iwk_rx_gain_diff
struct iwk_rx_gain_diff *gain_diff_p;
(void) memset(gain_diff_p, 0, sizeof (struct iwk_rx_gain_diff));
struct iwk_rx_gain_diff *gain_diff_p = &sc->sc_rxgain_diff;
struct iwk_rx_gain_diff sc_rxgain_diff;