nl80211/mac80211: Report signal average
Extend nl80211 to report an exponential weighted moving average (EWMA) of the
signal value. Since the signal value usually fluctuates between different
packets, an average can be more useful than the value of the last packet.
This uses the recently added generic EWMA library function.
--
v2: fix ABI breakage and change factor to be a power of 2.
Signed-off-by: Bruno Randolf <br1@einfach.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
index 410a06e..8e28053 100644
--- a/include/linux/nl80211.h
+++ b/include/linux/nl80211.h
@@ -1191,6 +1191,7 @@
* station)
* @NL80211_STA_INFO_TX_RETRIES: total retries (u32, to this station)
* @NL80211_STA_INFO_TX_FAILED: total failed packets (u32, to this station)
+ * @NL80211_STA_INFO_SIGNAL_AVG: signal strength average (u8, dBm)
*/
enum nl80211_sta_info {
__NL80211_STA_INFO_INVALID,
@@ -1206,6 +1207,7 @@
NL80211_STA_INFO_TX_PACKETS,
NL80211_STA_INFO_TX_RETRIES,
NL80211_STA_INFO_TX_FAILED,
+ NL80211_STA_INFO_SIGNAL_AVG,
/* keep last */
__NL80211_STA_INFO_AFTER_LAST,
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 788c398..8764c9a 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -420,6 +420,7 @@
* @STATION_INFO_TX_RETRIES: @tx_retries filled
* @STATION_INFO_TX_FAILED: @tx_failed filled
* @STATION_INFO_RX_DROP_MISC: @rx_dropped_misc filled
+ * @STATION_INFO_SIGNAL_AVG: @signal_avg filled
*/
enum station_info_flags {
STATION_INFO_INACTIVE_TIME = 1<<0,
@@ -435,6 +436,7 @@
STATION_INFO_TX_RETRIES = 1<<10,
STATION_INFO_TX_FAILED = 1<<11,
STATION_INFO_RX_DROP_MISC = 1<<12,
+ STATION_INFO_SIGNAL_AVG = 1<<13,
};
/**
@@ -481,6 +483,7 @@
* @plid: mesh peer link id
* @plink_state: mesh peer link state
* @signal: signal strength of last received packet in dBm
+ * @signal_avg: signal strength average in dBm
* @txrate: current unicast bitrate to this station
* @rx_packets: packets received from this station
* @tx_packets: packets transmitted to this station
@@ -501,6 +504,7 @@
u16 plid;
u8 plink_state;
s8 signal;
+ s8 signal_avg;
struct rate_info txrate;
u32 rx_packets;
u32 tx_packets;
diff --git a/net/mac80211/Kconfig b/net/mac80211/Kconfig
index 4d6f8653..798d9b9 100644
--- a/net/mac80211/Kconfig
+++ b/net/mac80211/Kconfig
@@ -6,6 +6,7 @@
select CRYPTO_ARC4
select CRYPTO_AES
select CRC32
+ select AVERAGE
---help---
This option enables the hardware independent IEEE 802.11
networking stack.
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 68329d7..af96204 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -342,8 +342,9 @@
if ((sta->local->hw.flags & IEEE80211_HW_SIGNAL_DBM) ||
(sta->local->hw.flags & IEEE80211_HW_SIGNAL_UNSPEC)) {
- sinfo->filled |= STATION_INFO_SIGNAL;
+ sinfo->filled |= STATION_INFO_SIGNAL | STATION_INFO_SIGNAL_AVG;
sinfo->signal = (s8)sta->last_signal;
+ sinfo->signal_avg = (s8) -ewma_read(&sta->avg_signal);
}
sinfo->txrate.flags = 0;
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 6289525..2fe8f5f 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1163,6 +1163,7 @@
sta->rx_fragments++;
sta->rx_bytes += rx->skb->len;
sta->last_signal = status->signal;
+ ewma_add(&sta->avg_signal, -status->signal);
/*
* Change STA power saving mode only at the end of a frame
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index eff5857..c426504 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -244,6 +244,8 @@
sta->local = local;
sta->sdata = sdata;
+ ewma_init(&sta->avg_signal, 1024, 8);
+
if (sta_prepare_rate_control(local, sta, gfp)) {
kfree(sta);
return NULL;
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 05f1130..fdca52c 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -13,6 +13,7 @@
#include <linux/types.h>
#include <linux/if_ether.h>
#include <linux/workqueue.h>
+#include <linux/average.h>
#include "key.h"
/**
@@ -223,6 +224,7 @@
* @rx_fragments: number of received MPDUs
* @rx_dropped: number of dropped MPDUs from this STA
* @last_signal: signal of last received frame from this STA
+ * @avg_signal: moving average of signal of received frames from this STA
* @last_seq_ctrl: last received seq/frag number from this STA (per RX queue)
* @tx_filtered_count: number of frames the hardware filtered for this STA
* @tx_retry_failed: number of frames that failed retry
@@ -291,6 +293,7 @@
unsigned long rx_fragments;
unsigned long rx_dropped;
int last_signal;
+ struct ewma avg_signal;
__le16 last_seq_ctrl[NUM_RX_DATA_QUEUES];
/* Updated from TX status path only, no locking requirements */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 56508d4..2cf03331 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1896,6 +1896,9 @@
if (sinfo->filled & STATION_INFO_SIGNAL)
NLA_PUT_U8(msg, NL80211_STA_INFO_SIGNAL,
sinfo->signal);
+ if (sinfo->filled & STATION_INFO_SIGNAL_AVG)
+ NLA_PUT_U8(msg, NL80211_STA_INFO_SIGNAL_AVG,
+ sinfo->signal_avg);
if (sinfo->filled & STATION_INFO_TX_BITRATE) {
txrate = nla_nest_start(msg, NL80211_STA_INFO_TX_BITRATE);
if (!txrate)