HIDP_WAITING_FOR_SEND_ACK
set_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
while (test_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags) &&
!test_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags)
clear_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
if (test_and_clear_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags))