pr_debug("stl_flushbuffer(tty=%p)\n", tty);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;
 
        pr_debug("stl_waituntilsent(tty=%p,timeout=%d)\n", tty, timeout);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;
 
        pr_debug("stl_putchar(tty=%p,ch=%x)\n", tty, ch);
 
-       if (tty == NULL)
-               return -EINVAL;
        portp = tty->driver_data;
        if (portp == NULL)
                return -EINVAL;
 
        pr_debug("stl_flushchars(tty=%p)\n", tty);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;
 
        pr_debug("stl_writeroom(tty=%p)\n", tty);
 
-       if (tty == NULL)
-               return 0;
        portp = tty->driver_data;
        if (portp == NULL)
                return 0;
 
        pr_debug("stl_charsinbuffer(tty=%p)\n", tty);
 
-       if (tty == NULL)
-               return 0;
        portp = tty->driver_data;
        if (portp == NULL)
                return 0;
 {
        struct stlport  *portp;
 
-       if (tty == NULL)
-               return -ENODEV;
        portp = tty->driver_data;
        if (portp == NULL)
                return -ENODEV;
        struct stlport  *portp;
        int rts = -1, dtr = -1;
 
-       if (tty == NULL)
-               return -ENODEV;
        portp = tty->driver_data;
        if (portp == NULL)
                return -ENODEV;
        pr_debug("stl_ioctl(tty=%p,file=%p,cmd=%x,arg=%lx)\n", tty, file, cmd,
                        arg);
 
-       if (tty == NULL)
-               return -ENODEV;
        portp = tty->driver_data;
        if (portp == NULL)
                return -ENODEV;
 
        pr_debug("stl_start(tty=%p)\n", tty);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;
 
        pr_debug("stl_settermios(tty=%p,old=%p)\n", tty, old);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;
 
        pr_debug("stl_throttle(tty=%p)\n", tty);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;
 
        pr_debug("stl_unthrottle(tty=%p)\n", tty);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;
 
        pr_debug("stl_stop(tty=%p)\n", tty);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;
 
        pr_debug("stl_hangup(tty=%p)\n", tty);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;
 
        pr_debug("stl_breakctl(tty=%p,state=%d)\n", tty, state);
 
-       if (tty == NULL)
-               return -EINVAL;
        portp = tty->driver_data;
        if (portp == NULL)
                return -EINVAL;
 
        pr_debug("stl_sendxchar(tty=%p,ch=%x)\n", tty, ch);
 
-       if (tty == NULL)
-               return;
        portp = tty->driver_data;
        if (portp == NULL)
                return;