/* This is actually a contract between the driver and the tty layer outlining how much write room the driver can guarantee will be sent OR BUFFERED. This driver MUST honor the return value.  */
static int hvc_write_room(struct tty_struct *tty)
/* This is actually a contract between the driver and the tty layer outlining how much write room the driver can guarantee will be sent OR BUFFERED. This driver MUST honor the return value.  */
static int hvc_write_room(struct tty_struct *tty)
{
	struct hvc_struct *hp = tty->driver_data;
	if (!hp)
		return -1;
	return hp->outbuf_size - hp->n_outbuf;
}