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy)756 intel_dp_link_training_clock_recovery(struct intel_dp *intel_dp,
757 const struct intel_crtc_state *crtc_state,
758 enum drm_dp_phy dp_phy)
759 {
760 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
761 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
762 u8 old_link_status[DP_LINK_STATUS_SIZE] = {};
763 int voltage_tries, cr_tries, max_cr_tries;
764 u8 link_status[DP_LINK_STATUS_SIZE];
765 bool max_vswing_reached = false;
766 int delay_us;
767
768 delay_us = drm_dp_read_clock_recovery_delay(&intel_dp->aux,
769 intel_dp->dpcd, dp_phy,
770 intel_dp_is_uhbr(crtc_state));
771
772 /* clock recovery */
773 if (!intel_dp_reset_link_train(intel_dp, crtc_state, dp_phy,
774 DP_TRAINING_PATTERN_1 |
775 DP_LINK_SCRAMBLING_DISABLE)) {
776 drm_err(&i915->drm, "[ENCODER:%d:%s][%s] Failed to enable link training\n",
777 encoder->base.base.id, encoder->base.name,
778 drm_dp_phy_name(dp_phy));
779 return false;
780 }
781
782 /*
783 * The DP 1.4 spec defines the max clock recovery retries value
784 * as 10 but for pre-DP 1.4 devices we set a very tolerant
785 * retry limit of 80 (4 voltage levels x 4 preemphasis levels x
786 * x 5 identical voltage retries). Since the previous specs didn't
787 * define a limit and created the possibility of an infinite loop
788 * we want to prevent any sync from triggering that corner case.
789 */
790 if (intel_dp->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14)
791 max_cr_tries = 10;
792 else
793 max_cr_tries = 80;
794
795 voltage_tries = 1;
796 for (cr_tries = 0; cr_tries < max_cr_tries; ++cr_tries) {
797 usleep_range(delay_us, 2 * delay_us);
798
799 if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, dp_phy,
800 link_status) < 0) {
801 drm_err(&i915->drm, "[ENCODER:%d:%s][%s] Failed to get link status\n",
802 encoder->base.base.id, encoder->base.name,
803 drm_dp_phy_name(dp_phy));
804 return false;
805 }
806
807 if (drm_dp_clock_recovery_ok(link_status, crtc_state->lane_count)) {
808 drm_dbg_kms(&i915->drm,
809 "[ENCODER:%d:%s][%s] Clock recovery OK\n",
810 encoder->base.base.id, encoder->base.name,
811 drm_dp_phy_name(dp_phy));
812 return true;
813 }
814
815 if (voltage_tries == 5) {
816 intel_dp_dump_link_status(intel_dp, dp_phy, link_status);
817 drm_dbg_kms(&i915->drm,
818 "[ENCODER:%d:%s][%s] Same voltage tried 5 times\n",
819 encoder->base.base.id, encoder->base.name,
820 drm_dp_phy_name(dp_phy));
821 return false;
822 }
823
824 if (max_vswing_reached) {
825 intel_dp_dump_link_status(intel_dp, dp_phy, link_status);
826 drm_dbg_kms(&i915->drm,
827 "[ENCODER:%d:%s][%s] Max Voltage Swing reached\n",
828 encoder->base.base.id, encoder->base.name,
829 drm_dp_phy_name(dp_phy));
830 return false;
831 }
832
833 /* Update training set as requested by target */
834 intel_dp_get_adjust_train(intel_dp, crtc_state, dp_phy,
835 link_status);
836 if (!intel_dp_update_link_train(intel_dp, crtc_state, dp_phy)) {
837 drm_err(&i915->drm,
838 "[ENCODER:%d:%s][%s] Failed to update link training\n",
839 encoder->base.base.id, encoder->base.name,
840 drm_dp_phy_name(dp_phy));
841 return false;
842 }
843
844 if (!intel_dp_adjust_request_changed(crtc_state, old_link_status, link_status))
845 ++voltage_tries;
846 else
847 voltage_tries = 1;
848
849 memcpy(old_link_status, link_status, sizeof(link_status));
850
851 if (intel_dp_link_max_vswing_reached(intel_dp, crtc_state))
852 max_vswing_reached = true;
853 }
854
855 intel_dp_dump_link_status(intel_dp, dp_phy, link_status);
856 drm_err(&i915->drm,
857 "[ENCODER:%d:%s][%s] Failed clock recovery %d times, giving up!\n",
858 encoder->base.base.id, encoder->base.name,
859 drm_dp_phy_name(dp_phy), max_cr_tries);
860
861 return false;
862 }
863
864 /*
865 * Pick Training Pattern Sequence (TPS) for channel equalization. 128b/132b TPS2
866 * for UHBR+, TPS4 for HBR3 or for 1.4 devices that support it, TPS3 for HBR2 or
867 * 1.2 devices that support it, TPS2 otherwise.
