[RFC] mac80211: allow drivers to provide any statistics

[RFC] mac80211: allow drivers to provide any statistics

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

In many cases, drivers can filter things like beacons that will
skew statistics reported by mac80211. To get correct statistics
in these cases, call drivers to obtain statistics and let them
override all values, filling values from mac80211 if the driver
didn't provide them.

Note that this doesn't currently allow a driver to say "I know
this value is wrong, don't report it at all", or to sum it up
with a mac80211 value (as could be useful for "dropped misc"),
that can be added if it turns out to be needed.

This also gets rid of the get_rssi() method as is can now be
implemented using sta_statistics().

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/ti/wlcore/main.c | 22 ++++----
 include/net/mac80211.h                | 14 +++--
 net/mac80211/driver-ops.h             | 30 +++++------
 net/mac80211/sta_info.c               | 97 +++++++++++++++++++++++------------
 net/mac80211/trace.h                  | 33 +++---------
 5 files changed, 108 insertions(+), 88 deletions(-)

diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
index 6ad3fcedab9b..f3d4adb54d6e 100644
--- a/drivers/net/wireless/ti/wlcore/main.c
+++ b/drivers/net/wireless/ti/wlcore/main.c
@@ -5375,16 +5375,17 @@ static void wlcore_op_sta_rc_update(struct ieee80211_hw *hw,
 	wlcore_hw_sta_rc_update(wl, wlvif, sta, changed);
 }
 
-static int wlcore_op_get_rssi(struct ieee80211_hw *hw,
-			       struct ieee80211_vif *vif,
-			       struct ieee80211_sta *sta,
-			       s8 *rssi_dbm)
+static void wlcore_op_sta_statistics(struct ieee80211_hw *hw,
+				     struct ieee80211_vif *vif,
+				     struct ieee80211_sta *sta,
+				     struct station_info *sinfo)
 {
 	struct wl1271 *wl = hw->priv;
 	struct wl12xx_vif *wlvif = wl12xx_vif_to_data(vif);
-	int ret = 0;
+	int ret;
+	s8 rssi_dbm;
 
-	wl1271_debug(DEBUG_MAC80211, "mac80211 get_rssi");
+	wl1271_debug(DEBUG_MAC80211, "mac80211 sta_statistics");
 
 	mutex_lock(&wl->mutex);
 
@@ -5395,17 +5396,18 @@ static int wlcore_op_get_rssi(struct ieee80211_hw *hw,
 	if (ret < 0)
 		goto out_sleep;
 
-	ret = wlcore_acx_average_rssi(wl, wlvif, rssi_dbm);
+	ret = wlcore_acx_average_rssi(wl, wlvif, &rssi_dbm);
 	if (ret < 0)
 		goto out_sleep;
 
+	sinfo->filled |= STATION_INFO_SIGNAL;
+	sinfo->signal = rssi_dbm;
+
 out_sleep:
 	wl1271_ps_elp_sleep(wl);
 
 out:
 	mutex_unlock(&wl->mutex);
-
-	return ret;
 }
 
 static bool wl1271_tx_frames_pending(struct ieee80211_hw *hw)
@@ -5605,7 +5607,7 @@ static const struct ieee80211_ops wl1271_ops = {
 	.assign_vif_chanctx = wlcore_op_assign_vif_chanctx,
 	.unassign_vif_chanctx = wlcore_op_unassign_vif_chanctx,
 	.sta_rc_update = wlcore_op_sta_rc_update,
-	.get_rssi = wlcore_op_get_rssi,
+	.sta_statistics = wlcore_op_sta_statistics,
 	CFG80211_TESTMODE_CMD(wl1271_tm_cmd)
 };
 
