diff --git a/drivers/net/wan/c101.c b/drivers/net/wan/c101.c
index 435e91ec462..6b63b350cd5 100644
--- a/drivers/net/wan/c101.c
+++ b/drivers/net/wan/c101.c
@@ -118,7 +118,7 @@ static inline void openwin(card_t *card, u8 page)
 
 static inline void set_carrier(port_t *port)
 {
-	if (!sca_in(MSCI1_OFFSET + ST3, port) & ST3_DCD)
+	if (!(sca_in(MSCI1_OFFSET + ST3, port) & ST3_DCD))
 		netif_carrier_on(port_to_dev(port));
 	else
 		netif_carrier_off(port_to_dev(port));
@@ -127,10 +127,10 @@ static inline void set_carrier(port_t *port)
 
 static void sca_msci_intr(port_t *port)
 {
-	u8 stat = sca_in(MSCI1_OFFSET + ST1, port); /* read MSCI ST1 status */
+	u8 stat = sca_in(MSCI0_OFFSET + ST1, port); /* read MSCI ST1 status */
 
-	/* Reset MSCI TX underrun status bit */
-	sca_out(stat & ST1_UDRN, MSCI0_OFFSET + ST1, port);
+	/* Reset MSCI TX underrun and CDCD (ignored) status bit */
+	sca_out(stat & (ST1_UDRN | ST1_CDCD), MSCI0_OFFSET + ST1, port);
 
 	if (stat & ST1_UDRN) {
 		struct net_device_stats *stats = hdlc_stats(port_to_dev(port));
@@ -138,6 +138,7 @@ static void sca_msci_intr(port_t *port)
 		stats->tx_fifo_errors++;
 	}
 
+	stat = sca_in(MSCI1_OFFSET + ST1, port); /* read MSCI1 ST1 status */
 	/* Reset MSCI CDCD status bit - uses ch#2 DCD input */
 	sca_out(stat & ST1_CDCD, MSCI1_OFFSET + ST1, port);