Both open count and INITIALIZED flag should be changed under lock.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: <osv@javad.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
         * and set the speed of the serial port
         */
        mxser_change_speed(info, NULL);
+       info->flags |= ASYNC_INITIALIZED;
        spin_unlock_irqrestore(&info->slock, flags);
 
-       info->flags |= ASYNC_INITIALIZED;
        return 0;
 }
 
 static int mxser_open(struct tty_struct *tty, struct file *filp)
 {
        struct mxser_port *info;
+       unsigned long flags;
        int retval, line;
 
        line = tty->index;
        /*
         * Start up serial port
         */
+       spin_lock_irqsave(&info->slock, flags);
        info->count++;
+       spin_unlock_irqrestore(&info->slock, flags);
        retval = mxser_startup(info);
        if (retval)
                return retval;