[B.A.T.M.A.N.] [RFCv2 0/6] Export the expected throughput

The "Expected throughput" towards a generic wireless peer is
a value that can be used by other kernel components to
achieve different goals.
In particular we have 802.11s and batman-adv which will
iuse this estimation to compute their throughput based
metric. Therefore with this patchset I wanted to export
this result and make it available for future use.

Changes included in this patchset:
- add the new get_expected_throughput() RC API
- export the result of such API via cfg80211::get_station()
- implement the get_expected_throughput() RC API for minstrel(_ht)


For what concerns Minstrel_HT I decided to directly re-use the
throughput value computed by the algorithm itself with
minstrel_ht_calc_tp() for max_tp_rate.

For the legacy Minstrel instead I computed the expected
throughput as the product of the max_tp bitrate multplied
by its probability of success.


I am not entirely sure about passing sband as third parameter
to get_expected_throughput()..maybe somebody can suggest a
better solution.



Cheers,


Antonio Quartulli (6):
  cfg80211: export expected throughput through get_station()
  mac80211: add new RC API to retrieve expected throughput
  mac80211: export expected throughput in set_sta_info()
  mac80211: minstrel - implement get_expected_throughput() API
  mac80211: minstrel_ht - implement get_expected_throughput() API
  cfg80211: implement cfg80211_get_station cfg80211 API

 include/net/cfg80211.h             | 74 +++++++++++++++++++++++---------------
 include/net/mac80211.h             |  3 ++
 net/mac80211/cfg.c                 | 17 +++++++++
 net/mac80211/rc80211_minstrel.c    | 15 ++++++++
 net/mac80211/rc80211_minstrel_ht.c | 19 ++++++++++
 net/wireless/util.c                | 18 ++++++++++
 6 files changed, 118 insertions(+), 28 deletions(-)

-- 
1.8.3.2

From: Antonio Quartulli <redacted>

Users may need information about the expected throughput
towards a given peer computed by the RC algorithm.
Export such value through the get_station() API.

This information is useful to the batman-adv module which
will use it for its new metric computation.

Signed-off-by: Antonio Quartulli <redacted>
---
 include/net/cfg80211.h | 63 ++++++++++++++++++++++++++++----------------------
 1 file changed, 35 insertions(+), 28 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index fb8afce..4c8ebe9 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h

