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[5/7] mac80211: Implement functionality to monitor station's rssi cross event

Message ID 1528886747-26342-6-git-send-email-tamizhr@codeaurora.org (mailing list archive)
State Changes Requested
Delegated to: Johannes Berg
Headers show

Commit Message

Tamizh chelvam June 13, 2018, 10:45 a.m. UTC
Triggers cfg80211_sta_mon_rssi_notify with the corresponding event when
station signal goes out of configured threshold. It uses rx data signal
to check against rssi threshold configured by the user.
This event will be useful for the application like steering to take
decision on any station depends on its current capability.

Signed-off-by: Tamizh chelvam <tamizhr@codeaurora.org>
---
 include/net/mac80211.h  |    6 ++++++
 net/mac80211/rx.c       |   42 +++++++++++++++++++++++++++++++++++++++++-
 net/mac80211/sta_info.h |    4 ++++
 3 files changed, 51 insertions(+), 1 deletion(-)

Comments

Johannes Berg June 29, 2018, 9:36 a.m. UTC | #1
On Wed, 2018-06-13 at 16:15 +0530, Tamizh chelvam wrote:
> 
> +	if (sta->rssi_thold && bss_conf->enable_beacon) {
> +		int last_event = sta->last_sta_mon_event_signal;
> +		int thold = sta->rssi_thold;
> +		int hyst = sta->rssi_hyst;
> +		int sig = -ewma_signal_read(&sta->rx_stats_avg.signal);
> +
> +		if (sig < thold &&
> +		    (last_event == 0 || sig < last_event - hyst)) {
> +			sta->last_sta_mon_event_signal = sig;
> +			cfg80211_sta_mon_rssi_notify(
> +				rx->sdata->dev, sta->addr,
> +				NL80211_STA_MON_RSSI_THRESHOLD_EVENT_LOW,
> +				sig, GFP_ATOMIC);
> +		} else if (sig > thold &&
> +			   (last_event == 0 || sig > last_event + hyst)) {
> +			sta->last_sta_mon_event_signal = sig;
> +			cfg80211_sta_mon_rssi_notify(
> +				rx->sdata->dev, sta->addr,
> +				NL80211_STA_MON_RSSI_THRESHOLD_EVENT_HIGH,
> +				sig, GFP_ATOMIC);
> +		}
> +	}

This seems really familiar - perhaps if you unify the cfg80211 API for
sta_mon and "normal" CQM (distinguish based on the peer address?) you
can unify this block of code too?

johannes
Tamizh chelvam July 4, 2018, 9:36 a.m. UTC | #2
On 2018-06-29 15:06, Johannes Berg wrote:
> On Wed, 2018-06-13 at 16:15 +0530, Tamizh chelvam wrote:
>> 
>> +	if (sta->rssi_thold && bss_conf->enable_beacon) {
>> +		int last_event = sta->last_sta_mon_event_signal;
>> +		int thold = sta->rssi_thold;
>> +		int hyst = sta->rssi_hyst;
>> +		int sig = -ewma_signal_read(&sta->rx_stats_avg.signal);
>> +
>> +		if (sig < thold &&
>> +		    (last_event == 0 || sig < last_event - hyst)) {
>> +			sta->last_sta_mon_event_signal = sig;
>> +			cfg80211_sta_mon_rssi_notify(
>> +				rx->sdata->dev, sta->addr,
>> +				NL80211_STA_MON_RSSI_THRESHOLD_EVENT_LOW,
>> +				sig, GFP_ATOMIC);
>> +		} else if (sig > thold &&
>> +			   (last_event == 0 || sig > last_event + hyst)) {
>> +			sta->last_sta_mon_event_signal = sig;
>> +			cfg80211_sta_mon_rssi_notify(
>> +				rx->sdata->dev, sta->addr,
>> +				NL80211_STA_MON_RSSI_THRESHOLD_EVENT_HIGH,
>> +				sig, GFP_ATOMIC);
>> +		}
>> +	}
> 
> This seems really familiar - perhaps if you unify the cfg80211 API for
> sta_mon and "normal" CQM (distinguish based on the peer address?) you
> can unify this block of code too?
> 
Sure I'll check and update it in the next version of the patch.
diff mbox

Patch

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 851a5e1..96fb9a8 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -802,6 +802,12 @@  enum mac80211_rate_control_flags {
 	IEEE80211_TX_RC_160_MHZ_WIDTH		= BIT(10),
 };
 
