mac80211: merge a fix for minstrel expected throughput reporting

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@48648 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 51 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/330-mac80211-minstrel-Change-expected-throughput-unit-ba.patch b/package/kernel/mac80211/patches/330-mac80211-minstrel-Change-expected-throughput-unit-ba.patch
new file mode 100644
index 0000000000..4dc6d663ed
--- /dev/null
+++ b/package/kernel/mac80211/patches/330-mac80211-minstrel-Change-expected-throughput-unit-ba.patch
@@ -0,0 +1,51 @@
+From: Sven Eckelmann <sven.eckelmann@open-mesh.com>
+Date: Tue, 2 Feb 2016 08:12:26 +0100
+Subject: [PATCH] mac80211: minstrel: Change expected throughput unit back to
+ Kbps
+
+The change from cur_tp to the function
+minstrel_get_tp_avg/minstrel_ht_get_tp_avg changed the unit used for the
+current throughput. For example in minstrel_ht the correct
+conversion between them would be:
+
+    mrs->cur_tp / 10 == minstrel_ht_get_tp_avg(..).
+
+This factor 10 must also be included in the calculation of
+minstrel_get_expected_throughput and minstrel_ht_get_expected_throughput to
+return values with the unit [Kbps] instead of [10Kbps]. Otherwise routing
+algorithms like B.A.T.M.A.N. V will make incorrect decision based on these
+values. Its kernel based implementation expects expected_throughput always
+to have the unit [Kbps] and not sometimes [10Kbps] and sometimes [Kbps].
+
+The same requirement has iw or olsrdv2's nl80211 based statistics module
+which retrieve the same data via NL80211_STA_INFO_TX_BITRATE.
+
+Cc: stable@vger.kernel.org
+Fixes: 6a27b2c40b48 ("mac80211: restructure per-rate throughput calculation into function")
+Signed-off-by: Sven Eckelmann <sven@open-mesh.com>
+Signed-off-by: Johannes Berg <johannes.berg@intel.com>
+---
+
+--- a/net/mac80211/rc80211_minstrel.c
++++ b/net/mac80211/rc80211_minstrel.c
+@@ -711,7 +711,7 @@ static u32 minstrel_get_expected_through
+ 	 * computing cur_tp
+ 	 */
+ 	tmp_mrs = &mi->r[idx].stats;
+-	tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_ewma);
++	tmp_cur_tp = minstrel_get_tp_avg(&mi->r[idx], tmp_mrs->prob_ewma) * 10;
+ 	tmp_cur_tp = tmp_cur_tp * 1200 * 8 / 1024;
+ 
+ 	return tmp_cur_tp;
+--- a/net/mac80211/rc80211_minstrel_ht.c
++++ b/net/mac80211/rc80211_minstrel_ht.c
+@@ -1335,7 +1335,8 @@ static u32 minstrel_ht_get_expected_thro
+ 	prob = mi->groups[i].rates[j].prob_ewma;
+ 
+ 	/* convert tp_avg from pkt per second in kbps */
+-	tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * AVG_PKT_SIZE * 8 / 1024;
++	tp_avg = minstrel_ht_get_tp_avg(mi, i, j, prob) * 10;
++	tp_avg = tp_avg * AVG_PKT_SIZE * 8 / 1024;
+ 
+ 	return tp_avg;
+ }