There are currently two situations that can trigger the PTP interrupt,
one is the PPS event, the other is the PEROUT event. However, the irq
handler fec_pps_interrupt() does not check the irq event type and
directly registers a PPS event into the system, but the event may be
a PEROUT event. This is incorrect because PEROUT is an output signal,
while PPS is the input of the kernel PPS system. Therefore, add a check
for the event type, if pps_enable is true, it means that the current
event is a PPS event, and then the PPS event is registered.

Fixes: 350749b909bf ("net: fec: Add support for periodic output signal of PPS")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
---
 drivers/net/ethernet/freescale/fec_ptp.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index ed5d59abeb53..4b7bad9a485d 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -718,8 +718,11 @@ static irqreturn_t fec_pps_interrupt(int irq, void *dev_id)
 		fep->next_counter = (fep->next_counter + fep->reload_period) &
 				fep->cc.mask;
 
-		event.type = PTP_CLOCK_PPS;
-		ptp_clock_event(fep->ptp_clock, &event);
+		if (fep->pps_enable) {
+			event.type = PTP_CLOCK_PPS;
+			ptp_clock_event(fep->ptp_clock, &event);
+		}
+
 		return IRQ_HANDLED;
 	}
 
-- 
2.34.1