cw1200: 11n verification and bugfixing.

 * MCS rate indexes were wrongly interpreted by the driver as legacy rate offsets
   in both TX and RX directions.
 * HT rates have not been marked as MCS rates in rate description table.
 * Driver should not expose AMPDU aggregation capability to the mac80211 stack,
   aggrehation is fully controlled by the firmware. Firmware takes care of block
   ACK negotiation.
 * Block ACK action frames are filtered by driver: mac80211 layer is not involved
   into BA dialog.
 * Block ACK in TX direction is enabled.
 * Block ACK in SoftAP mode is enabled.
 * RX'ed frames should not be marked as "aggregated" for the mac80211 stack,
   it confuses rate control algorithm quite a lot.
 * CONFIG_CW1200_HT_SUPPORT option is removed: drivers always supports HT.

TODO:
 - Modify minstrel rate policy "distillation" to prioritize higher bitrates.
 - Verify greenfield mode.

Change-Id: I9288a2b99984785ae97d85de98ea79d3a49ea64f
Signed-off-by: Dmitry Tarnyagin <dmitry.tarnyagin@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/24480
Reviewed-by: Robert MARKLUND <robert.marklund@stericsson.com>
Tested-by: Robert MARKLUND <robert.marklund@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/25620
Reviewed-by: Philippe LANGLAIS <philippe.langlais@stericsson.com>

6 files changed, 138 insertions, 83 deletions

diff --git a/drivers/staging/cw1200/Kconfig b/drivers/staging/cw1200/Kconfig
index ed2d23e5d47..8be1b909f6d 100644
--- a/drivers/staging/cw1200/Kconfig
+++ b/drivers/staging/cw1200/Kconfig
@@ -38,15 +38,6 @@ config CW1200_FIRMWARE_DOES_NOT_SUPPORT_KEEPALIVE
 
         If unsure, say N.
 
-config CW1200_HT_SUPPORT
-      bool "11n support (DEVELOPMENT)"
-      depends on CW1200
-      help
-        Say Y if you want to enable 11n support in the driver.
-        Note that 11n support is not 100% verified, status is unknown.
-
-        If unsure, say N.
-
 menu "Driver debug features"
       depends on CW1200
 
diff --git a/drivers/staging/cw1200/ap.c b/drivers/staging/cw1200/ap.c
index 7fa863c6f20..561dab3f94f 100644
--- a/drivers/staging/cw1200/ap.c
+++ b/drivers/staging/cw1200/ap.c
@@ -427,31 +427,11 @@ int cw1200_ampdu_action(struct ieee80211_hw *hw,
 			enum ieee80211_ampdu_mlme_action action,
 			struct ieee80211_sta *sta, u16 tid, u16 *ssn)
 {
-	int ret = 0;
-
-	switch (action) {
-	/*
-	 * The hw itself takes care of setting up BlockAck mechanisms.
-	 * So, we only have to allow mac80211 to nagotiate a BlockAck
-	 * agreement. Once that is done, the hw will BlockAck incoming
-	 * AMPDUs without further setup.
-	 */
-	case IEEE80211_AMPDU_RX_START:
-	case IEEE80211_AMPDU_RX_STOP:
-		break;
-	case IEEE80211_AMPDU_TX_START:
-		ieee80211_start_tx_ba_cb_irqsafe(vif, sta->addr, tid);
-		break;
-	case IEEE80211_AMPDU_TX_STOP:
-		ieee80211_stop_tx_ba_cb_irqsafe(vif, sta->addr, tid);
-		break;
-	case IEEE80211_AMPDU_TX_OPERATIONAL:
-		break;
-	default:
-		ret = -ENOTSUPP;
-	}
-
-	return ret;
+	/* Aggregation is implemented fully in firmware,
+	 * including block ack negotiation. Do not allow
+	 * mac80211 stack to do anything: it interferes with
+	 * the firmware. */
+	return -ENOTSUPP;
 }
 
 /* ******************************************************************** */
@@ -606,6 +586,8 @@ static int cw1200_start_ap(struct cw1200_common *priv)
 	if (!ret)
 		ret = WARN_ON(wsm_beacon_transmit(priv, &transmit));
 	if (!ret) {
+		WARN_ON(wsm_set_block_ack_policy(priv,
+			priv->ba_tid_mask, priv->ba_tid_mask));
 		priv->join_status = CW1200_JOIN_STATUS_AP;
 		cw1200_update_filtering(priv);
 	}
diff --git a/drivers/staging/cw1200/cw1200.h b/drivers/staging/cw1200/cw1200.h
index 0c88bfa48da..cd5061d1097 100644
--- a/drivers/staging/cw1200/cw1200.h
+++ b/drivers/staging/cw1200/cw1200.h
@@ -81,7 +81,8 @@ struct cw1200_common {
 	/* calibration, output power limit and rssi<->dBm conversation data */
 
