static void con_flush_chars(struct tty_struct *tty)
{
	struct vc_data *vc;

	if (in_interrupt())	/* from flush_to_ldisc */
		return;

	/* if we race with con_close(), vt may be null */
	console_lock();
	vc = tty->driver_data;
	if (vc)
		set_cursor(vc);
	console_unlock();
}
static void con_flush_chars(struct tty_struct *tty)
{
	struct vc_data *vc;

	if (in_interrupt())	 
		return;

	 
	console_lock();
	vc = tty->driver_data;
	if (vc)
		set_cursor(vc);
	console_unlock();
}