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Commit 102885a5 authored by Vasanthakumar Thiagarajan's avatar Vasanthakumar Thiagarajan Committed by John W. Linville
Browse files

ath9k: Implement an algorithm for Antenna diversity and combining 



This algorithm chooses the best main and alt lna out of
LNA1, LNA2, LNA1+LNA2 and LNA1-LNA2 to improve rx for single
chain chips(AR9285). This would greatly improve rx when there
is only one antenna is connected with AR9285.

Signed-off-by: default avatarVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 21cc630f

drivers/net/wireless/ath/ath9k/ath9k.h

+56 −0
Original line number Diff line number Diff line
@@ -481,6 +481,60 @@ struct ath_led { 
void ath_init_leds(struct ath_softc *sc);

void ath_deinit_leds(struct ath_softc *sc);



/* Antenna diversity/combining */

#define ATH_ANT_RX_CURRENT_SHIFT 4

#define ATH_ANT_RX_MAIN_SHIFT 2

#define ATH_ANT_RX_MASK 0x3



#define ATH_ANT_DIV_COMB_SHORT_SCAN_INTR 50

#define ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT 0x100

#define ATH_ANT_DIV_COMB_MAX_PKTCOUNT 0x200

#define ATH_ANT_DIV_COMB_INIT_COUNT 95

#define ATH_ANT_DIV_COMB_MAX_COUNT 100

#define ATH_ANT_DIV_COMB_ALT_ANT_RATIO 30

#define ATH_ANT_DIV_COMB_ALT_ANT_RATIO2 20



#define ATH_ANT_DIV_COMB_LNA1_LNA2_DELTA -3

#define ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA -1

#define ATH_ANT_DIV_COMB_LNA1_DELTA_HI -4

#define ATH_ANT_DIV_COMB_LNA1_DELTA_MID -2

#define ATH_ANT_DIV_COMB_LNA1_DELTA_LOW 2



enum ath9k_ant_div_comb_lna_conf {

	ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2,

	ATH_ANT_DIV_COMB_LNA2,

	ATH_ANT_DIV_COMB_LNA1,

	ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2,

};



struct ath_ant_comb {

	u16 count;

	u16 total_pkt_count;

	bool scan;

	bool scan_not_start;

	int main_total_rssi;

	int alt_total_rssi;

	int alt_recv_cnt;

	int main_recv_cnt;

	int rssi_lna1;

	int rssi_lna2;

	int rssi_add;

	int rssi_sub;

	int rssi_first;

	int rssi_second;

	int rssi_third;

	bool alt_good;

	int quick_scan_cnt;

	int main_conf;

	enum ath9k_ant_div_comb_lna_conf first_quick_scan_conf;

	enum ath9k_ant_div_comb_lna_conf second_quick_scan_conf;

	int first_bias;

	int second_bias;

	bool first_ratio;

	bool second_ratio;

	unsigned long scan_start_time;

};



/********************/

/* Main driver core */

/********************/
@@ -597,6 +651,8 @@ struct ath_softc { 
	struct ath_btcoex btcoex;



	struct ath_descdma txsdma;



	struct ath_ant_comb ant_comb;

};



struct ath_wiphy {

drivers/net/wireless/ath/ath9k/init.c

+3 −0
Original line number Diff line number Diff line
@@ -531,6 +531,9 @@ static void ath9k_init_misc(struct ath_softc *sc) 
		sc->beacon.bslot[i] = NULL;

		sc->beacon.bslot_aphy[i] = NULL;

	}



	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)

		sc->ant_comb.count = ATH_ANT_DIV_COMB_INIT_COUNT;

}



static int ath9k_init_softc(u16 devid, struct ath_softc *sc, u16 subsysid,

drivers/net/wireless/ath/ath9k/recv.c

+545 −0
Original line number Diff line number Diff line
@@ -19,6 +19,15 @@ 


#define SKB_CB_ATHBUF(__skb)	(*((struct ath_buf **)__skb->cb))



static inline bool ath_is_alt_ant_ratio_better(int alt_ratio, int maxdelta,

					       int mindelta, int main_rssi_avg,

					       int alt_rssi_avg, int pkt_count)

