drm/amd/display: add vbios table check for enabling dp ss

Signed-off-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Reviewed-by: Eric Bernstein <Eric.Bernstein@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1038,6 +1038,7 @@ static bool construct(
 	link->link_index = init_params->link_index;
 
 	link->link_id = bios->funcs->get_connector_id(bios, init_params->connector_index);
+	link->dp_ss_off = !!dc_ctx->dc_bios->integrated_info->dp_ss_control;;
 
 	if (link->link_id.type != OBJECT_TYPE_CONNECTOR) {
 		dm_error("%s: Invalid Connector ObjectID from Adapter Service for connector index:%d! type %d expected %d\n",

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

@@ -953,6 +953,9 @@ enum link_training_result dc_link_dp_perform_link_training(
 	 * LINK_SPREAD_05_DOWNSPREAD_30KHZ :
 	 * LINK_SPREAD_DISABLED;
 	 */
+	if (link->dp_ss_off)
+		lt_settings.link_settings.link_spread = LINK_SPREAD_DISABLED;
+	else
 		lt_settings.link_settings.link_spread = LINK_SPREAD_05_DOWNSPREAD_30KHZ;
 
 	/* 1. set link rate, lane count and spread*/

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

@@ -73,6 +73,7 @@ struct dc_link {
 	enum dc_irq_source irq_source_hpd;
 	enum dc_irq_source irq_source_hpd_rx;/* aka DP Short Pulse  */
 	bool is_hpd_filter_disabled;
+	bool dp_ss_off;
 
 	/* caps is the same as reported_link_cap. link_traing use
 	 * reported_link_cap. Will clean up.  TODO

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

@@ -395,6 +395,8 @@ struct integrated_info {
 	struct i2c_reg_info dp3_ext_hdmi_reg_settings[9];
 	unsigned char dp3_ext_hdmi_6g_reg_num;
 	struct i2c_reg_info dp3_ext_hdmi_6g_reg_settings[3];
+	/* V11 */
+	uint32_t dp_ss_control;
 };
 
 /**