 	/* BBP/MAC state */
-	struct ieee80211_rate *rates;
+	struct ieee80211_rate		*rates;
+	struct ieee80211_rate		*mcs_rates;
 	u8 mac_addr[ETH_ALEN];
 	struct ieee80211_channel	*channel;
 	u8 bssid[ETH_ALEN];
@@ -107,6 +108,7 @@ struct cw1200_common {
 	bool				listening;
 	struct wsm_rx_filter		rx_filter;
 	struct wsm_beacon_filter_control bf_control;
+	u8				ba_tid_mask;
 
 	/* BH */
 	atomic_t			bh_rx;
diff --git a/drivers/staging/cw1200/main.c b/drivers/staging/cw1200/main.c
index 0a1193b8b41..e22fbf2e22e 100644
--- a/drivers/staging/cw1200/main.c
+++ b/drivers/staging/cw1200/main.c
@@ -71,22 +71,22 @@ static struct ieee80211_rate cw1200_rates[] = {
 	RATETAB_ENT(360, 11, 0),
 	RATETAB_ENT(480, 12, 0),
 	RATETAB_ENT(540, 13, 0),
-#if defined(CONFIG_CW1200_HT_SUPPORT)
-	RATETAB_ENT(65,  14, 0),
-	RATETAB_ENT(130, 15, 0),
-	RATETAB_ENT(195, 16, 0),
-	RATETAB_ENT(260, 17, 0),
-	RATETAB_ENT(390, 18, 0),
-	RATETAB_ENT(520, 19, 0),
-	RATETAB_ENT(585, 20, 0),
-	RATETAB_ENT(650, 21, 0),
-#endif /* CONFIG_CW1200_HT_SUPPORT */
+	RATETAB_ENT(65,  14, IEEE80211_TX_RC_MCS),
+	RATETAB_ENT(130, 15, IEEE80211_TX_RC_MCS),
+	RATETAB_ENT(195, 16, IEEE80211_TX_RC_MCS),
+	RATETAB_ENT(260, 17, IEEE80211_TX_RC_MCS),
+	RATETAB_ENT(390, 18, IEEE80211_TX_RC_MCS),
+	RATETAB_ENT(520, 19, IEEE80211_TX_RC_MCS),
+	RATETAB_ENT(585, 20, IEEE80211_TX_RC_MCS),
+	RATETAB_ENT(650, 21, IEEE80211_TX_RC_MCS),
 };
 
 #define cw1200_a_rates		(cw1200_rates + 4)
 #define cw1200_a_rates_size	(ARRAY_SIZE(cw1200_rates) - 4)
 #define cw1200_g_rates		(cw1200_rates + 0)
 #define cw1200_g_rates_size	(ARRAY_SIZE(cw1200_rates))
+#define cw1200_n_rates		(cw1200_rates + 12)
+#define cw1200_n_rates_size	(ARRAY_SIZE(cw1200_rates) - 12)
 
 
 #define CHAN2G(_channel, _freq, _flags) {			\
@@ -151,7 +151,6 @@ static struct ieee80211_supported_band cw1200_band_2ghz = {
 	.n_channels = ARRAY_SIZE(cw1200_2ghz_chantable),
 	.bitrates = cw1200_g_rates,
 	.n_bitrates = cw1200_g_rates_size,
-#if defined(CONFIG_CW1200_HT_SUPPORT)
 	.ht_cap = {
 		.cap = IEEE80211_HT_CAP_SM_PS |
 			IEEE80211_HT_CAP_GRN_FLD |
@@ -160,8 +159,6 @@ static struct ieee80211_supported_band cw1200_band_2ghz = {
 			IEEE80211_HT_CAP_DELAY_BA |
 			IEEE80211_HT_CAP_MAX_AMSDU,
 		.ht_supported = 1,
-		/* TODO: It was 4K for cut 1.1 HW, if I remember
-		 * it correctly. Needs to be verified on cut 2 HW. */
 		.ampdu_factor = IEEE80211_HT_MAX_AMPDU_8K,
 		.ampdu_density = IEEE80211_HT_MPDU_DENSITY_NONE,
 		.mcs = {
@@ -170,7 +167,6 @@ static struct ieee80211_supported_band cw1200_band_2ghz = {
 			.tx_params = IEEE80211_HT_MCS_TX_DEFINED,
 		},
 	},
-#endif /* CONFIG_CW1200_HT_SUPPORT */
 };
 
