staging: dgnc: remove dead code in dgnc_tty_write()

Remove the dead code protected by in_user in dgnc_tty_write() because it
is set to 0 and never changed to 1 thus the code in ifs never gets
executed.

Signed-off-by: Giedrius Statkevičius <giedrius.statkevicius@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/dgnc/dgnc_tty.c b/drivers/staging/dgnc/dgnc_tty.c
index 6c9261cb88ecc73e6cba8ff37b445d86d6537bcc..cde55e001f8d40a6fe1d8f485c5526ebe55baa18 100644 (file)
--- a/drivers/staging/dgnc/dgnc_tty.c
+++ b/drivers/staging/dgnc/dgnc_tty.c
@@ -42,16 +42,11 @@
 #include "dgnc_sysfs.h"
 #include "dgnc_utils.h"
 
-#define init_MUTEX(sem)         sema_init(sem, 1)
-#define DECLARE_MUTEX(name)     \
-       struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1)
-
 /*
  * internal variables
  */
 static struct dgnc_board       *dgnc_BoardsByMajor[256];
 static unsigned char           *dgnc_TmpWriteBuf;
-static DECLARE_MUTEX(dgnc_TmpWriteSem);
 
 /*
  * Default transparent print information.
@@ -1692,7 +1687,6 @@ static int dgnc_tty_write(struct tty_struct *tty,
        ushort tail;
        ushort tmask;
        uint remain;
-       int from_user = 0;
 
        if (tty == NULL || dgnc_TmpWriteBuf == NULL)
                return 0;
@@ -1772,38 +1766,6 @@ static int dgnc_tty_write(struct tty_struct *tty,
        if (count <= 0)
                goto exit_retry;
 
-       if (from_user) {
-
-               count = min(count, WRITEBUFLEN);
-
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-
-               /*
-                * If data is coming from user space, copy it into a temporary
-                * buffer so we don't get swapped out while doing the copy to
-                * the board.
-                */
-               /* we're allowed to block if it's from_user */
-               if (down_interruptible(&dgnc_TmpWriteSem))
-                       return -EINTR;
-
-               /*
-                * copy_from_user() returns the number
-                * of bytes that could *NOT* be copied.
-                */
-               count -= copy_from_user(dgnc_TmpWriteBuf, (const unsigned char __user *) buf, count);
-
-               if (!count) {
-                       up(&dgnc_TmpWriteSem);
-                       return -EFAULT;
-               }
-
-               spin_lock_irqsave(&ch->ch_lock, flags);
-
-               buf = dgnc_TmpWriteBuf;
-
-       }
-
        n = count;
 
        /*
@@ -1840,12 +1802,7 @@ static int dgnc_tty_write(struct tty_struct *tty,
                ch->ch_cpstime += (HZ * count) / ch->ch_digi.digi_maxcps;
        }
 
-       if (from_user) {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-               up(&dgnc_TmpWriteSem);
-       } else {
-               spin_unlock_irqrestore(&ch->ch_lock, flags);
-       }
+       spin_unlock_irqrestore(&ch->ch_lock, flags);
 
        if (count) {
                /*