diff --git a/drivers/tty/serial/dz.c b/drivers/tty/serial/dz.c
index e53c54353c3e..d14a40e8cc0a 100644
--- a/drivers/tty/serial/dz.c
+++ b/drivers/tty/serial/dz.c
@@ -542,10 +542,31 @@ static int dz_encode_baud_rate(unsigned int baud)
 static void dz_reset(struct dz_port *dport)
 {
 	struct dz_mux *mux = dport->mux;
+	unsigned short tcr;
+	int loops = 10000;
 
 	if (mux->initialised)
 		return;
 
+	tcr = dz_in(dport, DZ_TCR);
+
+	/* Do not disturb any ongoing transmissions.  */
+	if (dz_in(dport, DZ_CSR) & DZ_MSE) {
+		unsigned short csr, mask;
+
+		mask = tcr;
+		while ((mask & DZ_LNENB) && loops--) {
+			csr = dz_in(dport, DZ_CSR);
+			if (!(csr & DZ_TRDY))
+				continue;
+			mask &= ~(1 << ((csr & DZ_TLINE) >> 8));
+			dz_out(dport, DZ_TCR, mask);
+			iob();
+			udelay(2);		/* 1.4us TRDY recovery.  */
+		}
+		udelay(1200);			/* Transmitter drain.  */
+	}
+
 	dz_out(dport, DZ_CSR, DZ_CLR);
 	while (dz_in(dport, DZ_CSR) & DZ_CLR);
 	iob();