drm/amd/display: Train DPIA links with fallback

[Why & How]
Conventional links are trained with fallback during sink detection.
Have DPIA links trained with fallback too.
Reviewed-by: NJun Lei <Jun.Lei@amd.com>
Acked-by: NWayne Lin <Wayne.Lin@amd.com>
Acked-by: NNicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NJimmy Kizito <Jimmy.Kizito@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -1862,6 +1862,12 @@ static enum dc_status enable_link_dp(struct dc_state *state,
 	/* get link settings for video mode timing */
 	decide_link_settings(stream, &link_settings);
 
+	/* Train with fallback when enabling DPIA link. Conventional links are
+	 * trained with fallback during sink detection.
+	 */
+	if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
+		do_fallback = true;
+
 #if defined(CONFIG_DRM_AMD_DC_DCN)
 	if (dp_get_link_encoding_format(&link_settings) == DP_128b_132b_ENCODING &&
 			pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT) {

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

@@ -2406,9 +2406,9 @@ bool perform_link_training_with_retries(
 			dc_link_dp_perform_link_training_skip_aux(link, &current_setting);
 			return true;
 		} else {
-			if (link->is_dig_mapping_flexible)
+			if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
 				status = dc_link_dpia_perform_link_training(link,
-									    link_setting,
+									    &current_setting,
 									    skip_video_pattern);
 			else
 				status = dc_link_dp_perform_link_training(link,