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 83232aa2f077..ab7b4bde4661 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2669,6 +2669,11 @@ enum ieee80211_reconfig_type {
  *	otherwise the rate control algorithm is notified directly.
  *	Must be atomic.
  *
+ * @sta_statistics: Get statistics for this station. For example with beacon
+ *	filtering, the statistics kept by mac80211 might not be accurate, so
+ *	let the driver pre-fill the statistics. Any statistics that the driver
+ *	doesn't fill will be filled by mac80211. The callback can sleep.
+ *
  * @conf_tx: Configure TX queue parameters (EDCF (aifs, cw_min, cw_max),
  *	bursting) for a hardware TX queue.
  *	Returns a negative error code on failure.
@@ -2829,9 +2834,6 @@ enum ieee80211_reconfig_type {
  * @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, the function is optional
- *	and can sleep.
- *
  * @mgd_prepare_tx: Prepare for transmitting a management frame for association
  *	before associated. In multi-channel scenarios, a virtual interface is
  *	bound to a channel before it is associated, but as it isn't associated
@@ -3009,6 +3011,10 @@ struct ieee80211_ops {
 			      struct ieee80211_vif *vif,
 			      struct ieee80211_sta *sta,
 			      u32 changed);
+	void (*sta_statistics)(struct ieee80211_hw *hw,
+			       struct ieee80211_vif *vif,
+			       struct ieee80211_sta *sta,
+			       struct station_info *sinfo);
 	int (*conf_tx)(struct ieee80211_hw *hw,
 		       struct ieee80211_vif *vif, u16 ac,
 		       const struct ieee80211_tx_queue_params *params);
@@ -3076,8 +3082,6 @@ struct ieee80211_ops {
 	void	(*get_et_strings)(struct ieee80211_hw *hw,
 				  struct ieee80211_vif *vif,
 				  u32 sset, u8 *data);
-	int	(*get_rssi)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
-			    struct ieee80211_sta *sta, s8 *rssi_dbm);
 
 	void	(*mgd_prepare_tx)(struct ieee80211_hw *hw,
 				  struct ieee80211_vif *vif);
diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index 9759dd1f0734..d3ccb553eb87 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -621,6 +621,21 @@ static inline void drv_sta_rc_update(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
+static inline void drv_sta_statistics(struct ieee80211_local *local,
+				      struct ieee80211_sub_if_data *sdata,
+				      struct ieee80211_sta *sta,
+				      struct station_info *sinfo)
+{
+	sdata = get_bss_sdata(sdata);
+	if (!check_sdata_in_driver(sdata))
+		return;
+
+	trace_drv_sta_statistics(local, sdata, sta);
+	if (local->ops->sta_statistics)
+		local->ops->sta_statistics(&local->hw, &sdata->vif, sta, sinfo);
+	trace_drv_return_void(local);
+}
+
 static inline int drv_conf_tx(struct ieee80211_local *local,
 			      struct ieee80211_sub_if_data *sdata, u16 ac,
 			      const struct ieee80211_tx_queue_params *params)
@@ -948,21 +963,6 @@ drv_allow_buffered_frames(struct ieee80211_local *local,
 	trace_drv_return_void(local);
 }
 
-static inline int drv_get_rssi(struct ieee80211_local *local,
-				struct ieee80211_sub_if_data *sdata,
-				struct ieee80211_sta *sta,
-				s8 *rssi_dbm)
-{
-	int ret;
-
-	might_sleep();
-
-	ret = local->ops->get_rssi(&local->hw, &sdata->vif, sta, rssi_dbm);
-	trace_drv_get_rssi(local, sta, *rssi_dbm, ret);
-
-	return ret;
-}
-
 static inline void drv_mgd_prepare_tx(struct ieee80211_local *local,
 				      struct ieee80211_sub_if_data *sdata)
 {
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index bffab579be1b..c9270c096470 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -1732,7 +1732,6 @@ void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 	struct ieee80211_local *local = sdata->local;
 	struct rate_control_ref *ref = NULL;
 	struct timespec uptime;
-	u64 packets = 0;
 	u32 thr = 0;
 	int i, ac;
 
@@ -1741,47 +1740,74 @@ void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 
 	sinfo->generation = sdata->local->sta_generation;
 
