[PATCH] tty_driver refcounting

drivers/char/mxser.c converted to dynamic allocation

drivers/char/mxser.c

@@ -288,7 +288,7 @@ static int mxserBoardCAP[MXSER_BOARDS] =
 };
 
 
-static struct tty_driver mxvar_sdriver;
+static struct tty_driver *mxvar_sdriver;
 static struct mxser_struct mxvar_table[MXSER_PORTS];
 static struct mxser_log mxvar_log;
 static int mxvar_diagflag;
@@ -364,8 +364,9 @@ static void __exit mxser_module_exit(void)
 
 	if (verbose)
 		printk("Unloading module mxser ...\n");
-	if ((err |= tty_unregister_driver(&mxvar_sdriver)))
+	if ((err |= tty_unregister_driver(mxvar_sdriver)))
 		printk("Couldn't unregister MOXA Smartio family serial driver\n");
+	put_tty_driver(mxvar_sdriver);
 
 	for (i = 0; i < MXSER_BOARDS; i++) {
 		if (mxsercfg[i].board_type == -1)
@@ -475,6 +476,24 @@ static int mxser_get_PCI_conf(struct pci_dev *pdev, int board_type, struct mxser
 	return (0);
 }
 
+static struct tty_operations mxser_ops = {
+	.open = mxser_open,
+	.close = mxser_close,
+	.write = mxser_write,
+	.put_char = mxser_put_char,
+	.flush_chars = mxser_flush_chars,
+	.write_room = mxser_write_room,
+	.chars_in_buffer = mxser_chars_in_buffer,
+	.flush_buffer = mxser_flush_buffer,
+	.ioctl = mxser_ioctl,
+	.throttle = mxser_throttle,
+	.unthrottle = mxser_unthrottle,
+	.set_termios = mxser_set_termios,
+	.stop = mxser_stop,
+	.start = mxser_start,
+	.hangup = mxser_hangup,
+};
+
 static int __init mxser_module_init(void)
 {
 	int i, m, retval, b;
@@ -482,39 +501,24 @@ static int __init mxser_module_init(void)
 	int ret1, ret2;
 	struct mxser_hwconf hwconf;
 
+	mxvar_sdriver = alloc_tty_driver(MXSER_PORTS + 1);
+	if (!mxvar_sdriver)
+		return -ENOMEM;
+
 	printk("MOXA Smartio family driver version %s\n", MXSER_VERSION);
 
 	/* Initialize the tty_driver structure */
 
-	memset(&mxvar_sdriver, 0, sizeof(struct tty_driver));
-	mxvar_sdriver.magic = TTY_DRIVER_MAGIC;
-	mxvar_sdriver.owner = THIS_MODULE;
-	mxvar_sdriver.name = "ttyM";
-	mxvar_sdriver.major = ttymajor;
-	mxvar_sdriver.minor_start = 0;
-	mxvar_sdriver.num = MXSER_PORTS + 1;
-	mxvar_sdriver.type = TTY_DRIVER_TYPE_SERIAL;
-	mxvar_sdriver.subtype = SERIAL_TYPE_NORMAL;
-	mxvar_sdriver.init_termios = tty_std_termios;
-	mxvar_sdriver.init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
-	mxvar_sdriver.flags = TTY_DRIVER_REAL_RAW;
-
-	mxvar_sdriver.open = mxser_open;
-	mxvar_sdriver.close = mxser_close;
-	mxvar_sdriver.write = mxser_write;
-	mxvar_sdriver.put_char = mxser_put_char;
-	mxvar_sdriver.flush_chars = mxser_flush_chars;
-	mxvar_sdriver.write_room = mxser_write_room;
-	mxvar_sdriver.chars_in_buffer = mxser_chars_in_buffer;
-	mxvar_sdriver.flush_buffer = mxser_flush_buffer;
-	mxvar_sdriver.ioctl = mxser_ioctl;
-	mxvar_sdriver.throttle = mxser_throttle;
-	mxvar_sdriver.unthrottle = mxser_unthrottle;
-	mxvar_sdriver.set_termios = mxser_set_termios;
-	mxvar_sdriver.stop = mxser_stop;
-	mxvar_sdriver.start = mxser_start;
-	mxvar_sdriver.hangup = mxser_hangup;
-
+	mxvar_sdriver->owner = THIS_MODULE;
+	mxvar_sdriver->name = "ttyM";
+	mxvar_sdriver->major = ttymajor;
+	mxvar_sdriver->minor_start = 0;
+	mxvar_sdriver->type = TTY_DRIVER_TYPE_SERIAL;
+	mxvar_sdriver->subtype = SERIAL_TYPE_NORMAL;
+	mxvar_sdriver->init_termios = tty_std_termios;
+	mxvar_sdriver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	mxvar_sdriver->flags = TTY_DRIVER_REAL_RAW;
+	tty_set_operations(mxvar_sdriver, &mxser_ops);
 	printk("Tty devices major number = %d\n", ttymajor);
 
 	mxvar_diagflag = 0;
@@ -640,9 +644,10 @@ static int __init mxser_module_init(void)
 	}
 
 
-	if (!tty_register_driver(&mxvar_sdriver))
+	if (!tty_register_driver(mxvar_sdriver))
 		return 0;
 
+	put_tty_driver(mxvar_sdriver);
 	printk("Couldn't install MOXA Smartio family driver !\n");
 
 	for (i = 0; i < MXSER_BOARDS; i++) {