@@ -862,36 +862,38 @@ int cfg80211_check_station_change(struct wiphy *wiphy,
  * @STATION_INFO_NONPEER_PM: @nonpeer_pm filled
  * @STATION_INFO_CHAIN_SIGNAL: @chain_signal filled
  * @STATION_INFO_CHAIN_SIGNAL_AVG: @chain_signal_avg filled
+ * @STATION_INFO_EXPECTED_THROUGHPUT: @expected_throughput filled
  */
 enum station_info_flags {
-	STATION_INFO_INACTIVE_TIME	= 1<<0,
-	STATION_INFO_RX_BYTES		= 1<<1,
-	STATION_INFO_TX_BYTES		= 1<<2,
-	STATION_INFO_LLID		= 1<<3,
-	STATION_INFO_PLID		= 1<<4,
-	STATION_INFO_PLINK_STATE	= 1<<5,
-	STATION_INFO_SIGNAL		= 1<<6,
-	STATION_INFO_TX_BITRATE		= 1<<7,
-	STATION_INFO_RX_PACKETS		= 1<<8,
-	STATION_INFO_TX_PACKETS		= 1<<9,
-	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,
-	STATION_INFO_RX_BITRATE		= 1<<14,
-	STATION_INFO_BSS_PARAM          = 1<<15,
-	STATION_INFO_CONNECTED_TIME	= 1<<16,
-	STATION_INFO_ASSOC_REQ_IES	= 1<<17,
-	STATION_INFO_STA_FLAGS		= 1<<18,
-	STATION_INFO_BEACON_LOSS_COUNT	= 1<<19,
-	STATION_INFO_T_OFFSET		= 1<<20,
-	STATION_INFO_LOCAL_PM		= 1<<21,
-	STATION_INFO_PEER_PM		= 1<<22,
-	STATION_INFO_NONPEER_PM		= 1<<23,
-	STATION_INFO_RX_BYTES64		= 1<<24,
-	STATION_INFO_TX_BYTES64		= 1<<25,
-	STATION_INFO_CHAIN_SIGNAL	= 1<<26,
-	STATION_INFO_CHAIN_SIGNAL_AVG	= 1<<27,
+	STATION_INFO_INACTIVE_TIME		= 1<<0,
+	STATION_INFO_RX_BYTES			= 1<<1,
+	STATION_INFO_TX_BYTES			= 1<<2,
+	STATION_INFO_LLID			= 1<<3,
+	STATION_INFO_PLID			= 1<<4,
+	STATION_INFO_PLINK_STATE		= 1<<5,
+	STATION_INFO_SIGNAL			= 1<<6,
+	STATION_INFO_TX_BITRATE			= 1<<7,
+	STATION_INFO_RX_PACKETS			= 1<<8,
+	STATION_INFO_TX_PACKETS			= 1<<9,
+	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,
+	STATION_INFO_RX_BITRATE			= 1<<14,
+	STATION_INFO_BSS_PARAM			= 1<<15,
+	STATION_INFO_CONNECTED_TIME		= 1<<16,
+	STATION_INFO_ASSOC_REQ_IES		= 1<<17,
+	STATION_INFO_STA_FLAGS			= 1<<18,
+	STATION_INFO_BEACON_LOSS_COUNT		= 1<<19,
+	STATION_INFO_T_OFFSET			= 1<<20,
+	STATION_INFO_LOCAL_PM			= 1<<21,
+	STATION_INFO_PEER_PM			= 1<<22,
+	STATION_INFO_NONPEER_PM			= 1<<23,
+	STATION_INFO_RX_BYTES64			= 1<<24,
+	STATION_INFO_TX_BYTES64			= 1<<25,
+	STATION_INFO_CHAIN_SIGNAL		= 1<<26,
+	STATION_INFO_CHAIN_SIGNAL_AVG		= 1<<27,
+	STATION_INFO_EXPECTED_THROUGHPUT	= 1<<28,
 };
 
 /**

@@ -1013,6 +1015,9 @@ struct sta_bss_parameters {
  * @local_pm: local mesh STA power save mode
  * @peer_pm: peer mesh STA power save mode
  * @nonpeer_pm: non-peer mesh STA power save mode
+ * @expected_throughput: expected throughput as reported by the RC algorithm
+ *  about the bitrate having the maximum throughput. This field can be filled
+ *  only by drivers using Minstrel
  */
 struct station_info {
 	u32 filled;

@@ -1051,6 +1056,8 @@ struct station_info {
 	enum nl80211_mesh_power_mode peer_pm;
 	enum nl80211_mesh_power_mode nonpeer_pm;
 
+	u32 expected_throughput;
+
 	/*
 	 * Note: Add a new enum station_info_flags value for each new field and
 	 * use it to check which fields are initialized.

-- 
1.8.3.2

From: Antonio Quartulli <redacted>

In order to make get_station() export the expected
throughput, we need a new API which extracts such
information from the Rate Control algorithm.
Therefore add the get_expected_throughput() member
to the rate_control_ops structure.

Signed-off-by: Antonio Quartulli <redacted>
---
 include/net/mac80211.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 604e279..209e004 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h

@@ -4476,6 +4476,9 @@ struct rate_control_ops {
 	void (*add_sta_debugfs)(void *priv, void *priv_sta,
 				struct dentry *dir);
 	void (*remove_sta_debugfs)(void *priv, void *priv_sta);
+
+	u32 (*get_expected_throughput)(void *priv, void *priv_sta,
+				       struct ieee80211_supported_band *sband);
 };
 
 static inline int rate_supported(struct ieee80211_sta *sta,

-- 
1.8.3.2

From: Antonio Quartulli <redacted>

If the RC algorithm implements the get_expected_throughput()
API fill the related member in the station_info object when
dumping a station.

