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linux-stable/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_training_dpia.c

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/*
* Copyright 2022 Advanced Micro Devices, Inc.
*
* 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
*
* Authors: AMD
*
*/
/* FILE POLICY AND INTENDED USAGE:
* This module implements functionality for training DPIA links.
*/
#include "link_dp_training_dpia.h"
#include "dc.h"
#include "inc/core_status.h"
#include "dpcd_defs.h"
#include "link_dp_dpia.h"
#include "link_hwss.h"
#include "dm_helpers.h"
#include "dmub/inc/dmub_cmd.h"
#include "link_dpcd.h"
#include "link_dp_phy.h"
#include "link_dp_training_8b_10b.h"
#include "link_dp_capability.h"
#include "dc_dmub_srv.h"
#define DC_LOGGER \
link->ctx->logger
/* The approximate time (us) it takes to transmit 9 USB4 DP clock sync packets. */
#define DPIA_CLK_SYNC_DELAY 16000
/* Extend interval between training status checks for manual testing. */
#define DPIA_DEBUG_EXTENDED_AUX_RD_INTERVAL_US 60000000
#define TRAINING_AUX_RD_INTERVAL 100 //us
/* SET_CONFIG message types sent by driver. */
enum dpia_set_config_type {
DPIA_SET_CFG_SET_LINK = 0x01,
DPIA_SET_CFG_SET_PHY_TEST_MODE = 0x05,
DPIA_SET_CFG_SET_TRAINING = 0x18,
DPIA_SET_CFG_SET_VSPE = 0x19
};
/* Training stages (TS) in SET_CONFIG(SET_TRAINING) message. */
enum dpia_set_config_ts {
DPIA_TS_DPRX_DONE = 0x00, /* Done training DPRX. */
DPIA_TS_TPS1 = 0x01,
DPIA_TS_TPS2 = 0x02,
DPIA_TS_TPS3 = 0x03,
DPIA_TS_TPS4 = 0x07,
DPIA_TS_UFP_DONE = 0xff /* Done training DPTX-to-DPIA hop. */
};
/* SET_CONFIG message data associated with messages sent by driver. */
union dpia_set_config_data {
struct {
uint8_t mode : 1;
uint8_t reserved : 7;
} set_link;
struct {
uint8_t stage;
} set_training;
struct {
uint8_t swing : 2;
uint8_t max_swing_reached : 1;
uint8_t pre_emph : 2;
uint8_t max_pre_emph_reached : 1;
uint8_t reserved : 2;
} set_vspe;
uint8_t raw;
};
/* Configure link as prescribed in link_setting; set LTTPR mode; and
* Initialize link training settings.
* Abort link training if sink unplug detected.
*
* @param link DPIA link being trained.
* @param[in] link_setting Lane count, link rate and downspread control.
* @param[out] lt_settings Link settings and drive settings (voltage swing and pre-emphasis).
*/
static enum link_training_result dpia_configure_link(
struct dc_link *link,
const struct link_resource *link_res,
const struct dc_link_settings *link_setting,
struct link_training_settings *lt_settings)
{
enum dc_status status;
bool fec_enable;
DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) configuring\n - LTTPR mode(%d)\n",
__func__,
link->link_id.enum_id - ENUM_ID_1,
lt_settings->lttpr_mode);
dp_decide_training_settings(
link,
link_setting,
lt_settings);
dp_get_lttpr_mode_override(link, &lt_settings->lttpr_mode);
status = dpcd_configure_channel_coding(link, lt_settings);
if (status != DC_OK && link->is_hpd_pending)
return LINK_TRAINING_ABORT;
/* Configure lttpr mode */
status = dpcd_configure_lttpr_mode(link, lt_settings);
if (status != DC_OK && link->is_hpd_pending)
return LINK_TRAINING_ABORT;
/* Set link rate, lane count and spread. */
status = dpcd_set_link_settings(link, lt_settings);
if (status != DC_OK && link->is_hpd_pending)
return LINK_TRAINING_ABORT;
if (link->preferred_training_settings.fec_enable != NULL)
fec_enable = *link->preferred_training_settings.fec_enable;
else
fec_enable = true;
status = dp_set_fec_ready(link, link_res, fec_enable);
if (status != DC_OK && link->is_hpd_pending)
return LINK_TRAINING_ABORT;
