drm/amd/display: Read DP tunneling support only for DPIA endpoints

Unconditionally reading DP tunneling support results in extraneous
errors messages on certain devices. Fix this by guarding the DPCD read
for DP tunneling support for USB4 DPIA endpoints.

Reviewed-by: Meenakshikumar Somasundaram <[email protected]>
Signed-off-by: Aurabindo Pillai <[email protected]>
Signed-off-by: Hamza Mahfooz <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

Author: Aurabindo Pillai

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

@@ -1633,9 +1633,11 @@ static bool retrieve_link_cap(struct dc_link *link)
 	}
 
 	/* Read DP tunneling information. */
-	status = dpcd_get_tunneling_device_data(link);
-	if (status != DC_OK)
-		dm_error("%s: Read tunneling device data failed.\n", __func__);
+	if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA) {
+		status = dpcd_get_tunneling_device_data(link);
+		if (status != DC_OK)
+			dm_error("%s: Read tunneling device data failed.\n", __func__);
+	}
 
 	dpcd_set_source_specific_data(link);
 	/* Sink may need to configure internals based on vendor, so allow some