Signed-off-by: Antonio Quartulli <redacted>
---
 net/mac80211/cfg.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index aa39381..0e80e2c 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c

@@ -472,9 +472,13 @@ 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 rate_control_ref *ref = local->rate_ctrl;
+	struct ieee80211_supported_band *sband;
+	enum ieee80211_band band;
 	struct timespec uptime;
 	u64 packets = 0;
 	int i, ac;
+	u32 thr;
 
 	sinfo->generation = sdata->local->sta_generation;
 

@@ -587,6 +591,19 @@ static void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
 		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_ASSOCIATED);
 	if (test_sta_flag(sta, WLAN_STA_TDLS_PEER))
 		sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_TDLS_PEER);
+
+	if (ref->ops->get_expected_throughput) {
+		band = ieee80211_get_sdata_band(sta->sdata);
+		sband = sta->local->hw.wiphy->bands[band];
+
+		thr = ref->ops->get_expected_throughput(ref->priv,
+							sta->rate_ctrl_priv,
+							sband);
+		if (thr != 0) {
+			sinfo->filled |= STATION_INFO_EXPECTED_THROUGHPUT;
+			sinfo->expected_throughput = thr;
+		}
+	}
 }
 
 static const char ieee80211_gstrings_sta_stats[][ETH_GSTRING_LEN] = {

-- 
1.8.3.2

From: Antonio Quartulli <redacted>

Cc: Felix Fietkau <redacted>
Signed-off-by: Antonio Quartulli <redacted>
---
 net/mac80211/rc80211_minstrel.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/net/mac80211/rc80211_minstrel.c b/net/mac80211/rc80211_minstrel.c
index 26fd94f..9434435d 100644
--- a/net/mac80211/rc80211_minstrel.c
+++ b/net/mac80211/rc80211_minstrel.c

@@ -657,6 +657,20 @@ minstrel_free(void *priv)
 	kfree(priv);
 }
 
+static u32
+minstrel_get_expected_throughput(void *priv, void *priv_sta,
+				 struct ieee80211_supported_band *sband)
+{
+	struct minstrel_sta_info *mi = priv_sta;
+	int idx = mi->max_tp_rate[0];
+	u32 bitrate, ret;
+
+	bitrate = sband->bitrates[mi->r[idx].rix].bitrate;
+	ret = bitrate * MINSTREL_TRUNC(mi->r[idx].probability * 1000) / 1000;
+
+	return ret;
+}
+
 const struct rate_control_ops mac80211_minstrel = {
 	.name = "minstrel",
 	.tx_status = minstrel_tx_status,

@@ -670,6 +684,7 @@ const struct rate_control_ops mac80211_minstrel = {
 	.add_sta_debugfs = minstrel_add_sta_debugfs,
 	.remove_sta_debugfs = minstrel_remove_sta_debugfs,
 #endif
+	.get_expected_throughput = minstrel_get_expected_throughput,
 };
 
 int __init

-- 
1.8.3.2

From: Antonio Quartulli <redacted>

Cc: Felix Fietkau <redacted>
Signed-off-by: Antonio Quartulli <redacted>
---
 net/mac80211/rc80211_minstrel_ht.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c
index bccaf85..480f657 100644
--- a/net/mac80211/rc80211_minstrel_ht.c
+++ b/net/mac80211/rc80211_minstrel_ht.c

@@ -1031,6 +1031,24 @@ minstrel_ht_free(void *priv)
 	mac80211_minstrel.free(priv);
 }
 
+static u32
+minstrel_ht_get_expected_throughput(void *priv, void *priv_sta,
+				    struct ieee80211_supported_band *sband)
+{
+	struct minstrel_ht_sta_priv *msp = priv_sta;
+	struct minstrel_ht_sta *mi = &msp->ht;
+	int i, j;
+
+	if (!msp->is_ht)
+		return mac80211_minstrel.get_expected_throughput(priv, priv_sta,
+								 sband);
+
+	i = mi->max_tp_rate / MCS_GROUP_RATES;
+	j = mi->max_tp_rate % MCS_GROUP_RATES;
+
+	return mi->groups[i].rates[j].cur_tp;
+}
+
 static const struct rate_control_ops mac80211_minstrel_ht = {
 	.name = "minstrel_ht",
 	.tx_status = minstrel_ht_tx_status,

@@ -1045,6 +1063,7 @@ static const struct rate_control_ops mac80211_minstrel_ht = {
 	.add_sta_debugfs = minstrel_ht_add_sta_debugfs,
 	.remove_sta_debugfs = minstrel_ht_remove_sta_debugfs,
 #endif
+	.get_expected_throughput = minstrel_ht_get_expected_throughput,
 };
 
 

-- 
1.8.3.2

From: Antonio Quartulli <redacted>

Implement and export the new cfg80211_get_station() API.
This utility can be used by other kernel modules to obtain
detailed information about a given wireless station.

