[v2] mac80211: mesh: Add support for HW RC implementation

Commit Message

Maxim Altshul June 23, 2016, 1:53 p.m. UTC

Mesh HWMP module will be able to rely on the HW
RC algorithm if it exists, for path metric calculations.

This allows the metric calculation mechanism to calculate
a correct metric, based on PER and last TX rate both via
HW RC algorithm if it exists or via parameters collected
by the SW.

Signed-off-by: Maxim Altshul <[e-mail]>
---
Changed previous implementation according to Johannes's
comment. Combined the RC test and throughput assignment
to a sta_get_expected_throughput function.
Using the function both from airtime_link_metric and
from sta_set_sinfo. 

 net/mac80211/mesh_hwmp.c | 22 ++++++++++++++--------
 net/mac80211/sta_info.c  | 22 +++++++++++++++++-----
 net/mac80211/sta_info.h  |  2 ++
 3 files changed, 33 insertions(+), 13 deletions(-)

Comments

Johannes Berg June 23, 2016, 7:26 p.m. UTC | #1

> +void sta_get_expected_throughput(struct sta_info *sta, u32 *thr)
> +{
> +	struct ieee80211_sub_if_data *sdata = sta->sdata;
> +	struct ieee80211_local *local = sdata->local;
> +	struct rate_control_ref *ref = NULL;
> +
> +	if (test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
> +		ref = local->rate_ctrl;
> +
> +	/* check if the driver has a SW RC implementation */
> +	if (ref && ref->ops->get_expected_throughput)
> +		*thr = ref->ops->get_expected_throughput(sta-
> >rate_ctrl_priv);
> +	else
> +		*thr = drv_get_expected_throughput(local, &sta-
> >sta);
> +}

I don't really see a reason for the function to take a u32 *thr, rather
than return u32? Would be clearer, IMHO, to just return the value.

Then in the user, it seems that you shouldn't use "rate" as the
variable that gets this result?

johannes
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Patch

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index c6be0b4..39f9541 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -322,19 +322,25 @@  static u32 airtime_link_metric_get(struct ieee80211_local *local,
 	int device_constant = 1 << ARITH_SHIFT;
 	int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
 	int s_unit = 1 << ARITH_SHIFT;
-	int rate, err;
+	int rate = 0, err = 0;
 	u32 tx_time, estimated_retx;
 	u64 result;
 
-	if (sta->mesh->fail_avg >= 100)
-		return MAX_METRIC;
+	/* try to get rate based on HW/SW RC algorithm */
+	sta_get_expected_throughput(sta, &rate);
 
-	sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
-	rate = cfg80211_calculate_bitrate(&rinfo);
-	if (WARN_ON(!rate))
-		return MAX_METRIC;
+	/* if we did not get a rate */
+	if (!rate) {
+		if (sta->mesh->fail_avg >= 100)
+			return MAX_METRIC;
 
-	err = (sta->mesh->fail_avg << ARITH_SHIFT) / 100;
+		sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
+		rate = cfg80211_calculate_bitrate(&rinfo);
+		if (WARN_ON(!rate))
+			return MAX_METRIC;
+
+		err = (sta->mesh->fail_avg << ARITH_SHIFT) / 100;
+	}
 
 	/* bitrate is in units of 100 Kbps, while we need rate in units of
 	 * 1Mbps. This will be corrected on tx_time computation.
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 63ea6cb..9580946 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2069,14 +2069,26 @@  void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 	if (test_sta_flag(sta, WLAN_STA_TDLS_PEER))
 		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_TDLS_PEER);
 
-	/* check if the driver has a SW RC implementation */
-	if (ref && ref->ops->get_expected_throughput)
-		thr = ref->ops->get_expected_throughput(sta->rate_ctrl_priv);
-	else
-		thr = drv_get_expected_throughput(local, &sta->sta);
+	sta_get_expected_throughput(sta, &thr);
 
 	if (thr != 0) {
 		sinfo->filled |= BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT);
 		sinfo->expected_throughput = thr;
 	}
 }
+
+void sta_get_expected_throughput(struct sta_info *sta, u32 *thr)
+{
+	struct ieee80211_sub_if_data *sdata = sta->sdata;
+	struct ieee80211_local *local = sdata->local;
+	struct rate_control_ref *ref = NULL;
+
+	if (test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
+		ref = local->rate_ctrl;
+
+	/* check if the driver has a SW RC implementation */
+	if (ref && ref->ops->get_expected_throughput)
+		*thr = ref->ops->get_expected_throughput(sta->rate_ctrl_priv);
+	else
+		*thr = drv_get_expected_throughput(local, &sta->sta);
+}
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 2cafb21..8535443 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -661,6 +661,8 @@  void sta_set_rate_info_tx(struct sta_info *sta,
 			  struct rate_info *rinfo);
 void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo);
 
+void sta_get_expected_throughput(struct sta_info *sta, u32 *thr);
+
 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
 			  unsigned long exp_time);
 u8 sta_info_tx_streams(struct sta_info *sta);