/* * Copyright © 2008-2015 Intel Corporation * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. */ #include "i915_drv.h" #include "intel_display_types.h" #include "intel_dp.h" #include "intel_dp_link_training.h" #define LT_MSG_PREFIX "[CONNECTOR:%d:%s][ENCODER:%d:%s][%s] " #define LT_MSG_ARGS(_intel_dp, _dp_phy) (_intel_dp)->attached_connector->base.base.id, \ (_intel_dp)->attached_connector->base.name, \ dp_to_dig_port(_intel_dp)->base.base.base.id, \ dp_to_dig_port(_intel_dp)->base.base.name, \ drm_dp_phy_name(_dp_phy) #define lt_dbg(_intel_dp, _dp_phy, _format, ...) \ drm_dbg_kms(&dp_to_i915(_intel_dp)->drm, \ LT_MSG_PREFIX _format, \ LT_MSG_ARGS(_intel_dp, _dp_phy), ## __VA_ARGS__) #define lt_err(_intel_dp, _dp_phy, _format, ...) do { \ if (intel_digital_port_connected(&dp_to_dig_port(_intel_dp)->base)) \ drm_err(&dp_to_i915(_intel_dp)->drm, \ LT_MSG_PREFIX _format, \ LT_MSG_ARGS(_intel_dp, _dp_phy), ## __VA_ARGS__); \ else \ lt_dbg(_intel_dp, _dp_phy, "Sink disconnected: " _format, ## __VA_ARGS__); \ } while (0) static void intel_dp_reset_lttpr_common_caps(struct intel_dp *intel_dp) { memset(intel_dp->lttpr_common_caps, 0, sizeof(intel_dp->lttpr_common_caps)); } static void intel_dp_reset_lttpr_count(struct intel_dp *intel_dp) { intel_dp->lttpr_common_caps[DP_PHY_REPEATER_CNT - DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV] = 0; } static u8 *intel_dp_lttpr_phy_caps(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy) { return intel_dp->lttpr_phy_caps[dp_phy - DP_PHY_LTTPR1]; } static void intel_dp_read_lttpr_phy_caps(struct intel_dp *intel_dp, const u8 dpcd[DP_RECEIVER_CAP_SIZE], enum drm_dp_phy dp_phy) { u8 *phy_caps = intel_dp_lttpr_phy_caps(intel_dp, dp_phy); if (drm_dp_read_lttpr_phy_caps(&intel_dp->aux, dpcd, dp_phy, phy_caps) < 0) { lt_dbg(intel_dp, dp_phy, "failed to read the PHY caps\n"); return; } lt_dbg(intel_dp, dp_phy, "PHY capabilities: %*ph\n", (int)sizeof(intel_dp->lttpr_phy_caps[0]), phy_caps); } static bool intel_dp_read_lttpr_common_caps(struct intel_dp *intel_dp, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { int ret; ret = drm_dp_read_lttpr_common_caps(&intel_dp->aux, dpcd, intel_dp->lttpr_common_caps); if (ret < 0) goto reset_caps; lt_dbg(intel_dp, DP_PHY_DPRX, "LTTPR common capabilities: %*ph\n", (int)sizeof(intel_dp->lttpr_common_caps), intel_dp->lttpr_common_caps); /* The minimum value of LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV is 1.4 */ if (intel_dp->lttpr_common_caps[0] < 0x14) goto reset_caps; return true; reset_caps: intel_dp_reset_lttpr_common_caps(intel_dp); return false; } static bool intel_dp_set_lttpr_transparent_mode(struct intel_dp *intel_dp, bool enable) { u8 val = enable ? DP_PHY_REPEATER_MODE_TRANSPARENT : DP_PHY_REPEATER_MODE_NON_TRANSPARENT; return drm_dp_dpcd_write(&intel_dp->aux, DP_PHY_REPEATER_MODE, &val, 1) == 1; } static int intel_dp_init_lttpr(struct intel_dp *intel_dp, const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { int lttpr_count; int i; if (!intel_dp_read_lttpr_common_caps(intel_dp, dpcd)) return 0; lttpr_count = drm_dp_lttpr_count(intel_dp->lttpr_common_caps); /* * Prevent setting LTTPR transparent mode explicitly if no LTTPRs are * detected as this breaks link training at least on the Dell WD19TB * dock. */ if (lttpr_count == 0) return 0; /* * See DP Standard v2.0 3.6.6.1. about the explicit disabling of * non-transparent mode and the disable->enable non-transparent mode * sequence. */ intel_dp_set_lttpr_transparent_mode(intel_dp, true); /* * In case of unsupported number of LTTPRs or failing to switch to * non-transparent mode fall-back to transparent link training mode, * still taking into account any LTTPR common lane- rate/count limits. */ if (lttpr_count < 0) return 0; if (!intel_dp_set_lttpr_transparent_mode(intel_dp, false)) { lt_dbg(intel_dp, DP_PHY_DPRX, "Switching to LTTPR non-transparent LT mode failed, fall-back to transparent mode\n"); intel_dp_set_lttpr_transparent_mode(intel_dp, true); intel_dp_reset_lttpr_count(intel_dp); return 0; } for (i = 0; i < lttpr_count; i++) intel_dp_read_lttpr_phy_caps(intel_dp, dpcd, DP_PHY_LTTPR(i)); return lttpr_count; } /** * intel_dp_init_lttpr_and_dprx_caps - detect LTTPR and DPRX caps, init the LTTPR link training mode * @intel_dp: Intel DP struct * * Read the LTTPR common and DPRX capabilities and switch to non-transparent * link training mode if any is detected and read the PHY capabilities for all * detected LTTPRs. In case of an LTTPR detection error or if the number of * LTTPRs is more than is supported (8), fall back to the no-LTTPR, * transparent mode link training mode. * * Returns: * >0 if LTTPRs were detected and the non-transparent LT mode was set. The * DPRX capabilities are read out. * 0 if no LTTPRs or more than 