--- zzzz-none-000/linux-3.10.107/drivers/net/ethernet/aeroflex/greth.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/net/ethernet/aeroflex/greth.h	2021-02-04 17:41:59.000000000 +0000
@@ -107,7 +107,7 @@
 
 	u16 tx_next;
 	u16 tx_last;
-	u16 tx_free;
+	u16 tx_free; /* only used on 10/100Mbit */
 	u16 rx_cur;
 
 	struct greth_regs *regs;	/* Address of controller registers. */