-	sinfo->filled = STATION_INFO_INACTIVE_TIME |
-			STATION_INFO_RX_BYTES64 |
-			STATION_INFO_TX_BYTES64 |
-			STATION_INFO_RX_PACKETS |
-			STATION_INFO_TX_PACKETS |
-			STATION_INFO_TX_RETRIES |
-			STATION_INFO_TX_FAILED |
-			STATION_INFO_TX_BITRATE |
-			STATION_INFO_RX_BITRATE |
-			STATION_INFO_RX_DROP_MISC |
-			STATION_INFO_BSS_PARAM |
-			STATION_INFO_CONNECTED_TIME |
-			STATION_INFO_STA_FLAGS |
-			STATION_INFO_BEACON_LOSS_COUNT;
+	drv_sta_statistics(local, sdata, &sta->sta, sinfo);
+
+	sinfo->filled |= STATION_INFO_INACTIVE_TIME |
+			 STATION_INFO_STA_FLAGS |
+			 STATION_INFO_BSS_PARAM |
+			 STATION_INFO_CONNECTED_TIME |
+			 STATION_INFO_RX_DROP_MISC |
+			 STATION_INFO_BEACON_LOSS_COUNT;
 
 	ktime_get_ts(&uptime);
 	sinfo->connected_time = uptime.tv_sec - sta->last_connected;
-
 	sinfo->inactive_time = jiffies_to_msecs(jiffies - sta->last_rx);
-	sinfo->tx_bytes = 0;
-	for (ac = 0; ac < IEEE80211_NUM_ACS; ac++) {
-		sinfo->tx_bytes += sta->tx_bytes[ac];
-		packets += sta->tx_packets[ac];
+
+	if (!(sinfo->filled & (STATION_INFO_TX_BYTES64 |
+			       STATION_INFO_TX_BYTES))) {
+		sinfo->tx_bytes = 0;
+		for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
+			sinfo->tx_bytes += sta->tx_bytes[ac];
+		sinfo->filled |= STATION_INFO_TX_BYTES64;
+	}
+
+	if (!(sinfo->filled & STATION_INFO_TX_PACKETS)) {
+		sinfo->tx_packets = 0;
+		for (ac = 0; ac < IEEE80211_NUM_ACS; ac++)
+			sinfo->tx_packets += sta->tx_packets[ac];
+		sinfo->filled |= STATION_INFO_TX_PACKETS;
+	}
+
+	if (!(sinfo->filled & (STATION_INFO_RX_BYTES64 |
+			       STATION_INFO_RX_BYTES))) {
+		sinfo->rx_bytes = sta->rx_bytes;
+		sinfo->filled |= STATION_INFO_RX_BYTES64;
+	}
+
+	if (!(sinfo->filled & STATION_INFO_RX_PACKETS)) {
+		sinfo->rx_packets = sta->rx_packets;
+		sinfo->filled |= STATION_INFO_RX_PACKETS;
+	}
+
+	if (!(sinfo->filled & STATION_INFO_TX_RETRIES)) {
+		sinfo->tx_retries = sta->tx_retry_count;
+		sinfo->filled |= STATION_INFO_TX_RETRIES;
+	}
+
+	if (!(sinfo->filled & STATION_INFO_TX_FAILED)) {
+		sinfo->tx_failed = sta->tx_retry_failed;
+		sinfo->filled |= STATION_INFO_TX_FAILED;
 	}
-	sinfo->tx_packets = packets;
-	sinfo->rx_bytes = sta->rx_bytes;
-	sinfo->rx_packets = sta->rx_packets;
-	sinfo->tx_retries = sta->tx_retry_count;
-	sinfo->tx_failed = sta->tx_retry_failed;
+
 	sinfo->rx_dropped_misc = sta->rx_dropped;
 	sinfo->beacon_loss_count = sta->beacon_loss_count;
 
 	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;
-		if (!local->ops->get_rssi ||
-		    drv_get_rssi(local, sdata, &sta->sta, &sinfo->signal))
+		if (!(sinfo->filled & STATION_INFO_SIGNAL)) {
 			sinfo->signal = (s8)sta->last_signal;
-		sinfo->signal_avg = (s8) -ewma_read(&sta->avg_signal);
+			sinfo->filled |= STATION_INFO_SIGNAL;
+		}
+
+		if (!(sinfo->filled & STATION_INFO_SIGNAL_AVG)) {
+			sinfo->signal_avg = (s8) -ewma_read(&sta->avg_signal);
+			sinfo->filled |= STATION_INFO_SIGNAL_AVG;
+		}
 	}
-	if (sta->chains) {
+
+	if (sta->chains &&
+	    !(sinfo->filled & (STATION_INFO_CHAIN_SIGNAL |
+			       STATION_INFO_CHAIN_SIGNAL_AVG))) {
 		sinfo->filled |= STATION_INFO_CHAIN_SIGNAL |
 				 STATION_INFO_CHAIN_SIGNAL_AVG;
 
