diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index d8d87213697c..d1e0e116b976 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -243,7 +243,7 @@
 #define MACB_NCR_TPF_SIZE	1
 #define MACB_TZQ_OFFSET		12 /* Transmit zero quantum pause frame */
 #define MACB_TZQ_SIZE		1
-#define MACB_SRTSM_OFFSET	15
+#define MACB_SRTSM_OFFSET	15 /* Store Receive Timestamp to Memory */
 #define MACB_OSSMODE_OFFSET 24 /* Enable One Step Synchro Mode */
 #define MACB_OSSMODE_SIZE	1