It will be in particular useful to batman-adv which will
implement a wireless rate based metric.

Signed-off-by: Antonio Quartulli <redacted>
---
 include/net/cfg80211.h | 11 +++++++++++
 net/wireless/util.c    | 18 ++++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 4c8ebe9..45062aa 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h

@@ -1065,6 +1065,17 @@ struct station_info {
 };
 
 /**
+ * cfg80211_get_station - retrieve information about a given station
+ * @dev: the device where the station is supposed to be connected to
+ * @mac_addr: the mac address of the station of interest
+ * @sinfo: pointer to the structure to fill with the information
+ *
+ * Returns 0 on success or a negative error code otherwise.
+ */
+int cfg80211_get_station(struct net_device *dev, u8 *mac_addr,
+			 struct station_info *sinfo);
+
+/**
  * enum monitor_flags - monitor flags
  *
  * Monitor interface configuration flags. Note that these must be the bits

diff --git a/net/wireless/util.c b/net/wireless/util.c
index c5d0208..c691cf8 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c

@@ -1482,6 +1482,24 @@ unsigned int ieee80211_get_num_supported_channels(struct wiphy *wiphy)
 }
 EXPORT_SYMBOL(ieee80211_get_num_supported_channels);
 
+int cfg80211_get_station(struct net_device *dev, u8 *mac_addr,
+			 struct station_info *sinfo)
+{
+	struct cfg80211_registered_device *rdev;
+	struct wireless_dev *wdev;
+
+	wdev = dev->ieee80211_ptr;
+	if (!wdev)
+		return -EOPNOTSUPP;
+
+	rdev = wiphy_to_dev(wdev->wiphy);
+	if (!rdev->ops->get_station)
+		return -EOPNOTSUPP;
+
+	return rdev_get_station(rdev, dev, mac_addr, sinfo);
+}
+EXPORT_SYMBOL(cfg80211_get_station);
+
 /* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
 /* Ethernet-II snap header (RFC1042 for most EtherTypes) */
 const unsigned char rfc1042_header[] __aligned(2) =

-- 
1.8.3.2

On Sun, Mar 30, 2014 at 10:34:59PM +0200, Antonio Quartulli wrote:

Hi Antonio

It would be nice to comment on what the units are. I known from our
BATMAN V discussions, it is something odd.

       Andrew

Hi Andrew,

On 31/03/14 10:22, Andrew Lunn wrote:

quoted

 /**

@@ -1013,6 +1015,9 @@ struct sta_bss_parameters {
  * @local_pm: local mesh STA power save mode
  * @peer_pm: peer mesh STA power save mode
  * @nonpeer_pm: non-peer mesh STA power save mode
+ * @expected_throughput: expected throughput as reported by the RC algorithm
+ *  about the bitrate having the maximum throughput. This field can be filled
+ *  only by drivers using Minstrel
  */
 struct station_info {
 	u32 filled;

@@ -1051,6 +1056,8 @@ struct station_info {
 	enum nl80211_mesh_power_mode peer_pm;
 	enum nl80211_mesh_power_mode nonpeer_pm;
 
+	u32 expected_throughput;
+

It would be nice to comment on what the units are. I known from our
BATMAN V discussions, it is something odd.

Thanks for raising the point.

Actually this is something we could discuss with Felix: at the moment
this value uses the same unit used by the cur_tp member of the
minstrel_ht_sta structure.

It should be Mbps/100 --> expected_throughput = 1 ==> 0.01Mbps

When exposing this value to the user (i.e. iw output) I'd recommend to
convert it to Mbps, but for internal purposes I don't see a clear
problem in exporting a value in this form.

Thoughts? Suggestions?

Cheers,

-- 
Antonio Quartulli

On 30/03/14 22:35, Antonio Quartulli wrote:

Thanks to the point raised by Andrew Lunn I just realised that this
value is expressed in Mbps/10 and so should be converted to Mbps/100
before being returned (assuming we agree on using this unit).

