Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 39a4cafe authored by Vasanthakumar Thiagarajan's avatar Vasanthakumar Thiagarajan Committed by John W. Linville
Browse files

ath9k: Remove dead code in rate control 



ath9k rate control is based on only PER (packet error rate),
remove unused code which was intented to do rssi based rate
selection.

Signed-off-by: default avatarVasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent e25739a1

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

+4 −159
Original line number Diff line number Diff line
@@ -607,47 +607,14 @@ static u8 ath_rc_get_highest_rix(struct ath_softc *sc, 
				 const struct ath_rate_table *rate_table,

				 int *is_probing)

{

	u32 dt, best_thruput, this_thruput, now_msec;

	u32 best_thruput, this_thruput, now_msec;

	u8 rate, next_rate, best_rate, maxindex, minindex;

	int8_t  rssi_last, rssi_reduce = 0, index = 0;



	*is_probing = 0;



	rssi_last = median(ath_rc_priv->rssi_last,

			   ath_rc_priv->rssi_last_prev,

			   ath_rc_priv->rssi_last_prev2);



	/*

	 * Age (reduce) last ack rssi based on how old it is.

	 * The bizarre numbers are so the delta is 160msec,

	 * meaning we divide by 16.

	 *   0msec   <= dt <= 25msec:   don't derate

	 *   25msec  <= dt <= 185msec:  derate linearly from 0 to 10dB

	 *   185msec <= dt:             derate by 10dB

	 */

	int8_t index = 0;



	now_msec = jiffies_to_msecs(jiffies);

	dt = now_msec - ath_rc_priv->rssi_time;



	if (dt >= 185)

		rssi_reduce = 10;

	else if (dt >= 25)

		rssi_reduce = (u8)((dt - 25) >> 4);



	/* Now reduce rssi_last by rssi_reduce */

	if (rssi_last < rssi_reduce)

		rssi_last = 0;

	else

		rssi_last -= rssi_reduce;



	/*

	 * Now look up the rate in the rssi table and return it.

	 * If no rates match then we return 0 (lowest rate)

	 */



	*is_probing = 0;

	best_thruput = 0;

	maxindex = ath_rc_priv->max_valid_rate-1;



	minindex = 0;

	best_rate = minindex;
@@ -687,7 +654,6 @@ static u8 ath_rc_get_highest_rix(struct ath_softc *sc, 
	}



	rate = best_rate;

	ath_rc_priv->rssi_last_lookup = rssi_last;



	/*

	 * Must check the actual rate (ratekbps) to account for
@@ -977,10 +943,6 @@ static bool ath_rc_update_per(struct ath_softc *sc, 
				     (nretry_to_per_lookup[retries] >> 3));

		}



		ath_rc_priv->rssi_last_prev2 = ath_rc_priv->rssi_last_prev;

		ath_rc_priv->rssi_last_prev  = ath_rc_priv->rssi_last;

		ath_rc_priv->rssi_last = tx_info_priv->tx.ts_rssi;

		ath_rc_priv->rssi_time = now_msec;



		/*

		 * If we got at most one retry then increase the max rate if
@@ -1024,18 +986,9 @@ static bool ath_rc_update_per(struct ath_softc *sc, 
			/*

			 * Don't update anything.  We don't know if

			 * this was because of collisions or poor signal.

			 *

			 * Later: if rssi_ack is close to

			 * ath_rc_priv->state[txRate].rssi_thres and we see lots

			 * of retries, then we could increase

			 * ath_rc_priv->state[txRate].rssi_thres.

			 */

			ath_rc_priv->hw_maxretry_pktcnt = 0;

		} else {

			int32_t rssi_ackAvg;

			int8_t rssi_thres;

			int8_t rssi_ack_vmin;



			/*

			 * It worked with no retries. First ignore bogus (small)

			 * rssi_ack values.
@@ -1045,43 +998,9 @@ static bool ath_rc_update_per(struct ath_softc *sc, 
				ath_rc_priv->hw_maxretry_pktcnt++;

			}



			if (tx_info_priv->tx.ts_rssi <

			    rate_table->info[tx_rate].rssi_ack_validmin)

				goto exit;



			/* Average the rssi */

			if (tx_rate != ath_rc_priv->rssi_sum_rate) {

				ath_rc_priv->rssi_sum_rate = tx_rate;

				ath_rc_priv->rssi_sum =

					ath_rc_priv->rssi_sum_cnt = 0;

		}



			ath_rc_priv->rssi_sum += tx_info_priv->tx.ts_rssi;

			ath_rc_priv->rssi_sum_cnt++;



			if (ath_rc_priv->rssi_sum_cnt < 4)

				goto exit;



			rssi_ackAvg =

				(ath_rc_priv->rssi_sum + 2) / 4;

			rssi_thres =

				ath_rc_priv->state[tx_rate].rssi_thres;

			rssi_ack_vmin =

				rate_table->info[tx_rate].rssi_ack_validmin;



			ath_rc_priv->rssi_sum =

				ath_rc_priv->rssi_sum_cnt = 0;



			/* Now reduce the current rssi threshold */

			if ((rssi_ackAvg < rssi_thres + 2) &&

			    (rssi_thres > rssi_ack_vmin)) {

				ath_rc_priv->state[tx_rate].rssi_thres--;

