mac80211: add driver RSSI threshold events

mac80211 maintains a running average of the RSSI when a STA
is associated to an AP. Report threshold events to any driver
that has registered callbacks for getting RSSI measurements.

Implement callbacks in mac80211 so that driver can set thresholds.
Add callbacks in mac80211 which is invoked when an RSSI threshold
event occurs.

mac80211: add tracing to rssi_reports api and remove extraneous fn argument
mac80211: scale up rssi thresholds from driver by 16 before storing

Signed-off-by: Meenakshi Venkataraman <meenakshi.venkataraman@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index b6d9bd5f4d3c..4b0460ad8c8f 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -1763,6 +1763,7 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
                 ifmgd->ave_beacon_signal = rx_status->signal * 16;
                 ifmgd->last_cqm_event_signal = 0;
                 ifmgd->count_beacon_signal = 1;
+                ifmgd->last_ave_beacon_signal = 0;
         } else {
                 ifmgd->ave_beacon_signal =
                         (IEEE80211_SIGNAL_AVE_WEIGHT * rx_status->signal * 16 +
@@ -1770,6 +1771,28 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
                          ifmgd->ave_beacon_signal) / 16;
                 ifmgd->count_beacon_signal++;
         }
+
+        if (ifmgd->rssi_min_thold != ifmgd->rssi_max_thold &&
+            ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT) {
+                int sig = ifmgd->ave_beacon_signal;
+                int last_sig = ifmgd->last_ave_beacon_signal;
+
+                /*
+                 * if signal crosses either of the boundaries, invoke callback
+                 * with appropriate parameters
+                 */
+                if (sig > ifmgd->rssi_max_thold &&
+                    (last_sig <= ifmgd->rssi_min_thold || last_sig == 0)) {
+                        ifmgd->last_ave_beacon_signal = sig;
+                        drv_rssi_callback(local, RSSI_EVENT_HIGH);
+                } else if (sig < ifmgd->rssi_min_thold &&
+                           (last_sig >= ifmgd->rssi_max_thold ||
+                           last_sig == 0)) {
+                        ifmgd->last_ave_beacon_signal = sig;
+                        drv_rssi_callback(local, RSSI_EVENT_LOW);
+                }
+        }
+
         if (bss_conf->cqm_rssi_thold &&
             ifmgd->count_beacon_signal >= IEEE80211_SIGNAL_AVE_MIN_COUNT &&
             !(local->hw.flags & IEEE80211_HW_SUPPORTS_CQM_RSSI)) {