[PATCH 0/3] IBSS rate scaling fixes

[PATCH 0/3] IBSS rate scaling fixes

[Tomas Winkler]

This series should fix fixed low rate (1Mbps) in IBSS. This is regression
from 2.6.26

I suggest merging patches 1 and 2 in 2.6.27, they are simple one-liners and provide 
the necessary fix for the regression.
Patch 3 provides more general fix and can go to 2.6.28

[PATCH 1/3] iwlwifi: rs - take a fresh set of supported rates at each cycle
[PATCH 2/3] mac80211: Fix low bit rate in IBSS
[PATCH 3/3] mac80211: Fix rate scale initialization in IBSS



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[PATCH 1/3] iwlwifi: rs - take a fresh set of supported rates at each cycle

[Tomas Winkler]

From: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

Regression iwl-agn-rs IBSS: work in single rate.

This patch fixes regression in iwlwifi IBSS rate scaling caused by patch:

commit 6bc37c06bc424bcf3f944e6a79e2d5bb537e02ed
Author: Vladimir Koutny <vlado@work.ksp.sk>
Date:   Fri Jun 13 16:50:44 2008 +0200

    mac80211: eliminate IBSS warning in rate_lowest_index()

An IBSS station might added on reception of a packet that doesn't
carry rate information (beacon, probe resp). In that case the rate
scaling was initialized only with single rate matching the received packet
rate with the hope that correct rate scale information will be updated
when beacon or probe for that station will arrive.

iwl-agn-rs copied supported rates on initialization and was never updated
again.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Reviewed-by: Tomas Winkler <tomas.winkler@intel.com>
Cc: Vladimir Koutny <vlado@work.ksp.sk>
---
 drivers/net/wireless/iwlwifi/iwl-agn-rs.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
index 754fef5..3dc57f5 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
@@ -1668,6 +1668,7 @@ static void rs_rate_scale_perform(struct iwl_priv *priv,
 		return;
 
 	lq_sta = (struct iwl_lq_sta *)sta->rate_ctrl_priv;
+	lq_sta->supp_rates = sta->supp_rates[lq_sta->band];
 
 	tid = rs_tl_add_packet(lq_sta, hdr);
 
-- 
1.5.4.1

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[PATCH 2/3] mac80211: Fix low bit rate in IBSS

[Tomas Winkler]

This patch fixes regression in iwlwifi IBSS rate scaling caused by patch:

    commit 6bc37c06bc424bcf3f944e6a79e2d5bb537e02ed
    Author: Vladimir Koutny <vlado@work.ksp.sk>
    Date:   Fri Jun 13 16:50:44 2008 +0200

        mac80211: eliminate IBSS warning in rate_lowest_index()

An IBSS station is added in prepare_for_handlers where the rate scaling was
initialized only with single rate matching the received packet.
The correct rate scale information should be updated only in
ieee80211_rx_bss_info function where beacon is parsed. Because
of coding error the rate info was left untouched.
If a beacon has triggered the connection the rate remined 1Mbps.
This patch fixes this coding error

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Cc: Vladimir Koutny <vlado@work.ksp.sk>
---
 net/mac80211/mlme.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 7d53382..75510a9 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2595,7 +2595,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 							rx_status->band);
 
 		prev_rates = sta->supp_rates[rx_status->band];
-		sta->supp_rates[rx_status->band] &= supp_rates;
+		sta->supp_rates[rx_status->band] = supp_rates;
 		if (sta->supp_rates[rx_status->band] == 0) {
 			/* No matching rates - this should not really happen.
 			 * Make sure that at least one rate is marked
-- 
1.5.4.1

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[PATCH 3/3] mac80211: Fix rate scale initialization in IBSS

[Tomas Winkler]

From: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

This patch address some IBSS rate issues introduced
or not covered by
6bc37c06bc424bcf3f944e6a79e2d5bb537e02ed
and 8318d78a44d49ac1edf2bdec7299de3617c4232e patches.