return LINK_TRAINING_SUCCESS;
}
static enum dc_status core_link_send_set_config(
struct dc_link *link,
uint8_t msg_type,
uint8_t msg_data)
{
struct set_config_cmd_payload payload;
enum set_config_status set_config_result = SET_CONFIG_PENDING;
/* prepare set_config payload */
payload.msg_type = msg_type;
payload.msg_data = msg_data;
if (!link->ddc->ddc_pin && !link->aux_access_disabled &&
(dm_helpers_dmub_set_config_sync(link->ctx,
link, &payload, &set_config_result) == -1)) {
return DC_ERROR_UNEXPECTED;
}
/* set_config should return ACK if successful */
return (set_config_result == SET_CONFIG_ACK_RECEIVED) ? DC_OK : DC_ERROR_UNEXPECTED;
}
/* Build SET_CONFIG message data payload for specified message type. */
static uint8_t dpia_build_set_config_data(
enum dpia_set_config_type type,
struct dc_link *link,
struct link_training_settings *lt_settings)
{
union dpia_set_config_data data;
data.raw = 0;
switch (type) {
case DPIA_SET_CFG_SET_LINK:
data.set_link.mode = lt_settings->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT ? 1 : 0;
break;
case DPIA_SET_CFG_SET_PHY_TEST_MODE:
break;
case DPIA_SET_CFG_SET_VSPE:
/* Assume all lanes have same drive settings. */
data.set_vspe.swing = lt_settings->hw_lane_settings[0].VOLTAGE_SWING;
data.set_vspe.pre_emph = lt_settings->hw_lane_settings[0].PRE_EMPHASIS;
data.set_vspe.max_swing_reached =
lt_settings->hw_lane_settings[0].VOLTAGE_SWING == VOLTAGE_SWING_MAX_LEVEL ? 1 : 0;
data.set_vspe.max_pre_emph_reached =
lt_settings->hw_lane_settings[0].PRE_EMPHASIS == PRE_EMPHASIS_MAX_LEVEL ? 1 : 0;
break;
default:
ASSERT(false); /* Message type not supported by helper function. */
break;
}
return data.raw;
}
/* Convert DC training pattern to DPIA training stage. */
static enum dc_status convert_trng_ptn_to_trng_stg(enum dc_dp_training_pattern tps, enum dpia_set_config_ts *ts)
{
enum dc_status status = DC_OK;
switch (tps) {
case DP_TRAINING_PATTERN_SEQUENCE_1:
*ts = DPIA_TS_TPS1;
break;
case DP_TRAINING_PATTERN_SEQUENCE_2:
*ts = DPIA_TS_TPS2;
break;
case DP_TRAINING_PATTERN_SEQUENCE_3:
*ts = DPIA_TS_TPS3;
break;
case DP_TRAINING_PATTERN_SEQUENCE_4:
*ts = DPIA_TS_TPS4;
break;
case DP_TRAINING_PATTERN_VIDEOIDLE:
*ts = DPIA_TS_DPRX_DONE;
break;
default: /* TPS not supported by helper function. */
ASSERT(false);
*ts = DPIA_TS_DPRX_DONE;
status = DC_UNSUPPORTED_VALUE;
break;
}
return status;
}
/* Write training pattern to DPCD. */
static enum dc_status dpcd_set_lt_pattern(
struct dc_link *link,
enum dc_dp_training_pattern pattern,
uint32_t hop)
{
union dpcd_training_pattern dpcd_pattern = {0};
uint32_t dpcd_tps_offset = DP_TRAINING_PATTERN_SET;
enum dc_status status;
if (hop != DPRX)
dpcd_tps_offset = DP_TRAINING_PATTERN_SET_PHY_REPEATER1 +
((DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE) * (hop - 1));
/* DpcdAddress_TrainingPatternSet */
dpcd_pattern.v1_4.TRAINING_PATTERN_SET =
dp_training_pattern_to_dpcd_training_pattern(link, pattern);
dpcd_pattern.v1_4.SCRAMBLING_DISABLE =
dp_initialize_scrambling_data_symbols(link, pattern);
if (hop != DPRX) {
DC_LOG_HW_LINK_TRAINING("%s\n LTTPR Repeater ID: %d\n 0x%X pattern = %x\n",
__func__,
hop,
dpcd_tps_offset,
dpcd_pattern.v1_4.TRAINING_PATTERN_SET);
} else {
DC_LOG_HW_LINK_TRAINING("%s\n 0x%X pattern = %x\n",
__func__,
dpcd_tps_offset,
dpcd_pattern.v1_4.TRAINING_PATTERN_SET);
}
status = core_link_write_dpcd(
link,
dpcd_tps_offset,
&dpcd_pattern.raw,
sizeof(dpcd_pattern.raw));
return status;
}
/* Execute clock recovery phase of link training for specified hop in display
* path.in non-transparent mode:
* - Driver issues both DPCD and SET_CONFIG transactions.