@@ -1793,8 +1819,15 @@ void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 		}
 	}
 
-	sta_set_rate_info_tx(sta, &sta->last_tx_rate, &sinfo->txrate);
-	sta_set_rate_info_rx(sta, &sinfo->rxrate);
+	if (!(sinfo->filled & STATION_INFO_TX_BITRATE)) {
+		sta_set_rate_info_tx(sta, &sta->last_tx_rate, &sinfo->txrate);
+		sinfo->filled |= STATION_INFO_TX_BITRATE;
+	}
+
+	if (!(sinfo->filled & STATION_INFO_RX_BITRATE)) {
+		sta_set_rate_info_rx(sta, &sinfo->rxrate);
+		sinfo->filled |= STATION_INFO_RX_BITRATE;
+	}
 
 	if (ieee80211_vif_is_mesh(&sdata->vif)) {
 #ifdef CONFIG_MAC80211_MESH
diff --git a/net/mac80211/trace.h b/net/mac80211/trace.h
index 96847e788488..e400e60bc6fd 100644
--- a/net/mac80211/trace.h
+++ b/net/mac80211/trace.h
@@ -805,6 +805,13 @@ DECLARE_EVENT_CLASS(sta_event,
 	)
 );
 
+DEFINE_EVENT(sta_event, drv_sta_statistics,
+	TP_PROTO(struct ieee80211_local *local,
+		 struct ieee80211_sub_if_data *sdata,
+		 struct ieee80211_sta *sta),
+	TP_ARGS(local, sdata, sta)
+);
+
 DEFINE_EVENT(sta_event, drv_sta_add,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata,
@@ -1302,32 +1309,6 @@ DEFINE_EVENT(release_evt, drv_allow_buffered_frames,
 	TP_ARGS(local, sta, tids, num_frames, reason, more_data)
 );
 
-TRACE_EVENT(drv_get_rssi,
-	TP_PROTO(struct ieee80211_local *local, struct ieee80211_sta *sta,
-		 s8 rssi, int ret),
-
-	TP_ARGS(local, sta, rssi, ret),
-
-	TP_STRUCT__entry(
-		LOCAL_ENTRY
-		STA_ENTRY
-		__field(s8, rssi)
-		__field(int, ret)
-	),
-
-	TP_fast_assign(
-		LOCAL_ASSIGN;
-		STA_ASSIGN;
-		__entry->rssi = rssi;
-		__entry->ret = ret;
-	),
-
-	TP_printk(
-		LOCAL_PR_FMT STA_PR_FMT " rssi:%d ret:%d",
-		LOCAL_PR_ARG, STA_PR_ARG, __entry->rssi, __entry->ret
-	)
-);
-
 DEFINE_EVENT(local_sdata_evt, drv_mgd_prepare_tx,
 	TP_PROTO(struct ieee80211_local *local,
 		 struct ieee80211_sub_if_data *sdata),
-- 
2.1.1

Re: [RFC] mac80211: allow drivers to provide any statistics

[Luca Coelho]

On Mon, 2014-11-17 at 11:48 +0100, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@intel.com>
> 
> In many cases, drivers can filter things like beacons that will
> skew statistics reported by mac80211. To get correct statistics
> in these cases, call drivers to obtain statistics and let them
> override all values, filling values from mac80211 if the driver
> didn't provide them.
> 
> Note that this doesn't currently allow a driver to say "I know
> this value is wrong, don't report it at all", or to sum it up
> with a mac80211 value (as could be useful for "dropped misc"),
> that can be added if it turns out to be needed.
> 
> This also gets rid of the get_rssi() method as is can now be
> implemented using sta_statistics().
> 
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
> ---
>  drivers/net/wireless/ti/wlcore/main.c | 22 ++++----

The wlcore part of this looks fine to me.

Acked-by: Luciano Coelho <luca@coelho.fi>

--
Luca.

