Re: [PATCH] mac80211: add command to get current rssi

[sylvain_gmail <sylvain.roger.rieunier@gmail.com>]

Hello Victor,

I am very pleased with your patch ;). I will be very useful. ;)

But do not you think it would be interesting to have a function that 
returns the RSSI signal by antennas?

Regards,
Sylvain


Le 22/05/2012 08:45, Victor Goldenshtein a écrit :
> Get current rssi (in dBm) from the driver/FW.
>
> Instead of reporting the signal received in the last
> rx packet, which might be inaccurate if rx traffic is
> low and beacon filtering is enabled, get the singal
> from the driver/FW.
>
> Signed-off-by: Victor Goldenshtein <victorg@ti.com>
> ---
>   include/net/mac80211.h      |    4 ++++
>   net/mac80211/cfg.c          |   22 ++++++++++++++--------
>   net/mac80211/driver-ops.h   |   11 +++++++++++
>   net/mac80211/driver-trace.h |    6 ++++++
>   4 files changed, 35 insertions(+), 8 deletions(-)
>
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index 4d6e6c6..279126a 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -2231,6 +2231,8 @@ enum ieee80211_rate_control_changed {
>    * @get_et_strings:  Ethtool API to get a set of strings to describe stats
>    *	and perhaps other supported types of ethtool data-sets.
>    *
> + * @get_rssi: Get current signal strength in dBm.
> + *
>    */
>   struct ieee80211_ops {
>   	void (*tx)(struct ieee80211_hw *hw, struct sk_buff *skb);
> @@ -2370,6 +2372,8 @@ struct ieee80211_ops {
>   	void	(*get_et_strings)(struct ieee80211_hw *hw,
>   				  struct ieee80211_vif *vif,
>   				  u32 sset, u8 *data);
> +	void (*get_rssi)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
> +			 s8 *rssi_dbm);
>   };
>   
>   /**
> diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
> index 0221270..41bdf02 100644
> --- a/net/mac80211/cfg.c
> +++ b/net/mac80211/cfg.c
> @@ -353,6 +353,7 @@ void sta_set_rate_info_tx(struct sta_info *sta,
>   static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
>   {
>   	struct ieee80211_sub_if_data *sdata = sta->sdata;
> +	struct ieee80211_local *local = sdata->local;
>   	struct timespec uptime;
>   
>   	sinfo->generation = sdata->local->sta_generation;
> @@ -388,7 +389,10 @@ 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 | STATION_INFO_SIGNAL_AVG;
> -		sinfo->signal = (s8)sta->last_signal;
> +		if (local->ops->get_rssi)
> +			drv_get_rssi(local, sdata, &sinfo->signal);
> +		else
> +			sinfo->signal = (s8)sta->last_signal;
>   		sinfo->signal_avg = (s8) -ewma_read(&sta->avg_signal);
>   	}
>   
> @@ -517,7 +521,7 @@ static void ieee80211_get_et_stats(struct wiphy *wiphy,
>   	 * network device.
>   	 */
>   
> -	rcu_read_lock();
> +	mutex_lock(&local->sta_mtx);
>   
>   	if (sdata->vif.type == NL80211_IFTYPE_STATION) {
>   		sta = sta_info_get_bss(sdata, sdata->u.mgd.bssid);
> @@ -546,7 +550,7 @@ static void ieee80211_get_et_stats(struct wiphy *wiphy,
>   			data[i] = (u8)sinfo.signal_avg;
>   		i++;
>   	} else {
> -		list_for_each_entry_rcu(sta, &local->sta_list, list) {
> +		list_for_each_entry(sta, &local->sta_list, list) {
>   			/* Make sure this station belongs to the proper dev */
>   			if (sta->sdata->dev != dev)
>   				continue;
> @@ -603,7 +607,7 @@ do_survey:
>   	else
>   		data[i++] = -1LL;
>   
> -	rcu_read_unlock();
> +	mutex_unlock(&local->sta_mtx);
>   
>   	if (WARN_ON(i != STA_STATS_LEN))
>   		return;
> @@ -629,10 +633,11 @@ static int ieee80211_dump_station(struct wiphy *wiphy, struct net_device *dev,
>   				 int idx, u8 *mac, struct station_info *sinfo)
>   {
>   	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
> +	struct ieee80211_local *local = sdata->local;
>   	struct sta_info *sta;
>   	int ret = -ENOENT;
>   
> -	rcu_read_lock();
> +	mutex_lock(&local->sta_mtx);
>   
>   	sta = sta_info_get_by_idx(sdata, idx);
>   	if (sta) {
> @@ -641,7 +646,7 @@ static int ieee80211_dump_station(struct wiphy *wiphy, struct net_device *dev,
>   		sta_set_sinfo(sta, sinfo);
>   	}
>   
> -	rcu_read_unlock();
> +	mutex_unlock(&local->sta_mtx);
>   
>   	return ret;
>   }
> @@ -658,10 +663,11 @@ static int ieee80211_get_station(struct wiphy *wiphy, struct net_device *dev,
>   				 u8 *mac, struct station_info *sinfo)
>   {
>   	struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
> +	struct ieee80211_local *local = sdata->local;
>   	struct sta_info *sta;
>   	int ret = -ENOENT;
>   
> -	rcu_read_lock();
> +	mutex_lock(&local->sta_mtx);
>   
>   	sta = sta_info_get_bss(sdata, mac);
>   	if (sta) {
> @@ -669,7 +675,7 @@ static int ieee80211_get_station(struct wiphy *wiphy, struct net_device *dev,
>   		sta_set_sinfo(sta, sinfo);
>   	}
>   
> -	rcu_read_unlock();
> +	mutex_unlock(&local->sta_mtx);
>   
>   	return ret;
>   }
> diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
> index 6d33a0c..cbfaf72 100644
> --- a/net/mac80211/driver-ops.h
> +++ b/net/mac80211/driver-ops.h
> @@ -845,4 +845,15 @@ drv_allow_buffered_frames(struct ieee80211_local *local,
>   						  more_data);
>   	trace_drv_return_void(local);
>   }
> +
> +static inline void drv_get_rssi(struct ieee80211_local *local,
> +				struct ieee80211_sub_if_data *sdata,
> +				s8 *rssi_dbm)
> +{
> +	might_sleep();
> +
> +	trace_drv_get_rssi(local, sdata);
> +	local->ops->get_rssi(&local->hw, &sdata->vif, rssi_dbm);
> +	trace_drv_return_void(local);
> +}
>   #endif /* __MAC80211_DRIVER_OPS */
> diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
> index 6de00b2..fc91ac4 100644
> --- a/net/mac80211/driver-trace.h
> +++ b/net/mac80211/driver-trace.h
> @@ -1218,6 +1218,12 @@ DEFINE_EVENT(release_evt, drv_allow_buffered_frames,
>   	TP_ARGS(local, sta, tids, num_frames, reason, more_data)
>   );
>   
> +DEFINE_EVENT(local_sdata_evt, drv_get_rssi,
> +	TP_PROTO(struct ieee80211_local *local,
> +		 struct ieee80211_sub_if_data *sdata),
> +	TP_ARGS(local, sdata)
> +);
> +
>   /*
>    * Tracing for API calls that drivers call.
>    */