868 */
intel_dp_training_pattern(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy)869 static u32 intel_dp_training_pattern(struct intel_dp *intel_dp,
870 const struct intel_crtc_state *crtc_state,
871 enum drm_dp_phy dp_phy)
872 {
873 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
874 bool source_tps3, sink_tps3, source_tps4, sink_tps4;
875
876 /* UHBR+ use separate 128b/132b TPS2 */
877 if (intel_dp_is_uhbr(crtc_state))
878 return DP_TRAINING_PATTERN_2;
879
880 /*
881 * TPS4 support is mandatory for all downstream devices that
882 * support HBR3. There are no known eDP panels that support
883 * TPS4 as of Feb 2018 as per VESA eDP_v1.4b_E1 specification.
884 * LTTPRs must support TPS4.
885 */
886 source_tps4 = intel_dp_source_supports_tps4(i915);
887 sink_tps4 = dp_phy != DP_PHY_DPRX ||
888 drm_dp_tps4_supported(intel_dp->dpcd);
889 if (source_tps4 && sink_tps4) {
890 return DP_TRAINING_PATTERN_4;
891 } else if (crtc_state->port_clock == 810000) {
892 if (!source_tps4)
893 drm_dbg_kms(&i915->drm,
894 "8.1 Gbps link rate without source TPS4 support\n");
895 if (!sink_tps4)
896 drm_dbg_kms(&i915->drm,
897 "8.1 Gbps link rate without sink TPS4 support\n");
898 }
899
900 /*
901 * TPS3 support is mandatory for downstream devices that
902 * support HBR2. However, not all sinks follow the spec.
903 */
904 source_tps3 = intel_dp_source_supports_tps3(i915);
905 sink_tps3 = dp_phy != DP_PHY_DPRX ||
906 drm_dp_tps3_supported(intel_dp->dpcd);
907 if (source_tps3 && sink_tps3) {
908 return DP_TRAINING_PATTERN_3;
909 } else if (crtc_state->port_clock >= 540000) {
910 if (!source_tps3)
911 drm_dbg_kms(&i915->drm,
912 ">=5.4/6.48 Gbps link rate without source TPS3 support\n");
913 if (!sink_tps3)
914 drm_dbg_kms(&i915->drm,
915 ">=5.4/6.48 Gbps link rate without sink TPS3 support\n");
916 }
917
918 return DP_TRAINING_PATTERN_2;
919 }
920
921 /*
922 * Perform the link training channel equalization phase on the given DP PHY
923 * using one of training pattern 2, 3 or 4 depending on the source and
924 * sink capabilities.
925 */
926 static bool
intel_dp_link_training_channel_equalization(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy)927 intel_dp_link_training_channel_equalization(struct intel_dp *intel_dp,
928 const struct intel_crtc_state *crtc_state,
929 enum drm_dp_phy dp_phy)
930 {
931 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
932 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
933 int tries;
934 u32 training_pattern;
935 u8 link_status[DP_LINK_STATUS_SIZE];
936 bool channel_eq = false;
937 int delay_us;
938
939 delay_us = drm_dp_read_channel_eq_delay(&intel_dp->aux,
940 intel_dp->dpcd, dp_phy,
941 intel_dp_is_uhbr(crtc_state));
942
943 training_pattern = intel_dp_training_pattern(intel_dp, crtc_state, dp_phy);
944 /* Scrambling is disabled for TPS2/3 and enabled for TPS4 */
945 if (training_pattern != DP_TRAINING_PATTERN_4)
946 training_pattern |= DP_LINK_SCRAMBLING_DISABLE;
947
948 /* channel equalization */
949 if (!intel_dp_set_link_train(intel_dp, crtc_state, dp_phy,
950 training_pattern)) {
951 drm_err(&i915->drm,
952 "[ENCODER:%d:%s][%s] Failed to start channel equalization\n",
953 encoder->base.base.id, encoder->base.name,
954 drm_dp_phy_name(dp_phy));
955 return false;
956 }
957
958 for (tries = 0; tries < 5; tries++) {
959 usleep_range(delay_us, 2 * delay_us);
960
961 if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, dp_phy,
962 link_status) < 0) {
963 drm_err(&i915->drm,
964 "[ENCODER:%d:%s][%s] Failed to get link status\n",
965 encoder->base.base.id, encoder->base.name,
966 drm_dp_phy_name(dp_phy));
967 break;
968 }
969
970 /* Make sure clock is still ok */
971 if (!drm_dp_clock_recovery_ok(link_status,
972 crtc_state->lane_count)) {
973 intel_dp_dump_link_status(intel_dp, dp_phy, link_status);
974 drm_dbg_kms(&i915->drm,
975 "[ENCODER:%d:%s][%s] Clock recovery check failed, cannot "
976 "continue channel equalization\n",
977 encoder->base.base.id, encoder->base.name,
978 drm_dp_phy_name(dp_phy));
979 break;
980 }
981
982 if (drm_dp_channel_eq_ok(link_status,
983 crtc_state->lane_count)) {
984 channel_eq = true;
985 drm_dbg_kms(&i915->drm,
986 "[ENCODER:%d:%s][%s] Channel EQ done. DP Training successful\n",
987 encoder->base.base.id, encoder->base.name,
988 drm_dp_phy_name(dp_phy));
989 break;
990 }
991
992 /* Update training set as requested by target */
993 intel_dp_get_adjust_train(intel_dp, crtc_state, dp_phy,
994 link_status);
995 if (!intel_dp_update_link_train(intel_dp, crtc_state, dp_phy)) {
996 drm_err(&i915->drm,
997 "[ENCODER:%d:%s][%s] Failed to update link training\n",
998 encoder->base.base.id, encoder->base.name,
999 drm_dp_phy_name(dp_phy));
1000 break;
1001 }
1002 }
1003
1004 /* Try 5 times, else fail and try at lower BW */
1005 if (tries == 5) {
1006 intel_dp_dump_link_status(intel_dp, dp_phy, link_status);
1007 drm_dbg_kms(&i915->drm,
1008 "[ENCODER:%d:%s][%s] Channel equalization failed 5 times\n",
1009 encoder->base.base.id, encoder->base.name,
1010 drm_dp_phy_name(dp_phy));
1011 }
1012
1013 return channel_eq;
1014 }
1015
intel_dp_disable_dpcd_training_pattern(struct intel_dp * intel_dp,enum drm_dp_phy dp_phy)1016 static bool intel_dp_disable_dpcd_training_pattern(struct intel_dp *intel_dp,
1017 enum drm_dp_phy dp_phy)
1018 {
1019 int reg = intel_dp_training_pattern_set_reg(intel_dp, dp_phy);
1020 u8 val = DP_TRAINING_PATTERN_DISABLE;
1021
1022 return drm_dp_dpcd_write(&intel_dp->aux, reg, &val, 1) == 1;
1023 }
1024
1025 static int
intel_dp_128b132b_intra_hop(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state)1026 intel_dp_128b132b_intra_hop(struct intel_dp *intel_dp,
1027 const struct intel_crtc_state *crtc_state)
1028 {
1029 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
1030 u8 sink_status;
1031 int ret;
1032
1033 ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_SINK_STATUS, &sink_status);
1034 if (ret != 1) {
1035 drm_dbg_kms(&i915->drm, "Failed to read sink status\n");
1036 return ret < 0 ? ret : -EIO;
1037 }
1038
1039 return sink_status & DP_INTRA_HOP_AUX_REPLY_INDICATION ? 1 : 0;
1040 }
1041
1042 /**
1043 * intel_dp_stop_link_train - stop link training
1044 * @intel_dp: DP struct
1045 * @crtc_state: state for CRTC attached to the encoder
1046 *
1047 * Stop the link training of the @intel_dp port, disabling the training
1048 * pattern in the sink's DPCD, and disabling the test pattern symbol
1049 * generation on the port.
1050 *
1051 * What symbols are output on the port after this point is
1052 * platform specific: On DDI/VLV/CHV platforms it will be the idle pattern
1053 * with the pipe being disabled, on older platforms it's HW specific if/how an
1054 * idle pattern is generated, as the pipe is already enabled here for those.