Re: [RFC] mac80211: allow drivers to provide any statistics

[Arend van Spriel]

On 17-11-14 11:48, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@intel.com>
> 
> In many cases, drivers can filter things like beacons that will
> skew statistics reported by mac80211. To get correct statistics
> in these cases, call drivers to obtain statistics and let them
> override all values, filling values from mac80211 if the driver
> didn't provide them.
> 
> Note that this doesn't currently allow a driver to say "I know
> this value is wrong, don't report it at all", or to sum it up
> with a mac80211 value (as could be useful for "dropped misc"),
> that can be added if it turns out to be needed.
> 
> This also gets rid of the get_rssi() method as is can now be
> implemented using sta_statistics().
> 
> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
> ---
>  drivers/net/wireless/ti/wlcore/main.c | 22 ++++----
>  include/net/mac80211.h                | 14 +++--
>  net/mac80211/driver-ops.h             | 30 +++++------
>  net/mac80211/sta_info.c               | 97 +++++++++++++++++++++++------------
>  net/mac80211/trace.h                  | 33 +++---------
>  5 files changed, 108 insertions(+), 88 deletions(-)
> 
> diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
> index 6ad3fcedab9b..f3d4adb54d6e 100644
> --- a/drivers/net/wireless/ti/wlcore/main.c
> +++ b/drivers/net/wireless/ti/wlcore/main.c
> @@ -5375,16 +5375,17 @@ static void wlcore_op_sta_rc_update(struct ieee80211_hw *hw,
>  	wlcore_hw_sta_rc_update(wl, wlvif, sta, changed);
>  }
>  
> -static int wlcore_op_get_rssi(struct ieee80211_hw *hw,
> -			       struct ieee80211_vif *vif,
> -			       struct ieee80211_sta *sta,
> -			       s8 *rssi_dbm)
> +static void wlcore_op_sta_statistics(struct ieee80211_hw *hw,
> +				     struct ieee80211_vif *vif,
> +				     struct ieee80211_sta *sta,
> +				     struct station_info *sinfo)
>  {
>  	struct wl1271 *wl = hw->priv;
>  	struct wl12xx_vif *wlvif = wl12xx_vif_to_data(vif);
> -	int ret = 0;
> +	int ret;
> +	s8 rssi_dbm;
>  
> -	wl1271_debug(DEBUG_MAC80211, "mac80211 get_rssi");
> +	wl1271_debug(DEBUG_MAC80211, "mac80211 sta_statistics");
>  
>  	mutex_lock(&wl->mutex);
>  
> @@ -5395,17 +5396,18 @@ static int wlcore_op_get_rssi(struct ieee80211_hw *hw,
>  	if (ret < 0)
>  		goto out_sleep;
>  
> -	ret = wlcore_acx_average_rssi(wl, wlvif, rssi_dbm);
> +	ret = wlcore_acx_average_rssi(wl, wlvif, &rssi_dbm);
>  	if (ret < 0)
>  		goto out_sleep;
>  
> +	sinfo->filled |= STATION_INFO_SIGNAL;
> +	sinfo->signal = rssi_dbm;
> +
>  out_sleep:
>  	wl1271_ps_elp_sleep(wl);
>  
>  out:
>  	mutex_unlock(&wl->mutex);
> -
> -	return ret;
>  }
>  
>  static bool wl1271_tx_frames_pending(struct ieee80211_hw *hw)
> @@ -5605,7 +5607,7 @@ static const struct ieee80211_ops wl1271_ops = {
>  	.assign_vif_chanctx = wlcore_op_assign_vif_chanctx,
>  	.unassign_vif_chanctx = wlcore_op_unassign_vif_chanctx,
>  	.sta_rc_update = wlcore_op_sta_rc_update,
> -	.get_rssi = wlcore_op_get_rssi,
> +	.sta_statistics = wlcore_op_sta_statistics,
>  	CFG80211_TESTMODE_CMD(wl1271_tm_cmd)
>  };
>  
> diff --git a/include/net/mac80211.h b/include/net/mac80211.h
> index 83232aa2f077..ab7b4bde4661 100644
> --- a/include/net/mac80211.h
> +++ b/include/net/mac80211.h
> @@ -2669,6 +2669,11 @@ enum ieee80211_reconfig_type {
>   *	otherwise the rate control algorithm is notified directly.
>   *	Must be atomic.
>   *
> + * @sta_statistics: Get statistics for this station. For example with beacon
> + *	filtering, the statistics kept by mac80211 might not be accurate, so
> + *	let the driver pre-fill the statistics. Any statistics that the driver
> + *	doesn't fill will be filled by mac80211. The callback can sleep.
> + *
>   * @conf_tx: Configure TX queue parameters (EDCF (aifs, cw_min, cw_max),
>   *	bursting) for a hardware TX queue.
>   *	Returns a negative error code on failure.
> @@ -2829,9 +2834,6 @@ enum ieee80211_reconfig_type {
>   * @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, the function is optional
> - *	and can sleep.
> - *
>   * @mgd_prepare_tx: Prepare for transmitting a management frame for association
>   *	before associated. In multi-channel scenarios, a virtual interface is
>   *	bound to a channel before it is associated, but as it isn't associated
> @@ -3009,6 +3011,10 @@ struct ieee80211_ops {
>  			      struct ieee80211_vif *vif,
>  			      struct ieee80211_sta *sta,
>  			      u32 changed);
> +	void (*sta_statistics)(struct ieee80211_hw *hw,
> +			       struct ieee80211_vif *vif,
> +			       struct ieee80211_sta *sta,
> +			       struct station_info *sinfo);

