mac80211: merge EWMA calculation of minstrel_ht and minstrel

Both rate control algorithms (minstrel and minstrel_ht) calculate
averages based on EWMA. Shift function minstrel_ewma() into
rc80211_minstrel.h and make use of it in both minstrel version.
Also shift the default EWMA level (75%) definition to the header file
and clean up variable usage.

Acked-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Thomas Huehn <thomas@net.t-labs.tu-berlin.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/net/mac80211/rc80211_minstrel.h b/net/mac80211/rc80211_minstrel.h
index 5ecf757817f2..98db93f96add 100644
--- a/net/mac80211/rc80211_minstrel.h
+++ b/net/mac80211/rc80211_minstrel.h
@@ -9,6 +9,18 @@
 #ifndef __RC_MINSTREL_H
 #define __RC_MINSTREL_H
 
+#define EWMA_LEVEL 75   /* ewma weighting factor [%] */
+
+/*
+ * Perform EWMA (Exponentially Weighted Moving Average) calculation
+  */
+static inline int
+minstrel_ewma(int old, int new, int weight)
+{
+        return (new * (100 - weight) + old * weight) / 100;
+}
+
+
 struct minstrel_rate {
         int bitrate;
         int rix;
@@ -73,7 +85,6 @@ struct minstrel_priv {
         unsigned int cw_min;
         unsigned int cw_max;
         unsigned int max_retry;
-        unsigned int ewma_level;
         unsigned int segment_size;
         unsigned int update_interval;
         unsigned int lookaround_rate;