8 LTTPRs were detected or in case of a * detection failure and the transparent LT mode was set. The DPRX * capabilities are read out. * <0 Reading out the DPRX capabilities failed. */ int intel_dp_init_lttpr_and_dprx_caps(struct intel_dp *intel_dp) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); int lttpr_count = 0; /* * Detecting LTTPRs must be avoided on platforms with an AUX timeout * period < 3.2ms. (see DP Standard v2.0, 2.11.2, 3.6.6.1). */ if (!intel_dp_is_edp(intel_dp) && (DISPLAY_VER(i915) >= 10 && !IS_GEMINILAKE(i915))) { u8 dpcd[DP_RECEIVER_CAP_SIZE]; if (drm_dp_dpcd_probe(&intel_dp->aux, DP_LT_TUNABLE_PHY_REPEATER_FIELD_DATA_STRUCTURE_REV)) return -EIO; if (drm_dp_read_dpcd_caps(&intel_dp->aux, dpcd)) return -EIO; lttpr_count = intel_dp_init_lttpr(intel_dp, dpcd); } /* * The DPTX shall read the DPRX caps after LTTPR detection, so re-read * it here. */ if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd)) { intel_dp_reset_lttpr_common_caps(intel_dp); return -EIO; } return lttpr_count; } static u8 dp_voltage_max(u8 preemph) { switch (preemph & DP_TRAIN_PRE_EMPHASIS_MASK) { case DP_TRAIN_PRE_EMPH_LEVEL_0: return DP_TRAIN_VOLTAGE_SWING_LEVEL_3; case DP_TRAIN_PRE_EMPH_LEVEL_1: return DP_TRAIN_VOLTAGE_SWING_LEVEL_2; case DP_TRAIN_PRE_EMPH_LEVEL_2: return DP_TRAIN_VOLTAGE_SWING_LEVEL_1; case DP_TRAIN_PRE_EMPH_LEVEL_3: default: return DP_TRAIN_VOLTAGE_SWING_LEVEL_0; } } static u8 intel_dp_lttpr_voltage_max(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy) { const u8 *phy_caps = intel_dp_lttpr_phy_caps(intel_dp, dp_phy); if (drm_dp_lttpr_voltage_swing_level_3_supported(phy_caps)) return DP_TRAIN_VOLTAGE_SWING_LEVEL_3; else return DP_TRAIN_VOLTAGE_SWING_LEVEL_2; } static u8 intel_dp_lttpr_preemph_max(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy) { const u8 *phy_caps = intel_dp_lttpr_phy_caps(intel_dp, dp_phy); if (drm_dp_lttpr_pre_emphasis_level_3_supported(phy_caps)) return DP_TRAIN_PRE_EMPH_LEVEL_3; else return DP_TRAIN_PRE_EMPH_LEVEL_2; } static bool intel_dp_phy_is_downstream_of_source(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); int lttpr_count = drm_dp_lttpr_count(intel_dp->lttpr_common_caps); drm_WARN_ON_ONCE(&i915->drm, lttpr_count <= 0 && dp_phy != DP_PHY_DPRX); return lttpr_count <= 0 || dp_phy == DP_PHY_LTTPR(lttpr_count - 1); } static u8 intel_dp_phy_voltage_max(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state, enum drm_dp_phy dp_phy) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); u8 voltage_max; /* * Get voltage_max from the DPTX_PHY (source or LTTPR) upstream from * the DPRX_PHY we train. */ if (intel_dp_phy_is_downstream_of_source(intel_dp, dp_phy)) voltage_max = intel_dp->voltage_max(intel_dp, crtc_state); else voltage_max = intel_dp_lttpr_voltage_max(intel_dp, dp_phy + 1); drm_WARN_ON_ONCE(&i915->drm, voltage_max != DP_TRAIN_VOLTAGE_SWING_LEVEL_2 && voltage_max != DP_TRAIN_VOLTAGE_SWING_LEVEL_3); return voltage_max; } static u8 intel_dp_phy_preemph_max(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); u8 preemph_max; /* * Get preemph_max from the DPTX_PHY (source or LTTPR) upstream from * the DPRX_PHY we train. */ if (intel_dp_phy_is_downstream_of_source(intel_dp, dp_phy)) preemph_max = intel_dp->preemph_max(intel_dp); else preemph_max = intel_dp_lttpr_preemph_max(intel_dp, dp_phy + 1); drm_WARN_ON_ONCE(&i915->drm, preemph_max != DP_TRAIN_PRE_EMPH_LEVEL_2 && preemph_max != DP_TRAIN_PRE_EMPH_LEVEL_3); return preemph_max; } static bool has_per_lane_signal_levels(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); return !intel_dp_phy_is_downstream_of_source(intel_dp, dp_phy) || DISPLAY_VER(i915) >= 11; } /* 128b/132b */ static u8 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) { u8 tx_ffe = 0; if (has_per_lane_signal_levels(intel_dp, dp_phy)) { lane = min(lane, crtc_state->lane_count - 1); tx_ffe = drm_dp_get_adjust_tx_ffe_preset(link_status, lane); } else { for (lane = 0; lane < crtc_state->lane_count; lane++) tx_ffe = max(tx_ffe, drm_dp_get_adjust_tx_ffe_preset(link_status, lane)); } return tx_ffe; } /* 8b/10b */ static u8 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) { u8 v = 0; u8 p = 0; u8 voltage_max; u8 preemph_max; if (has_per_lane_signal_levels(intel_dp, dp_phy)) { lane = min(lane, crtc_state->lane_count - 1); v = drm_dp_get_adjust_request_voltage(link_status, lane); p = drm_dp_get_adjust_request_pre_emphasis(link_status, lane); } else { for (lane = 0; lane < crtc_state->lane_count; lane++) { v = max(v, drm_dp_get_adjust_request_voltage(link_status, lane)); p = max(p, drm_dp_get_adjust_request_pre_emphasis(link_status, lane)); } } preemph_max = intel_dp_phy_preemph_max(intel_dp, dp_phy); if (p >= preemph_max) p = preemph_max | DP_TRAIN_MAX_PRE_EMPHASIS_REACHED; v = min(v, dp_voltage_max(p)); voltage_max = intel_dp_phy_voltage_max(intel_dp, crtc_state, dp_phy); if (v >= voltage_max) v = voltage_max | DP_TRAIN_MAX_SWING_REACHED; return v | p; } static u8 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) { if (intel_dp_is_uhbr(crtc_state)) return intel_dp_get_lane_adjust_tx_ffe_preset(intel_dp, crtc_state, dp_phy, link_status, lane); else return intel_dp_get_lane_adjust_vswing_preemph(intel_dp, crtc_state, dp_phy, link_status, lane); } #define TRAIN_REQ_FMT "%d/%d/%d/%d" #define _TRAIN_REQ_VSWING_ARGS(link_status, lane) \ (drm_dp_get_adjust_request_voltage((link_status), (lane)) >> DP_TRAIN_VOLTAGE_SWING_SHIFT) #define TRAIN_REQ_VSWING_ARGS(link_status) \ _TRAIN_REQ_VSWING_ARGS(link_status, 0), \ _TRAIN_REQ_VSWING_ARGS(link_status, 1), \ _TRAIN_REQ_VSWING_ARGS(link_status, 2), \ _TRAIN_REQ_VSWING_ARGS(link_status, 3) #define _TRAIN_REQ_PREEMPH_ARGS(link_status, lane) \ (drm_dp_get_adjust_request_pre_emphasis((link_status), (lane)) >> DP_TRAIN_PRE_EMPHASIS_SHIFT) #define TRAIN_REQ_PREEMPH_ARGS(link_status) \ _TRAIN_REQ_PREEMPH_ARGS(link_status, 0), \ _TRAIN_REQ_PREEMPH_ARGS(link_status, 1), \ _TRAIN_REQ_PREEMPH_ARGS(link_status, 2), \ _TRAIN_REQ_PREEMPH_ARGS(link_status, 3) #define _TRAIN_REQ_TX_FFE_ARGS(link_status, lane) \ drm_dp_get_adjust_tx_ffe_preset((link_status), (lane)) #define TRAIN_REQ_TX_FFE_ARGS(link_status) \ _TRAIN_REQ_TX_FFE_ARGS(link_status, 0), \ _TRAIN_REQ_TX_FFE_ARGS(link_status, 1), \ _TRAIN_REQ_TX_FFE_ARGS(link_status, 2), \ _TRAIN_REQ_TX_FFE_ARGS(link_status, 3) 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]) { int lane; if (intel_dp_is_uhbr(crtc_state)) { lt_dbg(intel_dp, dp_phy, "128b/132b, lanes: %d, " "TX FFE request: " TRAIN_REQ_FMT "\n", crtc_state->lane_count, TRAIN_REQ_TX_FFE_ARGS(link_status)); } else { lt_dbg(intel_dp, dp_phy, "8b/10b, lanes: %d, " "vswing request: " TRAIN_REQ_FMT ", " "pre-emphasis request: " TRAIN_REQ_FMT "\n", crtc_state->lane_count, TRAIN_REQ_VSWING_ARGS(link_status), TRAIN_REQ_PREEMPH_ARGS(link_status)); } for (lane = 0; lane < 4; lane++) intel_dp->train_set[lane] = intel_dp_get_lane_adjust_train(intel_dp, crtc_state, dp_phy, link_status, lane); } static int intel_dp_training_pattern_set_reg(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy) { return dp_phy == DP_PHY_DPRX ? DP_TRAINING_PATTERN_SET : DP_TRAINING_PATTERN_SET_PHY_REPEATER(dp_phy); } 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) { int reg = intel_dp_training_pattern_set_reg(intel_dp, dp_phy); u8 buf[sizeof(intel_dp->train_set) + 1]; int len; intel_dp_program_link_training_pattern(intel_dp, crtc_state, dp_phy, dp_train_pat); buf[0] = dp_train_pat; /* DP_TRAINING_LANEx_SET follow DP_TRAINING_PATTERN_SET */ memcpy(buf + 1, intel_dp->train_set, crtc_state->lane_count); len = crtc_state->lane_count + 1; return drm_dp_dpcd_write(&intel_dp->aux, reg, buf, len) == len; } static char dp_training_pattern_name(u8 train_pat) { switch (train_pat) { case DP_TRAINING_PATTERN_1: case DP_TRAINING_PATTERN_2: case DP_TRAINING_PATTERN_3: return '0' + train_pat; case DP_TRAINING_PATTERN_4: return '4'; default: MISSING_CASE(train_pat); return '?'; } } 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) { u8 train_pat = intel_dp_training_pattern_symbol(dp_train_pat); if (train_pat != DP_TRAINING_PATTERN_DISABLE) lt_dbg(intel_dp, dp_phy, "Using DP training pattern TPS%c\n", dp_training_pattern_name(train_pat)); intel_dp->set_link_train(intel_dp, crtc_state, dp_train_pat); } #define TRAIN_SET_FMT "%d%s/%d%s/%d%s/%d%s" #define _TRAIN_SET_VSWING_ARGS(train_set) \ ((train_set) & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT, \ (train_set) & DP_TRAIN_MAX_SWING_REACHED ? "(max)" : "" #define TRAIN_SET_VSWING_ARGS(train_set) \ _TRAIN_SET_VSWING_ARGS((train_set)[0]), \ _TRAIN_SET_VSWING_ARGS((train_set)[1]), \ _TRAIN_SET_VSWING_ARGS((train_set)[2]), \ _TRAIN_SET_VSWING_ARGS((train_set)[3]) #define _TRAIN_SET_PREEMPH_ARGS(train_set) \ ((train_set) & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT, \ (train_set) & DP_TRAIN_MAX_PRE_EMPHASIS_REACHED ? "(max)" : "" #define TRAIN_SET_PREEMPH_ARGS(train_set) \ _TRAIN_SET_PREEMPH_ARGS((train_set)[0]), \ _TRAIN_SET_PREEMPH_ARGS((train_set)[1]), \ _TRAIN_SET_PREEMPH_ARGS((train_set)[2]), \ _TRAIN_SET_PREEMPH_ARGS((train_set)[3]) #define _TRAIN_SET_TX_FFE_ARGS(train_set) \ ((train_set) & DP_TX_FFE_PRESET_VALUE_MASK), "" #define TRAIN_SET_TX_FFE_ARGS(train_set) \ _TRAIN_SET_TX_FFE_ARGS((train_set)[0]), \ _TRAIN_SET_TX_FFE_ARGS((train_set)[1]), \ _TRAIN_SET_TX_FFE_ARGS((train_set)[2]), \ _TRAIN_SET_TX_FFE_ARGS((train_set)[3]) void intel_dp_set_signal_levels(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state, enum drm_dp_phy dp_phy) { struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base; if (intel_dp_is_uhbr(crtc_state)) { lt_dbg(intel_dp, dp_phy, "128b/132b, lanes: %d, " "TX FFE presets: " TRAIN_SET_FMT "\n", crtc_state->lane_count, TRAIN_SET_TX_FFE_ARGS(intel_dp->train_set)); } else { lt_dbg(intel_dp, dp_phy, "8b/10b, lanes: %d, " "vswing levels: " TRAIN_SET_FMT ", " "pre-emphasis levels: " TRAIN_SET_FMT "\n", crtc_state->lane_count, TRAIN_SET_VSWING_ARGS(intel_dp->train_set), TRAIN_SET_PREEMPH_ARGS(intel_dp->train_set)); } if (intel_dp_phy_is_downstream_of_source(intel_dp, dp_phy)) encoder->set_signal_levels(encoder, crtc_state); } 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) { memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set)); intel_dp_set_signal_levels(intel_dp, crtc_state, dp_phy); return intel_dp_set_link_train(intel_dp, crtc_state, dp_phy, dp_train_pat); } 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) { int reg = dp_phy == DP_PHY_DPRX ? DP_TRAINING_LANE0_SET : DP_TRAINING_LANE0_SET_PHY_REPEATER(dp_phy); int ret; intel_dp_set_signal_levels(intel_dp, crtc_state, dp_phy); ret = drm_dp_dpcd_write(&intel_dp->aux, reg, intel_dp->train_set, crtc_state->lane_count); return ret == crtc_state->lane_count; } /* 128b/132b */ static bool intel_dp_lane_max_tx_ffe_reached(u8 train_set_lane) { return (train_set_lane & DP_TX_FFE_PRESET_VALUE_MASK) == DP_TX_FFE_PRESET_VALUE_MASK; } /* * 8b/10b * * FIXME: The DP spec is very confusing here, also the Link CTS spec seems to * have self contradicting tests around this area. * * In lieu of better ideas let's just stop when we've reached the max supported * vswing with its max pre-emphasis, which is either 2+1 or 3+0 depending on * whether vswing level 3 is supported or not. */ static bool intel_dp_lane_max_vswing_reached(u8 train_set_lane) { u8 v = (train_set_lane & DP_TRAIN_VOLTAGE_SWING_MASK) >> DP_TRAIN_VOLTAGE_SWING_SHIFT; u8 p = (train_set_lane & DP_TRAIN_PRE_EMPHASIS_MASK) >> DP_TRAIN_PRE_EMPHASIS_SHIFT; if ((train_set_lane & DP_TRAIN_MAX_SWING_REACHED) == 0) return false; if (v + p != 3) return false; return true; } static bool intel_dp_link_max_vswing_reached(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { int lane; for (lane = 0; lane < crtc_state->lane_count; lane++) { u8 train_set_lane = intel_dp->train_set[lane]; if (intel_dp_is_uhbr(crtc_state)) { if (!intel_dp_lane_max_tx_ffe_reached(train_set_lane)) return false; } else { if (!intel_dp_lane_max_vswing_reached(train_set_lane)) return false; } } return true; } static void intel_dp_update_downspread_ctrl(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { u8 link_config[2]; link_config[0] = crtc_state->vrr.flipline ? DP_MSA_TIMING_PAR_IGNORE_EN : 0; link_config[1] = intel_dp_is_uhbr(crtc_state) ? DP_SET_ANSI_128B132B : DP_SET_ANSI_8B10B; drm_dp_dpcd_write(&intel_dp->aux, DP_DOWNSPREAD_CTRL, link_config, 2); } static void intel_dp_update_link_bw_set(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state, u8 link_bw, u8 rate_select) { u8 link_config[2]; /* Write the link configuration data */ link_config[0] = link_bw; link_config[1] = crtc_state->lane_count; if (drm_dp_enhanced_frame_cap(intel_dp->dpcd)) link_config[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN; drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_BW_SET, link_config, 2); /* eDP 1.4 rate select method. */ if (!link_bw) drm_dp_dpcd_write(&intel_dp->aux, DP_LINK_RATE_SET, &rate_select, 1); } /* * Prepare link training by configuring the link parameters. On DDI platforms * also enable the port here. */ static bool intel_dp_prepare_link_train(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { u8 link_bw, rate_select; if (intel_dp->prepare_link_retrain) intel_dp->prepare_link_retrain(intel_dp, crtc_state); intel_dp_compute_rate(intel_dp, crtc_state->port_clock, &link_bw, &rate_select); /* * WaEdpLinkRateDataReload * * Parade PS8461E MUX (used on varius TGL+ laptops) needs * to snoop the link rates reported by the sink when we * use LINK_RATE_SET in order to operate in jitter cleaning * mode (as opposed to redriver mode). Unfortunately it * loses track of the snooped link rates when powered down, * so we need to make it re-snoop often. Without this high * link rates are not stable. */ if (!link_bw) { __le16 sink_rates[DP_MAX_SUPPORTED_RATES]; lt_dbg(intel_dp, DP_PHY_DPRX, "Reloading eDP link rates\n"); drm_dp_dpcd_read(&intel_dp->aux, DP_SUPPORTED_LINK_RATES, sink_rates, sizeof(sink_rates)); } if (link_bw) lt_dbg(intel_dp, DP_PHY_DPRX, "Using LINK_BW_SET value %02x\n", link_bw); else lt_dbg(intel_dp, DP_PHY_DPRX, "Using LINK_RATE_SET value %02x\n", rate_select); /* * Spec DP2.1 Section 3.5.2.16 * Prior to LT DPTX should set 128b/132b DP Channel coding and then set link rate */ intel_dp_update_downspread_ctrl(intel_dp, crtc_state); intel_dp_update_link_bw_set(intel_dp, crtc_state, link_bw, rate_select); return