*/
{
struct list_head *pool = &port->write_pool;
- struct usb_ep *in = port->port_usb->in;
+ struct usb_ep *in;
int status = 0;
bool do_tty_wake = false;
+ if (!port->port_usb)
+ return status;
+
+ in = port->port_usb->in;
+
while (!port->write_busy && !list_empty(pool)) {
struct usb_request *req;
int len;