1055 *
1056 * This function must be called after intel_dp_start_link_train().
1057 */
intel_dp_stop_link_train(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state)1058 void intel_dp_stop_link_train(struct intel_dp *intel_dp,
1059 const struct intel_crtc_state *crtc_state)
1060 {
1061 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
1062 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
1063
1064 intel_dp->link_trained = true;
1065
1066 intel_dp_disable_dpcd_training_pattern(intel_dp, DP_PHY_DPRX);
1067 intel_dp_program_link_training_pattern(intel_dp, crtc_state, DP_PHY_DPRX,
1068 DP_TRAINING_PATTERN_DISABLE);
1069
1070 if (intel_dp_is_uhbr(crtc_state) &&
1071 wait_for(intel_dp_128b132b_intra_hop(intel_dp, crtc_state) == 0, 500)) {
1072 drm_dbg_kms(&i915->drm,
1073 "[ENCODER:%d:%s] 128b/132b intra-hop not clearing\n",
1074 encoder->base.base.id, encoder->base.name);
1075 }
1076 }
1077
1078 static bool
intel_dp_link_train_phy(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,enum drm_dp_phy dp_phy)1079 intel_dp_link_train_phy(struct intel_dp *intel_dp,
1080 const struct intel_crtc_state *crtc_state,
1081 enum drm_dp_phy dp_phy)
1082 {
1083 struct intel_connector *connector = intel_dp->attached_connector;
1084 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
1085 bool ret = false;
1086
1087 if (!intel_dp_link_training_clock_recovery(intel_dp, crtc_state, dp_phy))
1088 goto out;
1089
1090 if (!intel_dp_link_training_channel_equalization(intel_dp, crtc_state, dp_phy))
1091 goto out;
1092
1093 ret = true;
1094
1095 out:
1096 drm_dbg_kms(&dp_to_i915(intel_dp)->drm,
1097 "[CONNECTOR:%d:%s][ENCODER:%d:%s][%s] Link Training %s at link rate = %d, lane count = %d\n",
1098 connector->base.base.id, connector->base.name,
1099 encoder->base.base.id, encoder->base.name,
1100 drm_dp_phy_name(dp_phy),
1101 ret ? "passed" : "failed",
1102 crtc_state->port_clock, crtc_state->lane_count);
1103
1104 return ret;
1105 }
1106
intel_dp_schedule_fallback_link_training(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state)1107 static void intel_dp_schedule_fallback_link_training(struct intel_dp *intel_dp,
1108 const struct intel_crtc_state *crtc_state)
1109 {
1110 struct intel_connector *intel_connector = intel_dp->attached_connector;
1111 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
1112
1113 if (intel_dp->hobl_active) {
1114 drm_dbg_kms(&dp_to_i915(intel_dp)->drm,
1115 "[ENCODER:%d:%s] Link Training failed with HOBL active, "
1116 "not enabling it from now on",
1117 encoder->base.base.id, encoder->base.name);
1118 intel_dp->hobl_failed = true;
1119 } else if (intel_dp_get_link_train_fallback_values(intel_dp,
1120 crtc_state->port_clock,
1121 crtc_state->lane_count)) {
1122 return;
1123 }
1124
1125 /* Schedule a Hotplug Uevent to userspace to start modeset */
1126 schedule_work(&intel_connector->modeset_retry_work);
1127 }
1128
1129 /* Perform the link training on all LTTPRs and the DPRX on a link. */
1130 static bool
intel_dp_link_train_all_phys(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,int lttpr_count)1131 intel_dp_link_train_all_phys(struct intel_dp *intel_dp,
1132 const struct intel_crtc_state *crtc_state,
1133 int lttpr_count)
1134 {
1135 bool ret = true;
1136 int i;
1137
1138 for (i = lttpr_count - 1; i >= 0; i--) {
1139 enum drm_dp_phy dp_phy = DP_PHY_LTTPR(i);
1140
1141 ret = intel_dp_link_train_phy(intel_dp, crtc_state, dp_phy);
1142 intel_dp_disable_dpcd_training_pattern(intel_dp, dp_phy);
1143
1144 if (!ret)
1145 break;
1146 }
1147
1148 if (ret)
1149 ret = intel_dp_link_train_phy(intel_dp, crtc_state, DP_PHY_DPRX);
1150
1151 if (intel_dp->set_idle_link_train)
1152 intel_dp->set_idle_link_train(intel_dp, crtc_state);
1153
1154 return ret;
1155 }
1156
1157 /*
1158 * 128b/132b DP LANEx_EQ_DONE Sequence (DP 2.0 E11 3.5.2.16.1)
1159 */
1160 static bool
intel_dp_128b132b_lane_eq(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state)1161 intel_dp_128b132b_lane_eq(struct intel_dp *intel_dp,
1162 const struct intel_crtc_state *crtc_state)
1163 {
1164 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
1165 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
1166 u8 link_status[DP_LINK_STATUS_SIZE];
1167 int delay_us;
1168 int try, max_tries = 20;
1169 unsigned long deadline;
1170 bool timeout = false;
1171
1172 /*
1173 * Reset signal levels. Start transmitting 128b/132b TPS1.
