drm/amd/display: add option to override cr training pattern

Signed-off-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c

@@ -101,7 +101,16 @@ static void dpcd_set_training_pattern(
 		dpcd_pattern.v1_4.TRAINING_PATTERN_SET);
 }
 
-static enum dc_dp_training_pattern get_supported_tp(struct dc_link *link)
+static enum dc_dp_training_pattern decide_cr_training_pattern(
+		const struct dc_link_settings *link_settings)
+{
+	enum dc_dp_training_pattern pattern = DP_TRAINING_PATTERN_SEQUENCE_1;
+
+	return pattern;
+}
+
+static enum dc_dp_training_pattern decide_eq_training_pattern(struct dc_link *link,
+		const struct dc_link_settings *link_settings)
 {
 	enum dc_dp_training_pattern highest_tp = DP_TRAINING_PATTERN_SEQUENCE_2;
 	struct encoder_feature_support *features = &link->link_enc->features;
@@ -132,7 +141,6 @@ static void dpcd_set_link_settings(
 
 	union down_spread_ctrl downspread = { {0} };
 	union lane_count_set lane_count_set = { {0} };
-	enum dc_dp_training_pattern dp_tr_pattern;
 
 	downspread.raw = (uint8_t)
 	(lt_settings->link_settings.link_spread);
@@ -143,9 +151,8 @@ static void dpcd_set_link_settings(
 	lane_count_set.bits.ENHANCED_FRAMING = lt_settings->enhanced_framing;
 	lane_count_set.bits.POST_LT_ADJ_REQ_GRANTED = 0;
 
-	dp_tr_pattern = get_supported_tp(link);
 
-	if (dp_tr_pattern != DP_TRAINING_PATTERN_SEQUENCE_4) {
+	if (lt_settings->pattern_for_eq < DP_TRAINING_PATTERN_SEQUENCE_4) {
 		lane_count_set.bits.POST_LT_ADJ_REQ_GRANTED =
 				link->dpcd_caps.max_ln_count.bits.POST_LT_ADJ_REQ_SUPPORTED;
 	}
@@ -979,7 +986,7 @@ static void start_clock_recovery_pattern_early(struct dc_link *link,
 {
 	DC_LOG_HW_LINK_TRAINING("%s\n GPU sends TPS1. Wait 400us.\n",
 			__func__);
-	dp_set_hw_training_pattern(link, DP_TRAINING_PATTERN_SEQUENCE_1, offset);
+	dp_set_hw_training_pattern(link, lt_settings->pattern_for_cr, offset);
 	dp_set_hw_lane_settings(link, lt_settings, offset);
 	udelay(400);
 }
@@ -994,7 +1001,6 @@ static enum link_training_result perform_clock_recovery_sequence(
 	uint32_t wait_time_microsec;
 	struct link_training_settings req_settings;
 	enum dc_lane_count lane_count = lt_settings->link_settings.lane_count;
-	enum dc_dp_training_pattern tr_pattern = DP_TRAINING_PATTERN_SEQUENCE_1;
 	union lane_status dpcd_lane_status[LANE_COUNT_DP_MAX];
 	union lane_align_status_updated dpcd_lane_status_updated;
 
@@ -1002,7 +1008,7 @@ static enum link_training_result perform_clock_recovery_sequence(
 	retry_count = 0;
 
 	if (!link->ctx->dc->work_arounds.lt_early_cr_pattern)
-		dp_set_hw_training_pattern(link, tr_pattern, offset);
+		dp_set_hw_training_pattern(link, lt_settings->pattern_for_cr, offset);
 
 	/* najeeb - The synaptics MST hub can put the LT in
 	* infinite loop by switching the VS
@@ -1029,7 +1035,7 @@ static enum link_training_result perform_clock_recovery_sequence(
 			dpcd_set_lt_pattern_and_lane_settings(
 					link,
 					lt_settings,
-					tr_pattern,
+					lt_settings->pattern_for_cr,
 					offset);
 		else
 			dpcd_set_lane_settings(
@@ -1113,7 +1119,7 @@ static inline enum link_training_result perform_link_training_int(
 	 * TPS4 must be used instead of POST_LT_ADJ_REQ.
 	 */
 	if (link->dpcd_caps.max_ln_count.bits.POST_LT_ADJ_REQ_SUPPORTED != 1 ||
-			get_supported_tp(link) == DP_TRAINING_PATTERN_SEQUENCE_4)
+			lt_settings->pattern_for_eq == DP_TRAINING_PATTERN_SEQUENCE_4)
 		return status;
 
 	if (status == LINK_TRAINING_SUCCESS &&
@@ -1252,10 +1258,14 @@ static void initialize_training_settings(
 	else
 		lt_settings->eq_pattern_time = get_training_aux_rd_interval(link, 400);
 
+	if (overrides->pattern_for_cr != NULL)
+		lt_settings->pattern_for_cr = *overrides->pattern_for_cr;
+	else
+		lt_settings->pattern_for_cr = decide_cr_training_pattern(link_setting);
 	if (overrides->pattern_for_eq != NULL)
 		lt_settings->pattern_for_eq = *overrides->pattern_for_eq;
 	else
-		lt_settings->pattern_for_eq = get_supported_tp(link);
+		lt_settings->pattern_for_eq = decide_eq_training_pattern(link, link_setting);
 
 	if (overrides->enhanced_framing != NULL)
 		lt_settings->enhanced_framing = *overrides->enhanced_framing;
@@ -1457,7 +1467,6 @@ bool dc_link_dp_perform_link_training_skip_aux(
 	const struct dc_link_settings *link_setting)
 {
 	struct link_training_settings lt_settings;
-	enum dc_dp_training_pattern pattern_for_cr = DP_TRAINING_PATTERN_SEQUENCE_1;
 
 	initialize_training_settings(
 			link,
@@ -1468,7 +1477,7 @@ bool dc_link_dp_perform_link_training_skip_aux(
 	/* 1. Perform_clock_recovery_sequence. */
 
 	/* transmit training pattern for clock recovery */
-	dp_set_hw_training_pattern(link, pattern_for_cr, DPRX);
+	dp_set_hw_training_pattern(link, lt_settings.pattern_for_cr, DPRX);
 
 	/* call HWSS to set lane settings*/
 	dp_set_hw_lane_settings(link, &lt_settings, DPRX);

drivers/gpu/drm/amd/display/dc/dc_dp_types.h

@@ -123,6 +123,7 @@ struct dc_link_training_overrides {
 
 	uint16_t *cr_pattern_time;
 	uint16_t *eq_pattern_time;
+	enum dc_dp_training_pattern *pattern_for_cr;
 	enum dc_dp_training_pattern *pattern_for_eq;
 
 	enum dc_link_spread *downspread;

drivers/gpu/drm/amd/display/include/link_service_types.h

@@ -80,6 +80,7 @@ struct link_training_settings {
 
 	uint16_t cr_pattern_time;
 	uint16_t eq_pattern_time;
+	enum dc_dp_training_pattern pattern_for_cr;
 	enum dc_dp_training_pattern pattern_for_eq;
 
 	bool enhanced_framing;