Cheers,

-- 
Antonio Quartulli

On Sun, 2014-03-30 at 22:34 +0200, Antonio Quartulli wrote:

-	STATION_INFO_INACTIVE_TIME	= 1<<0,

Since you're touching these all anyway, maybe convert to use BIT().

This value needs a documented unit ... :)

johannes

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

From: Antonio Quartulli <redacted>

In order to make get_station() export the expected
throughput, we need a new API which extracts such
information from the Rate Control algorithm.
Therefore add the get_expected_throughput() member
to the rate_control_ops structure.

What about drivers with HW rate control?

johannes

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

+	u32 (*get_expected_throughput)(void *priv, void *priv_sta,
+				       struct ieee80211_supported_band *sband);

why would that need an sband argument?

johannes

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

You don't need a ret variable.

johannes

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

mac_addr should be const

Any thoughts about clearing/filling/partially filling *sinfo when
returning an error?

johannes

On 08/04/14 12:03, Johannes Berg wrote:

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

quoted

From: Antonio Quartulli <redacted>

In order to make get_station() export the expected
throughput, we need a new API which extracts such
information from the Rate Control algorithm.
Therefore add the get_expected_throughput() member
to the rate_control_ops structure.

What about drivers with HW rate control?

True, they do not implement the rate_control_ops API.

Therefore, as discussed on IRC, I need to move this new API at the
mac80211 level, so that each driver can implement it the way it prefer.

Cheers,

-- 
Antonio Quartulli

On 08/04/14 12:04, Johannes Berg wrote:

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

quoted

+	u32 (*get_expected_throughput)(void *priv, void *priv_sta,
+				       struct ieee80211_supported_band *sband);

why would that need an sband argument?

I needed this because I saw it is required by some RC algo (only
minstrel) to extract the bitrate starting from the index.

You can check patch 4/6 for this:

+	bitrate = sband->bitrates[mi->r[idx].rix].bitrate;

maybe I can extract it from another structure? I couldn't find any way..

Cheers,

-- 
Antonio Quartulli

On 08/04/14 12:05, Johannes Berg wrote:

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

quoted

+static u32
+minstrel_get_expected_throughput(void *priv, void *priv_sta,
+				 struct ieee80211_supported_band *sband)
+{
+	struct minstrel_sta_info *mi = priv_sta;
+	int idx = mi->max_tp_rate[0];
+	u32 bitrate, ret;
+
+	bitrate = sband->bitrates[mi->r[idx].rix].bitrate;
+	ret = bitrate * MINSTREL_TRUNC(mi->r[idx].probability * 1000) / 1000;
+
+	return ret;

You don't need a ret variable.

True.
thanks!


-- 
Antonio Quartulli

On 08/04/14 12:06, Johannes Berg wrote:

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

quoted

 /**
+ * cfg80211_get_station - retrieve information about a given station
+ * @dev: the device where the station is supposed to be connected to
+ * @mac_addr: the mac address of the station of interest
+ * @sinfo: pointer to the structure to fill with the information
+ *
+ * Returns 0 on success or a negative error code otherwise.
+ */
+int cfg80211_get_station(struct net_device *dev, u8 *mac_addr,
+			 struct station_info *sinfo);

mac_addr should be const

True

Any thoughts about clearing/filling/partially filling *sinfo when
returning an error?

At the moment this function relies on what rdev_get_station() does and I
always assumed that in case of error the content of *sinfo should be
considered "undefined".

An option can be to set the object to 0 in case of error, but is it
really needed?

Any other change should be applied to rdev->ops->get_station(), not
here. I.e. fill the object as much as possible and never return an error
- just flag what was filled.


Cheers,

-- 
Antonio Quartulli

On 08/04/14 12:03, Johannes Berg wrote:

On Sun, 2014-03-30 at 22:34 +0200, Antonio Quartulli wrote:

quoted

-	STATION_INFO_INACTIVE_TIME	= 1<<0,

Since you're touching these all anyway, maybe convert to use BIT().

