Function ble_hs_hci_get_avail_pkts 

pub unsafe extern "C" fn ble_hs_hci_get_avail_pkts() -> u16

Returns the number of available ACL transmit buffers on the controller.

Applications can use this to implement notification throttling — only enqueue new notifications when available buffers are above a waterline.

@return The number of ACL packet buffers the controller can currently accept from the host.