true; } static bool 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]) { int lane; for (lane = 0; lane < crtc_state->lane_count; lane++) { u8 old, new; if (intel_dp_is_uhbr(crtc_state)) { old = drm_dp_get_adjust_tx_ffe_preset(old_link_status, lane); new = drm_dp_get_adjust_tx_ffe_preset(new_link_status, lane); } else { old = drm_dp_get_adjust_request_voltage(old_link_status, lane) | drm_dp_get_adjust_request_pre_emphasis(old_link_status, lane); new = drm_dp_get_adjust_request_voltage(new_link_status, lane) | drm_dp_get_adjust_request_pre_emphasis(new_link_status, lane); } if (old != new) return true; } return false; } 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]) { lt_dbg(intel_dp, dp_phy, "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", link_status[0], link_status[1], link_status[2], link_status[3], link_status[4], link_status[5]); } /* * Perform the link training clock recovery phase on the given DP PHY using * training pattern 1. */ 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) { u8 old_link_status[DP_LINK_STATUS_SIZE] = {}; int voltage_tries, cr_tries, max_cr_tries; u8 link_status[DP_LINK_STATUS_SIZE]; bool max_vswing_reached = false; int delay_us; delay_us = drm_dp_read_clock_recovery_delay(&intel_dp->aux, intel_dp->dpcd, dp_phy, intel_dp_is_uhbr(crtc_state)); /* clock recovery */ if (!intel_dp_reset_link_train(intel_dp, crtc_state, dp_phy, DP_TRAINING_PATTERN_1 | DP_LINK_SCRAMBLING_DISABLE)) { lt_err(intel_dp, dp_phy, "Failed to enable link training\n"); return false; } /* * The DP 1.4 spec defines the max clock recovery retries value * as 10 but for pre-DP 1.4 devices we set a very tolerant * retry limit of 80 (4 voltage levels x 4 preemphasis levels x * x 5 identical voltage retries). Since the previous specs didn't * define a limit and created the possibility of an infinite loop * we want to prevent any sync from triggering that corner case. */ if (intel_dp->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14) max_cr_tries = 10; else max_cr_tries = 80; voltage_tries = 1; for (cr_tries = 0; cr_tries < max_cr_tries; ++cr_tries) { usleep_range(delay_us, 2 * delay_us); if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, dp_phy, link_status) < 0) { lt_err(intel_dp, dp_phy, "Failed to get link status\n"); return false; } if (drm_dp_clock_recovery_ok(link_status, crtc_state->lane_count)) { lt_dbg(intel_dp, dp_phy, "Clock recovery OK\n"); return true; } if (voltage_tries == 5) { intel_dp_dump_link_status(intel_dp, dp_phy, link_status); lt_dbg(intel_dp, dp_phy, "Same voltage tried 5 times\n"); return false; } if (max_vswing_reached) { intel_dp_dump_link_status(intel_dp, dp_phy, link_status); lt_dbg(intel_dp, dp_phy, "Max Voltage Swing reached\n"); return false; } /* Update training set as requested by target */ intel_dp_get_adjust_train(intel_dp, crtc_state, dp_phy, link_status); if (!intel_dp_update_link_train(intel_dp, crtc_state, dp_phy)) { lt_err(intel_dp, dp_phy, "Failed to update link training\n"); return false; } if (!intel_dp_adjust_request_changed(crtc_state, old_link_status, link_status)) ++voltage_tries; else voltage_tries = 1; memcpy(old_link_status, link_status, sizeof(link_status)); if (intel_dp_link_max_vswing_reached(intel_dp, crtc_state)) max_vswing_reached = true; } intel_dp_dump_link_status(intel_dp, dp_phy, link_status); lt_err(intel_dp, dp_phy, "Failed clock recovery %d times, giving up!\n", max_cr_tries); return false; } /* * Pick Training Pattern Sequence (TPS) for channel equalization. 128b/132b TPS2 * for UHBR+, TPS4 for HBR3 or for 1.4 devices that support it, TPS3 for HBR2 or * 1.2 devices that support it, TPS2 otherwise. */ static u32 intel_dp_training_pattern(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state, enum drm_dp_phy dp_phy) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); bool source_tps3, sink_tps3, source_tps4, sink_tps4; /* UHBR+ use separate 128b/132b TPS2 */ if (intel_dp_is_uhbr(crtc_state)) return DP_TRAINING_PATTERN_2; /* * TPS4 support is mandatory for all downstream devices that * support HBR3. There are no known eDP panels that support * TPS4 as of Feb 2018 as per VESA eDP_v1.4b_E1 specification. * LTTPRs must support TPS4. */ source_tps4 = intel_dp_source_supports_tps4(i915); sink_tps4 = dp_phy != DP_PHY_DPRX || drm_dp_tps4_supported(intel_dp->dpcd); if (source_tps4 && sink_tps4) { return DP_TRAINING_PATTERN_4; } else if (crtc_state->port_clock == 810000) { if (!source_tps4) lt_dbg(intel_dp, dp_phy, "8.1 Gbps link rate without source TPS4 support\n"); if (!sink_tps4) lt_dbg(intel_dp, dp_phy, "8.1 Gbps link rate without sink TPS4 support\n"); } /* * TPS3 support is mandatory for downstream devices that * support