UVC_BUF_STATE_ACTIVE
if (buf->status != UVC_BUF_STATE_ACTIVE) {
buf->status = UVC_BUF_STATE_ACTIVE;
if (buf->status != UVC_BUF_STATE_ACTIVE) {
buf->status = UVC_BUF_STATE_ACTIVE;
case UVC_BUF_STATE_ACTIVE: