Gigaset: permit module unload

Fix the initialization and reference counting of the Gigaset driver modules
so that they can be unloaded when they are not actually in use.

Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Cc: Hansjoerg Lipp <hjlipp@web.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Karsten Keil <kkeil@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 1 deletions

diff --git a/drivers/isdn/gigaset/interface.c b/drivers/isdn/gigaset/interface.c
index f4731c9984f6..af195b07c191 100644
--- a/drivers/isdn/gigaset/interface.c
+++ b/drivers/isdn/gigaset/interface.c
@@ -161,7 +161,7 @@ static int if_open(struct tty_struct *tty, struct file *filp)
         tty->driver_data = NULL;
 
         cs = gigaset_get_cs_by_tty(tty);
-        if (!cs)
+        if (!cs || !try_module_get(cs->driver->owner))
                 return -ENODEV;
 
         if (mutex_lock_interruptible(&cs->mutex))
@@ -207,6 +207,8 @@ static void if_close(struct tty_struct *tty, struct file *filp)
         }
 
         mutex_unlock(&cs->mutex);
+
+        module_put(cs->driver->owner);
 }
 
 static int if_ioctl(struct tty_struct *tty, struct file *file,