--- zzzz-none-000/linux-3.10.107/net/mac80211/rc80211_minstrel.h	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/net/mac80211/rc80211_minstrel.h	2021-02-04 17:41:59.000000000 +0000
@@ -13,7 +13,6 @@
 #define EWMA_DIV	128
 #define SAMPLE_COLUMNS	10	/* number of columns in sample table */
 
-
 /* scaled fraction values */
 #define MINSTREL_SCALE  16
 #define MINSTREL_FRAC(val, div) (((val) << MINSTREL_SCALE) / div)
@@ -24,48 +23,79 @@
 
 /*
  * Perform EWMA (Exponentially Weighted Moving Average) calculation
-  */
+ */
 static inline int
 minstrel_ewma(int old, int new, int weight)
 {
-	return (new * (EWMA_DIV - weight) + old * weight) / EWMA_DIV;
+	int diff, incr;
+
+	diff = new - old;
+	incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
+
+	return old + incr;
+}
+
+/*
+ * Perform EWMSD (Exponentially Weighted Moving Standard Deviation) calculation
+ */
+static inline int
+minstrel_ewmsd(int old_ewmsd, int cur_prob, int prob_ewma, int weight)
+{
+	int diff, incr, tmp_var;
+
+	/* calculate exponential weighted moving variance */
+	diff = MINSTREL_TRUNC((cur_prob - prob_ewma) * 1000000);
+	incr = (EWMA_DIV - weight) * diff / EWMA_DIV;
+	tmp_var = old_ewmsd * old_ewmsd;
+	tmp_var = weight * (tmp_var + diff * incr / 1000000) / EWMA_DIV;
+
+	/* return standard deviation */
+	return (u16) int_sqrt(tmp_var);
 }
 
+struct minstrel_rate_stats {
+	/* current / last sampling period attempts/success counters */
+	u16 attempts, last_attempts;
+	u16 success, last_success;
+
+	/* total attempts/success counters */
+	u64 att_hist, succ_hist;
+
+	/* statistis of packet delivery probability
+	 *  cur_prob  - current prob within last update intervall
+	 *  prob_ewma - exponential weighted moving average of prob
+	 *  prob_ewmsd - exp. weighted moving standard deviation of prob */
+	unsigned int cur_prob;
+	unsigned int prob_ewma;
+	u16 prob_ewmsd;
+
+	/* maximum retry counts */
+	u8 retry_count;
+	u8 retry_count_rtscts;
+
+	u8 sample_skipped;
+	bool retry_updated;
+};
 
 struct minstrel_rate {
 	int bitrate;
-	int rix;
+
+	s8 rix;
+	u8 retry_count_cts;
+	u8 adjusted_retry_count;
 
 	unsigned int perfect_tx_time;
 	unsigned int ack_time;
 
 	int sample_limit;
-	unsigned int retry_count;
-	unsigned int retry_count_cts;
-	unsigned int retry_count_rtscts;
-	unsigned int adjusted_retry_count;
-
-	u32 success;
-	u32 attempts;
-	u32 last_attempts;
-	u32 last_success;
-	u8 sample_skipped;
 
-	/* parts per thousand */
-	u32 cur_prob;
-	u32 probability;
-
-	/* per-rate throughput */
-	u32 cur_tp;
-
-	u64 succ_hist;
-	u64 att_hist;
+	struct minstrel_rate_stats stats;
 };
 
 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;
 
@@ -73,8 +103,8 @@
 
 	u8 max_tp_rate[MAX_THR_RATES];
 	u8 max_prob_rate;
-	unsigned int packet_count;
-	unsigned int sample_count;
+	unsigned int total_packets;
+	unsigned int sample_packets;
 	int sample_deferred;
 
 	unsigned int sample_row;
@@ -89,6 +119,7 @@
 
 #ifdef CONFIG_MAC80211_DEBUGFS
 	struct dentry *dbg_stats;
+	struct dentry *dbg_stats_csv;
 #endif
 };
 
@@ -115,7 +146,6 @@
 	u32 fixed_rate_idx;
 	struct dentry *dbg_fixed_rate;
 #endif
-
 };
 
 struct minstrel_debugfs_info {
@@ -123,12 +153,17 @@
 	char buf[];
 };
 
-extern struct rate_control_ops mac80211_minstrel;
+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 *mrs);
+int minstrel_get_tp_avg(struct minstrel_rate *mr, int prob_ewma);
+
 /* debugfs */
 int minstrel_stats_open(struct inode *inode, struct file *file);
+int minstrel_stats_csv_open(struct inode *inode, struct file *file);
 ssize_t minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos);
 int minstrel_stats_release(struct inode *inode, struct file *file);