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>

1 files changed, 4 insertions, 2 deletions

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) ;