HBR2. However, not all sinks follow the spec. */ source_tps3 = intel_dp_source_supports_tps3(i915); sink_tps3 = dp_phy != DP_PHY_DPRX || drm_dp_tps3_supported(intel_dp->dpcd); if (source_tps3 && sink_tps3) { return DP_TRAINING_PATTERN_3; } else if (crtc_state->port_clock >= 540000) { if (!source_tps3) lt_dbg(intel_dp, dp_phy, ">=5.4/6.48 Gbps link rate without source TPS3 support\n"); if (!sink_tps3) lt_dbg(intel_dp, dp_phy, ">=5.4/6.48 Gbps link rate without sink TPS3 support\n"); } return DP_TRAINING_PATTERN_2; } /* * Perform the link training channel equalization phase on the given DP PHY * using one of training pattern 2, 3 or 4 depending on the source and * sink capabilities. */ 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) { int tries; u32 training_pattern; u8 link_status[DP_LINK_STATUS_SIZE]; bool channel_eq = false; int delay_us; delay_us = drm_dp_read_channel_eq_delay(&intel_dp->aux, intel_dp->dpcd, dp_phy, intel_dp_is_uhbr(crtc_state)); training_pattern = intel_dp_training_pattern(intel_dp, crtc_state, dp_phy); /* Scrambling is disabled for TPS2/3 and enabled for TPS4 */ if (training_pattern != DP_TRAINING_PATTERN_4) training_pattern |= DP_LINK_SCRAMBLING_DISABLE; /* channel equalization */ if (!intel_dp_set_link_train(intel_dp, crtc_state, dp_phy, training_pattern)) { lt_err(intel_dp, dp_phy, "Failed to start channel equalization\n"); return false; } for (tries = 0; tries < 5; tries++) { usleep_range(delay_us, 2 * delay_us); if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, dp_phy, link_status) < 0) { lt_err(intel_dp, dp_phy, "Failed to get link status\n"); break; } /* Make sure clock is still ok */ if (!drm_dp_clock_recovery_ok(link_status, crtc_state->lane_count)) { intel_dp_dump_link_status(intel_dp, dp_phy, link_status); lt_dbg(intel_dp, dp_phy, "Clock recovery check failed, cannot continue channel equalization\n"); break; } if (drm_dp_channel_eq_ok(link_status, crtc_state->lane_count)) { channel_eq = true; lt_dbg(intel_dp, dp_phy, "Channel EQ done. DP Training successful\n"); break; } /* Update training set as requested by target */ intel_dp_get_adjust_train(intel_dp, crtc_state, dp_phy, link_status); if (!intel_dp_update_link_train(intel_dp, crtc_state, dp_phy)) { lt_err(intel_dp, dp_phy, "Failed to update link training\n"); break; } } /* Try 5 times, else fail and try at lower BW */ if (tries == 5) { intel_dp_dump_link_status(intel_dp, dp_phy, link_status); lt_dbg(intel_dp, dp_phy, "Channel equalization failed 5 times\n"); } return channel_eq; } static bool intel_dp_disable_dpcd_training_pattern(struct intel_dp *intel_dp, enum drm_dp_phy dp_phy) { int reg = intel_dp_training_pattern_set_reg(intel_dp, dp_phy); u8 val = DP_TRAINING_PATTERN_DISABLE; return drm_dp_dpcd_write(&intel_dp->aux, reg, &val, 1) == 1; } static int intel_dp_128b132b_intra_hop(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { u8 sink_status; int ret; ret = drm_dp_dpcd_readb(&intel_dp->aux, DP_SINK_STATUS, &sink_status); if (ret != 1) { lt_dbg(intel_dp, DP_PHY_DPRX, "Failed to read sink status\n"); return ret < 0 ? ret : -EIO; } return sink_status & DP_INTRA_HOP_AUX_REPLY_INDICATION ? 1 : 0; } /** * intel_dp_stop_link_train - stop link training * @intel_dp: DP struct * @crtc_state: state for CRTC attached to the encoder * * Stop the link training of the @intel_dp port, disabling the training * pattern in the sink's DPCD, and disabling the test pattern symbol * generation on the port. * * What symbols are output on the port after this point is * platform specific: On DDI/VLV/CHV platforms it will be the idle pattern * with the pipe being disabled, on older platforms it's HW specific if/how an * idle pattern is generated, as the pipe is already enabled here for those. * * This function must be called after intel_dp_start_link_train(). */ void intel_dp_stop_link_train(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { intel_dp->link_trained = true; intel_dp_disable_dpcd_training_pattern(intel_dp, DP_PHY_DPRX); intel_dp_program_link_training_pattern(intel_dp, crtc_state, DP_PHY_DPRX, DP_TRAINING_PATTERN_DISABLE); if (intel_dp_is_uhbr(crtc_state) && wait_for(intel_dp_128b132b_intra_hop(intel_dp, crtc_state) == 0, 500)) { lt_dbg(intel_dp, DP_PHY_DPRX, "128b/132b intra-hop not clearing\n"); } } 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) { bool ret = false; if (!intel_dp_link_training_clock_recovery(intel_dp, crtc_state, dp_phy)) goto out; if (!intel_dp_link_training_channel_equalization(intel_dp, crtc_state, dp_phy)) goto out; ret = true; out: lt_dbg(intel_dp, dp_phy, "Link Training %s at link rate = %d, lane count = %d\n", ret ? "passed" : "failed", crtc_state->port_clock, crtc_state->lane_count); return ret; } static void intel_dp_schedule_fallback_link_training(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { struct intel_connector *intel_connector = intel_dp->attached_connector; struct drm_i915_private *i915 = dp_to_i915(intel_dp); if (!intel_digital_port_connected(&dp_to_dig_port(intel_dp)->base)) { lt_dbg(intel_dp, DP_PHY_DPRX, "Link Training failed on disconnected sink.