* - TPS1 is transmitted for any hops downstream of DPOA.
* - Drive (VS/PE) only transmitted for the hop immediately downstream of DPOA.
* - CR for the first hop (DPTX-to-DPIA) is assumed to be successful.
*
* @param link DPIA link being trained.
* @param lt_settings link_setting and drive settings (voltage swing and pre-emphasis).
* @param hop Hop in display path. DPRX = 0.
*/
static enum link_training_result dpia_training_cr_non_transparent(
struct dc_link *link,
const struct link_resource *link_res,
struct link_training_settings *lt_settings,
uint32_t hop)
{
enum link_training_result result = LINK_TRAINING_CR_FAIL_LANE0;
uint8_t repeater_cnt = 0; /* Number of hops/repeaters in display path. */
enum dc_status status;
uint32_t retries_cr = 0; /* Number of consecutive attempts with same VS or PE. */
uint32_t retry_count = 0;
uint32_t wait_time_microsec = TRAINING_AUX_RD_INTERVAL; /* From DP spec, CR read interval is always 100us. */
enum dc_lane_count lane_count = lt_settings->link_settings.lane_count;
union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX] = {0};
union lane_align_status_updated dpcd_lane_status_updated = {0};
union lane_adjust dpcd_lane_adjust[LANE_COUNT_DP_MAX] = {0};
uint8_t set_cfg_data;
enum dpia_set_config_ts ts;
repeater_cnt = dp_parse_lttpr_repeater_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt);
/* Cap of LINK_TRAINING_MAX_CR_RETRY attempts at clock recovery.
* Fix inherited from perform_clock_recovery_sequence() -
* the DP equivalent of this function:
* Required for Synaptics MST hub which can put the LT in
* infinite loop by switching the VS between level 0 and level 1
* continuously.
*/
while ((retries_cr < LINK_TRAINING_MAX_RETRY_COUNT) &&
(retry_count < LINK_TRAINING_MAX_CR_RETRY)) {
/* DPTX-to-DPIA */
if (hop == repeater_cnt) {
/* Send SET_CONFIG(SET_LINK:LC,LR,LTTPR) to notify DPOA that
* non-transparent link training has started.
* This also enables the transmission of clk_sync packets.
*/
set_cfg_data = dpia_build_set_config_data(
DPIA_SET_CFG_SET_LINK,
link,
lt_settings);
status = core_link_send_set_config(
link,
DPIA_SET_CFG_SET_LINK,
set_cfg_data);
/* CR for this hop is considered successful as long as
* SET_CONFIG message is acknowledged by DPOA.
*/
if (status == DC_OK)
result = LINK_TRAINING_SUCCESS;
else
result = LINK_TRAINING_ABORT;
break;
}
/* DPOA-to-x */
/* Instruct DPOA to transmit TPS1 then update DPCD. */
if (retry_count == 0) {
status = convert_trng_ptn_to_trng_stg(lt_settings->pattern_for_cr, &ts);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
status = core_link_send_set_config(
link,
DPIA_SET_CFG_SET_TRAINING,
ts);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
status = dpcd_set_lt_pattern(link, lt_settings->pattern_for_cr, hop);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
}
/* Update DPOA drive settings then DPCD. DPOA does only adjusts
* drive settings for hops immediately downstream.
*/
if (hop == repeater_cnt - 1) {
set_cfg_data = dpia_build_set_config_data(
DPIA_SET_CFG_SET_VSPE,
link,
lt_settings);
status = core_link_send_set_config(
link,
DPIA_SET_CFG_SET_VSPE,
set_cfg_data);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
}
status = dpcd_set_lane_settings(link, lt_settings, hop);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
dp_wait_for_training_aux_rd_interval(link, wait_time_microsec);
/* Read status and adjustment requests from DPCD. */
status = dp_get_lane_status_and_lane_adjust(
link,
lt_settings,
dpcd_lane_status,
&dpcd_lane_status_updated,
dpcd_lane_adjust,
hop);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
/* Check if clock recovery successful. */
if (dp_is_cr_done(lane_count, dpcd_lane_status)) {
DC_LOG_HW_LINK_TRAINING("%s: Clock recovery OK\n", __func__);
result = LINK_TRAINING_SUCCESS;
break;
}
result = dp_get_cr_failure(lane_count, dpcd_lane_status);
if (dp_is_max_vs_reached(lt_settings))
break;
/* Count number of attempts with same drive settings.