1174 *
1175 * Put DPRX and LTTPRs (if any) into intra-hop AUX mode by writing TPS1
1176 * in DP_TRAINING_PATTERN_SET.
1177 */
1178 if (!intel_dp_reset_link_train(intel_dp, crtc_state, DP_PHY_DPRX,
1179 DP_TRAINING_PATTERN_1)) {
1180 drm_err(&i915->drm,
1181 "[ENCODER:%d:%s] Failed to start 128b/132b TPS1\n",
1182 encoder->base.base.id, encoder->base.name);
1183 return false;
1184 }
1185
1186 delay_us = drm_dp_128b132b_read_aux_rd_interval(&intel_dp->aux);
1187
1188 /* Read the initial TX FFE settings. */
1189 if (drm_dp_dpcd_read_link_status(&intel_dp->aux, link_status) < 0) {
1190 drm_err(&i915->drm,
1191 "[ENCODER:%d:%s] Failed to read TX FFE presets\n",
1192 encoder->base.base.id, encoder->base.name);
1193 return false;
1194 }
1195
1196 /* Update signal levels and training set as requested. */
1197 intel_dp_get_adjust_train(intel_dp, crtc_state, DP_PHY_DPRX, link_status);
1198 if (!intel_dp_update_link_train(intel_dp, crtc_state, DP_PHY_DPRX)) {
1199 drm_err(&i915->drm,
1200 "[ENCODER:%d:%s] Failed to set initial TX FFE settings\n",
1201 encoder->base.base.id, encoder->base.name);
1202 return false;
1203 }
1204
1205 /* Start transmitting 128b/132b TPS2. */
1206 if (!intel_dp_set_link_train(intel_dp, crtc_state, DP_PHY_DPRX,
1207 DP_TRAINING_PATTERN_2)) {
1208 drm_err(&i915->drm,
1209 "[ENCODER:%d:%s] Failed to start 128b/132b TPS2\n",
1210 encoder->base.base.id, encoder->base.name);
1211 return false;
1212 }
1213
1214 /* Time budget for the LANEx_EQ_DONE Sequence */
1215 deadline = jiffies + msecs_to_jiffies_timeout(400);
1216
1217 for (try = 0; try < max_tries; try++) {
1218 usleep_range(delay_us, 2 * delay_us);
1219
1220 /*
1221 * The delay may get updated. The transmitter shall read the
1222 * delay before link status during link training.
