mac80211: improve Minstrel variable & function naming

This patch ensures a consistent usage of variable names for type
"minstrel_rate_stats" to be used as "mrs" and from type minstrel_rate
as "mr" across both Minstrel & Minstrel-HT. In addition some
variable and function names got changed to more meaningful ones.
Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rc80211_minstrel.c

@@ -137,9 +137,9 @@ minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs)
 		mrs->sample_skipped = 0;
 		mrs->cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
 		if (unlikely(!mrs->att_hist))
-			mrs->probability = mrs->cur_prob;
+			mrs->prob_ewma = mrs->cur_prob;
 		else
-			mrs->probability = minstrel_ewma(mrs->probability,
+			mrs->prob_ewma = minstrel_ewma(mrs->prob_ewma,
 						     mrs->cur_prob, EWMA_LEVEL);
 		mrs->att_hist += mrs->attempts;
 		mrs->succ_hist += mrs->success;
@@ -176,15 +176,15 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 		minstrel_calc_rate_stats(mrs);
 
 		/* Update throughput per rate, reset thr. below 10% success */
-		if (mrs->probability < MINSTREL_FRAC(10, 100))
+		if (mrs->prob_ewma < MINSTREL_FRAC(10, 100))
 			mrs->cur_tp = 0;
 		else
-			mrs->cur_tp = mrs->probability * (1000000 / usecs);
+			mrs->cur_tp = mrs->prob_ewma * (1000000 / usecs);
 
 		/* Sample less often below the 10% chance of success.
 		 * Sample less often above the 95% chance of success. */
-		if (mrs->probability > MINSTREL_FRAC(95, 100) ||
-		    mrs->probability < MINSTREL_FRAC(10, 100)) {
+		if (mrs->prob_ewma > MINSTREL_FRAC(95, 100) ||
+		    mrs->prob_ewma < MINSTREL_FRAC(10, 100)) {
 			mr->adjusted_retry_count = mrs->retry_count >> 1;
 			if (mr->adjusted_retry_count > 2)
 				mr->adjusted_retry_count = 2;
@@ -204,11 +204,11 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 		 * choose the maximum throughput rate as max_prob_rate
 		 * (2) if all success probabilities < 95%, the rate with
 		 * highest success probability is chosen as max_prob_rate */
-		if (mrs->probability >= MINSTREL_FRAC(95, 100)) {
+		if (mrs->prob_ewma >= MINSTREL_FRAC(95, 100)) {
 			if (mrs->cur_tp >= mi->r[tmp_prob_rate].stats.cur_tp)
 				tmp_prob_rate = i;
 		} else {
-			if (mrs->probability >= mi->r[tmp_prob_rate].stats.probability)
+			if (mrs->prob_ewma >= mi->r[tmp_prob_rate].stats.prob_ewma)
 				tmp_prob_rate = i;
 		}
 	}
@@ -227,7 +227,7 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 #endif
 
 	/* Reset update timer */
-	mi->stats_update = jiffies;
+	mi->last_stats_update = jiffies;
 
 	minstrel_update_rates(mp, mi);
 }
@@ -265,7 +265,7 @@ minstrel_tx_status(void *priv, struct ieee80211_supported_band *sband,
 	if (mi->sample_deferred > 0)
 		mi->sample_deferred--;
 
-	if (time_after(jiffies, mi->stats_update +
+	if (time_after(jiffies, mi->last_stats_update +
 				(mp->update_interval * HZ) / 1000))
 		minstrel_update_stats(mp, mi);
 }
@@ -397,7 +397,7 @@ minstrel_get_rate(void *priv, struct ieee80211_sta *sta,
 	 * has a probability of >95%, we shouldn't be attempting
 	 * to use it, as this only wastes precious airtime */
 	if (!mrr_capable &&
-	   (mi->r[ndx].stats.probability > MINSTREL_FRAC(95, 100)))
+	   (mi->r[ndx].stats.prob_ewma > MINSTREL_FRAC(95, 100)))
 		return;
 
 	mi->prev_sample = true;
@@ -531,7 +531,7 @@ minstrel_rate_init(void *priv, struct ieee80211_supported_band *sband,
 	}
 
 	mi->n_rates = n;
-	mi->stats_update = jiffies;
+	mi->last_stats_update = jiffies;
 
 	init_sample_table(mi);
 	minstrel_update_rates(mp, mi);
@@ -565,7 +565,7 @@ minstrel_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 	if (!mi->sample_table)
 		goto error1;
 
-	mi->stats_update = jiffies;
+	mi->last_stats_update = jiffies;
 	return mi;
 
 error1:

net/mac80211/rc80211_minstrel.h

@@ -38,11 +38,14 @@ struct minstrel_rate_stats {
 	/* total attempts/success counters */
 	u64 att_hist, succ_hist;
 
-	/* current throughput */
+	/* current EWMA of rate throughput */
 	unsigned int cur_tp;
 
-	/* packet delivery probabilities */
-	unsigned int cur_prob, probability;
+	/* statistis of packet delivery probability
+	 *  cur_prob  - current prob within last update intervall
+	 *  prob_ewma - exponential weighted moving average of prob */
+	unsigned int cur_prob;
+	unsigned int prob_ewma;
 
 	/* maximum retry counts */
 	u8 retry_count;
@@ -70,7 +73,7 @@ struct minstrel_rate {
 struct minstrel_sta_info {
 	struct ieee80211_sta *sta;
 
-	unsigned long stats_update;
+	unsigned long last_stats_update;
 	unsigned int sp_ack_dur;
 	unsigned int rate_avg;
 
