+static int acm_tty_chars_in_buffer(struct tty_struct *tty);
+
+static void acm_port_down(struct acm *acm, int drain)
+{
+ int i, nr = acm->rx_buflimit;
+ mutex_lock(&open_mutex);
+ if (acm->dev) {
+ usb_autopm_get_interface(acm->control);
+ acm_set_control(acm, acm->ctrlout = 0);
+ /* try letting the last writes drain naturally */
+ if (drain) {
+ wait_event_interruptible_timeout(acm->drain_wait,
+ (ACM_NW == acm_wb_is_avail(acm)) || !acm->dev,
+ ACM_CLOSE_TIMEOUT * HZ);
+ }
+ usb_kill_urb(acm->ctrlurb);
+ for (i = 0; i < ACM_NW; i++)
+ usb_kill_urb(acm->wb[i].urb);
+ for (i = 0; i < nr; i++)
+ usb_kill_urb(acm->ru[i].urb);
+ acm->control->needs_remote_wakeup = 0;
+ usb_autopm_put_interface(acm->control);
+ }
+ mutex_unlock(&open_mutex);
+}
+
+static void acm_tty_hangup(struct tty_struct *tty)
+{
+ struct acm *acm = tty->driver_data;
+ tty_port_hangup(&acm->port);
+ acm_port_down(acm, 0);
+}
+