 static struct ieee80211_supported_band cw1200_band_5ghz = {
@@ -178,7 +174,6 @@ static struct ieee80211_supported_band cw1200_band_5ghz = {
 	.n_channels = ARRAY_SIZE(cw1200_5ghz_chantable),
 	.bitrates = cw1200_a_rates,
 	.n_bitrates = cw1200_a_rates_size,
-#if defined(CONFIG_CW1200_HT_SUPPORT)
 	.ht_cap = {
 		.cap = IEEE80211_HT_CAP_SM_PS |
 			IEEE80211_HT_CAP_GRN_FLD |
@@ -187,8 +182,6 @@ static struct ieee80211_supported_band cw1200_band_5ghz = {
 			IEEE80211_HT_CAP_DELAY_BA |
 			IEEE80211_HT_CAP_MAX_AMSDU,
 		.ht_supported = 1,
-		/* TODO: It was 4K for cut 1.1 HW, if I remember
-		* it correctly. Needs to be verified on cut 2 HW. */
 		.ampdu_factor = IEEE80211_HT_MAX_AMPDU_8K,
 		.ampdu_density = IEEE80211_HT_MPDU_DENSITY_NONE,
 		.mcs = {
@@ -197,7 +190,6 @@ static struct ieee80211_supported_band cw1200_band_5ghz = {
 			.tx_params = IEEE80211_HT_MCS_TX_DEFINED,
 		},
 	},
-#endif /* CONFIG_CW1200_HT_SUPPORT */
 };
 
 static const struct ieee80211_ops cw1200_ops = {
@@ -240,15 +232,18 @@ struct ieee80211_hw *cw1200_init_common(size_t priv_data_len)
 	priv->hw = hw;
 	priv->mode = NL80211_IFTYPE_UNSPECIFIED;
 	priv->rates = cw1200_rates; /* TODO: fetch from FW */
+	priv->mcs_rates = cw1200_n_rates;
+	/* Enable block ACK for every TID but voice. */
+	priv->ba_tid_mask = 0x3F;
 
 	hw->flags = IEEE80211_HW_SIGNAL_DBM |
 		    IEEE80211_HW_SUPPORTS_PS |
 		    /* IEEE80211_HW_SUPPORTS_UAPSD | */
 		    IEEE80211_HW_CONNECTION_MONITOR |
 		    IEEE80211_HW_SUPPORTS_CQM_RSSI |
-#if defined(CONFIG_CW1200_HT_SUPPORT)
-		    IEEE80211_HW_AMPDU_AGGREGATION |
-#endif
+		    /* Aggregation is fully controlled by firmware.
+		     * Do not need any support from the mac80211 stack */
+		    /* IEEE80211_HW_AMPDU_AGGREGATION | */
 #if defined(CONFIG_CW1200_USE_STE_EXTENSIONS)
 		    IEEE80211_HW_SUPPORTS_CQM_BEACON_MISS |
 		    IEEE80211_HW_SUPPORTS_CQM_TX_FAIL |
diff --git a/drivers/staging/cw1200/sta.c b/drivers/staging/cw1200/sta.c
index 60a3c57100b..65df33ac61f 100644
--- a/drivers/staging/cw1200/sta.c
+++ b/drivers/staging/cw1200/sta.c
@@ -972,12 +972,8 @@ void cw1200_join_work(struct work_struct *work)
 
 		wsm_flush_tx(priv);
 
-		/* TX block_ack can use only 3 TX buffers,
-		 * which is /slightly/ :) unefficient => disabled.
-		 * RX block ACK is enabled for everything but voice.
-		 * TODO: Verify video lags, change 0x3F -> 0x0F
-		 * if necessary. */
-		WARN_ON(wsm_set_block_ack_policy(priv, 0x00, 0x3F));
+		WARN_ON(wsm_set_block_ack_policy(priv,
+				priv->ba_tid_mask, priv->ba_tid_mask));
 
 #if defined(CW1200_FIRMWARE_DOES_NOT_SUPPORT_KEEPALIVE)
 		priv->last_activity_time = jiffies;
diff --git a/drivers/staging/cw1200/txrx.c b/drivers/staging/cw1200/txrx.c
index 005654eabe8..16a85b39b99 100644
--- a/drivers/staging/cw1200/txrx.c
+++ b/drivers/staging/cw1200/txrx.c
@@ -22,6 +22,14 @@
 #define tx_policy_printk(...)
 #endif
 
