char: switch gs, cyclades and esp to return int for put_char

Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/cyclades.c

@@ -2814,7 +2814,7 @@ static int cy_write(struct tty_struct *tty, const unsigned char *buf, int count)
  * done stuffing characters into the driver.  If there is no room
  * in the queue, the character is ignored.
  */
-static void cy_put_char(struct tty_struct *tty, unsigned char ch)
+static int cy_put_char(struct tty_struct *tty, unsigned char ch)
 {
 	struct cyclades_port *info = tty->driver_data;
 	unsigned long flags;
@@ -2824,15 +2824,15 @@ static void cy_put_char(struct tty_struct *tty, unsigned char ch)
 #endif
 
 	if (serial_paranoia_check(info, tty->name, "cy_put_char"))
-		return;
+		return 0;
 
 	if (!info->xmit_buf)
-		return;
+		return 0;
 
 	spin_lock_irqsave(&info->card->card_lock, flags);
 	if (info->xmit_cnt >= (int)(SERIAL_XMIT_SIZE - 1)) {
 		spin_unlock_irqrestore(&info->card->card_lock, flags);
-		return;
+		return 0;
 	}
 
 	info->xmit_buf[info->xmit_head++] = ch;
@@ -2841,6 +2841,7 @@ static void cy_put_char(struct tty_struct *tty, unsigned char ch)
 	info->idle_stats.xmit_bytes++;
 	info->idle_stats.xmit_idle = jiffies;
 	spin_unlock_irqrestore(&info->card->card_lock, flags);
+	return 1;
 }				/* cy_put_char */
 
 /*

drivers/char/esp.c

@@ -1156,24 +1156,27 @@ static void change_speed(struct esp_struct *info)
 	spin_unlock_irqrestore(&info->lock, flags);
 }
 
-static void rs_put_char(struct tty_struct *tty, unsigned char ch)
+static int rs_put_char(struct tty_struct *tty, unsigned char ch)
 {
 	struct esp_struct *info = (struct esp_struct *)tty->driver_data;
 	unsigned long flags;
+	int ret = 0;
 
 	if (serial_paranoia_check(info, tty->name, "rs_put_char"))
-		return;
+		return 0;
 
 	if (!info->xmit_buf)
-		return;
+		return 0;
 
 	spin_lock_irqsave(&info->lock, flags);
 	if (info->xmit_cnt < ESP_XMIT_SIZE - 1) {
 		info->xmit_buf[info->xmit_head++] = ch;
 		info->xmit_head &= ESP_XMIT_SIZE-1;
 		info->xmit_cnt++;
+		ret = 1;
 	}
 	spin_unlock_irqrestore(&info->lock, flags);
+	return ret;
 }
 
 static void rs_flush_chars(struct tty_struct *tty)

drivers/char/generic_serial.c

@@ -48,19 +48,19 @@ static int gs_debug;
 module_param(gs_debug, int, 0644);
 
 
-void gs_put_char(struct tty_struct * tty, unsigned char ch)
+int gs_put_char(struct tty_struct * tty, unsigned char ch)
 {
 	struct gs_port *port;
 
 	func_enter (); 
 
-	if (!tty) return;
+	if (!tty) return 0;
 
 	port = tty->driver_data;
 
-	if (!port) return;
+	if (!port) return 0;
 
-	if (! (port->flags & ASYNC_INITIALIZED)) return;
+	if (! (port->flags & ASYNC_INITIALIZED)) return 0;
 
 	/* Take a lock on the serial tranmit buffer! */
 	mutex_lock(& port->port_write_mutex);
@@ -68,7 +68,7 @@ void gs_put_char(struct tty_struct * tty, unsigned char ch)
 	if (port->xmit_cnt >= SERIAL_XMIT_SIZE - 1) {
 		/* Sorry, buffer is full, drop character. Update statistics???? -- REW */
 		mutex_unlock(&port->port_write_mutex);
-		return;
+		return 0;
 	}
 
 	port->xmit_buf[port->xmit_head++] = ch;
@@ -77,6 +77,7 @@ void gs_put_char(struct tty_struct * tty, unsigned char ch)
 
 	mutex_unlock(&port->port_write_mutex);
 	func_exit ();
+	return 1;
 }
 
 

include/linux/generic_serial.h

@@ -78,7 +78,7 @@ struct gs_port {
 #define GS_DEBUG_WRITE   0x00000040
 
 #ifdef __KERNEL__
-void gs_put_char(struct tty_struct *tty, unsigned char ch);
+int gs_put_char(struct tty_struct *tty, unsigned char ch);
 int  gs_write(struct tty_struct *tty, 
              const unsigned char *buf, int count);
 int  gs_write_room(struct tty_struct *tty);