Could consider exposing station_info through ieee80211_sta struct.

Regards,
Arend

Re: [RFC] mac80211: allow drivers to provide any statistics

[Johannes Berg]

On Mon, 2014-11-17 at 13:03 +0100, Arend van Spriel wrote:

> > +	void (*sta_statistics)(struct ieee80211_hw *hw,
> > +			       struct ieee80211_vif *vif,
> > +			       struct ieee80211_sta *sta,
> > +			       struct station_info *sinfo);
> 
> Could consider exposing station_info through ieee80211_sta struct.

We don't keep it in there though, we build it on the fly when we're
asked for statistics, and keep the actual values elsewhere (or even
calculate them on the fly). That'd be a bigger change then to keep in
the struct, and I'm not sure it's worth it since some need more info
than just the value (like ewma) etc.

johannes

Re: [RFC] mac80211: allow drivers to provide any statistics

[Bob Copeland]

On Mon, Nov 17, 2014 at 11:48:06AM +0100, Johannes Berg wrote:
> From: Johannes Berg <johannes.berg@intel.com>
> 
> In many cases, drivers can filter things like beacons that will
> skew statistics reported by mac80211. To get correct statistics
> in these cases, call drivers to obtain statistics and let them
> override all values, filling values from mac80211 if the driver
> didn't provide them.

Neat.

For mesh, it's handy to have the (somewhat imperfectly specified)
sta->fail_avg too for drivers that implement all the rate control
in firmware and thus may not report tx status for all frames.

At cozybit we had implemented a drv_link_stats driver op (hack) that
just got last_tx_rate and fail_avg so that the airtime link metric
could work on such devices; this call could replace that, I hope.

-- 
Bob Copeland %% http://bobcopeland.com/

Re: [RFC] mac80211: allow drivers to provide any statistics

[Ben Greear]

On 11/19/2014 09:49 AM, Bob Copeland wrote:
> On Mon, Nov 17, 2014 at 11:48:06AM +0100, Johannes Berg wrote:
>> From: Johannes Berg <johannes.berg@intel.com>
>>
>> In many cases, drivers can filter things like beacons that will
>> skew statistics reported by mac80211. To get correct statistics
>> in these cases, call drivers to obtain statistics and let them
>> override all values, filling values from mac80211 if the driver
>> didn't provide them.
> 
> Neat.
> 
> For mesh, it's handy to have the (somewhat imperfectly specified)
> sta->fail_avg too for drivers that implement all the rate control
> in firmware and thus may not report tx status for all frames.
> 
> At cozybit we had implemented a drv_link_stats driver op (hack) that
> just got last_tx_rate and fail_avg so that the airtime link metric
> could work on such devices; this call could replace that, I hope.


The ethtool stats API could also handle at least some of this,
but it's a bit free-form to program against...

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com