mac80211: Track Beacon signal strength and implement cqm events

Calculate a running average of the signal strength reported for Beacon
frames and indicate cqm events if the average value moves below or
above the configured threshold value (and filter out repetitive events
with by using the configured hysteresis).

Signed-off-by: Jouni Malinen <j@w1.fi>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index a4ca425e4f3f..4edd73cbf052 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1415,9 +1415,6 @@ static int ieee80211_set_cqm_rssi_config(struct wiphy *wiphy,
         struct ieee80211_vif *vif = &sdata->vif;
         struct ieee80211_bss_conf *bss_conf = &vif->bss_conf;
 
-        if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_CQM_RSSI))
-                return -EOPNOTSUPP;
-
         if (rssi_thold == bss_conf->cqm_rssi_thold &&
             rssi_hyst == bss_conf->cqm_rssi_hyst)
                 return 0;
@@ -1425,6 +1422,12 @@ static int ieee80211_set_cqm_rssi_config(struct wiphy *wiphy,
         bss_conf->cqm_rssi_thold = rssi_thold;
         bss_conf->cqm_rssi_hyst = rssi_hyst;
 
+        if (!(local->hw.flags & IEEE80211_HW_SUPPORTS_CQM_RSSI)) {
+                if (sdata->vif.type != NL80211_IFTYPE_STATION)
+                        return -EOPNOTSUPP;
+                return 0;
+        }
+
         /* tell the driver upon association, unless already associated */
         if (sdata->u.mgd.associated)
                 ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_CQM);