[PATCH] tty_driver refcounting

drivers/char/rio/rio_linux.c converted to dynamic allocation

drivers/char/rio/rio_linux.c

@@ -201,7 +201,7 @@ static int rio_init_drivers(void);
 
 void my_hd (void *addr, int len);
 
-static struct tty_driver rio_driver, rio_driver2;
+static struct tty_driver *rio_driver, *rio_driver2;
 
 /* The name "p" is a bit non-descript. But that's what the rio-lynxos
 sources use all over the place. */
@@ -361,7 +361,7 @@ int RIODelay_ni (struct Port *PortP, int njiffies)
 
 int rio_minor(struct tty_struct *tty)
 {
-	return tty->index + (tty->driver == &rio_driver) ? 0 : 256;
+	return tty->index + (tty->driver == rio_driver) ? 0 : 256;
 }
 
 
@@ -860,60 +860,77 @@ struct vpd_prom *get_VPD_PROM (struct Host *hp)
   return &vpdp;
 }
 
-
+static struct tty_operations rio_ops = {
+	.open  = riotopen,
+	.close = gs_close,
+	.write = gs_write,
+	.put_char = gs_put_char,
+	.flush_chars = gs_flush_chars,
+	.write_room = gs_write_room,
+	.chars_in_buffer = gs_chars_in_buffer,
+	.flush_buffer = gs_flush_buffer,
+	.ioctl = rio_ioctl,
+	.throttle = rio_throttle,
+	.unthrottle = rio_unthrottle,
+	.set_termios = gs_set_termios,
+	.stop = gs_stop,
+	.start = gs_start,
+	.hangup = gs_hangup,
+};
 
 static int rio_init_drivers(void)
 {
-  int error;
-  
-  func_enter();
-
-  memset(&rio_driver, 0, sizeof(rio_driver));
-  rio_driver.magic = TTY_DRIVER_MAGIC;
-  rio_driver.owner = THIS_MODULE;
-  rio_driver.driver_name = "specialix_rio";
-  rio_driver.name = "ttySR";
-  rio_driver.major = RIO_NORMAL_MAJOR0;
-  rio_driver.num = 256;
-  rio_driver.type = TTY_DRIVER_TYPE_SERIAL;
-  rio_driver.subtype = SERIAL_TYPE_NORMAL;
-  rio_driver.init_termios = tty_std_termios;
-  rio_driver.init_termios.c_cflag =
-    B9600 | CS8 | CREAD | HUPCL | CLOCAL;
-  rio_driver.flags = TTY_DRIVER_REAL_RAW;
-
-  rio_driver.open  = riotopen;
-  rio_driver.close = gs_close;
-  rio_driver.write = gs_write;
-  rio_driver.put_char = gs_put_char;
-  rio_driver.flush_chars = gs_flush_chars;
-  rio_driver.write_room = gs_write_room;
-  rio_driver.chars_in_buffer = gs_chars_in_buffer;
-  rio_driver.flush_buffer = gs_flush_buffer;
-  rio_driver.ioctl = rio_ioctl;
-  rio_driver.throttle = rio_throttle;
-  rio_driver.unthrottle = rio_unthrottle;
-  rio_driver.set_termios = gs_set_termios;
-  rio_driver.stop = gs_stop;
-  rio_driver.start = gs_start;
-  rio_driver.hangup = gs_hangup;
-
-  rio_driver2 = rio_driver;
-  rio_driver2.major = RIO_NORMAL_MAJOR1;
-
-  rio_dprintk (RIO_DEBUG_INIT, "set_termios = %p\n", gs_set_termios);
-
-  if ((error = tty_register_driver(&rio_driver))) goto bad1;
-  if ((error = tty_register_driver(&rio_driver2))) goto bad2;
-
-  func_exit();
-  return 0;
-  /* 
- bad3:tty_unregister_driver (&rio_driver2);
- bad2:tty_unregister_driver (&rio_driver);
- bad1:printk(KERN_ERR "rio: Couldn't register a rio driver, error = %d\n",
-             error);
-  return 1;
+	int error = -ENOMEM;
+
+	rio_driver = alloc_tty_driver(256);
+	if (!rio_driver)
+		goto out;
+	rio_driver2 = alloc_tty_driver(256);
+	if (!rio_driver2)
+		goto out1;
+
+	func_enter();
+
+	rio_driver->owner = THIS_MODULE;
+	rio_driver->driver_name = "specialix_rio";
+	rio_driver->name = "ttySR";
+	rio_driver->major = RIO_NORMAL_MAJOR0;
+	rio_driver->type = TTY_DRIVER_TYPE_SERIAL;
+	rio_driver->subtype = SERIAL_TYPE_NORMAL;
+	rio_driver->init_termios = tty_std_termios;
+	rio_driver->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	rio_driver->flags = TTY_DRIVER_REAL_RAW;
+	tty_set_operations(rio_driver, &rio_ops);
+
+	rio_driver2->owner = THIS_MODULE;
+	rio_driver2->driver_name = "specialix_rio";
+	rio_driver2->name = "ttySR";
+	rio_driver2->major = RIO_NORMAL_MAJOR1;
+	rio_driver2->type = TTY_DRIVER_TYPE_SERIAL;
+	rio_driver2->subtype = SERIAL_TYPE_NORMAL;
+	rio_driver2->init_termios = tty_std_termios;
+	rio_driver2->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+	rio_driver2->flags = TTY_DRIVER_REAL_RAW;
+	tty_set_operations(rio_driver2, &rio_ops);
+
+	rio_dprintk (RIO_DEBUG_INIT, "set_termios = %p\n", gs_set_termios);
+
+	if ((error = tty_register_driver(rio_driver)))
+		goto out2;
+	if ((error = tty_register_driver(rio_driver2)))
+		goto out3;
+	func_exit();
+	return 0;
+out3:
+	tty_unregister_driver(rio_driver);
+out2:
+	put_tty_driver(rio_driver2);
+out1:
+	put_tty_driver(rio_driver);
+out:
+	printk(KERN_ERR "rio: Couldn't register a rio driver, error = %d\n",
+	     error);
+	return 1;
 }
 
 
@@ -1009,8 +1026,10 @@ static int rio_init_datastructures (void)
 static void  __exit rio_release_drivers(void)
 {
   func_enter();
-  tty_unregister_driver (&rio_driver2);
-  tty_unregister_driver (&rio_driver);
+  tty_unregister_driver(rio_driver2);
+  tty_unregister_driver(rio_driver);
+  put_tty_driver(rio_driver2);
+  put_tty_driver(rio_driver);
   func_exit();
 }