{

	return (((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&

		(alt_rssi_avg > main_rssi_avg + maxdelta)) ||

		(alt_rssi_avg > main_rssi_avg + mindelta)) && (pkt_count > 50);

}



static inline bool ath9k_check_auto_sleep(struct ath_softc *sc)

{

	return sc->ps_enabled &&
@@ -1076,6 +1085,539 @@ static void ath9k_rx_skb_postprocess(struct ath_common *common, 
		rxs->flag &= ~RX_FLAG_DECRYPTED;

}



static void ath_lnaconf_alt_good_scan(struct ath_ant_comb *antcomb,

				      struct ath_hw_antcomb_conf ant_conf,

				      int main_rssi_avg)

{

	antcomb->quick_scan_cnt = 0;



	if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA2)

		antcomb->rssi_lna2 = main_rssi_avg;

	else if (ant_conf.main_lna_conf == ATH_ANT_DIV_COMB_LNA1)

		antcomb->rssi_lna1 = main_rssi_avg;



	switch ((ant_conf.main_lna_conf << 4) | ant_conf.alt_lna_conf) {

	case (0x10): /* LNA2 A-B */

		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;

		antcomb->first_quick_scan_conf =

			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;

		break;

	case (0x20): /* LNA1 A-B */

		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;

		antcomb->first_quick_scan_conf =

			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;

		break;

	case (0x21): /* LNA1 LNA2 */

		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA2;

		antcomb->first_quick_scan_conf =

			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;

		antcomb->second_quick_scan_conf =

			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

		break;

	case (0x12): /* LNA2 LNA1 */

		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1;

		antcomb->first_quick_scan_conf =

			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;

		antcomb->second_quick_scan_conf =

			ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

		break;

	case (0x13): /* LNA2 A+B */

		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

		antcomb->first_quick_scan_conf =

			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;

		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA1;

		break;

	case (0x23): /* LNA1 A+B */

		antcomb->main_conf = ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

		antcomb->first_quick_scan_conf =

			ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;

		antcomb->second_quick_scan_conf = ATH_ANT_DIV_COMB_LNA2;

		break;

	default:

		break;

	}

}



static void ath_select_ant_div_from_quick_scan(struct ath_ant_comb *antcomb,

				struct ath_hw_antcomb_conf *div_ant_conf,

				int main_rssi_avg, int alt_rssi_avg,

				int alt_ratio)

{

	/* alt_good */

	switch (antcomb->quick_scan_cnt) {

	case 0:

		/* set alt to main, and alt to first conf */

		div_ant_conf->main_lna_conf = antcomb->main_conf;

		div_ant_conf->alt_lna_conf = antcomb->first_quick_scan_conf;

		break;

	case 1:

		/* set alt to main, and alt to first conf */

		div_ant_conf->main_lna_conf = antcomb->main_conf;

		div_ant_conf->alt_lna_conf = antcomb->second_quick_scan_conf;

		antcomb->rssi_first = main_rssi_avg;

		antcomb->rssi_second = alt_rssi_avg;



		if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {

			/* main is LNA1 */

			if (ath_is_alt_ant_ratio_better(alt_ratio,

						ATH_ANT_DIV_COMB_LNA1_DELTA_HI,

						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,

						main_rssi_avg, alt_rssi_avg,

						antcomb->total_pkt_count))

				antcomb->first_ratio = true;

			else

				antcomb->first_ratio = false;

		} else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {

			if (ath_is_alt_ant_ratio_better(alt_ratio,

						ATH_ANT_DIV_COMB_LNA1_DELTA_MID,

						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,

						main_rssi_avg, alt_rssi_avg,

						antcomb->total_pkt_count))

				antcomb->first_ratio = true;

			else

				antcomb->first_ratio = false;

		} else {

			if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&

			    (alt_rssi_avg > main_rssi_avg +

			    ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||

			    (alt_rssi_avg > main_rssi_avg)) &&

			    (antcomb->total_pkt_count > 50))

				antcomb->first_ratio = true;

			else

				antcomb->first_ratio = false;

