staging: dgnc: Remove some redundant functions

dgnc_tty_preinit() and dgnc_tty_post_uninit() functions are used to
allocate and free "dgnc_TmpWriteBuf" and this "dgnc_TmpWriteBuf" is
not really getting used. Hence remove these redundant functions.

Also remove dgnc_TmpWriteBuf variable as it is not used anymore.
Signed-off-by: Pankaj Bharadiya <pankaj.bharadiya@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgnc/dgnc_driver.c

@@ -151,7 +151,6 @@ static void cleanup(bool sysfiles)
 		dgnc_cleanup_board(dgnc_board[i]);
 	}
 
-	dgnc_tty_post_uninit();
 }
 
 /*
@@ -241,16 +240,6 @@ static int dgnc_start(void)
 		goto failed_device;
 	}
 
-	/*
-	 * Init any global tty stuff.
-	 */
-	rc = dgnc_tty_preinit();
-
-	if (rc < 0) {
-		pr_err(DRVSTR ": tty preinit - not enough memory (%d)\n", rc);
-		goto failed_tty;
-	}
-
 	/* Start the poller */
 	spin_lock_irqsave(&dgnc_poll_lock, flags);
 	setup_timer(&dgnc_poll_timer, dgnc_poll_handler, 0);
@@ -262,8 +251,6 @@ static int dgnc_start(void)
 
 	return 0;
 
-failed_tty:
-	device_destroy(dgnc_class, MKDEV(dgnc_major, 0));
 failed_device:
 	class_destroy(dgnc_class);
 failed_class:

drivers/staging/dgnc/dgnc_tty.c

@@ -42,11 +42,6 @@
 #include "dgnc_sysfs.h"
 #include "dgnc_utils.h"
 
-/*
- * internal variables
- */
-static unsigned char		*dgnc_TmpWriteBuf;
-
 /*
  * Default transparent print information.
  */
@@ -143,31 +138,6 @@ static const struct tty_operations dgnc_tty_ops = {
  *
  ************************************************************************/
 
-/*
- * dgnc_tty_preinit()
- *
- * Initialize any global tty related data before we download any boards.
- */
-int dgnc_tty_preinit(void)
-{
-	/*
-	 * Allocate a buffer for doing the copy from user space to
-	 * kernel space in dgnc_write().  We only use one buffer and
-	 * control access to it with a semaphore.  If we are paging, we
-	 * are already in trouble so one buffer won't hurt much anyway.
-	 *
-	 * We are okay to sleep in the malloc, as this routine
-	 * is only called during module load, (not in interrupt context),
-	 * and with no locks held.
-	 */
-	dgnc_TmpWriteBuf = kmalloc(WRITEBUFLEN, GFP_KERNEL);
-
-	if (!dgnc_TmpWriteBuf)
-		return -ENOMEM;
-
-	return 0;
-}
-
 /*
  * dgnc_tty_register()
  *
@@ -364,17 +334,6 @@ int dgnc_tty_init(struct dgnc_board *brd)
 	return -ENOMEM;
 }
 
-/*
- * dgnc_tty_post_uninit()
- *
- * UnInitialize any global tty related data.
- */
-void dgnc_tty_post_uninit(void)
-{
-	kfree(dgnc_TmpWriteBuf);
-	dgnc_TmpWriteBuf = NULL;
-}
-
 /*
  * dgnc_cleanup_tty()
  *
@@ -1543,7 +1502,7 @@ static int dgnc_tty_write_room(struct tty_struct *tty)
 	int ret = 0;
 	unsigned long flags;
 
-	if (!tty || !dgnc_TmpWriteBuf)
+	if (!tty)
 		return 0;
 
 	un = tty->driver_data;
@@ -1623,7 +1582,7 @@ static int dgnc_tty_write(struct tty_struct *tty,
 	ushort tmask;
 	uint remain;
 
-	if (!tty || !dgnc_TmpWriteBuf)
+	if (!tty)
 		return 0;
 
 	un = tty->driver_data;

drivers/staging/dgnc/dgnc_tty.h

@@ -21,10 +21,8 @@
 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 *);
 
-void	dgnc_tty_post_uninit(void);
 void	dgnc_cleanup_tty(struct dgnc_board *);
 
 void	dgnc_input(struct channel_t *ch);