@@ -133,7 +136,7 @@ void minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir);
 void minstrel_remove_sta_debugfs(void *priv, void *priv_sta);
 
 /* Recalculate success probabilities and counters for a given rate using EWMA */
-void minstrel_calc_rate_stats(struct minstrel_rate_stats *mr);
+void minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs);
 
 /* debugfs */
 int minstrel_stats_open(struct inode *inode, struct file *file);

net/mac80211/rc80211_minstrel_debugfs.c

@@ -107,7 +107,7 @@ minstrel_stats_open(struct inode *inode, struct file *file)
 
 		tp = MINSTREL_TRUNC(mrs->cur_tp / 10);
 		prob = MINSTREL_TRUNC(mrs->cur_prob * 1000);
-		eprob = MINSTREL_TRUNC(mrs->probability * 1000);
+		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
 
 		p += sprintf(p, " %4u.%1u   %3u.%1u     %3u.%1u %3u"
 				"   %3u %-3u   %9llu   %-9llu\n",
@@ -171,7 +171,7 @@ minstrel_stats_csv_open(struct inode *inode, struct file *file)
 
 		tp = MINSTREL_TRUNC(mrs->cur_tp / 10);
 		prob = MINSTREL_TRUNC(mrs->cur_prob * 1000);
-		eprob = MINSTREL_TRUNC(mrs->probability * 1000);
+		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
 
 		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u,%u,%u,"
 				"%llu,%llu,%d,%d\n",

net/mac80211/rc80211_minstrel_ht.h

@@ -78,7 +78,7 @@ struct minstrel_ht_sta {
 	u16 max_prob_rate;
 
 	/* time of last status update */
-	unsigned long stats_update;
+	unsigned long last_stats_update;
 
 	/* overhead time in usec for each frame */
 	unsigned int overhead;

net/mac80211/rc80211_minstrel_ht_debugfs.c

@@ -38,7 +38,7 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		gimode = 'S';
 
 	for (j = 0; j < MCS_GROUP_RATES; j++) {
-		struct minstrel_rate_stats *mr = &mi->groups[i].rates[j];
+		struct minstrel_rate_stats *mrs = &mi->groups[i].rates[j];
 		static const int bitrates[4] = { 10, 20, 55, 110 };
 		int idx = i * MCS_GROUP_RATES + j;
 
@@ -81,20 +81,20 @@ minstrel_ht_stats_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		tx_time = DIV_ROUND_CLOSEST(mg->duration[j], 1000);
 		p += sprintf(p, "%6u   ", tx_time);
 
-		tp = mr->cur_tp / 10;
-		prob = MINSTREL_TRUNC(mr->cur_prob * 1000);
-		eprob = MINSTREL_TRUNC(mr->probability * 1000);
+		tp = mrs->cur_tp / 10;
+		prob = MINSTREL_TRUNC(mrs->cur_prob * 1000);
+		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
 
 		p += sprintf(p, "%4u.%1u   %3u.%1u     %3u.%1u "
 				"%3u   %3u %-3u   %9llu   %-9llu\n",
 				tp / 10, tp % 10,
 				eprob / 10, eprob % 10,
 				prob / 10, prob % 10,
-				mr->retry_count,
-				mr->last_success,
-				mr->last_attempts,
-				(unsigned long long)mr->succ_hist,
-				(unsigned long long)mr->att_hist);
+				mrs->retry_count,
+				mrs->last_success,
+				mrs->last_attempts,
+				(unsigned long long)mrs->succ_hist,
+				(unsigned long long)mrs->att_hist);
 	}
 
 	return p;
@@ -182,7 +182,7 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		gimode = 'S';
 
 	for (j = 0; j < MCS_GROUP_RATES; j++) {
-		struct minstrel_rate_stats *mr = &mi->groups[i].rates[j];
+		struct minstrel_rate_stats *mrs = &mi->groups[i].rates[j];
 		static const int bitrates[4] = { 10, 20, 55, 110 };
 		int idx = i * MCS_GROUP_RATES + j;
 
@@ -222,19 +222,19 @@ minstrel_ht_stats_csv_dump(struct minstrel_ht_sta *mi, int i, char *p)
 		tx_time = DIV_ROUND_CLOSEST(mg->duration[j], 1000);
 		p += sprintf(p, "%u,", tx_time);
 
-		tp = mr->cur_tp / 10;
-		prob = MINSTREL_TRUNC(mr->cur_prob * 1000);
-		eprob = MINSTREL_TRUNC(mr->probability * 1000);
+		tp = mrs->cur_tp / 10;
+		prob = MINSTREL_TRUNC(mrs->cur_prob * 1000);
+		eprob = MINSTREL_TRUNC(mrs->prob_ewma * 1000);
 
 		p += sprintf(p, "%u.%u,%u.%u,%u.%u,%u,%u,%u,%llu,%llu,",
 				tp / 10, tp % 10,
 				eprob / 10, eprob % 10,
 				prob / 10, prob % 10,
-				mr->retry_count,
-				mr->last_success,
-				mr->last_attempts,
-				(unsigned long long)mr->succ_hist,
-				(unsigned long long)mr->att_hist);
+				mrs->retry_count,
+				mrs->last_success,
+				mrs->last_attempts,
+				(unsigned long long)mrs->succ_hist,
+				(unsigned long long)mrs->att_hist);
 		p += sprintf(p, "%d,%d,%d.%d\n",
 				max(0, (int) mi->total_packets -
 				(int) mi->sample_packets),