		}

		break;

	case 2:

		antcomb->alt_good = false;

		antcomb->scan_not_start = false;

		antcomb->scan = false;

		antcomb->rssi_first = main_rssi_avg;

		antcomb->rssi_third = alt_rssi_avg;



		if (antcomb->second_quick_scan_conf == ATH_ANT_DIV_COMB_LNA1)

			antcomb->rssi_lna1 = alt_rssi_avg;

		else if (antcomb->second_quick_scan_conf ==

			 ATH_ANT_DIV_COMB_LNA2)

			antcomb->rssi_lna2 = alt_rssi_avg;

		else if (antcomb->second_quick_scan_conf ==

			 ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2) {

			if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2)

				antcomb->rssi_lna2 = main_rssi_avg;

			else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1)

				antcomb->rssi_lna1 = main_rssi_avg;

		}



		if (antcomb->rssi_lna2 > antcomb->rssi_lna1 +

		    ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)

			div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA2;

		else

			div_ant_conf->main_lna_conf = ATH_ANT_DIV_COMB_LNA1;



		if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) {

			if (ath_is_alt_ant_ratio_better(alt_ratio,

						ATH_ANT_DIV_COMB_LNA1_DELTA_HI,

						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,

						main_rssi_avg, alt_rssi_avg,

						antcomb->total_pkt_count))

				antcomb->second_ratio = true;

			else

				antcomb->second_ratio = false;

		} else if (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2) {

			if (ath_is_alt_ant_ratio_better(alt_ratio,

						ATH_ANT_DIV_COMB_LNA1_DELTA_MID,

						ATH_ANT_DIV_COMB_LNA1_DELTA_LOW,

						main_rssi_avg, alt_rssi_avg,

						antcomb->total_pkt_count))

				antcomb->second_ratio = true;

			else

				antcomb->second_ratio = false;

		} else {

			if ((((alt_ratio >= ATH_ANT_DIV_COMB_ALT_ANT_RATIO2) &&

			    (alt_rssi_avg > main_rssi_avg +

			    ATH_ANT_DIV_COMB_LNA1_DELTA_HI)) ||

			    (alt_rssi_avg > main_rssi_avg)) &&

			    (antcomb->total_pkt_count > 50))

				antcomb->second_ratio = true;

			else

				antcomb->second_ratio = false;

		}



		/* set alt to the conf with maximun ratio */

		if (antcomb->first_ratio && antcomb->second_ratio) {

			if (antcomb->rssi_second > antcomb->rssi_third) {

				/* first alt*/

				if ((antcomb->first_quick_scan_conf ==

				    ATH_ANT_DIV_COMB_LNA1) ||

				    (antcomb->first_quick_scan_conf ==

				    ATH_ANT_DIV_COMB_LNA2))

					/* Set alt LNA1 or LNA2*/

					if (div_ant_conf->main_lna_conf ==

					    ATH_ANT_DIV_COMB_LNA2)

						div_ant_conf->alt_lna_conf =

							ATH_ANT_DIV_COMB_LNA1;

					else

						div_ant_conf->alt_lna_conf =

							ATH_ANT_DIV_COMB_LNA2;

				else

					/* Set alt to A+B or A-B */

					div_ant_conf->alt_lna_conf =

						antcomb->first_quick_scan_conf;

			} else if ((antcomb->second_quick_scan_conf ==

				   ATH_ANT_DIV_COMB_LNA1) ||

				   (antcomb->second_quick_scan_conf ==

				   ATH_ANT_DIV_COMB_LNA2)) {

				/* Set alt LNA1 or LNA2 */

				if (div_ant_conf->main_lna_conf ==

				    ATH_ANT_DIV_COMB_LNA2)

					div_ant_conf->alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

				else

					div_ant_conf->alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;

			} else {

				/* Set alt to A+B or A-B */

				div_ant_conf->alt_lna_conf =

					antcomb->second_quick_scan_conf;

			}

		} else if (antcomb->first_ratio) {

			/* first alt */

			if ((antcomb->first_quick_scan_conf ==

			    ATH_ANT_DIV_COMB_LNA1) ||

			    (antcomb->first_quick_scan_conf ==

			    ATH_ANT_DIV_COMB_LNA2))