* Note: settings are the same for all lanes,
* so comparing first lane is sufficient.
*/
if ((lt_settings->dpcd_lane_settings[0].bits.VOLTAGE_SWING_SET ==
dpcd_lane_adjust[0].bits.VOLTAGE_SWING_LANE)
&& (lt_settings->dpcd_lane_settings[0].bits.PRE_EMPHASIS_SET ==
dpcd_lane_adjust[0].bits.PRE_EMPHASIS_LANE))
retries_cr++;
else
retries_cr = 0;
/* Update VS/PE. */
dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
lt_settings->hw_lane_settings,
lt_settings->dpcd_lane_settings);
retry_count++;
}
/* Abort link training if clock recovery failed due to HPD unplug. */
if (link->is_hpd_pending)
result = LINK_TRAINING_ABORT;
DC_LOG_HW_LINK_TRAINING(
"%s\n DPIA(%d) clock recovery\n -hop(%d)\n - result(%d)\n - retries(%d)\n - status(%d)\n",
__func__,
link->link_id.enum_id - ENUM_ID_1,
hop,
result,
retry_count,
status);
return result;
}
/* Execute clock recovery phase of link training in transparent LTTPR mode:
* - Driver only issues DPCD transactions and leaves USB4 tunneling (SET_CONFIG) messages to DPIA.
* - Driver writes TPS1 to DPCD to kick off training.
* - Clock recovery (CR) for link is handled by DPOA, which reports result to DPIA on completion.
* - DPIA communicates result to driver by updating CR status when driver reads DPCD.
*
* @param link DPIA link being trained.
* @param lt_settings link_setting and drive settings (voltage swing and pre-emphasis).
*/
static enum link_training_result dpia_training_cr_transparent(
struct dc_link *link,
const struct link_resource *link_res,
struct link_training_settings *lt_settings)
{
enum link_training_result result = LINK_TRAINING_CR_FAIL_LANE0;
enum dc_status status;
uint32_t retries_cr = 0; /* Number of consecutive attempts with same VS or PE. */
uint32_t retry_count = 0;
uint32_t wait_time_microsec = lt_settings->cr_pattern_time;
enum dc_lane_count lane_count = lt_settings->link_settings.lane_count;
union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX] = {0};
union lane_align_status_updated dpcd_lane_status_updated = {0};
union lane_adjust dpcd_lane_adjust[LANE_COUNT_DP_MAX] = {0};
/* Cap of LINK_TRAINING_MAX_CR_RETRY attempts at clock recovery.
* Fix inherited from perform_clock_recovery_sequence() -
* the DP equivalent of this function:
* Required for Synaptics MST hub which can put the LT in
* infinite loop by switching the VS between level 0 and level 1
* continuously.
*/
while ((retries_cr < LINK_TRAINING_MAX_RETRY_COUNT) &&
(retry_count < LINK_TRAINING_MAX_CR_RETRY)) {
/* Write TPS1 (not VS or PE) to DPCD to start CR phase.
* DPIA sends SET_CONFIG(SET_LINK) to notify DPOA to
* start link training.
*/
if (retry_count == 0) {
status = dpcd_set_lt_pattern(link, lt_settings->pattern_for_cr, DPRX);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
}
dp_wait_for_training_aux_rd_interval(link, wait_time_microsec);
/* Read status and adjustment requests from DPCD. */
status = dp_get_lane_status_and_lane_adjust(
link,
lt_settings,
dpcd_lane_status,
&dpcd_lane_status_updated,
dpcd_lane_adjust,
DPRX);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
/* Check if clock recovery successful. */
if (dp_is_cr_done(lane_count, dpcd_lane_status)) {
DC_LOG_HW_LINK_TRAINING("%s: Clock recovery OK\n", __func__);
result = LINK_TRAINING_SUCCESS;
break;
}
result = dp_get_cr_failure(lane_count, dpcd_lane_status);
if (dp_is_max_vs_reached(lt_settings))
break;
/* Count number of attempts with same drive settings.
* Note: settings are the same for all lanes,
* so comparing first lane is sufficient.