\n"); return; } if (intel_dp->hobl_active) { lt_dbg(intel_dp, DP_PHY_DPRX, "Link Training failed with HOBL active, not enabling it from now on\n"); intel_dp->hobl_failed = true; } else if (intel_dp_get_link_train_fallback_values(intel_dp, crtc_state->port_clock, crtc_state->lane_count)) { return; } /* Schedule a Hotplug Uevent to userspace to start modeset */ queue_work(i915->unordered_wq, &intel_connector->modeset_retry_work); } /* Perform the link training on all LTTPRs and the DPRX on a link. */ static bool intel_dp_link_train_all_phys(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state, int lttpr_count) { bool ret = true; int i; for (i = lttpr_count - 1; i >= 0; i--) { enum drm_dp_phy dp_phy = DP_PHY_LTTPR(i); ret = intel_dp_link_train_phy(intel_dp, crtc_state, dp_phy); intel_dp_disable_dpcd_training_pattern(intel_dp, dp_phy); if (!ret) break; } if (ret) ret = intel_dp_link_train_phy(intel_dp, crtc_state, DP_PHY_DPRX); if (intel_dp->set_idle_link_train) intel_dp->set_idle_link_train(intel_dp, crtc_state); return ret; } /* * 128b/132b DP LANEx_EQ_DONE Sequence (DP 2.0 E11 3.5.2.16.1) */ static bool intel_dp_128b132b_lane_eq(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { u8 link_status[DP_LINK_STATUS_SIZE]; int delay_us; int try, max_tries = 20; unsigned long deadline; bool timeout = false; /* * Reset signal levels. Start transmitting 128b/132b TPS1. * * Put DPRX and LTTPRs (if any) into intra-hop AUX mode by writing TPS1 * in DP_TRAINING_PATTERN_SET. */ if (!intel_dp_reset_link_train(intel_dp, crtc_state, DP_PHY_DPRX, DP_TRAINING_PATTERN_1)) { lt_err(intel_dp, DP_PHY_DPRX, "Failed to start 128b/132b TPS1\n"); return false; } delay_us = drm_dp_128b132b_read_aux_rd_interval(&intel_dp->aux); /* Read the initial TX FFE settings. */ if (drm_dp_dpcd_read_link_status(&intel_dp->aux, link_status) < 0) { lt_err(intel_dp, DP_PHY_DPRX, "Failed to read TX FFE presets\n"); return false; } /* Update signal levels and training set as requested. */ intel_dp_get_adjust_train(intel_dp, crtc_state, DP_PHY_DPRX, link_status); if (!intel_dp_update_link_train(intel_dp, crtc_state, DP_PHY_DPRX)) { lt_err(intel_dp, DP_PHY_DPRX, "Failed to set initial TX FFE settings\n"); return false; } /* Start transmitting 128b/132b TPS2. */ if (!intel_dp_set_link_train(intel_dp, crtc_state, DP_PHY_DPRX, DP_TRAINING_PATTERN_2)) { lt_err(intel_dp, DP_PHY_DPRX, "Failed to start 128b/132b TPS2\n"); return false; } /* Time budget for the LANEx_EQ_DONE Sequence */ deadline = jiffies + msecs_to_jiffies_timeout(400); for (try = 0; try < max_tries; try++) { usleep_range(delay_us, 2 * delay_us); /* * The delay may get updated. The transmitter shall read the * delay before link status during link training. */ delay_us = drm_dp_128b132b_read_aux_rd_interval(&intel_dp->aux); if (drm_dp_dpcd_read_link_status(&intel_dp->aux, link_status) < 0) { lt_err(intel_dp, DP_PHY_DPRX, "Failed to read link status\n"); return false; } if (drm_dp_128b132b_link_training_failed(link_status)) { intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); lt_err(intel_dp, DP_PHY_DPRX, "Downstream link training failure\n"); return false; } if (drm_dp_128b132b_lane_channel_eq_done(link_status, crtc_state->lane_count)) { lt_dbg(intel_dp, DP_PHY_DPRX, "Lane channel eq done\n"); break; } if (timeout) { intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); lt_err(intel_dp, DP_PHY_DPRX, "Lane channel eq timeout\n"); return false; } if (time_after(jiffies, deadline)) timeout = true; /* try one last time after deadline */ /* Update signal levels and training set as requested. */ intel_dp_get_adjust_train(intel_dp, crtc_state, DP_PHY_DPRX, link_status); if (!intel_dp_update_link_train(intel_dp, crtc_state, DP_PHY_DPRX)) { lt_err(intel_dp, DP_PHY_DPRX, "Failed to update TX FFE settings\n"); return false; } } if (try == max_tries) { intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); lt_err(intel_dp, DP_PHY_DPRX, "Max loop count reached\n"); return false; } for (;;) { if (time_after(jiffies, deadline)) timeout = true; /* try one last time after deadline */ if (drm_dp_dpcd_read_link_status(&intel_dp->aux, link_status) < 0) { lt_err(intel_dp, DP_PHY_DPRX, "Failed to read link status\n"); return false; } if (drm_dp_128b132b_link_training_failed(link_status)) { intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); lt_err(intel_dp, DP_PHY_DPRX, "Downstream link training failure\n"); return false; } if (drm_dp_128b132b_eq_interlane_align_done(link_status)) { lt_dbg(intel_dp, DP_PHY_DPRX, "Interlane align done\n"); break; } if (timeout) { intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); lt_err(intel_dp, DP_PHY_DPRX, "Interlane align timeout\n"); return false; } usleep_range(2000, 3000); } return true; } /* * 128b/132b DP LANEx_CDS_DONE Sequence (DP 2.0 E11 3.5.2.16.2) */ static bool intel_dp_128b132b_lane_cds(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state, int lttpr_count) { u8 link_status[DP_LINK_STATUS_SIZE]; unsigned long deadline; if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TRAINING_PATTERN_SET, DP_TRAINING_PATTERN_2_CDS) != 1) { lt_err(intel_dp, DP_PHY_DPRX, "Failed to start 128b/132b TPS2 CDS\n"); return false; } /* Time budget for the LANEx_CDS_DONE Sequence */ deadline = jiffies + msecs_to_jiffies_timeout((lttpr_count + 1) * 20); for (;;) { bool timeout = false; if (time_after(jiffies, deadline)) timeout = true; /* try one last time after deadline */ usleep_range(2000, 3000); if (drm_dp_dpcd_read_link_status(&intel_dp->aux, link_status) < 0) { lt_err(intel_dp, DP_PHY_DPRX, "Failed to read link status\n"); return false; } if (drm_dp_128b132b_eq_interlane_align_done(link_status) && drm_dp_128b132b_cds_interlane_align_done(link_status) && drm_dp_128b132b_lane_symbol_locked(link_status, crtc_state->lane_count)) { lt_dbg(intel_dp, DP_PHY_DPRX, "CDS interlane align done\n"); break; } if (drm_dp_128b132b_link_training_failed(link_status)) { intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); lt_err(intel_dp, DP_PHY_DPRX, "Downstream link training failure\n"); return false; } if (timeout) { intel_dp_dump_link_status(intel_dp, DP_PHY_DPRX, link_status); lt_err(intel_dp, DP_PHY_DPRX, "CDS timeout\n"); return false; } } return true; } /* * 128b/132b link training sequence. (DP 2.0 E11 SCR on link training.) */ static bool intel_dp_128b132b_link_train(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state, int lttpr_count) { bool passed = false; if (wait_for(intel_dp_128b132b_intra_hop(intel_dp, crtc_state) == 0, 500)) { lt_err(intel_dp, DP_PHY_DPRX, "128b/132b intra-hop not clear\n"); return false; } if (intel_dp_128b132b_lane_eq(intel_dp, crtc_state) && intel_dp_128b132b_lane_cds(intel_dp, crtc_state, lttpr_count)) passed = true; lt_dbg(intel_dp, DP_PHY_DPRX, "128b/132b Link Training %s at link rate = %d, lane count = %d\n", passed ? "passed" : "failed", crtc_state->port_clock, crtc_state->lane_count); return passed; } /** * intel_dp_start_link_train - start link training * @intel_dp: DP struct * @crtc_state: state for CRTC attached to the encoder * * Start the link training of the @intel_dp port, scheduling a fallback * retraining with reduced link rate/lane parameters if the link training * fails. * After calling this function intel_dp_stop_link_train() must be called. */ void intel_dp_start_link_train(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { struct drm_i915_private *i915 = dp_to_i915(intel_dp); bool passed; /* * TODO: Reiniting LTTPRs here won't be needed once proper connector * HW state readout is added. */ int lttpr_count = intel_dp_init_lttpr_and_dprx_caps(intel_dp); if (lttpr_count < 0) /* Still continue with enabling the port and link training. */ lttpr_count = 0; intel_dp_prepare_link_train(intel_dp, crtc_state); if (intel_dp_is_uhbr(crtc_state)) passed = intel_dp_128b132b_link_train(intel_dp, crtc_state, lttpr_count); else passed = intel_dp_link_train_all_phys(intel_dp, crtc_state, lttpr_count); /* * Ignore the link failure in CI * * In fixed enviroments like CI, sometimes unexpected long HPDs are * generated by the displays. If ignore_long_hpd flag is set, such long * HPDs are ignored. And probably as a consequence of these ignored * long HPDs, subsequent link trainings are failed resulting into CI * execution failures. * * For test cases which rely on the link training or processing of HPDs * ignore_long_hpd flag can unset from the testcase. */ if (!passed && i915->display.hotplug.ignore_long_hpd) { lt_dbg(intel_dp, DP_PHY_DPRX, "Ignore the link failure\n"); return; } if (!passed) intel_dp_schedule_fallback_link_training(intel_dp, crtc_state); } void intel_dp_128b132b_sdp_crc16(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state) { /* * VIDEO_DIP_CTL register bit 31 should be set to '0' to not * disable SDP CRC. This is applicable for Display version 13. * Default value of bit 31 is '0' hence discarding the write * TODO: Corrective actions on SDP corruption yet to be defined */ if (intel_dp_is_uhbr(crtc_state)) /* DP v2.0 SCR on SDP CRC16 for 128b/132b Link Layer */ drm_dp_dpcd_writeb(&intel_dp->aux, DP_SDP_ERROR_DETECTION_CONFIGURATION, DP_SDP_CRC16_128B132B_EN); lt_dbg(intel_dp, DP_PHY_DPRX, "DP2.0 SDP CRC16 for 128b/132b enabled\n"); }