					/* Set alt LNA1 or LNA2 */

				if (div_ant_conf->main_lna_conf ==

				    ATH_ANT_DIV_COMB_LNA2)

					div_ant_conf->alt_lna_conf =

							ATH_ANT_DIV_COMB_LNA1;

				else

					div_ant_conf->alt_lna_conf =

							ATH_ANT_DIV_COMB_LNA2;

			else

				/* Set alt to A+B or A-B */

				div_ant_conf->alt_lna_conf =

						antcomb->first_quick_scan_conf;

		} else if (antcomb->second_ratio) {

				/* second alt */

			if ((antcomb->second_quick_scan_conf ==

			    ATH_ANT_DIV_COMB_LNA1) ||

			    (antcomb->second_quick_scan_conf ==

			    ATH_ANT_DIV_COMB_LNA2))

				/* Set alt LNA1 or LNA2 */

				if (div_ant_conf->main_lna_conf ==

				    ATH_ANT_DIV_COMB_LNA2)

					div_ant_conf->alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

				else

					div_ant_conf->alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;

			else

				/* Set alt to A+B or A-B */

				div_ant_conf->alt_lna_conf =

						antcomb->second_quick_scan_conf;

		} else {

			/* main is largest */

			if ((antcomb->main_conf == ATH_ANT_DIV_COMB_LNA1) ||

			    (antcomb->main_conf == ATH_ANT_DIV_COMB_LNA2))

				/* Set alt LNA1 or LNA2 */

				if (div_ant_conf->main_lna_conf ==

				    ATH_ANT_DIV_COMB_LNA2)

					div_ant_conf->alt_lna_conf =

							ATH_ANT_DIV_COMB_LNA1;

				else

					div_ant_conf->alt_lna_conf =

							ATH_ANT_DIV_COMB_LNA2;

			else

				/* Set alt to A+B or A-B */

				div_ant_conf->alt_lna_conf = antcomb->main_conf;

		}

		break;

	default:

		break;

	}

}



void ath_ant_div_conf_fast_divbias(struct ath_hw_antcomb_conf *ant_conf)

{

	/* Adjust the fast_div_bias based on main and alt lna conf */

	switch ((ant_conf->main_lna_conf << 4) | ant_conf->alt_lna_conf) {

	case (0x01): /* A-B LNA2 */

		ant_conf->fast_div_bias = 0x3b;

		break;

	case (0x02): /* A-B LNA1 */

		ant_conf->fast_div_bias = 0x3d;

		break;

	case (0x03): /* A-B A+B */

		ant_conf->fast_div_bias = 0x1;

		break;

	case (0x10): /* LNA2 A-B */

		ant_conf->fast_div_bias = 0x7;

		break;

	case (0x12): /* LNA2 LNA1 */

		ant_conf->fast_div_bias = 0x2;

		break;

	case (0x13): /* LNA2 A+B */

		ant_conf->fast_div_bias = 0x7;

		break;

	case (0x20): /* LNA1 A-B */

		ant_conf->fast_div_bias = 0x6;

		break;

	case (0x21): /* LNA1 LNA2 */

		ant_conf->fast_div_bias = 0x0;

		break;

	case (0x23): /* LNA1 A+B */

		ant_conf->fast_div_bias = 0x6;

		break;

	case (0x30): /* A+B A-B */

		ant_conf->fast_div_bias = 0x1;

		break;

	case (0x31): /* A+B LNA2 */

		ant_conf->fast_div_bias = 0x3b;

		break;

	case (0x32): /* A+B LNA1 */

		ant_conf->fast_div_bias = 0x3d;

		break;

	default:

		break;

	}

}



/* Antenna diversity and combining */

static void ath_ant_comb_scan(struct ath_softc *sc, struct ath_rx_status *rs)

{

	struct ath_hw_antcomb_conf div_ant_conf;

	struct ath_ant_comb *antcomb = &sc->ant_comb;

	int alt_ratio = 0, alt_rssi_avg = 0, main_rssi_avg = 0, curr_alt_set;

	int curr_main_set, curr_bias;

	int main_rssi = rs->rs_rssi_ctl0;

	int alt_rssi = rs->rs_rssi_ctl1;

	int rx_ant_conf,  main_ant_conf;

	bool short_scan = false;



	rx_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_CURRENT_SHIFT) &

		       ATH_ANT_RX_MASK;

	main_ant_conf = (rs->rs_rssi_ctl2 >> ATH_ANT_RX_MAIN_SHIFT) &

			 ATH_ANT_RX_MASK;



