diff --git a/src/libboard_artiq/src/cxp_downconn.rs b/src/libboard_artiq/src/cxp_downconn.rs
index 0a1e5ec..b16fba9 100644
--- a/src/libboard_artiq/src/cxp_downconn.rs
+++ b/src/libboard_artiq/src/cxp_downconn.rs
@@ -6,7 +6,7 @@ use crate::{cxp_phys, cxp_proto, pl::csr::CXP};
 
 pub fn loopback_testing(channel: usize, timer: &mut GlobalTimer, speed: cxp_phys::CXP_SPEED) {
     println!("==============================================================================");
-    cxp_phys::change_linerate(channel, timer, speed);
+    cxp_phys::change_linerate(speed);
 
     unsafe {
         info!("waiting for tx&rx setup...");