+static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
+{
+ struct ssu100_port_private *priv = usb_get_serial_port_data(port);
+ struct async_icount prev, cur;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->status_lock, flags);
+ prev = priv->icount;
+ spin_unlock_irqrestore(&priv->status_lock, flags);
+
+ while (1) {
+ wait_event_interruptible(priv->delta_msr_wait,
+ ((priv->icount.rng != prev.rng) ||
+ (priv->icount.dsr != prev.dsr) ||
+ (priv->icount.dcd != prev.dcd) ||
+ (priv->icount.cts != prev.cts)));
+
+ if (signal_pending(current))
+ return -ERESTARTSYS;
+
+ spin_lock_irqsave(&priv->status_lock, flags);
+ cur = priv->icount;
+ spin_unlock_irqrestore(&priv->status_lock, flags);
+
+ if ((prev.rng == cur.rng) &&
+ (prev.dsr == cur.dsr) &&
+ (prev.dcd == cur.dcd) &&
+ (prev.cts == cur.cts))
+ return -EIO;
+
+ if ((arg & TIOCM_RNG && (prev.rng != cur.rng)) ||
+ (arg & TIOCM_DSR && (prev.dsr != cur.dsr)) ||
+ (arg & TIOCM_CD && (prev.dcd != cur.dcd)) ||
+ (arg & TIOCM_CTS && (prev.cts != cur.cts)))
+ return 0;
+ }
+ return 0;
+}
+