+static int cw1200_handle_action_rx(struct cw1200_common *priv,
+				   struct sk_buff *skb);
+static int cw1200_handle_action_tx(struct cw1200_common *priv,
+				   struct sk_buff *skb);
+static const struct ieee80211_rate *
+cw1200_get_tx_rate(const struct cw1200_common *priv,
+		   const struct ieee80211_tx_rate *rate);
+
 /* ******************************************************************** */
 /* TX queue lock / unlock						*/
 
@@ -67,8 +75,7 @@ static void tx_policy_build(const struct cw1200_common *priv,
 	/* [out] */ struct tx_policy *policy,
 	struct ieee80211_tx_rate *rates, size_t count)
 {
-	int i;
-	const struct ieee80211_rate *rates_tbl = priv->rates;
+	int i, j;
 	unsigned limit = priv->short_frame_max_tx_count;
 	unsigned total = 0;
 	BUG_ON(rates[0].idx < 0);
@@ -76,22 +83,34 @@ static void tx_policy_build(const struct cw1200_common *priv,
 
 	/* minstrel is buggy a little bit, so distille
 	 * incoming rates first. */
-	for (i = 0; i < count; ++i) {
-		if (rates[i].idx < 0)
-			break;
-		/* minstrel is buggy a little bit. */
-		if (i && (rates[i].idx == rates[i - 1].idx)) {
-			rates[i - 1].count += rates[i].count;
+	for (i = 1; i < count; ++i) {
+		if (rates[i].idx < 0) {
+			count = i;
 			break;
 		}
-		total += rates[i].count;
-		if (i && (rates[i].idx > rates[i - 1].idx)) {
+		if (rates[i].idx > rates[i - 1].idx) {
 			struct ieee80211_tx_rate tmp = rates[i - 1];
 			rates[i - 1] = rates[i];
 			rates[i] = tmp;
 		}
 	}
-	count = i;
+
+	total = rates[0].count;
+	for (i = 0, j = 1; j < count; ++j) {
+		if (rates[j].idx == rates[i].idx) {
+			rates[i].count += rates[j].count;
+		} else if (rates[j].idx > rates[i].idx) {
+			break;
+		} else {
+			++i;
+			if (i != j)
+				rates[i] = rates[j];
+		}
+		total += rates[j].count;
+	}
+	if (i + 1 < count)
+		count = i + 1;
+
 	if (limit < count)
 		limit = count;
 
@@ -102,12 +121,12 @@ static void tx_policy_build(const struct cw1200_common *priv,
 			limit -= rates[i].count;
 		}
 	}
-	policy->defined = rates_tbl[rates[0].idx].hw_value + 1;
+	policy->defined = cw1200_get_tx_rate(priv, &rates[0])->hw_value + 1;
 
 	for (i = 0; i < count; ++i) {
 		register unsigned rateid, off, shift, retries;
 
-		rateid = rates_tbl[rates[i].idx].hw_value;
+		rateid = cw1200_get_tx_rate(priv, &rates[i])->hw_value;
 		off = rateid >> 3;		/* eq. rateid / 8 */
 		shift = (rateid & 0x07) << 2;	/* eq. (rateid % 8) * 4 */
 
@@ -331,13 +350,26 @@ u32 cw1200_rate_mask_to_wsm(struct cw1200_common *priv, u32 rates)
 	return ret;
 }
 
+static const struct ieee80211_rate *
+cw1200_get_tx_rate(const struct cw1200_common *priv,
+		   const struct ieee80211_tx_rate *rate)
+{
+	if (rate->idx < 0)
+		return NULL;
+	if (rate->flags & IEEE80211_TX_RC_MCS)
+		return &priv->mcs_rates[rate->idx];
+	return &priv->hw->wiphy->bands[priv->channel->band]->
+		bitrates[rate->idx];
+}
+
 /* NOTE: cw1200_skb_to_wsm executes in atomic context. */
 int cw1200_skb_to_wsm(struct cw1200_common *priv, struct sk_buff *skb,
 			struct wsm_tx *wsm)
 {
 	bool tx_policy_renew = false;
 	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
-	struct ieee80211_rate *rate = ieee80211_get_tx_rate(priv->hw, tx_info);
+	const struct ieee80211_rate *rate = cw1200_get_tx_rate(priv,
+		&tx_info->control.rates[0]);
 
 	memset(wsm, 0, sizeof(*wsm));
 	wsm->hdr.len = __cpu_to_le16(skb->len);
@@ -467,6 +499,10 @@ int cw1200_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
 		skb_trim(skb, skb->len - offset);
 	}
 
