usb_get_current_frame_number (9) - Linux Manuals
usb_get_current_frame_number: return current bus frame number
usb_get_current_frame_number - return current bus frame number
int usb_get_current_frame_number(struct usb_device
- the device whose bus is being queried
Different kinds of host controller have different "scheduling horizons". While one type might support scheduling only 32 frames into the future, others could support scheduling up to 1024 frames into the future.