1223 */
1224 delay_us = drm_dp_128b132b_read_aux_rd_interval(&intel_dp->aux);
1225
1226 if (drm_dp_dpcd_read_link_status(&intel_dp->aux, link_status) < 0) {
1227 drm_err(&i915->drm,
1228 "[ENCODER:%d:%s] Failed to read link status\n",
1229 encoder->base.base.id, encoder->base.name);
1230 return false;
1231 }
1232
1233 if (drm_dp_128b132b_link_training_failed(link_status)) {
1234 intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status);
1235 drm_err(&i915->drm,
1236 "[ENCODER:%d:%s] Downstream link training failure\n",
1237 encoder->base.base.id, encoder->base.name);
1238 return false;
1239 }
1240
1241 if (drm_dp_128b132b_lane_channel_eq_done(link_status, crtc_state->lane_count)) {
1242 drm_dbg_kms(&i915->drm,
1243 "[ENCODER:%d:%s] Lane channel eq done\n",
1244 encoder->base.base.id, encoder->base.name);
1245 break;
1246 }
1247
1248 if (timeout) {
1249 intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status);
1250 drm_err(&i915->drm,
1251 "[ENCODER:%d:%s] Lane channel eq timeout\n",
1252 encoder->base.base.id, encoder->base.name);
1253 return false;
1254 }
1255
1256 if (time_after(jiffies, deadline))
1257 timeout = true; /* try one last time after deadline */
1258
1259 /* Update signal levels and training set as requested. */
1260 intel_dp_get_adjust_train(intel_dp, crtc_state, DP_PHY_DPRX, link_status);
1261 if (!intel_dp_update_link_train(intel_dp, crtc_state, DP_PHY_DPRX)) {
1262 drm_err(&i915->drm,
1263 "[ENCODER:%d:%s] Failed to update TX FFE settings\n",
1264 encoder->base.base.id, encoder->base.name);
1265 return false;
1266 }
1267 }
1268
1269 if (try == max_tries) {
1270 intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status);
1271 drm_err(&i915->drm,
1272 "[ENCODER:%d:%s] Max loop count reached\n",
1273 encoder->base.base.id, encoder->base.name);
1274 return false;
1275 }
1276
1277 for (;;) {
1278 if (time_after(jiffies, deadline))
1279 timeout = true; /* try one last time after deadline */
1280
1281 if (drm_dp_dpcd_read_link_status(&intel_dp->aux, link_status) < 0) {
1282 drm_err(&i915->drm,
1283 "[ENCODER:%d:%s] Failed to read link status\n",
1284 encoder->base.base.id, encoder->base.name);
1285 return false;
1286 }
1287
1288 if (drm_dp_128b132b_link_training_failed(link_status)) {
1289 intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status);
1290 drm_err(&i915->drm,
1291 "[ENCODER:%d:%s] Downstream link training failure\n",
1292 encoder->base.base.id, encoder->base.name);
1293 return false;
1294 }
1295
1296 if (drm_dp_128b132b_eq_interlane_align_done(link_status)) {
1297 drm_dbg_kms(&i915->drm,
1298 "[ENCODER:%d:%s] Interlane align done\n",
1299 encoder->base.base.id, encoder->base.name);
1300 break;
1301 }
1302
1303 if (timeout) {
1304 intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status);
1305 drm_err(&i915->drm,
1306 "[ENCODER:%d:%s] Interlane align timeout\n",
1307 encoder->base.base.id, encoder->base.name);
1308 return false;
1309 }
1310
1311 usleep_range(2000, 3000);
1312 }
1313
1314 return true;
1315 }
1316
1317 /*
1318 * 128b/132b DP LANEx_CDS_DONE Sequence (DP 2.0 E11 3.5.2.16.2)
1319 */
1320 static bool
intel_dp_128b132b_lane_cds(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,int lttpr_count)1321 intel_dp_128b132b_lane_cds(struct intel_dp *intel_dp,
1322 const struct intel_crtc_state *crtc_state,
1323 int lttpr_count)
1324 {
1325 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
1326 struct drm_i915_private *i915 = to_i915(encoder->base.dev);
1327 u8 link_status[DP_LINK_STATUS_SIZE];
1328 unsigned long deadline;
1329
1330 if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TRAINING_PATTERN_SET,
1331 DP_TRAINING_PATTERN_2_CDS) != 1) {
1332 drm_err(&i915->drm,
1333 "[ENCODER:%d:%s] Failed to start 128b/132b TPS2 CDS\n",
1334 encoder->base.base.id, encoder->base.name);
1335 return false;
1336 }
1337
1338 /* Time budget for the LANEx_CDS_DONE Sequence */
1339 deadline = jiffies + msecs_to_jiffies_timeout((lttpr_count + 1) * 20);
1340
1341 for (;;) {
1342 bool timeout = false;
1343
1344 if (time_after(jiffies, deadline))
1345 timeout = true; /* try one last time after deadline */
1346
1347 usleep_range(2000, 3000);
1348
1349 if (drm_dp_dpcd_read_link_status(&intel_dp->aux, link_status) < 0) {
1350 drm_err(&i915->drm,
1351 "[ENCODER:%d:%s] Failed to read link status\n",
1352 encoder->base.base.id, encoder->base.name);
1353 return false;
1354 }
1355
1356 if (drm_dp_128b132b_eq_interlane_align_done(link_status) &&
1357 drm_dp_128b132b_cds_interlane_align_done(link_status) &&
1358 drm_dp_128b132b_lane_symbol_locked(link_status, crtc_state->lane_count)) {
1359 drm_dbg_kms(&i915->drm,
1360 "[ENCODER:%d:%s] CDS interlane align done\n",
1361 encoder->base.base.id, encoder->base.name);
1362 break;
1363 }
1364
1365 if (drm_dp_128b132b_link_training_failed(link_status)) {
1366 intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status);
1367 drm_err(&i915->drm,
1368 "[ENCODER:%d:%s] Downstream link training failure\n",
1369 encoder->base.base.id, encoder->base.name);
1370 return false;
1371 }
1372
1373 if (timeout) {
1374 intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status);
1375 drm_err(&i915->drm,
1376 "[ENCODER:%d:%s] CDS timeout\n",
1377 encoder->base.base.id, encoder->base.name);
1378 return false;
1379 }
1380 }
1381
1382 /* FIXME: Should DP_TRAINING_PATTERN_DISABLE be written first? */
1383 if (intel_dp->set_idle_link_train)
1384 intel_dp->set_idle_link_train(intel_dp, crtc_state);
1385
1386 return true;
1387 }
1388
1389 /*
1390 * 128b/132b link training sequence. (DP 2.0 E11 SCR on link training.)
