mac80211: fix mesh airtime link metric estimating

Airtime link metric estimation was broken in HT mesh, use
cfg80211_calculate_bitrate to get the right rate value.

Also factor out tx rate copying from sta_set_sinfo().

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 22 insertions, 10 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index ab31cc56a2fb..677d65929780 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -336,6 +336,20 @@ static void rate_idx_to_bitrate(struct rate_info *rate, struct sta_info *sta, in
                 rate->mcs = idx;
 }
 
+void sta_set_rate_info_tx(struct sta_info *sta,
+                          const struct ieee80211_tx_rate *rate,
+                          struct rate_info *rinfo)
+{
+        rinfo->flags = 0;
+        if (rate->flags & IEEE80211_TX_RC_MCS)
+                rinfo->flags |= RATE_INFO_FLAGS_MCS;
+        if (rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
+                rinfo->flags |= RATE_INFO_FLAGS_40_MHZ_WIDTH;
+        if (rate->flags & IEEE80211_TX_RC_SHORT_GI)
+                rinfo->flags |= RATE_INFO_FLAGS_SHORT_GI;
+        rate_idx_to_bitrate(rinfo, sta, rate->idx);
+}
+
 static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 {
         struct ieee80211_sub_if_data *sdata = sta->sdata;
@@ -378,14 +392,7 @@ static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
                 sinfo->signal_avg = (s8) -ewma_read(&sta->avg_signal);
         }
 
-        sinfo->txrate.flags = 0;
-        if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
-                sinfo->txrate.flags |= RATE_INFO_FLAGS_MCS;
-        if (sta->last_tx_rate.flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
-                sinfo->txrate.flags |= RATE_INFO_FLAGS_40_MHZ_WIDTH;
-        if (sta->last_tx_rate.flags & IEEE80211_TX_RC_SHORT_GI)
-                sinfo->txrate.flags |= RATE_INFO_FLAGS_SHORT_GI;
-        rate_idx_to_bitrate(&sinfo->txrate, sta, sta->last_tx_rate.idx);
+        sta_set_rate_info_tx(sta, &sta->last_tx_rate, &sinfo->txrate);
 
         sinfo->rxrate.flags = 0;
         if (sta->last_rx_rate_flag & RX_FLAG_HT)
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 4a993f2d1ae1..1c6f3d02aebf 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -324,6 +324,7 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
                                    struct sta_info *sta)
 {
         struct ieee80211_supported_band *sband;
+        struct rate_info rinfo;
         /* This should be adjusted for each device */
         int device_constant = 1 << ARITH_SHIFT;
         int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
@@ -337,7 +338,9 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
         if (sta->fail_avg >= 100)
                 return MAX_METRIC;
 
-        if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
+        sta_set_rate_info_tx(sta, &sta->last_tx_rate, &rinfo);
+        rate = cfg80211_calculate_bitrate(&rinfo);
+        if (WARN_ON(!rate))
                 return MAX_METRIC;
 
         err = (sta->fail_avg << ARITH_SHIFT) / 100;
@@ -345,7 +348,6 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
         /* bitrate is in units of 100 Kbps, while we need rate in units of
          * 1Mbps. This will be corrected on tx_time computation.
          */
-        rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
         tx_time = (device_constant + 10 * test_frame_len / rate);
         estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
         result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 3336d54e5558..ab0576827baf 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -529,6 +529,9 @@ void sta_info_init(struct ieee80211_local *local);
 void sta_info_stop(struct ieee80211_local *local);
 int sta_info_flush(struct ieee80211_local *local,
                    struct ieee80211_sub_if_data *sdata);
+void sta_set_rate_info_tx(struct sta_info *sta,
+                          const struct ieee80211_tx_rate *rate,
+                          struct rate_info *rinfo);
 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
                           unsigned long exp_time);