[PATCH] tty_driver refcounting

drivers/char/istallion.c converted to dynamic allocation

drivers/char/istallion.c

@@ -170,7 +170,7 @@ static char	*stli_drvname = "istallion";
 static char	*stli_drvversion = "5.6.0";
 static char	*stli_serialname = "ttyE";
 
-static struct tty_driver	stli_serial;
+static struct tty_driver	*stli_serial;
 
 /*
  *	We will need to allocate a temporary write buffer for chars that
@@ -847,13 +847,14 @@ static void __exit istallion_module_exit(void)
 		del_timer(&stli_timerlist);
 	}
 
-	i = tty_unregister_driver(&stli_serial);
+	i = tty_unregister_driver(stli_serial);
 	if (i) {
 		printk("STALLION: failed to un-register tty driver, "
 			"errno=%d,%d\n", -i);
 		restore_flags(flags);
 		return;
 	}
+	put_tty_driver(stli_serial);
 	for (i = 0; i < 4; i++)
 		devfs_remove("staliomem/%d", i);
 	devfs_remove("staliomem");
@@ -5237,6 +5238,28 @@ static int stli_memioctl(struct inode *ip, struct file *fp, unsigned int cmd, un
 	return(rc);
 }
 
+static struct tty_operations stli_ops = {
+	.open = stli_open,
+	.close = stli_close,
+	.write = stli_write,
+	.put_char = stli_putchar,
+	.flush_chars = stli_flushchars,
+	.write_room = stli_writeroom,
+	.chars_in_buffer = stli_charsinbuffer,
+	.ioctl = stli_ioctl,
+	.set_termios = stli_settermios,
+	.throttle = stli_throttle,
+	.unthrottle = stli_unthrottle,
+	.stop = stli_stop,
+	.start = stli_start,
+	.hangup = stli_hangup,
+	.flush_buffer = stli_flushbuffer,
+	.break_ctl = stli_breakctl,
+	.wait_until_sent = stli_waituntilsent,
+	.send_xchar = stli_sendxchar,
+	.read_proc = stli_readproc,
+};
+
 /*****************************************************************************/
 
 int __init stli_init(void)
@@ -5246,6 +5269,10 @@ int __init stli_init(void)
 
 	stli_initbrds();
 
+	stli_serial = alloc_tty_driver(STL_MAXBRDS * STL_MAXPORTS);
+	if (!stli_serial)
+		return -ENOMEM;
+
 /*
  *	Allocate a temporary write buffer.
  */
@@ -5276,41 +5303,22 @@ int __init stli_init(void)
 /*
  *	Set up the tty driver structure and register us as a driver.
  */
-	memset(&stli_serial, 0, sizeof(struct tty_driver));
-	stli_serial.magic = TTY_DRIVER_MAGIC;
-	stli_serial.owner = THIS_MODULE;
-	stli_serial.driver_name = stli_drvname;
-	stli_serial.name = stli_serialname;
-	stli_serial.major = STL_SERIALMAJOR;
-	stli_serial.minor_start = 0;
-	stli_serial.num = STL_MAXBRDS * STL_MAXPORTS;
-	stli_serial.type = TTY_DRIVER_TYPE_SERIAL;
-	stli_serial.subtype = SERIAL_TYPE_NORMAL;
-	stli_serial.init_termios = stli_deftermios;
-	stli_serial.flags = TTY_DRIVER_REAL_RAW;
-	
-	stli_serial.open = stli_open;
-	stli_serial.close = stli_close;
-	stli_serial.write = stli_write;
-	stli_serial.put_char = stli_putchar;
-	stli_serial.flush_chars = stli_flushchars;
-	stli_serial.write_room = stli_writeroom;
-	stli_serial.chars_in_buffer = stli_charsinbuffer;
-	stli_serial.ioctl = stli_ioctl;
-	stli_serial.set_termios = stli_settermios;
-	stli_serial.throttle = stli_throttle;
-	stli_serial.unthrottle = stli_unthrottle;
-	stli_serial.stop = stli_stop;
-	stli_serial.start = stli_start;
-	stli_serial.hangup = stli_hangup;
-	stli_serial.flush_buffer = stli_flushbuffer;
-	stli_serial.break_ctl = stli_breakctl;
-	stli_serial.wait_until_sent = stli_waituntilsent;
-	stli_serial.send_xchar = stli_sendxchar;
-	stli_serial.read_proc = stli_readproc;
-
-	if (tty_register_driver(&stli_serial))
+	stli_serial->owner = THIS_MODULE;
+	stli_serial->driver_name = stli_drvname;
+	stli_serial->name = stli_serialname;
+	stli_serial->major = STL_SERIALMAJOR;
+	stli_serial->minor_start = 0;
+	stli_serial->type = TTY_DRIVER_TYPE_SERIAL;
+	stli_serial->subtype = SERIAL_TYPE_NORMAL;
+	stli_serial->init_termios = stli_deftermios;
+	stli_serial->flags = TTY_DRIVER_REAL_RAW;
+	tty_set_operations(stli_serial, &stli_ops);
+
+	if (tty_register_driver(stli_serial)) {
+		put_tty_driver(stli_serial);
 		printk(KERN_ERR "STALLION: failed to register serial driver\n");
+		return -EBUSY;
+	}
 	return(0);
 }