From 40976e772d4d2cb1a26ec71080c73b170f868f35 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Mon, 13 Apr 2026 20:49:34 -0700
Subject: [PATCH] [time-sync] add compile-time check for TREL incompatibility
 (#12880)

This commit adds a compile-time check in `time_sync_service.hpp` to
ensure that `OPENTHREAD_CONFIG_RADIO_LINK_TREL_ENABLE` is not
enabled alongside `OPENTHREAD_CONFIG_TIME_SYNC_ENABLE`. The time
synchronization feature is experimental and currently only supports
IEEE 802.15.4 radio links. Attempting to use it over TREL is
unsupported and will now result in a build failure.
---
 src/core/thread/time_sync_service.hpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/core/thread/time_sync_service.hpp b/src/core/thread/time_sync_service.hpp
index 1e0c01bee..bd81c28ea 100644
--- a/src/core/thread/time_sync_service.hpp
+++ b/src/core/thread/time_sync_service.hpp
@@ -38,6 +38,11 @@
 
 #if OPENTHREAD_CONFIG_TIME_SYNC_ENABLE
 
+#if OPENTHREAD_CONFIG_RADIO_LINK_TREL_ENABLE
+#error "TIME_SYNC feature is not supported under RADIO_LINK_TREL. " \
+       "TIME_SYNC is an experimental feature that only works on 15.4 radio."
+#endif
+
 #include <openthread/network_time.h>
 
 #include "common/as_core_type.hpp"