	}



			state_change = true;

		}

	}

exit:

	return state_change;

}
@@ -1093,11 +1012,6 @@ static void ath_rc_update_ht(struct ath_softc *sc, 
			     struct ath_tx_info_priv *tx_info_priv,

			     int tx_rate, int xretries, int retries)

{

#define CHK_RSSI(rate)					\

	((ath_rc_priv->state[(rate)].rssi_thres +	\

	  rate_table->info[(rate)].rssi_ack_deltamin) > \

	 ath_rc_priv->state[(rate)+1].rssi_thres)



	u32 now_msec = jiffies_to_msecs(jiffies);

	int rate;

	u8 last_per;
@@ -1108,13 +1022,6 @@ static void ath_rc_update_ht(struct ath_softc *sc, 
	if ((tx_rate < 0) || (tx_rate > rate_table->rate_cnt))

		return;



	/* To compensate for some imbalance between ctrl and ext. channel */



	if (WLAN_RC_PHY_40(rate_table->info[tx_rate].phy))

		tx_info_priv->tx.ts_rssi =

			tx_info_priv->tx.ts_rssi < 3 ? 0 :

			tx_info_priv->tx.ts_rssi - 3;



	last_per = ath_rc_priv->state[tx_rate].per;



	/* Update PER first */
@@ -1136,51 +1043,6 @@ static void ath_rc_update_ht(struct ath_softc *sc, 
		ath_rc_priv->probe_time = now_msec;

	}



	if (state_change) {

		/*

		 * Make sure the rates above this have higher rssi thresholds.

		 * (Note:  Monotonicity is kept within the OFDM rates and

		 *         within the CCK rates. However, no adjustment is

		 *         made to keep the rssi thresholds monotonically

		 *         increasing between the CCK and OFDM rates.)

		 */

		for (rate = tx_rate; rate < size - 1; rate++) {

			if (rate_table->info[rate+1].phy !=

			    rate_table->info[tx_rate].phy)

				break;



			if (CHK_RSSI(rate)) {

				ath_rc_priv->state[rate+1].rssi_thres =

					ath_rc_priv->state[rate].rssi_thres +

					rate_table->info[rate].rssi_ack_deltamin;

			}

		}



		/* Make sure the rates below this have lower rssi thresholds. */

		for (rate = tx_rate - 1; rate >= 0; rate--) {

			if (rate_table->info[rate].phy !=

			    rate_table->info[tx_rate].phy)

				break;



			if (CHK_RSSI(rate)) {

				if (ath_rc_priv->state[rate+1].rssi_thres <

				    rate_table->info[rate].rssi_ack_deltamin)

					ath_rc_priv->state[rate].rssi_thres = 0;

				else {

					ath_rc_priv->state[rate].rssi_thres =

					ath_rc_priv->state[rate+1].rssi_thres -

					rate_table->info[rate].rssi_ack_deltamin;

				}



				if (ath_rc_priv->state[rate].rssi_thres <

				    rate_table->info[rate].rssi_ack_validmin) {

					ath_rc_priv->state[rate].rssi_thres =

					rate_table->info[rate].rssi_ack_validmin;

				}

			}

		}

	}



	/* Make sure the rates below this have lower PER */

	/* Monotonicity is kept only for rates below the current rate. */

	if (ath_rc_priv->state[tx_rate].per < last_per) {
@@ -1205,19 +1067,6 @@ static void ath_rc_update_ht(struct ath_softc *sc, 
				ath_rc_priv->state[rate].per;

	}



	/* Every so often, we reduce the thresholds and

	 * PER (different for CCK and OFDM). */

	if (now_msec - ath_rc_priv->rssi_down_time >=

	    rate_table->rssi_reduce_interval) {



		for (rate = 0; rate < size; rate++) {

			if (ath_rc_priv->state[rate].rssi_thres >

			    rate_table->info[rate].rssi_ack_validmin)

				ath_rc_priv->state[rate].rssi_thres -= 1;

		}

		ath_rc_priv->rssi_down_time = now_msec;

	}



	/* Every so often, we reduce the thresholds

	 * and PER (different for CCK and OFDM). */

	if (now_msec - ath_rc_priv->per_down_time >=
@@ -1233,7 +1082,6 @@ static void ath_rc_update_ht(struct ath_softc *sc, 
	ath_debug_stat_retries(sc, tx_rate, xretries, retries,

			       ath_rc_priv->state[tx_rate].per);



#undef CHK_RSSI

}



static int ath_rc_get_rateindex(const struct ath_rate_table *rate_table,
@@ -1369,8 +1217,6 @@ static void ath_rc_init(struct ath_softc *sc, 


	/* Initialize thresholds according to the global rate table */

	for (i = 0 ; i < ath_rc_priv->rate_table_size; i++) {

		ath_rc_priv->state[i].rssi_thres =

			rate_table->info[i].rssi_ack_validmin;

		ath_rc_priv->state[i].per = 0;

	}
@@ -1631,7 +1477,6 @@ static void *ath_rate_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp 
		return NULL;

	}



	rate_priv->rssi_down_time = jiffies_to_msecs(jiffies);

	rate_priv->tx_triglevel_max = sc->sc_ah->caps.tx_triglevel_max;



	return rate_priv;