mac80211: merge minstrel_ht rate control performance improvements

SVN-Revision: 35847

package/mac80211/patches/300-pending_work.patch

@@ -623,3 +623,132 @@
  		    BIT(NL80211_IFTYPE_WDS);
  
  	rt2x00dev->hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -26,11 +26,11 @@
+ /* Number of symbols for a packet with (bps) bits per symbol */
+ #define MCS_NSYMS(bps) ((MCS_NBITS + (bps) - 1) / (bps))
+ 
+-/* Transmission time for a packet containing (syms) symbols */
++/* Transmission time (nanoseconds) for a packet containing (syms) symbols */
+ #define MCS_SYMBOL_TIME(sgi, syms)					\
+ 	(sgi ?								\
+-	  ((syms) * 18 + 4) / 5 :	/* syms * 3.6 us */		\
+-	  (syms) << 2			/* syms * 4 us */		\
++	  ((syms) * 18000 + 4000) / 5 :	/* syms * 3.6 us */		\
++	  ((syms) * 1000) << 2		/* syms * 4 us */		\
+ 	)
+ 
+ /* Transmit duration for the raw data part of an average sized packet */
+@@ -64,9 +64,9 @@
+ }
+ 
+ #define CCK_DURATION(_bitrate, _short, _len)		\
+-	(10 /* SIFS */ +				\
++	(1000 * (10 /* SIFS */ +			\
+ 	 (_short ? 72 + 24 : 144 + 48 ) +		\
+-	 (8 * (_len + 4) * 10) / (_bitrate))
++	 (8 * (_len + 4) * 10) / (_bitrate)))
+ 
+ #define CCK_ACK_DURATION(_bitrate, _short)			\
+ 	(CCK_DURATION((_bitrate > 10 ? 20 : 10), false, 60) +	\
+@@ -211,7 +211,8 @@ static void
+ minstrel_ht_calc_tp(struct minstrel_ht_sta *mi, int group, int rate)
+ {
+ 	struct minstrel_rate_stats *mr;
+-	unsigned int usecs = 0;
++	unsigned int nsecs = 0;
++	unsigned int tp;
+ 
+ 	mr = &mi->groups[group].rates[rate];
+ 
+@@ -221,10 +222,12 @@ minstrel_ht_calc_tp(struct minstrel_ht_s
+ 	}
+ 
+ 	if (group != MINSTREL_CCK_GROUP)
+-		usecs = mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
++		nsecs = 1000 * mi->overhead / MINSTREL_TRUNC(mi->avg_ampdu_len);
+ 
+-	usecs += minstrel_mcs_groups[group].duration[rate];
+-	mr->cur_tp = MINSTREL_TRUNC((1000000 / usecs) * mr->probability);
++	nsecs += minstrel_mcs_groups[group].duration[rate];
++	tp = 1000000 * ((mr->probability * 1000) / nsecs);
++
++	mr->cur_tp = MINSTREL_TRUNC(tp);
+ }
+ 
+ /*
+@@ -243,6 +246,7 @@ minstrel_ht_update_stats(struct minstrel
+ 	struct minstrel_rate_stats *mr;
+ 	int cur_prob, cur_prob_tp, cur_tp, cur_tp2;
+ 	int group, i, index;
++	int prob_max_streams = 1;
+ 
+ 	if (mi->ampdu_packets > 0) {
+ 		mi->avg_ampdu_len = minstrel_ewma(mi->avg_ampdu_len,
+@@ -308,8 +312,8 @@ minstrel_ht_update_stats(struct minstrel
+ 		}
+ 	}
+ 
+-	/* try to sample up to half of the available rates during each interval */
+-	mi->sample_count *= 4;
++	/* try to sample all available rates during each interval */
++	mi->sample_count *= 8;
+ 
+ 	cur_prob = 0;
+ 	cur_prob_tp = 0;
+@@ -320,20 +324,13 @@ minstrel_ht_update_stats(struct minstrel
+ 		if (!mg->supported)
+ 			continue;
+ 
+-		mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
+-		if (cur_prob_tp < mr->cur_tp &&
+-		    minstrel_mcs_groups[group].streams == 1) {
+-			mi->max_prob_rate = mg->max_prob_rate;
+-			cur_prob = mr->cur_prob;
+-			cur_prob_tp = mr->cur_tp;
+-		}
+-
+ 		mr = minstrel_get_ratestats(mi, mg->max_tp_rate);
+ 		if (cur_tp < mr->cur_tp) {
+ 			mi->max_tp_rate2 = mi->max_tp_rate;
+ 			cur_tp2 = cur_tp;
+ 			mi->max_tp_rate = mg->max_tp_rate;
+ 			cur_tp = mr->cur_tp;
++			prob_max_streams = minstrel_mcs_groups[group].streams - 1;
+ 		}
+ 
+ 		mr = minstrel_get_ratestats(mi, mg->max_tp_rate2);
+@@ -343,6 +340,23 @@ minstrel_ht_update_stats(struct minstrel
+ 		}
+ 	}
+ 
++	if (prob_max_streams < 1)
++		prob_max_streams = 1;
++
++	for (group = 0; group < ARRAY_SIZE(minstrel_mcs_groups); group++) {
++		mg = &mi->groups[group];
++		if (!mg->supported)
++			continue;
++		mr = minstrel_get_ratestats(mi, mg->max_prob_rate);
++		if (cur_prob_tp < mr->cur_tp &&
++		    minstrel_mcs_groups[group].streams <= prob_max_streams) {
++			mi->max_prob_rate = mg->max_prob_rate;
++			cur_prob = mr->cur_prob;
++			cur_prob_tp = mr->cur_tp;
++		}
++	}
++
++
+ 	mi->stats_update = jiffies;
+ }
+ 
+@@ -536,7 +550,7 @@ minstrel_calc_retransmit(struct minstrel
+ 	mr->retry_updated = true;
+ 
+ 	group = &minstrel_mcs_groups[index / MCS_GROUP_RATES];
+-	tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len;
++	tx_time_data = group->duration[index % MCS_GROUP_RATES] * ampdu_len / 1000;
+ 
+ 	/* Contention time for first 2 tries */
+ 	ctime = (t_slot * cw) >> 1;