diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index f05bd757dfe5..5ef52ef2698f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -218,6 +218,7 @@ static void timestamp_interrupt(struct stmmac_priv *priv)
 {
 	u32 num_snapshot, ts_status, tsync_int;
 	struct ptp_clock_event event;
+	u32 acr_value, channel;
 	unsigned long flags;
 	u64 ptp_time;
 	int i;
@@ -243,12 +244,15 @@ static void timestamp_interrupt(struct stmmac_priv *priv)
 	num_snapshot = (ts_status & GMAC_TIMESTAMP_ATSNS_MASK) >>
 		       GMAC_TIMESTAMP_ATSNS_SHIFT;
 
+	acr_value = readl(priv->ptpaddr + PTP_ACR);
+	channel = ilog2(FIELD_GET(PTP_ACR_MASK, acr_value));
+
 	for (i = 0; i < num_snapshot; i++) {
 		read_lock_irqsave(&priv->ptp_lock, flags);
 		get_ptptime(priv->ptpaddr, &ptp_time);
 		read_unlock_irqrestore(&priv->ptp_lock, flags);
 		event.type = PTP_CLOCK_EXTTS;
-		event.index = 0;
+		event.index = channel;
 		event.timestamp = ptp_time;
 		ptp_clock_event(priv->ptp_clock, &event);
 	}