unsigned long ptp_tx_start;
        unsigned long last_rx_ptp_check;
        unsigned long last_rx_timestamp;
+       unsigned int ptp_flags;
        spinlock_t tmreg_lock;
        struct cyclecounter cc;
        struct timecounter tc;
        u16 eee_advert;
 };
 
+/* flags controlling PTP/1588 function */
+#define IGB_PTP_ENABLED                BIT(0)
+
 #define IGB_FLAG_HAS_MSI               BIT(0)
 #define IGB_FLAG_DCA_ENABLED           BIT(1)
 #define IGB_FLAG_QUAD_PORT_A           BIT(2)
 #define IGB_FLAG_QUEUE_PAIRS           BIT(3)
 #define IGB_FLAG_DMAC                  BIT(4)
-#define IGB_FLAG_PTP                   BIT(5)
 #define IGB_FLAG_RSS_FIELD_IPV4_UDP    BIT(6)
 #define IGB_FLAG_RSS_FIELD_IPV6_UDP    BIT(7)
 #define IGB_FLAG_WOL_SUPPORTED         BIT(8)
 
        u32 tsyncrxctl = rd32(E1000_TSYNCRXCTL);
        unsigned long rx_event;
 
+       /* Other hardware uses per-packet timestamps */
        if (hw->mac.type != e1000_82576)
                return;
 
        } else {
                dev_info(&adapter->pdev->dev, "added PHC on %s\n",
                         adapter->netdev->name);
-               adapter->flags |= IGB_FLAG_PTP;
+               adapter->ptp_flags |= IGB_PTP_ENABLED;
        }
 }
 
                ptp_clock_unregister(adapter->ptp_clock);
                dev_info(&adapter->pdev->dev, "removed PHC on %s\n",
                         adapter->netdev->name);
-               adapter->flags &= ~IGB_FLAG_PTP;
+               adapter->ptp_flags &= ~IGB_PTP_ENABLED;
        }
 }
 
        struct e1000_hw *hw = &adapter->hw;
        unsigned long flags;
 
-       if (!(adapter->flags & IGB_FLAG_PTP))
+       if (!(adapter->ptp_flags & IGB_PTP_ENABLED))
                return;
 
        /* reset the tstamp_config */