diff --git a/drivers/char/synclink.c b/drivers/char/synclink.c
index dbbd998ae103ad032b1718e259a5855a6d9190a9..4fbfff7a442e1555d73c64fb7ed105e1dad052bf 100644
--- a/drivers/char/synclink.c
+++ b/drivers/char/synclink.c
@@ -2026,10 +2026,11 @@ static void mgsl_change_params(struct mgsl_struct *info)
  * 		
  * Return Value:	None
  */
-static void mgsl_put_char(struct tty_struct *tty, unsigned char ch)
+static int mgsl_put_char(struct tty_struct *tty, unsigned char ch)
 {
 	struct mgsl_struct *info = (struct mgsl_struct *)tty->driver_data;
 	unsigned long flags;
+	int ret;
 
 	if ( debug_level >= DEBUG_LEVEL_INFO ) {
 		printk( "%s(%d):mgsl_put_char(%d) on %s\n",
@@ -2037,23 +2038,23 @@ static void mgsl_put_char(struct tty_struct *tty, unsigned char ch)
 	}		
 	
 	if (mgsl_paranoia_check(info, tty->name, "mgsl_put_char"))
-		return;
+		return 0;
 
 	if (!tty || !info->xmit_buf)
-		return;
+		return 0;
 
 	spin_lock_irqsave(&info->irq_spinlock,flags);
 	
 	if ( (info->params.mode == MGSL_MODE_ASYNC ) || !info->tx_active ) {
-	
 		if (info->xmit_cnt < SERIAL_XMIT_SIZE - 1) {
 			info->xmit_buf[info->xmit_head++] = ch;
 			info->xmit_head &= SERIAL_XMIT_SIZE-1;
 			info->xmit_cnt++;
+			ret = 1;
 		}
 	}
-	
 	spin_unlock_irqrestore(&info->irq_spinlock,flags);
+	return ret;
 	
 }	/* end of mgsl_put_char() */
 
diff --git a/drivers/char/synclink_gt.c b/drivers/char/synclink_gt.c
index 1a11717b1adc38ff519a7bfcd1ee919082003fe0..430f5bc0ae30d8ed08f688c6e4a535cb120037c9 100644
--- a/drivers/char/synclink_gt.c
+++ b/drivers/char/synclink_gt.c
@@ -151,7 +151,7 @@ static void hangup(struct tty_struct *tty);
 static void set_termios(struct tty_struct *tty, struct ktermios *old_termios);
 
 static int  write(struct tty_struct *tty, const unsigned char *buf, int count);
-static void put_char(struct tty_struct *tty, unsigned char ch);
+static int put_char(struct tty_struct *tty, unsigned char ch);
 static void send_xchar(struct tty_struct *tty, char ch);
 static void wait_until_sent(struct tty_struct *tty, int timeout);
 static int  write_room(struct tty_struct *tty);
@@ -912,20 +912,24 @@ static int write(struct tty_struct *tty,
 	return ret;
 }
 
-static void put_char(struct tty_struct *tty, unsigned char ch)
+static int put_char(struct tty_struct *tty, unsigned char ch)
 {
 	struct slgt_info *info = tty->driver_data;
 	unsigned long flags;
+	int ret;
 
 	if (sanity_check(info, tty->name, "put_char"))
-		return;
+		return 0;
 	DBGINFO(("%s put_char(%d)\n", info->device_name, ch));
 	if (!info->tx_buf)
-		return;
+		return 0;
 	spin_lock_irqsave(&info->lock,flags);
-	if (!info->tx_active && (info->tx_count < info->max_frame_size))
+	if (!info->tx_active && (info->tx_count < info->max_frame_size)) {
 		info->tx_buf[info->tx_count++] = ch;
+		ret = 1;
+	}
 	spin_unlock_irqrestore(&info->lock,flags);
+	return ret;
 }
 
 static void send_xchar(struct tty_struct *tty, char ch)
diff --git a/drivers/char/synclinkmp.c b/drivers/char/synclinkmp.c
index 2f1988c48ee30247396f1dc507bf7bec0fb6f0cb..a624ffd7baaa146b9ad6b1479b55133110d44896 100644
--- a/drivers/char/synclinkmp.c
+++ b/drivers/char/synclinkmp.c
@@ -519,7 +519,7 @@ static void hangup(struct tty_struct *tty);
 static void set_termios(struct tty_struct *tty, struct ktermios *old_termios);
 
 static int  write(struct tty_struct *tty, const unsigned char *buf, int count);
-static void put_char(struct tty_struct *tty, unsigned char ch);
+static int put_char(struct tty_struct *tty, unsigned char ch);
 static void send_xchar(struct tty_struct *tty, char ch);
 static void wait_until_sent(struct tty_struct *tty, int timeout);
 static int  write_room(struct tty_struct *tty);
@@ -1045,10 +1045,11 @@ static int write(struct tty_struct *tty,
 
 /* Add a character to the transmit buffer.
  */
-static void put_char(struct tty_struct *tty, unsigned char ch)
+static int put_char(struct tty_struct *tty, unsigned char ch)
 {
 	SLMP_INFO *info = (SLMP_INFO *)tty->driver_data;
 	unsigned long flags;
+	int ret = 0;
 
 	if ( debug_level >= DEBUG_LEVEL_INFO ) {
 		printk( "%s(%d):%s put_char(%d)\n",
@@ -1056,10 +1057,10 @@ static void put_char(struct tty_struct *tty, unsigned char ch)
 	}
 
 	if (sanity_check(info, tty->name, "put_char"))
-		return;
+		return 0;
 
 	if (!info->tx_buf)
-		return;
+		return 0;
 
 	spin_lock_irqsave(&info->lock,flags);
 
@@ -1071,10 +1072,12 @@ static void put_char(struct tty_struct *tty, unsigned char ch)
 			if (info->tx_put >= info->max_frame_size)
 				info->tx_put -= info->max_frame_size;
 			info->tx_count++;
+			ret = 1;
 		}
 	}
 
 	spin_unlock_irqrestore(&info->lock,flags);
+	return ret;
 }
 
 /* Send a high-priority XON/XOFF character