+/*
+ * How many frames need to have been used in average station's
+ * signal strength before checking against the threshold
+ */
+#define IEEE80211_STA_SIGNAL_AVE_MIN_COUNT	4
+
 
 /* there are 40 bytes if you don't need the rateset to be kept */
 #define IEEE80211_TX_INFO_DRIVER_DATA_SIZE 40
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 0a38cc1..06a6111 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1534,6 +1534,43 @@  void ieee80211_sta_uapsd_trigger(struct ieee80211_sta *pubsta, u8 tid)
 	return RX_CONTINUE;
 }
 
+static void ieee80211_sta_rx_signal_thold_check(struct ieee80211_rx_data *rx)
+{
+	struct sta_info *sta = rx->sta;
+	struct ieee80211_bss_conf *bss_conf = &rx->sdata->vif.bss_conf;
+
+	if (!wiphy_ext_feature_isset(rx->local->hw.wiphy,
+				NL80211_EXT_FEATURE_STA_MON_RSSI_CONFIG))
+		return;
+
+	sta->count_rx_signal++;
+	if (sta->count_rx_signal < IEEE80211_STA_SIGNAL_AVE_MIN_COUNT)
+		return;
+
+	if (sta->rssi_thold && bss_conf->enable_beacon) {
+		int last_event = sta->last_sta_mon_event_signal;
+		int thold = sta->rssi_thold;
+		int hyst = sta->rssi_hyst;
+		int sig = -ewma_signal_read(&sta->rx_stats_avg.signal);
+
+		if (sig < thold &&
+		    (last_event == 0 || sig < last_event - hyst)) {
+			sta->last_sta_mon_event_signal = sig;
+			cfg80211_sta_mon_rssi_notify(
+				rx->sdata->dev, sta->addr,
+				NL80211_STA_MON_RSSI_THRESHOLD_EVENT_LOW,
+				sig, GFP_ATOMIC);
+		} else if (sig > thold &&
+			   (last_event == 0 || sig > last_event + hyst)) {
+			sta->last_sta_mon_event_signal = sig;
+			cfg80211_sta_mon_rssi_notify(
+				rx->sdata->dev, sta->addr,
+				NL80211_STA_MON_RSSI_THRESHOLD_EVENT_HIGH,
+				sig, GFP_ATOMIC);
+		}
+	}
+}
+
 static ieee80211_rx_result debug_noinline
 ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
 {
@@ -1589,6 +1626,7 @@  void ieee80211_sta_uapsd_trigger(struct ieee80211_sta *pubsta, u8 tid)
 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
 		sta->rx_stats.last_signal = status->signal;
 		ewma_signal_add(&sta->rx_stats_avg.signal, -status->signal);
+		ieee80211_sta_rx_signal_thold_check(rx);
 	}
 
 	if (status->chains) {
@@ -4030,9 +4068,11 @@  static bool ieee80211_invoke_fast_rx(struct ieee80211_rx_data *rx,
 	/* statistics part of ieee80211_rx_h_sta_process() */
 	if (!(status->flag & RX_FLAG_NO_SIGNAL_VAL)) {
 		stats->last_signal = status->signal;
-		if (!fast_rx->uses_rss)
+		if (!fast_rx->uses_rss) {
 			ewma_signal_add(&sta->rx_stats_avg.signal,
 					-status->signal);
+			ieee80211_sta_rx_signal_thold_check(rx);
+		}
 	}
 
 	if (status->chains) {
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 8c459a7..e130f6d 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -490,6 +490,9 @@  struct ieee80211_sta_rx_stats {
  * @last_sta_mon_event_signal: Last signal strength average for a station
  *	that triggered a sta_mon event. 0 indicates that no event has been
  *	generated for the current association
+ * @count_rx_signal: Number of data frames used in averaging station signal.
+ *	This can be used to avoid generating less reliable station rssi cross
+ *	events that would be based only on couple of received frames
  */
 struct sta_info {
 	/* General information, mostly static */
@@ -594,6 +597,7 @@  struct sta_info {
 	s32 rssi_thold;
 	u32 rssi_hyst;
 	int last_sta_mon_event_signal;
+	unsigned int count_rx_signal;
 
 	/* keep last! */
 	struct ieee80211_sta sta;