[PATCH 1/3] mac80211: expose sta_set_sinfo()

[PATCH 1/3] mac80211: expose sta_set_sinfo()

[Thomas Pedersen]

Expose sta_set_sinfo() in sta_info.h so other code (i.e. mesh) can take
advantage of some cfg80211 utility functions.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
---
 net/mac80211/cfg.c      |    2 +-
 net/mac80211/sta_info.h |    1 +
 2 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 6a77d4c..4ae0197 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -336,7 +336,7 @@ static void rate_idx_to_bitrate(struct rate_info *rate, struct sta_info *sta, in
 		rate->mcs = idx;
 }
 
-static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
+void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 {
 	struct ieee80211_sub_if_data *sdata = sta->sdata;
 	struct timespec uptime;
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 23a97c9..c6f46c3 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -528,6 +528,7 @@ void sta_info_init(struct ieee80211_local *local);
 void sta_info_stop(struct ieee80211_local *local);
 int sta_info_flush(struct ieee80211_local *local,
 		   struct ieee80211_sub_if_data *sdata);
+void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo);
 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
 			  unsigned long exp_time);
 
-- 
1.7.5.4

[PATCH 2/3] cfg80211: expose cfg80211_calculate_bitrate()

[Thomas Pedersen]

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
---
 include/net/cfg80211.h |    8 ++++++++
 net/wireless/util.c    |    1 +
 2 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 0178c74..64f6181 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -3334,6 +3334,14 @@ int cfg80211_can_beacon_sec_chan(struct wiphy *wiphy,
 				 struct ieee80211_channel *chan,
 				 enum nl80211_channel_type channel_type);
 
+/*
+ * cfg80211_calculate_bitrate - calculate actual bitrate (in 100Kbps units)
+ * @rate: given rate_info to calculate bitrate from
+ *
+ * return 0 if MCS index >= 32
+ */
+u16 cfg80211_calculate_bitrate(struct rate_info *rate);
+
 /* Logging, debugging and troubleshooting/diagnostic helpers. */
 
 /* wiphy_printk helpers, similar to dev_printk */
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 9aa9db6..1b7a08d 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -904,6 +904,7 @@ u16 cfg80211_calculate_bitrate(struct rate_info *rate)
 	/* do NOT round down here */
 	return (bitrate + 50000) / 100000;
 }
+EXPORT_SYMBOL(cfg80211_calculate_bitrate);
 
 int cfg80211_validate_beacon_int(struct cfg80211_registered_device *rdev,
 				 u32 beacon_int)
-- 
1.7.5.4

[PATCH 3/3] mac80211: fix mesh airtime link metric estimating

[Thomas Pedersen]

Airtime link metric estimation was broken in HT mesh, use
cfg80211_calculate_bitrate to get the right rate value.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
---
 net/mac80211/mesh_hwmp.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index 31bc762..d4cc3e3 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -323,6 +323,7 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
 				   struct sta_info *sta)
 {
 	struct ieee80211_supported_band *sband;
+	struct station_info sinfo;
 	/* This should be adjusted for each device */
 	int device_constant = 1 << ARITH_SHIFT;
 	int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
@@ -336,7 +337,9 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
 	if (sta->fail_avg >= 100)
 		return MAX_METRIC;
 
-	if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
+	sta_set_sinfo(sta, &sinfo);
+	rate = cfg80211_calculate_bitrate(&sinfo.txrate);
+	if (WARN_ON(!rate))
 		return MAX_METRIC;
 
 	err = (sta->fail_avg << ARITH_SHIFT) / 100;
@@ -344,7 +347,6 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
 	/* bitrate is in units of 100 Kbps, while we need rate in units of
 	 * 1Mbps. This will be corrected on tx_time computation.
 	 */
-	rate = sband->bitrates[sta->last_tx_rate.idx].bitrate;
 	tx_time = (device_constant + 10 * test_frame_len / rate);
 	estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
 	result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
-- 
1.7.5.4

Re: [PATCH 3/3] mac80211: fix mesh airtime link metric estimating

[Johannes Berg]

On Fri, 2012-03-02 at 15:05 -0800, Thomas Pedersen wrote:
> Airtime link metric estimation was broken in HT mesh, use
> cfg80211_calculate_bitrate to get the right rate value.

> -	if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
> +	sta_set_sinfo(sta, &sinfo);
> +	rate = cfg80211_calculate_bitrate(&sinfo.txrate);
> +	if (WARN_ON(!rate))
>  		return MAX_METRIC;

Patch 1 should be rolled into this, but I don't like it -- you fill a
lot of info you don't need, I think the rate should be factored out of
sta_set_sinfo then

johannes

Re: [PATCH 3/3] mac80211: fix mesh airtime link metric estimating

[Thomas Pedersen]

On Fri, Mar 2, 2012 at 3:18 PM, Johannes Berg <johannes@sipsolutions.net> wrote:
> On Fri, 2012-03-02 at 15:05 -0800, Thomas Pedersen wrote:
>> Airtime link metric estimation was broken in HT mesh, use
>> cfg80211_calculate_bitrate to get the right rate value.
>
>> -     if (sta->last_tx_rate.flags & IEEE80211_TX_RC_MCS)
>> +     sta_set_sinfo(sta, &sinfo);
>> +     rate = cfg80211_calculate_bitrate(&sinfo.txrate);
>> +     if (WARN_ON(!rate))
>>               return MAX_METRIC;
>
> Patch 1 should be rolled into this, but I don't like it -- you fill a
> lot of info you don't need, I think the rate should be factored out of
> sta_set_sinfo then
>

Yes that would be better.

Thanks,
Thomas