mac80211: unify Minstrel & Minstrel-HTs calculation of rate statistics

This patch unifies the calculation of Minstrels and Minstrel-HTs
per-rate statistic. The new common function minstrel_calc_rate_stats()
is called when a statistic update is performed.

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>

3 files changed, 32 insertions, 43 deletions

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index ef6e8a6c4253..5528037021ad 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c
@@ -127,6 +127,32 @@ minstrel_update_rates(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
         rate_control_set_rates(mp->hw, mi->sta, ratetbl);
 }
 
+/*
+* Recalculate success probabilities and counters for a given rate using EWMA
+*/
+void
+minstrel_calc_rate_stats(struct minstrel_rate_stats *mrs)
+{
+        if (unlikely(mrs->attempts > 0)) {
+                mrs->sample_skipped = 0;
+                mrs->cur_prob = MINSTREL_FRAC(mrs->success, mrs->attempts);
+                if (unlikely(!mrs->att_hist))
+                        mrs->probability = mrs->cur_prob;
+                else
+                        mrs->probability = minstrel_ewma(mrs->probability,
+                                                     mrs->cur_prob, EWMA_LEVEL);
+                mrs->att_hist += mrs->attempts;
+                mrs->succ_hist += mrs->success;
+        } else {
+                mrs->sample_skipped++;
+        }
+
+        mrs->last_success = mrs->success;
+        mrs->last_attempts = mrs->attempts;
+        mrs->success = 0;
+        mrs->attempts = 0;
+}
+
 static void
 minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
 {
@@ -146,22 +172,8 @@ minstrel_update_stats(struct minstrel_priv *mp, struct minstrel_sta_info *mi)
                 if (!usecs)
                         usecs = 1000000;
 
-                if (unlikely(mrs->attempts > 0)) {
-                        mrs->sample_skipped = 0;
-                        mrs->cur_prob = MINSTREL_FRAC(mrs->success,
-                                                      mrs->attempts);
-                        mrs->succ_hist += mrs->success;
-                        mrs->att_hist += mrs->attempts;
-                        mrs->probability = minstrel_ewma(mrs->probability,
-                                                         mrs->cur_prob,
-                                                         EWMA_LEVEL);
-                } else
-                        mrs->sample_skipped++;
-
-                mrs->last_success = mrs->success;
-                mrs->last_attempts = mrs->attempts;
-                mrs->success = 0;
-                mrs->attempts = 0;
+                /* Update success probabilities per rate */
+                minstrel_calc_rate_stats(mrs);
 
                 /* Update throughput per rate, reset thr. below 10% success */
                 if (mrs->probability < MINSTREL_FRAC(10, 100))
diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 9613e7392c7d..728144c8df3f 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -132,6 +132,9 @@ extern const struct rate_control_ops mac80211_minstrel;
 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);
+
 /* debugfs */
 int minstrel_stats_open(struct inode *inode, struct file *file);
 int minstrel_stats_csv_open(struct inode *inode, struct file *file);
diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index 60698fc7042e..7afa5623a5ee 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c
@@ -313,32 +313,6 @@ minstrel_get_ratestats(struct minstrel_ht_sta *mi, int index)
         return &mi->groups[index / MCS_GROUP_RATES].rates[index % MCS_GROUP_RATES];
 }
 
-
-/*
- * Recalculate success probabilities and counters for a rate using EWMA
- */
-static void
-minstrel_calc_rate_ewma(struct minstrel_rate_stats *mr)
-{
-        if (unlikely(mr->attempts > 0)) {
-                mr->sample_skipped = 0;
-                mr->cur_prob = MINSTREL_FRAC(mr->success, mr->attempts);
-                if (!mr->att_hist)
-                        mr->probability = mr->cur_prob;
-                else
-                        mr->probability = minstrel_ewma(mr->probability,
-                                mr->cur_prob, EWMA_LEVEL);
-                mr->att_hist += mr->attempts;
-                mr->succ_hist += mr->success;
-        } else {
-                mr->sample_skipped++;
-        }
-        mr->last_success = mr->success;
-        mr->last_attempts = mr->attempts;
-        mr->success = 0;
-        mr->attempts = 0;
-}
-
 /*
  * Calculate throughput based on the average A-MPDU length, taking into account
  * the expected number of retransmissions and their expected length
@@ -567,7 +541,7 @@ minstrel_ht_update_stats(struct minstrel_priv *mp, struct minstrel_ht_sta *mi)
 
                         mr = &mg->rates[i];
                         mr->retry_updated = false;
-                        minstrel_calc_rate_ewma(mr);
+                        minstrel_calc_rate_stats(mr);
                         minstrel_ht_calc_tp(mi, group, i);
 
                         if (!mr->cur_tp)