staging: dgnc: introduce the dgnc_tty_unregister()

The dgnc_tty_unregister() will be called when
the dgnc_tty_register() is failed.
Signed-off-by: Daeseok Youn <daeseok.youn@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgnc/dgnc_driver.c

@@ -299,13 +299,13 @@ static int dgnc_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	rc = dgnc_finalize_board_init(brd);
 	if (rc < 0) {
 		pr_err(DRVSTR ": Can't finalize board init (%d)\n", rc);
-		goto failed;
+		goto unregister_tty;
 	}
 
 	rc = dgnc_tty_init(brd);
 	if (rc < 0) {
 		pr_err(DRVSTR ": Can't init tty devices (%d)\n", rc);
-		goto failed;
+		goto unregister_tty;
 	}
 
 	brd->state = BOARD_READY;
@@ -317,6 +317,9 @@ static int dgnc_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	return 0;
 
+unregister_tty:
+	dgnc_tty_unregister(brd);
+
 failed:
 	kfree(brd);
 

drivers/staging/dgnc/dgnc_tty.c

@@ -273,6 +273,14 @@ int dgnc_tty_register(struct dgnc_board *brd)
 	return rc;
 }
 
+void dgnc_tty_unregister(struct dgnc_board *brd)
+{
+	tty_unregister_driver(brd->print_driver);
+	tty_unregister_driver(brd->serial_driver);
+	put_tty_driver(brd->print_driver);
+	put_tty_driver(brd->serial_driver);
+}
+
 /*
  * dgnc_tty_init()
  *

drivers/staging/dgnc/dgnc_tty.h

@@ -19,6 +19,7 @@
 #include "dgnc_driver.h"
 
 int	dgnc_tty_register(struct dgnc_board *brd);
+void dgnc_tty_unregister(struct dgnc_board *brd);
 
 int	dgnc_tty_preinit(void);
 int     dgnc_tty_init(struct dgnc_board *);