+	if (ieee80211_is_action(hdr->frame_control))
+		if (cw1200_handle_action_tx(priv, skb))
+			goto drop;
+
 	ret = cw1200_queue_put(&priv->tx_queue[queue], priv, skb,
 			link_id);
 	if (!WARN_ON(ret))
@@ -480,12 +516,42 @@ err:
 	/* TODO: Update TX failure counters */
 	dev_kfree_skb_any(skb);
 	return NETDEV_TX_OK;
+
+drop:
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+/* ******************************************************************** */
+
+static int cw1200_handle_action_rx(struct cw1200_common *priv,
+				   struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+
+	/* Filter block ACK negotiation: fully controlled by firmware */
+	if (mgmt->u.action.category == WLAN_CATEGORY_BACK)
+		return 1;
+
+	return 0;
+}
+
+static int cw1200_handle_action_tx(struct cw1200_common *priv,
+				   struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt = (void *)skb->data;
+
+	/* Filter block ACK negotiation: fully controlled by firmware */
+	if (mgmt->u.action.category == WLAN_CATEGORY_BACK)
+		return 1;
+
+	return 0;
 }
 
 /* ******************************************************************** */
 
 void cw1200_tx_confirm_cb(struct cw1200_common *priv,
-				struct wsm_tx_confirm *arg)
+			  struct wsm_tx_confirm *arg)
 {
 	u8 queue_id = cw1200_queue_get_queue_id(arg->packetID);
 	struct cw1200_queue *queue = &priv->tx_queue[queue_id];
@@ -527,7 +593,9 @@ void cw1200_tx_confirm_cb(struct cw1200_common *priv,
 			++tx_count;
 			cw1200_debug_txed(priv);
 			if (arg->flags & WSM_TX_STATUS_AGGREGATION) {
-				tx->flags |= IEEE80211_TX_STAT_AMPDU;
+				/* Do not report aggregation to mac80211:
+				 * it confuses minstrel a lot. */
+				/* tx->flags |= IEEE80211_TX_STAT_AMPDU; */
 				cw1200_debug_txed_agg(priv);
 			}
 		} else {
@@ -569,6 +637,8 @@ void cw1200_rx_cb(struct cw1200_common *priv,
 {
 	struct sk_buff *skb = *skb_p;
 	struct ieee80211_rx_status *hdr = IEEE80211_SKB_RXCB(skb);
+	const struct ieee80211_rate *rate;
+	__le16 frame_control;
 	hdr->flag = 0;
 
 	if (unlikely(priv->mode == NL80211_IFTYPE_UNSPECIFIED)) {
@@ -590,13 +660,29 @@ void cw1200_rx_cb(struct cw1200_common *priv,
 		}
 	}
 
+	if (skb->len < sizeof(struct ieee80211_hdr_3addr)) {
+		wiphy_warn(priv->hw->wiphy, "Mailformed SDU rx'ed.\n");
+		return;
+	}
+
+	frame_control = *(__le16*)skb->data;
 	hdr->mactime = 0; /* Not supported by WSM */
 	hdr->freq = ieee80211_channel_to_frequency(arg->channelNumber);
 	hdr->band = (hdr->freq >= 5000) ?
 		IEEE80211_BAND_5GHZ : IEEE80211_BAND_2GHZ;
-	hdr->rate_idx = arg->rxedRate;
-	if (hdr->rate_idx >= 4) /* TODO: Use common convert function. */
-		hdr->rate_idx -= 2;
+
+	if (arg->rxedRate >= 4)
+		rate = &priv->rates[arg->rxedRate - 2];
+	else
+		rate = &priv->rates[arg->rxedRate];
+
+	if (rate >= priv->mcs_rates) {
+		hdr->rate_idx = rate - priv->mcs_rates;
+		hdr->flag |= RX_FLAG_HT;
+	} else {
+		hdr->rate_idx = rate - priv->rates;
+	}
+
 	hdr->signal = (s8)arg->rcpiRssi;
 	hdr->antenna = 0;
 
@@ -609,13 +695,16 @@ void cw1200_rx_cb(struct cw1200_common *priv,
 			skb_trim(skb, skb->len - 8 /*MICHAEL_MIC_LEN*/);
 		}
 	}
-	if (arg->flags & WSM_RX_STATUS_HT)
-		hdr->flag |= RX_FLAG_HT;
 
 	cw1200_debug_rxed(priv);
 	if (arg->flags & WSM_RX_STATUS_AGGREGATE)
 		cw1200_debug_rxed_agg(priv);
 
+	if (ieee80211_is_action(frame_control) &&
+			(arg->flags & WSM_RX_STATUS_ADDRESS1))
+		if (cw1200_handle_action_rx(priv, skb))
+			return;
+
 	/* Not that we really need _irqsafe variant here,
 	 * but it offloads realtime bh thread and improve
 	 * system performance. */