frame_diff
if (frame_diff(max3421_ep->last_active,
&& (frame_diff(max3421_ep->last_active,
if (frame_diff(max3421_hcd->frame_number,
unsigned int frame_diff;
frame_diff = (current_frame_number - subs->last_frame_number) & 0xff;
est_delay = frame_diff * runtime->rate / 1000;