On Thu, Nov 11, 2010 at 10:00 PM, Bruno Randolf <br1@xxxxxxxxxxx> wrote:
> 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.
>
> Signed-off-by: Bruno Randolf <br1@xxxxxxxxxxx>
> ---
> include/linux/nl80211.h | 2 ++
> include/net/cfg80211.h | 4 ++++
> net/mac80211/Kconfig | 1 +
> net/mac80211/cfg.c | 3 ++-
> net/mac80211/rx.c | 1 +
> net/mac80211/sta_info.c | 2 ++
> net/mac80211/sta_info.h | 3 +++
> net/wireless/nl80211.c | 3 +++
> 8 files changed, 18 insertions(+), 1 deletions(-)
>
> diff --git a/include/linux/nl80211.h b/include/linux/nl80211.h
> index fb877b5..0ceb552 100644
> --- a/include/linux/nl80211.h
> +++ b/include/linux/nl80211.h
> @@ -1132,6 +1132,7 @@ enum nl80211_rate_info {
> * @__NL80211_STA_INFO_AFTER_LAST: internal
> * @NL80211_STA_INFO_MAX: highest possible station info attribute
> * @NL80211_STA_INFO_SIGNAL: signal strength of last received PPDU (u8, dBm)
> + * @NL80211_STA_INFO_SIGNAL_AVG: signal strength average (u8, dBm)
> * @NL80211_STA_INFO_TX_BITRATE: current unicast tx rate, nested attribute
> * containing info as possible, see &enum nl80211_sta_info_txrate.
> * @NL80211_STA_INFO_RX_PACKETS: total received packet (u32, from this station)
> @@ -1149,6 +1150,7 @@ enum nl80211_sta_info {
> NL80211_STA_INFO_PLID,
> NL80211_STA_INFO_PLINK_STATE,
> NL80211_STA_INFO_SIGNAL,
> + NL80211_STA_INFO_SIGNAL_AVG,
> NL80211_STA_INFO_TX_BITRATE,
> NL80211_STA_INFO_RX_PACKETS,
> NL80211_STA_INFO_TX_PACKETS,
> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
> index e5702f5..f21f701 100644
> --- a/include/net/cfg80211.h
> +++ b/include/net/cfg80211.h
> @@ -424,6 +424,7 @@ struct station_parameters {
> * @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,
> @@ -439,6 +440,7 @@ enum station_info_flags {
> 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,
> };
>
> /**
> @@ -485,6 +487,7 @@ struct rate_info {
> * @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
> @@ -505,6 +508,7 @@ struct station_info {
> 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 4d6f865..798d9b9 100644
> --- a/net/mac80211/Kconfig
> +++ b/net/mac80211/Kconfig
> @@ -6,6 +6,7 @@ config MAC80211
> 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 18bd0e5..d327918 100644
> --- a/net/mac80211/cfg.c
> +++ b/net/mac80211/cfg.c
> @@ -343,8 +343,9 @@ static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
>
> 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_get(&sta->avg_signal);
> }
>
> sinfo->txrate.flags = 0;
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index 902b03e..34bcc84 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -1158,6 +1158,7 @@ ieee80211_rx_h_sta_process(struct ieee80211_rx_data *rx)
> 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 6d8f897..bed23e1 100644
> --- a/net/mac80211/sta_info.c
> +++ b/net/mac80211/sta_info.c
> @@ -241,6 +241,8 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
> sta->local = local;
> sta->sdata = sdata;
>
> + ewma_init(&sta->avg_signal, 1000, 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 9265aca..84062e2 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"
>
> /**
> @@ -224,6 +225,7 @@ enum plink_state {
> * @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 @@ struct sta_info {
> 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 4e78e3f..660987d 100644
> --- a/net/wireless/nl80211.c
> +++ b/net/wireless/nl80211.c
> @@ -1841,6 +1841,9 @@ static int nl80211_send_station(struct sk_buff *msg, u32 pid, u32 seq,
> 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)
>
Someone's probably already on this, but these signal averaging patches
have broken compat-wireless. Seeing as how this is a compat-wireless
issue, I trimmed the recipients. compat-wireless-2010-11-19 under
2.6.32.23 fails with the following error:
In file included from
compat-wireless-2010-11-19/drivers/net/wireless/ath/ath5k/caps.c:24:
compat-wireless-2010-11-19/drivers/net/wireless/ath/ath5k/ath5k.h:28:27:
error: linux/average.h: No such file or directory
In file included from
compat-wireless-2010-11-19/drivers/net/wireless/ath/ath5k/caps.c:24:
compat-wireless-2010-11-19/drivers/net/wireless/ath/ath5k/ath5k.h:1106:
error: field ‘ah_beacon_rssi_avg’ has incomplete type
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