*/
if ((lt_settings->dpcd_lane_settings[0].bits.VOLTAGE_SWING_SET ==
dpcd_lane_adjust[0].bits.VOLTAGE_SWING_LANE)
&& (lt_settings->dpcd_lane_settings[0].bits.PRE_EMPHASIS_SET ==
dpcd_lane_adjust[0].bits.PRE_EMPHASIS_LANE))
retries_cr++;
else
retries_cr = 0;
/* Update VS/PE. */
dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);
retry_count++;
}
/* Abort link training if clock recovery failed due to HPD unplug. */
if (link->is_hpd_pending)
result = LINK_TRAINING_ABORT;
DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) clock recovery\n -hop(%d)\n - result(%d)\n - retries(%d)\n",
__func__,
link->link_id.enum_id - ENUM_ID_1,
DPRX,
result,
retry_count);
return result;
}
/* Execute clock recovery phase of link training for specified hop in display
* path.
*
* @param link DPIA link being trained.
* @param lt_settings link_setting and drive settings (voltage swing and pre-emphasis).
* @param hop Hop in display path. DPRX = 0.
*/
static enum link_training_result dpia_training_cr_phase(
struct dc_link *link,
const struct link_resource *link_res,
struct link_training_settings *lt_settings,
uint32_t hop)
{
enum link_training_result result = LINK_TRAINING_CR_FAIL_LANE0;
if (lt_settings->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT)
result = dpia_training_cr_non_transparent(link, link_res, lt_settings, hop);
else
result = dpia_training_cr_transparent(link, link_res, lt_settings);
return result;
}
/* Return status read interval during equalization phase. */
static uint32_t dpia_get_eq_aux_rd_interval(
const struct dc_link *link,
const struct link_training_settings *lt_settings,
uint32_t hop)
{
uint32_t wait_time_microsec;
if (hop == DPRX)
wait_time_microsec = lt_settings->eq_pattern_time;
else
wait_time_microsec =
dp_translate_training_aux_read_interval(
link->dpcd_caps.lttpr_caps.aux_rd_interval[hop - 1]);
/* Check debug option for extending aux read interval. */
if (link->dc->debug.dpia_debug.bits.extend_aux_rd_interval)
wait_time_microsec = DPIA_DEBUG_EXTENDED_AUX_RD_INTERVAL_US;
return wait_time_microsec;
}
/* Execute equalization phase of link training for specified hop in display
* path in non-transparent mode:
* - driver issues both DPCD and SET_CONFIG transactions.
* - TPSx is transmitted for any hops downstream of DPOA.
* - Drive (VS/PE) only transmitted for the hop immediately downstream of DPOA.
* - EQ for the first hop (DPTX-to-DPIA) is assumed to be successful.
* - DPRX EQ only reported successful when both DPRX and DPIA requirements (clk sync packets sent) fulfilled.
*
* @param link DPIA link being trained.
* @param lt_settings link_setting and drive settings (voltage swing and pre-emphasis).
* @param hop Hop in display path. DPRX = 0.
*/
static enum link_training_result dpia_training_eq_non_transparent(
struct dc_link *link,
const struct link_resource *link_res,
struct link_training_settings *lt_settings,
uint32_t hop)
{
enum link_training_result result = LINK_TRAINING_EQ_FAIL_EQ;
uint8_t repeater_cnt = 0; /* Number of hops/repeaters in display path. */
uint32_t retries_eq = 0;
enum dc_status status;
enum dc_dp_training_pattern tr_pattern;
uint32_t wait_time_microsec = 0;
enum dc_lane_count lane_count = lt_settings->link_settings.lane_count;
union lane_align_status_updated dpcd_lane_status_updated = {0};
union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX] = {0};
union lane_adjust dpcd_lane_adjust[LANE_COUNT_DP_MAX] = {0};
uint8_t set_cfg_data;
enum dpia_set_config_ts ts;
/* Training pattern is TPS4 for repeater;
* TPS2/3/4 for DPRX depending on what it supports.
*/
if (hop == DPRX)
tr_pattern = lt_settings->pattern_for_eq;
else
tr_pattern = DP_TRAINING_PATTERN_SEQUENCE_4;
repeater_cnt = dp_parse_lttpr_repeater_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt);
for (retries_eq = 0; retries_eq < LINK_TRAINING_MAX_RETRY_COUNT; retries_eq++) {
/* DPTX-to-DPIA equalization always successful. */
if (hop == repeater_cnt) {
result = LINK_TRAINING_SUCCESS;
break;
}
/* Instruct DPOA to transmit TPSn then update DPCD. */
if (retries_eq == 0) {
status = convert_trng_ptn_to_trng_stg(tr_pattern, &ts);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
status = core_link_send_set_config(
link,
DPIA_SET_CFG_SET_TRAINING,
ts);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
status = dpcd_set_lt_pattern(link, tr_pattern, hop);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
}
/* Update DPOA drive settings then DPCD. DPOA only adjusts
* drive settings for hop immediately downstream.
