#define TX_MODE_FLOW_CTRL_ENABLE 0x00000010
#define TX_MODE_BIG_BCKOFF_ENABLE 0x00000020
#define TX_MODE_LONG_PAUSE_ENABLE 0x00000040
+#define TX_MODE_MBUF_LOCKUP_FIX 0x00000100
#define MAC_TX_STATUS 0x00000460
#define TX_STATUS_XOFFED 0x00000001
#define TX_STATUS_SENT_XOFF 0x00000002