igb: restore PPS signal on igb_ptp_reset

When a reset occurs, the PPS SYS_WRAP interrupt was not re-enabled which
resulted in disabling of the PPS signaling. Fix this by recording when
the interrupt is on and ensuring that we re-enable it every time we
reset.
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igb/igb.h

@@ -489,6 +489,7 @@ struct igb_adapter {
 	struct timecounter tc;
 	u32 tx_hwtstamp_timeouts;
 	u32 rx_hwtstamp_cleared;
+	bool pps_sys_wrap_on;
 
 	struct ptp_pin_desc sdp_config[IGB_N_SDP];
 	struct {

drivers/net/ethernet/intel/igb/igb_ptp.c

@@ -591,6 +591,7 @@ static int igb_ptp_feature_enable_i210(struct ptp_clock_info *ptp,
 			tsim |= TSINTR_SYS_WRAP;
 		else
 			tsim &= ~TSINTR_SYS_WRAP;
+		igb->pps_sys_wrap_on = !!on;
 		wr32(E1000_TSIM, tsim);
 		spin_unlock_irqrestore(&igb->tmreg_lock, flags);
 		return 0;
@@ -1235,7 +1236,9 @@ void igb_ptp_reset(struct igb_adapter *adapter)
 	case e1000_i211:
 		wr32(E1000_TSAUXC, 0x0);
 		wr32(E1000_TSSDP, 0x0);
-		wr32(E1000_TSIM, TSYNC_INTERRUPTS);
+		wr32(E1000_TSIM,
+		     TSYNC_INTERRUPTS |
+		     (adapter->pps_sys_wrap_on ? TSINTR_SYS_WRAP : 0));
 		wr32(E1000_IMS, E1000_IMS_TS);
 		break;
 	default: