diff --git a/os/hal/ports/SAMA/SAMA5D2x/hal_lld.c b/os/hal/ports/SAMA/SAMA5D2x/hal_lld.c
index fb3399316..4e4e50b49 100644
--- a/os/hal/ports/SAMA/SAMA5D2x/hal_lld.c
+++ b/os/hal/ports/SAMA/SAMA5D2x/hal_lld.c
@@ -140,8 +140,9 @@ void sama_clock_init(void) {
   mainf = CKGR_MCFR_MAINF(PMC->CKGR_MCFR);
   /*
    * TODO: check mainf
-   * select alternate clock source if mainf is out of range.
-   * This function should start trying to use crystal osc sources and
+   * select alternate clock source if mainf is out of range:
+   * if the system is configured to use crystal osc,
+   * this function should start trying to use crystal osc sources and
    * should switch to alternate sources if mainf is invalid.
    */
   (void)mainf;