*/
if (hop == repeater_cnt - 1) {
set_cfg_data = dpia_build_set_config_data(
DPIA_SET_CFG_SET_VSPE,
link,
lt_settings);
status = core_link_send_set_config(
link,
DPIA_SET_CFG_SET_VSPE,
set_cfg_data);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
}
status = dpcd_set_lane_settings(link, lt_settings, hop);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
/* Extend wait time on second equalisation attempt on final hop to
* ensure clock sync packets have been sent.
*/
if (hop == DPRX && retries_eq == 1)
wait_time_microsec = max(wait_time_microsec, (uint32_t) DPIA_CLK_SYNC_DELAY);
else
wait_time_microsec = dpia_get_eq_aux_rd_interval(link, lt_settings, hop);
dp_wait_for_training_aux_rd_interval(link, wait_time_microsec);
/* Read status and adjustment requests from DPCD. */
status = dp_get_lane_status_and_lane_adjust(
link,
lt_settings,
dpcd_lane_status,
&dpcd_lane_status_updated,
dpcd_lane_adjust,
hop);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
/* CR can still fail during EQ phase. Fail training if CR fails. */
if (!dp_is_cr_done(lane_count, dpcd_lane_status)) {
result = LINK_TRAINING_EQ_FAIL_CR;
break;
}
if (dp_is_ch_eq_done(lane_count, dpcd_lane_status) &&
dp_is_symbol_locked(link->cur_link_settings.lane_count, dpcd_lane_status) &&
dp_is_interlane_aligned(dpcd_lane_status_updated)) {
result = LINK_TRAINING_SUCCESS;
break;
}
/* Update VS/PE. */
dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);
}
/* Abort link training if equalization failed due to HPD unplug. */
if (link->is_hpd_pending)
result = LINK_TRAINING_ABORT;
DC_LOG_HW_LINK_TRAINING(
"%s\n DPIA(%d) equalization\n - hop(%d)\n - result(%d)\n - retries(%d)\n - status(%d)\n",
__func__,
link->link_id.enum_id - ENUM_ID_1,
hop,
result,
retries_eq,
status);
return result;
}
/* Execute equalization phase of link training for specified hop in display
* path in transparent LTTPR mode:
* - driver only issues DPCD transactions leaves USB4 tunneling (SET_CONFIG) messages to DPIA.
* - driver writes TPSx to DPCD to notify DPIA that is in equalization phase.
* - equalization (EQ) for link is handled by DPOA, which reports result to DPIA on completion.
* - DPIA communicates result to driver by updating EQ status when driver reads DPCD.
*
* @param link DPIA link being trained.
* @param lt_settings link_setting and drive settings (voltage swing and pre-emphasis).
* @param hop Hop in display path. DPRX = 0.
*/
static enum link_training_result dpia_training_eq_transparent(
struct dc_link *link,
const struct link_resource *link_res,
struct link_training_settings *lt_settings)
{
enum link_training_result result = LINK_TRAINING_EQ_FAIL_EQ;
uint32_t retries_eq = 0;
enum dc_status status;
enum dc_dp_training_pattern tr_pattern = lt_settings->pattern_for_eq;
uint32_t wait_time_microsec;
enum dc_lane_count lane_count = lt_settings->link_settings.lane_count;
union lane_align_status_updated dpcd_lane_status_updated = {0};
union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX] = {0};
union lane_adjust dpcd_lane_adjust[LANE_COUNT_DP_MAX] = {0};
wait_time_microsec = dpia_get_eq_aux_rd_interval(link, lt_settings, DPRX);
for (retries_eq = 0; retries_eq < LINK_TRAINING_MAX_RETRY_COUNT; retries_eq++) {
if (retries_eq == 0) {
status = dpcd_set_lt_pattern(link, tr_pattern, DPRX);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
}
dp_wait_for_training_aux_rd_interval(link, wait_time_microsec);
/* Read status and adjustment requests from DPCD. */
status = dp_get_lane_status_and_lane_adjust(
