drm/amd/display: allow diags to skip initial link training

[why]
diag specify what the full config and is only concerned about pass/fail at the end

having inter-op code like verifiying we can actually train at reported link rate
slows down diag test and add complexity we don't need

[how]
add dc_debug option to skip capability link trianing

also  remove hbr in function name as verify is not specific to hbr
Signed-off-by: Tony Cheng <tony.cheng@amd.com>
Reviewed-by: Ken Chalmers <ken.chalmers@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -760,7 +760,7 @@ bool dc_link_detect(struct dc_link *link, enum dc_detect_reason reason)
 				 */
 
 				/* deal with non-mst cases */
-				dp_hbr_verify_link_cap(link, &link->reported_link_cap);
+				dp_verify_link_cap(link, &link->reported_link_cap);
 			}
 
 			/* HDMI-DVI Dongle */

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

@@ -1086,7 +1086,7 @@ static struct dc_link_settings get_max_link_cap(struct dc_link *link)
 	return max_link_cap;
 }
 
-bool dp_hbr_verify_link_cap(
+bool dp_verify_link_cap(
 	struct dc_link *link,
 	struct dc_link_settings *known_limit_link_setting)
 {
@@ -1101,6 +1101,11 @@ bool dp_hbr_verify_link_cap(
 	enum clock_source_id dp_cs_id = CLOCK_SOURCE_ID_EXTERNAL;
 	enum link_training_result status;
 
+	if (link->dc->debug.skip_detection_link_training) {
+		link->verified_link_cap = *known_limit_link_setting;
+		return true;
+	}
+
 	success = false;
 	skip_link_training = false;
 

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

@@ -258,6 +258,7 @@ struct dc_debug {
 	bool avoid_vbios_exec_table;
 	bool scl_reset_length10;
 	bool hdmi20_disable;
+	bool skip_detection_link_training;
 
 	struct {
 		uint32_t ltFailCount;

drivers/gpu/drm/amd/display/dc/inc/dc_link_dp.h

@@ -33,7 +33,7 @@ struct dc_link;
 struct dc_stream_state;
 struct dc_link_settings;
 
-bool dp_hbr_verify_link_cap(
+bool dp_verify_link_cap(
 	struct dc_link *link,
 	struct dc_link_settings *known_limit_link_setting);