	/* Record packet only when alt_rssi is positive */

	if (alt_rssi > 0) {

		antcomb->total_pkt_count++;

		antcomb->main_total_rssi += main_rssi;

		antcomb->alt_total_rssi  += alt_rssi;

		if (main_ant_conf == rx_ant_conf)

			antcomb->main_recv_cnt++;

		else

			antcomb->alt_recv_cnt++;

	}



	/* Short scan check */

	if (antcomb->scan && antcomb->alt_good) {

		if (time_after(jiffies, antcomb->scan_start_time +

		    msecs_to_jiffies(ATH_ANT_DIV_COMB_SHORT_SCAN_INTR)))

			short_scan = true;

		else

			if (antcomb->total_pkt_count ==

			    ATH_ANT_DIV_COMB_SHORT_SCAN_PKTCOUNT) {

				alt_ratio = ((antcomb->alt_recv_cnt * 100) /

					    antcomb->total_pkt_count);

				if (alt_ratio < ATH_ANT_DIV_COMB_ALT_ANT_RATIO)

					short_scan = true;

			}

	}



	if (((antcomb->total_pkt_count < ATH_ANT_DIV_COMB_MAX_PKTCOUNT) ||

	    rs->rs_moreaggr) && !short_scan)

		return;



	if (antcomb->total_pkt_count) {

		alt_ratio = ((antcomb->alt_recv_cnt * 100) /

			     antcomb->total_pkt_count);

		main_rssi_avg = (antcomb->main_total_rssi /

				 antcomb->total_pkt_count);

		alt_rssi_avg = (antcomb->alt_total_rssi /

				 antcomb->total_pkt_count);

	}





	ath9k_hw_antdiv_comb_conf_get(sc->sc_ah, &div_ant_conf);

	curr_alt_set = div_ant_conf.alt_lna_conf;

	curr_main_set = div_ant_conf.main_lna_conf;

	curr_bias = div_ant_conf.fast_div_bias;



	antcomb->count++;



	if (antcomb->count == ATH_ANT_DIV_COMB_MAX_COUNT) {

		if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {

			ath_lnaconf_alt_good_scan(antcomb, div_ant_conf,

						  main_rssi_avg);

			antcomb->alt_good = true;

		} else {

			antcomb->alt_good = false;

		}



		antcomb->count = 0;

		antcomb->scan = true;

		antcomb->scan_not_start = true;

	}



	if (!antcomb->scan) {

		if (alt_ratio > ATH_ANT_DIV_COMB_ALT_ANT_RATIO) {

			if (curr_alt_set == ATH_ANT_DIV_COMB_LNA2) {

				/* Switch main and alt LNA */

				div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;

				div_ant_conf.alt_lna_conf  =

						ATH_ANT_DIV_COMB_LNA1;

			} else if (curr_alt_set == ATH_ANT_DIV_COMB_LNA1) {

				div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

				div_ant_conf.alt_lna_conf  =

						ATH_ANT_DIV_COMB_LNA2;

			}



			goto div_comb_done;

		} else if ((curr_alt_set != ATH_ANT_DIV_COMB_LNA1) &&

			   (curr_alt_set != ATH_ANT_DIV_COMB_LNA2)) {

			/* Set alt to another LNA */

			if (curr_main_set == ATH_ANT_DIV_COMB_LNA2)

				div_ant_conf.alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

			else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1)

				div_ant_conf.alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;



			goto div_comb_done;

		}



		if ((alt_rssi_avg < (main_rssi_avg +

		    ATH_ANT_DIV_COMB_LNA1_LNA2_DELTA)))

			goto div_comb_done;

	}



	if (!antcomb->scan_not_start) {

		switch (curr_alt_set) {

		case ATH_ANT_DIV_COMB_LNA2:

			antcomb->rssi_lna2 = alt_rssi_avg;

			antcomb->rssi_lna1 = main_rssi_avg;

			antcomb->scan = true;