This patch:
1. Moves addition of IBSS station from
prepare_for_handlers to ieee80211_rx_bss_info when triggered from beacon
eliminating bogus supported rates.
2. Initialize properly supported rates also in IBSS merging
3. Ensure that mandatory rates are always added into supported
rates. This is needed in case when station addition is triggered from
non beacon/probe packet. Some management frames need to be sent
4. Remove initialization of supported rates from self rates. This path
was dead code after 6bc37c06bc4 and in general incorrect.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Cc: Vladimir Koutny <vlado@work.ksp.sk>
---
 net/mac80211/mlme.c |   90 ++++++++++++++++++++++++++++++++++++---------------
 net/mac80211/rx.c   |    4 --
 2 files changed, 64 insertions(+), 30 deletions(-)

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 75510a9..c396c35 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2557,6 +2557,33 @@ u64 ieee80211_sta_get_rates(struct ieee80211_local *local,
 	return supp_rates;
 }
 
+static u64 ieee80211_sta_get_mandatory_rates(struct ieee80211_local *local,
+					enum ieee80211_band band)
+{
+	struct ieee80211_supported_band *sband;
+	struct ieee80211_rate *bitrates;
+	u64 mandatory_rates;
+	enum ieee80211_rate_flags mandatory_flag;
+	int i;
+
+	sband = local->hw.wiphy->bands[band];
+	if (!sband) {
+		WARN_ON(1);
+		sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
+	}
+
+	if (band == IEEE80211_BAND_2GHZ)
+		mandatory_flag = IEEE80211_RATE_MANDATORY_B;
+	else
+		mandatory_flag = IEEE80211_RATE_MANDATORY_A;
+
+	bitrates = sband->bitrates;
+	mandatory_rates = 0;
+	for (i = 0; i < sband->n_bitrates; i++)
+		if (bitrates[i].flags & mandatory_flag)
+			mandatory_rates |= BIT(i);
+	return mandatory_rates;
+}
 
 static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 				  struct ieee80211_mgmt *mgmt,
@@ -2568,9 +2595,11 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 	int freq, clen;
 	struct ieee80211_sta_bss *bss;
 	struct sta_info *sta;
-	u64 beacon_timestamp, rx_timestamp;
 	struct ieee80211_channel *channel;
+	u64 beacon_timestamp, rx_timestamp;
+	u64 supp_rates = 0;
 	bool beacon = ieee80211_is_beacon(mgmt->frame_control);
+	enum ieee80211_band band = rx_status->band;
 	DECLARE_MAC_BUF(mac);
 	DECLARE_MAC_BUF(mac2);
 
@@ -2578,30 +2607,41 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 
 	if (ieee80211_vif_is_mesh(&sdata->vif) && elems->mesh_id &&
 	    elems->mesh_config && mesh_matches_local(elems, sdata)) {
-		u64 rates = ieee80211_sta_get_rates(local, elems,
-						rx_status->band);
+		supp_rates = ieee80211_sta_get_rates(local, elems, band);
 
-		mesh_neighbour_update(mgmt->sa, rates, sdata,
+		mesh_neighbour_update(mgmt->sa, supp_rates, sdata,
 				      mesh_peer_accepts_plinks(elems));
 	}
 
 	rcu_read_lock();
 
 	if (sdata->vif.type == IEEE80211_IF_TYPE_IBSS && elems->supp_rates &&
-	    memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0 &&
-	    (sta = sta_info_get(local, mgmt->sa))) {
-		u64 prev_rates;
-		u64 supp_rates = ieee80211_sta_get_rates(local, elems,
-							rx_status->band);
-
-		prev_rates = sta->supp_rates[rx_status->band];
-		sta->supp_rates[rx_status->band] = supp_rates;
-		if (sta->supp_rates[rx_status->band] == 0) {
-			/* No matching rates - this should not really happen.
-			 * Make sure that at least one rate is marked
-			 * supported to avoid issues with TX rate ctrl. */
-			sta->supp_rates[rx_status->band] =
-				sdata->u.sta.supp_rates_bits[rx_status->band];
+	    memcmp(mgmt->bssid, sdata->u.sta.bssid, ETH_ALEN) == 0) {
+
+		supp_rates = ieee80211_sta_get_rates(local, elems, band);
+
+		sta = sta_info_get(local, mgmt->sa);
+		if (sta) {
+			u64 prev_rates;
+
+			prev_rates = sta->supp_rates[band];
+			/* make sure mandatory rates are always added */
+			sta->supp_rates[band] = supp_rates |
+				ieee80211_sta_get_mandatory_rates(local, band);
+
+#ifdef CONFIG_MAC80211_IBSS_DEBUG
+			if (sta->supp_rates[band] != prev_rates)
+				printk(KERN_DEBUG "%s: updated supp_rates set "
+				    "for %s based on beacon info (0x%llx | "
+				    "0x%llx -> 0x%llx)\n",
+				    sdata->dev->name, print_mac(mac, sta->addr),
+				    (unsigned long long) prev_rates,
+				    (unsigned long long) supp_rates,
+				    (unsigned long long) sta->supp_rates[band]);
+#endif
+		} else {
+			ieee80211_ibss_add_sta(sdata, NULL, mgmt->bssid,
+					       mgmt->sa, supp_rates);
 		}
 	}
 
@@ -2683,7 +2723,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 		bss->supp_rates_len += clen;
 	}
 
-	bss->band = rx_status->band;
+	bss->band = band;
 
 	bss->timestamp = beacon_timestamp;
 	bss->last_update = jiffies;
@@ -2738,7 +2778,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 			 * e.g: at 1 MBit that means mactime is 192 usec earlier
 			 * (=24 bytes * 8 usecs/byte) than the beacon timestamp.
 			 */
-			int rate = local->hw.wiphy->bands[rx_status->band]->
+			int rate = local->hw.wiphy->bands[band]->
 					bitrates[rx_status->rate_idx].bitrate;
 			rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate);
 		} else if (local && local->ops && local->ops->get_tsf)
@@ -2766,7 +2806,7 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata,
 			ieee80211_sta_join_ibss(sdata, &sdata->u.sta, bss);
 			ieee80211_ibss_add_sta(sdata, NULL,
 					       mgmt->bssid, mgmt->sa,
-					       BIT(rx_status->rate_idx));
+					       supp_rates);
 		}
 	}
 
@@ -3032,7 +3072,6 @@ void ieee80211_sta_rx_mgmt(struct ieee80211_sub_if_data *sdata, struct sk_buff *
 	kfree_skb(skb);
 }
 
-
 static void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,
 					 struct sk_buff *skb)
 {
@@ -4316,10 +4355,9 @@ struct sta_info *ieee80211_ibss_add_sta(struct ieee80211_sub_if_data *sdata,
 
 	set_sta_flags(sta, WLAN_STA_AUTHORIZED);
 
-	if (supp_rates)
-		sta->supp_rates[band] = supp_rates;
-	else
-		sta->supp_rates[band] = sdata->u.sta.supp_rates_bits[band];
+	/* make sure mandatory rates are always added */
+	sta->supp_rates[band] = supp_rates |
+			ieee80211_sta_get_mandatory_rates(local, band);
 
 	rate_control_rate_init(sta, local);
 
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index fd83ef7..7e09b30 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1743,10 +1743,6 @@ static int prepare_for_handlers(struct ieee80211_sub_if_data *sdata,
 		if (!bssid)
 			return 0;
 		if (ieee80211_is_beacon(hdr->frame_control)) {
-			if (!rx->sta)
-				rx->sta = ieee80211_ibss_add_sta(sdata,
-						rx->skb, bssid, hdr->addr2,
-						BIT(rx->status->rate_idx));
 			return 1;
 		}
 		else if (!ieee80211_bssid_match(bssid, sdata->u.sta.bssid)) {
-- 
1.5.4.1

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Re: [PATCH 0/3] IBSS rate scaling fixes

[Jan Willies]

Tomas Winkler wrote:
> This series should fix fixed low rate (1Mbps) in IBSS. This is regression
> from 2.6.26
>   
Thanks, I was just about to ask why my bitrate is fixed at 1Mbps. Will 
this be going into 2.6.27?


- jan