link,
lt_settings,
dpcd_lane_status,
&dpcd_lane_status_updated,
dpcd_lane_adjust,
DPRX);
if (status != DC_OK) {
result = LINK_TRAINING_ABORT;
break;
}
/* CR can still fail during EQ phase. Fail training if CR fails. */
if (!dp_is_cr_done(lane_count, dpcd_lane_status)) {
result = LINK_TRAINING_EQ_FAIL_CR;
break;
}
if (dp_is_ch_eq_done(lane_count, dpcd_lane_status) &&
dp_is_symbol_locked(link->cur_link_settings.lane_count, dpcd_lane_status)) {
/* Take into consideration corner case for DP 1.4a LL Compliance CTS as USB4
* has to share encoders unlike DP and USBC
*/
if (dp_is_interlane_aligned(dpcd_lane_status_updated) || (link->skip_fallback_on_link_loss && retries_eq)) {
result = LINK_TRAINING_SUCCESS;
break;
}
}
/* Update VS/PE. */
dp_decide_lane_settings(lt_settings, dpcd_lane_adjust,
lt_settings->hw_lane_settings, lt_settings->dpcd_lane_settings);
}
/* Abort link training if equalization failed due to HPD unplug. */
if (link->is_hpd_pending)
result = LINK_TRAINING_ABORT;
DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) equalization\n - hop(%d)\n - result(%d)\n - retries(%d)\n",
__func__,
link->link_id.enum_id - ENUM_ID_1,
DPRX,
result,
retries_eq);
return result;
}
/* Execute equalization phase of link training for specified hop in display
* path.
*
* @param link DPIA link being trained.
* @param lt_settings link_setting and drive settings (voltage swing and pre-emphasis).
* @param hop Hop in display path. DPRX = 0.
*/
static enum link_training_result dpia_training_eq_phase(
struct dc_link *link,
const struct link_resource *link_res,
struct link_training_settings *lt_settings,
uint32_t hop)
{
enum link_training_result result;
if (lt_settings->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT)
result = dpia_training_eq_non_transparent(link, link_res, lt_settings, hop);
else
result = dpia_training_eq_transparent(link, link_res, lt_settings);
return result;
}
/* End training of specified hop in display path. */
static enum dc_status dpcd_clear_lt_pattern(
struct dc_link *link,
uint32_t hop)
{
union dpcd_training_pattern dpcd_pattern = {0};
uint32_t dpcd_tps_offset = DP_TRAINING_PATTERN_SET;
enum dc_status status;
if (hop != DPRX)
dpcd_tps_offset = DP_TRAINING_PATTERN_SET_PHY_REPEATER1 +
((DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE) * (hop - 1));
status = core_link_write_dpcd(
link,
dpcd_tps_offset,
&dpcd_pattern.raw,
sizeof(dpcd_pattern.raw));
return status;
}
/* End training of specified hop in display path.
*
* In transparent LTTPR mode:
* - driver clears training pattern for the specified hop in DPCD.
* In non-transparent LTTPR mode:
* - in addition to clearing training pattern, driver issues USB4 tunneling
* (SET_CONFIG) messages to notify DPOA when training is done for first hop
* (DPTX-to-DPIA) and last hop (DPRX).
*
* @param link DPIA link being trained.
* @param hop Hop in display path. DPRX = 0.
*/
static enum link_training_result dpia_training_end(
struct dc_link *link,
struct link_training_settings *lt_settings,
uint32_t hop)
{
enum link_training_result result = LINK_TRAINING_SUCCESS;
uint8_t repeater_cnt = 0; /* Number of hops/repeaters in display path. */
enum dc_status status;
if (lt_settings->lttpr_mode == LTTPR_MODE_NON_TRANSPARENT) {
repeater_cnt = dp_parse_lttpr_repeater_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt);
if (hop == repeater_cnt) { /* DPTX-to-DPIA */
/* Send SET_CONFIG(SET_TRAINING:0xff) to notify DPOA that
* DPTX-to-DPIA hop trained. No DPCD write needed for first hop.
