drm/amd/display: Skip DPIA-specific DP LL automation flag for non-DPIA links

[Why]
The is_automated flag logic only applies to USB4 DPIA links during DP LL
compliance test automation. The flag should not be set for non-DPIA
cases.

[How]
Add check for DPIA link endpoint type before setting the flag. Also,
rename is_automated to skip_fallback_on_link_loss for clarity.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Meenakshikumar Somasundaram <meenakshikumar.somasundaram@amd.com>
Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: George Shen <george.shen@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1541,7 +1541,13 @@ struct dc_link {
 	bool is_dig_mapping_flexible;
 	bool hpd_status; /* HPD status of link without physical HPD pin. */
 	bool is_hpd_pending; /* Indicates a new received hpd */
-	bool is_automated; /* Indicates automated testing */
+
+	/* USB4 DPIA links skip verifying link cap, instead performing the fallback method
+	 * for every link training. This is incompatible with DP LL compliance automation,
+	 * which expects the same link settings to be used every retry on a link loss.
+	 * This flag is used to skip the fallback when link loss occurs during automation.
+	 */
+	bool skip_fallback_on_link_loss;
 
 	bool edp_sink_present;
 

drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_irq_handler.c

@@ -265,7 +265,7 @@ void dp_handle_link_loss(struct dc_link *link)
 
 	for (i = count - 1; i >= 0; i--) {
 		// Always use max settings here for DP 1.4a LL Compliance CTS
-		if (link->is_automated) {
+		if (link->skip_fallback_on_link_loss) {
 			pipes[i]->link_config.dp_link_settings.lane_count =
 					link->verified_link_cap.lane_count;
 			pipes[i]->link_config.dp_link_settings.link_rate =
@@ -404,7 +404,9 @@ bool dp_handle_hpd_rx_irq(struct dc_link *link,
 
 	if (hpd_irq_dpcd_data.bytes.device_service_irq.bits.AUTOMATED_TEST) {
 		// Workaround for DP 1.4a LL Compliance CTS as USB4 has to share encoders unlike DP and USBC
-		link->is_automated = true;
+		if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA)
+			link->skip_fallback_on_link_loss = true;
+
 		device_service_clear.bits.AUTOMATED_TEST = 1;
 		core_link_write_dpcd(
 			link,

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

@@ -811,7 +811,7 @@ static enum link_training_result dpia_training_eq_transparent(
 			/* 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->is_automated && retries_eq)) {
+			if (dp_is_interlane_aligned(dpcd_lane_status_updated) || (link->skip_fallback_on_link_loss && retries_eq)) {
 				result =  LINK_TRAINING_SUCCESS;
 				break;
 			}
@@ -1037,7 +1037,7 @@ enum link_training_result dpia_perform_link_training(
 	 */
 	if (result == LINK_TRAINING_SUCCESS) {
 		fsleep(5000);
-		if (!link->is_automated)
+		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);