Will do!

quoted

@@ -1013,6 +1015,9 @@ struct sta_bss_parameters {
  * @local_pm: local mesh STA power save mode
  * @peer_pm: peer mesh STA power save mode
  * @nonpeer_pm: non-peer mesh STA power save mode
+ * @expected_throughput: expected throughput as reported by the RC algorithm
+ *  about the bitrate having the maximum throughput. This field can be filled
+ *  only by drivers using Minstrel

This value needs a documented unit ... :)

Yep. As suggested by Andrew, I will try to be clear about what unit is
returned.

Thanks a lot for your review!!!!

Cheers,

-- 
Antonio Quartulli

On Thu, 2014-04-10 at 18:02 +0200, Antonio Quartulli wrote:

quoted

Any thoughts about clearing/filling/partially filling *sinfo when
returning an error?

At the moment this function relies on what rdev_get_station() does and I
always assumed that in case of error the content of *sinfo should be
considered "undefined".

That's fine, maybe add a line of documentation?

johannes

On Thu, 2014-04-10 at 17:46 +0200, Antonio Quartulli wrote:

quoted

What about drivers with HW rate control?

True, they do not implement the rate_control_ops API.

Therefore, as discussed on IRC, I need to move this new API at the
mac80211 level, so that each driver can implement it the way it prefer.

Well, not *move*, but rather have both. Or you can just say that the
drivers that may need this can worry about it ...

johannes

On Thu, 2014-04-10 at 17:53 +0200, Antonio Quartulli wrote:

On 08/04/14 12:04, Johannes Berg wrote:

quoted

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

quoted

+	u32 (*get_expected_throughput)(void *priv, void *priv_sta,
+				       struct ieee80211_supported_band *sband);

why would that need an sband argument?

I needed this because I saw it is required by some RC algo (only
minstrel) to extract the bitrate starting from the index.

You can check patch 4/6 for this:

+	bitrate = sband->bitrates[mi->r[idx].rix].bitrate;

maybe I can extract it from another structure? I couldn't find any way..

Bit strange that the algorithm doesn't have the band, if it has an
index? but I guess I didn't check all the patches...

johannes

On 10/04/14 19:13, Johannes Berg wrote:

On Thu, 2014-04-10 at 17:46 +0200, Antonio Quartulli wrote:

quoted

quoted

What about drivers with HW rate control?

True, they do not implement the rate_control_ops API.

Therefore, as discussed on IRC, I need to move this new API at the
mac80211 level, so that each driver can implement it the way it prefer.

Well, not *move*, but rather have both. Or you can just say that the
drivers that may need this can worry about it ...

You are right, I meant to *add* another API at the mac80211 level and
have both. I think this is the cleanest solution.

Cheers,

-- 
Antonio Quartulli

On 10/04/14 19:12, Johannes Berg wrote:

On Thu, 2014-04-10 at 18:02 +0200, Antonio Quartulli wrote:

quoted

quoted

Any thoughts about clearing/filling/partially filling *sinfo when
returning an error?

At the moment this function relies on what rdev_get_station() does and I
always assumed that in case of error the content of *sinfo should be
considered "undefined".

That's fine, maybe add a line of documentation?

Oky! will do.

Cheers,

-- 
Antonio Quartulli

On 10/04/14 19:14, Johannes Berg wrote:

On Thu, 2014-04-10 at 17:53 +0200, Antonio Quartulli wrote:

quoted

On 08/04/14 12:04, Johannes Berg wrote:

quoted

On Sun, 2014-03-30 at 22:35 +0200, Antonio Quartulli wrote:

quoted

+	u32 (*get_expected_throughput)(void *priv, void *priv_sta,
+				       struct ieee80211_supported_band *sband);

why would that need an sband argument?

I needed this because I saw it is required by some RC algo (only
minstrel) to extract the bitrate starting from the index.

You can check patch 4/6 for this:

+	bitrate = sband->bitrates[mi->r[idx].rix].bitrate;

maybe I can extract it from another structure? I couldn't find any way..

Bit strange that the algorithm doesn't have the band, if it has an
index? but I guess I didn't check all the patches...

I just rechecked, and it looked to me that all the other functions in
Minstreal (non-HT) take the sband as argument.

It is not stored anywhere and therefore it has to be passed as argument
to this new API as well..

A general beautification might be applied to rate_control_ops (and not
only)...but it is out of the scope of this patchset :)

Cheers,


-- 
Antonio Quartulli