1391 */
1392 static bool
intel_dp_128b132b_link_train(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state,int lttpr_count)1393 intel_dp_128b132b_link_train(struct intel_dp *intel_dp,
1394 const struct intel_crtc_state *crtc_state,
1395 int lttpr_count)
1396 {
1397 struct drm_i915_private *i915 = dp_to_i915(intel_dp);
1398 struct intel_connector *connector = intel_dp->attached_connector;
1399 struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
1400 bool passed = false;
1401
1402 if (wait_for(intel_dp_128b132b_intra_hop(intel_dp, crtc_state) == 0, 500)) {
1403 drm_err(&i915->drm,
1404 "[ENCODER:%d:%s] 128b/132b intra-hop not clear\n",
1405 encoder->base.base.id, encoder->base.name);
1406 return false;
1407 }
1408
1409 if (intel_dp_128b132b_lane_eq(intel_dp, crtc_state) &&
1410 intel_dp_128b132b_lane_cds(intel_dp, crtc_state, lttpr_count))
1411 passed = true;
1412
1413 drm_dbg_kms(&i915->drm,
1414 "[CONNECTOR:%d:%s][ENCODER:%d:%s] 128b/132b Link Training %s at link rate = %d, lane count = %d\n",
1415 connector->base.base.id, connector->base.name,
1416 encoder->base.base.id, encoder->base.name,
1417 passed ? "passed" : "failed",
1418 crtc_state->port_clock, crtc_state->lane_count);
1419
1420 return passed;
1421 }
1422
1423 /**
1424 * intel_dp_start_link_train - start link training
1425 * @intel_dp: DP struct
1426 * @crtc_state: state for CRTC attached to the encoder
1427 *
1428 * Start the link training of the @intel_dp port, scheduling a fallback
1429 * retraining with reduced link rate/lane parameters if the link training
1430 * fails.
1431 * After calling this function intel_dp_stop_link_train() must be called.
1432 */
intel_dp_start_link_train(struct intel_dp * intel_dp,const struct intel_crtc_state * crtc_state)1433 void intel_dp_start_link_train(struct intel_dp *intel_dp,
1434 const struct intel_crtc_state *crtc_state)
1435 {
1436 bool passed;
1437 /*
1438 * TODO: Reiniting LTTPRs here won't be needed once proper connector
1439 * HW state readout is added.
1440 */
1441 int lttpr_count = intel_dp_init_lttpr_and_dprx_caps(intel_dp);
1442
1443 if (lttpr_count < 0)
1444 /* Still continue with enabling the port and link training. */
1445 lttpr_count = 0;
1446
1447 intel_dp_prepare_link_train(intel_dp, crtc_state);
1448
1449 if (intel_dp_is_uhbr(crtc_state))
1450 passed = intel_dp_128b132b_link_train(intel_dp, crtc_state, lttpr_count);
1451 else
1452 passed = intel_dp_link_train_all_phys(intel_dp, crtc_state, lttpr_count);
1453
1454 if (!passed)
1455 intel_dp_schedule_fallback_link_training(intel_dp, crtc_state);
1456 }
1457