*/
status = core_link_send_set_config(
link,
DPIA_SET_CFG_SET_TRAINING,
DPIA_TS_UFP_DONE);
if (status != DC_OK)
result = LINK_TRAINING_ABORT;
} else { /* DPOA-to-x */
/* Write 0x0 to TRAINING_PATTERN_SET */
status = dpcd_clear_lt_pattern(link, hop);
if (status != DC_OK)
result = LINK_TRAINING_ABORT;
}
/* Notify DPOA that non-transparent link training of DPRX done. */
if (hop == DPRX && result != LINK_TRAINING_ABORT) {
status = core_link_send_set_config(
link,
DPIA_SET_CFG_SET_TRAINING,
DPIA_TS_DPRX_DONE);
if (status != DC_OK)
result = LINK_TRAINING_ABORT;
}
} else { /* non-LTTPR or transparent LTTPR. */
/* Write 0x0 to TRAINING_PATTERN_SET */
status = dpcd_clear_lt_pattern(link, hop);
if (status != DC_OK)
result = LINK_TRAINING_ABORT;
}
DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) end\n - hop(%d)\n - result(%d)\n - LTTPR mode(%d)\n",
__func__,
link->link_id.enum_id - ENUM_ID_1,
hop,
result,
lt_settings->lttpr_mode);
return result;
}
/* When aborting training of specified hop in display path, clean up by:
* - Attempting to clear DPCD TRAINING_PATTERN_SET, LINK_BW_SET and LANE_COUNT_SET.
* - Sending SET_CONFIG(SET_LINK) with lane count and link rate set to 0.
*
* @param link DPIA link being trained.
* @param hop Hop in display path. DPRX = 0.
*/
static void dpia_training_abort(
struct dc_link *link,
struct link_training_settings *lt_settings,
uint32_t hop)
{
uint8_t data = 0;
uint32_t dpcd_tps_offset = DP_TRAINING_PATTERN_SET;
DC_LOG_HW_LINK_TRAINING("%s\n DPIA(%d) aborting\n - LTTPR mode(%d)\n - HPD(%d)\n",
__func__,
link->link_id.enum_id - ENUM_ID_1,
lt_settings->lttpr_mode,
link->is_hpd_pending);
/* Abandon clean-up if sink unplugged. */
if (link->is_hpd_pending)
return;
if (hop != DPRX)
dpcd_tps_offset = DP_TRAINING_PATTERN_SET_PHY_REPEATER1 +
((DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE) * (hop - 1));
core_link_write_dpcd(link, dpcd_tps_offset, &data, 1);
core_link_write_dpcd(link, DP_LINK_BW_SET, &data, 1);
core_link_write_dpcd(link, DP_LANE_COUNT_SET, &data, 1);
core_link_send_set_config(link, DPIA_SET_CFG_SET_LINK, data);
}
enum link_training_result dpia_perform_link_training(
struct dc_link *link,
const struct link_resource *link_res,
const struct dc_link_settings *link_setting,
bool skip_video_pattern)
{
enum link_training_result result;
struct link_training_settings lt_settings = {0};
uint8_t repeater_cnt = 0; /* Number of hops/repeaters in display path. */
int8_t repeater_id; /* Current hop. */
struct dc_link_settings link_settings = *link_setting; // non-const copy to pass in
lt_settings.lttpr_mode = dp_decide_lttpr_mode(link, &link_settings);
/* Configure link as prescribed in link_setting and set LTTPR mode. */
result = dpia_configure_link(link, link_res, link_setting, &lt_settings);
if (result != LINK_TRAINING_SUCCESS)
return result;
if (lt_settings.lttpr_mode == LTTPR_MODE_NON_TRANSPARENT)
repeater_cnt = dp_parse_lttpr_repeater_count(link->dpcd_caps.lttpr_caps.phy_repeater_cnt);
/* Train each hop in turn starting with the one closest to DPTX.
* In transparent or non-LTTPR mode, train only the final hop (DPRX).
*/
for (repeater_id = repeater_cnt; repeater_id >= 0; repeater_id--) {
/* Clock recovery. */
result = dpia_training_cr_phase(link, link_res, &lt_settings, repeater_id);
if (result != LINK_TRAINING_SUCCESS)
break;
/* Equalization. */
result = dpia_training_eq_phase(link, link_res, &lt_settings, repeater_id);
if (result != LINK_TRAINING_SUCCESS)
break;
/* Stop training hop. */
result = dpia_training_end(link, &lt_settings, repeater_id);
if (result != LINK_TRAINING_SUCCESS)
break;
}
/* Double-check link status if training successful; gracefully abort
* training of current hop if training failed due to message tunneling
* failure; end training of hop if training ended conventionally and
* falling back to lower bandwidth settings possible.
*/
if (result == LINK_TRAINING_SUCCESS) {
fsleep(5000);
if (!link->skip_fallback_on_link_loss)
result = dp_check_link_loss_status(link, &lt_settings);
} else if (result == LINK_TRAINING_ABORT)
dpia_training_abort(link, &lt_settings, repeater_id);
else
dpia_training_end(link, &lt_settings, repeater_id);
return result;
}
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