			/* set to A+B */

			div_ant_conf.main_lna_conf =

				ATH_ANT_DIV_COMB_LNA1;

			div_ant_conf.alt_lna_conf  =

				ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

			break;

		case ATH_ANT_DIV_COMB_LNA1:

			antcomb->rssi_lna1 = alt_rssi_avg;

			antcomb->rssi_lna2 = main_rssi_avg;

			antcomb->scan = true;

			/* set to A+B */

			div_ant_conf.main_lna_conf = ATH_ANT_DIV_COMB_LNA2;

			div_ant_conf.alt_lna_conf  =

				ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

			break;

		case ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2:

			antcomb->rssi_add = alt_rssi_avg;

			antcomb->scan = true;

			/* set to A-B */

			div_ant_conf.alt_lna_conf =

				ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;

			break;

		case ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2:

			antcomb->rssi_sub = alt_rssi_avg;

			antcomb->scan = false;

			if (antcomb->rssi_lna2 >

			    (antcomb->rssi_lna1 +

			    ATH_ANT_DIV_COMB_LNA1_LNA2_SWITCH_DELTA)) {

				/* use LNA2 as main LNA */

				if ((antcomb->rssi_add > antcomb->rssi_lna1) &&

				    (antcomb->rssi_add > antcomb->rssi_sub)) {

					/* set to A+B */

					div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;

					div_ant_conf.alt_lna_conf  =

						ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

				} else if (antcomb->rssi_sub >

					   antcomb->rssi_lna1) {

					/* set to A-B */

					div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;

					div_ant_conf.alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;

				} else {

					/* set to LNA1 */

					div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;

					div_ant_conf.alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

				}

			} else {

				/* use LNA1 as main LNA */

				if ((antcomb->rssi_add > antcomb->rssi_lna2) &&

				    (antcomb->rssi_add > antcomb->rssi_sub)) {

					/* set to A+B */

					div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

					div_ant_conf.alt_lna_conf  =

						ATH_ANT_DIV_COMB_LNA1_PLUS_LNA2;

				} else if (antcomb->rssi_sub >

					   antcomb->rssi_lna1) {

					/* set to A-B */

					div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

					div_ant_conf.alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA1_MINUS_LNA2;

				} else {

					/* set to LNA2 */

					div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

					div_ant_conf.alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;

				}

			}

			break;

		default:

			break;

		}

	} else {

		if (!antcomb->alt_good) {

			antcomb->scan_not_start = false;

			/* Set alt to another LNA */

			if (curr_main_set == ATH_ANT_DIV_COMB_LNA2) {

				div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;

				div_ant_conf.alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

			} else if (curr_main_set == ATH_ANT_DIV_COMB_LNA1) {

				div_ant_conf.main_lna_conf =

						ATH_ANT_DIV_COMB_LNA1;

				div_ant_conf.alt_lna_conf =

						ATH_ANT_DIV_COMB_LNA2;

			}

			goto div_comb_done;

		}

	}



	ath_select_ant_div_from_quick_scan(antcomb, &div_ant_conf,

					   main_rssi_avg, alt_rssi_avg,

					   alt_ratio);



	antcomb->quick_scan_cnt++;



div_comb_done:

	ath_ant_div_conf_fast_divbias(&div_ant_conf);



	ath9k_hw_antdiv_comb_conf_set(sc->sc_ah, &div_ant_conf);



	antcomb->scan_start_time = jiffies;

	antcomb->total_pkt_count = 0;

	antcomb->main_total_rssi = 0;

	antcomb->alt_total_rssi = 0;

	antcomb->main_recv_cnt = 0;

	antcomb->alt_recv_cnt = 0;

}



int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)

{

	struct ath_buf *bf;
@@ -1213,6 +1755,9 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) 
					      PS_WAIT_FOR_PSPOLL_DATA))))

			ath_rx_ps(sc, skb);



		if (ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB)

			ath_ant_comb_scan(sc, &rs);



		ath_rx_send_to_mac80211(hw, sc, skb, rxs);



requeue: