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From:   Karthik M <quic_karm@quicinc.com>
To:     <johannes@sipsolutions.net>
CC:     <linux-wireless@vger.kernel.org>,
        Karthik M <quic_karm@quicinc.com>,
        Tamizh Chelvam Raja <quic_tamizhr@quicinc.com>
Subject: [PATCH v1] wifi: mac80211: Initialize EWMA fail avg to 1
Date:   Mon, 17 Apr 2023 15:32:58 +0530
Message-ID: <20230417100258.22965-1-quic_karm@quicinc.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

If the average value in mesh metrics calculation
has been rounded to 0 (success), this resets it to
the smallest nonzero value (similarly to the initialization)
to avoid a case where a single failure would result in
an average value that goes beyond the value
of 95 (Link Failure Threshold).

Signed-off-by: Tamizh Chelvam Raja <quic_tamizhr@quicinc.com>
Signed-off-by: Karthik M <quic_karm@quicinc.com>
---
Changes since v1:
 - Altered the comment to mention "mesh" and thershold value.
 - Checkpatch done
---
 net/mac80211/mesh_hwmp.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 9b1ce7c3925a..f89cbcf212d5 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -298,10 +298,23 @@ void ieee80211s_update_metric(struct ieee80211_local *local,
 {
 	struct ieee80211_tx_info *txinfo = st->info;
 	int failed;
+	u32 fail_avg;
 	struct rate_info rinfo;
 
 	failed = !(txinfo->flags & IEEE80211_TX_STAT_ACK);
 
+	fail_avg = ewma_mesh_fail_avg_read(&sta->mesh->fail_avg);
+	if (!fail_avg) {
+		/* If the average value in mesh metrics calculation
+		 * has been rounded to 0 (success), this resets it to
+		 * the smallest nonzero value (similarly to the initialization)
+		 * to avoid a case where a single failure would result in
+		 * an average value that goes beyond the value
+		 * of 95 (Link Failure Threshold)
+		 */
+		ewma_mesh_fail_avg_add(&sta->mesh->fail_avg, 1);
+	}
+
 	/* moving average, scaled to 100.
 	 * feed failure as 100 and success as 0
 	 */
-- 
2.17.1