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From:   greearb@candelatech.com
To:     linux-wireless@vger.kernel.org
Cc:     Ben Greear <greearb@candelatech.com>
Subject: [PATCH v2 10/11] mt76: mt7915:  Report tx-retries
Date:   Thu, 22 Jul 2021 13:28:33 -0700
Message-Id: <20210722202834.6826-10-greearb@candelatech.com>
In-Reply-To: <20210722202834.6826-1-greearb@candelatech.com>
References: <20210722202834.6826-1-greearb@candelatech.com>
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From: Ben Greear <greearb@candelatech.com>

mac80211 stack will only report tx-status for skb claiming to be ampdu heads,
so lie a bit in mt7915 and set the flag so that mac80211 will record status
for each skb.

mt7915 appears to report retry status on an individual per-skb manner,
so that method above seems to work.

Re-constitute the txinfo status rate info so that the rix and flags
is also at least close to correct.  No direct way to report HE
rates that way, so mac80211 might could use some tweaking in
the ieee80211_tx_status_ext to take both info and status->rate
into account.

Signed-off-by: Ben Greear <greearb@candelatech.com>
---
 .../net/wireless/mediatek/mt76/mt7915/init.c  |  1 +
 .../net/wireless/mediatek/mt76/mt7915/mac.c   | 82 +++++++++++++++++--
 .../net/wireless/mediatek/mt76/mt7915/mac.h   |  4 +-
 drivers/net/wireless/mediatek/mt76/tx.c       |  6 +-
 4 files changed, 86 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/init.c b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
index a0d282771d77..9dc7a67dd76f 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/init.c
@@ -217,6 +217,7 @@ mt7915_init_wiphy(struct ieee80211_hw *hw)
 	struct wiphy *wiphy = hw->wiphy;
 
 	hw->queues = 4;
+	hw->max_report_rates = 1;
 	hw->max_rx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF;
 	hw->max_tx_aggregation_subframes = IEEE80211_MAX_AMPDU_BUF;
 	hw->netdev_features = NETIF_F_RXCSUM;
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
index d5747d61404a..09c91f887ae9 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
@@ -1257,17 +1257,22 @@ mt7915_txp_skb_unmap(struct mt76_dev *dev, struct mt76_txwi_cache *t)
 
 static void
 mt7915_txwi_free(struct mt7915_dev *dev, struct mt76_txwi_cache *t,
-		 struct ieee80211_sta *sta, struct list_head *free_list)
+		 struct ieee80211_sta *sta, struct list_head *free_list,
+		 u32 tx_cnt, u32 tx_status, u32 ampdu)
 {
 	struct mt76_dev *mdev = &dev->mt76;
 	struct mt76_wcid *wcid;
 	__le32 *txwi;
 	u16 wcid_idx;
+	struct ieee80211_tx_info *info;
+	struct ieee80211_tx_rate *rate;
 
 	mt7915_txp_skb_unmap(mdev, t);
 	if (!t->skb)
 		goto out;
 
+	rcu_read_lock(); /* protect wcid access */
+
 	txwi = (__le32 *)mt76_get_txwi_ptr(mdev, t);
 	if (sta) {
 		wcid = (struct mt76_wcid *)sta->drv_priv;
@@ -1277,6 +1282,64 @@ mt7915_txwi_free(struct mt7915_dev *dev, struct mt76_txwi_cache *t,
 			mt7915_tx_check_aggr(sta, txwi);
 	} else {
 		wcid_idx = FIELD_GET(MT_TXD1_WLAN_IDX, le32_to_cpu(txwi[1]));
+		wcid = rcu_dereference(mdev->wcid[wcid_idx]);
+	}
+
+	info = IEEE80211_SKB_CB(t->skb);
+
+	/* Cannot clear all of info->status, we need the driver private
+	 * status intact.
+	 */
+	info->status.is_valid_ack_signal = 0;
+
+	rate = &info->status.rates[0];
+	rate->idx = -1; /* will over-write below if we found wcid */
+	info->status.rates[1].idx = -1; /* terminate rate list */
+
+	/* force TX_STAT_AMPDU to be set, or mac80211 will ignore status */
+	if (ampdu || (info->flags & IEEE80211_TX_CTL_AMPDU)) {
+		info->flags |= IEEE80211_TX_STAT_AMPDU | IEEE80211_TX_CTL_AMPDU;
+		info->status.ampdu_len = 1;
+	}
+
+	/* update info status based on cached wcid rate info since
+	 * txfree path doesn't give us a lot of info.
+	 */
+	if (wcid) {
+		if (wcid->rate.flags & RATE_INFO_FLAGS_MCS) {
+			rate->flags |= IEEE80211_TX_RC_MCS;
+			rate->idx = wcid->rate.mcs + wcid->rate.nss * 8;
+		} else if (wcid->rate.flags & RATE_INFO_FLAGS_VHT_MCS) {
+			rate->flags |= IEEE80211_TX_RC_VHT_MCS;
+			rate->idx = (wcid->rate.nss << 4) | wcid->rate.mcs;
+		} else if (wcid->rate.flags & RATE_INFO_FLAGS_HE_MCS) {
+			rate->idx = (wcid->rate.nss << 4) | wcid->rate.mcs;
+		} else {
+			rate->idx = wcid->rate.mcs;
+		}
+
+		switch (wcid->rate.bw) {
+		case RATE_INFO_BW_160:
+			rate->flags |= IEEE80211_TX_RC_160_MHZ_WIDTH;
+			break;
+		case RATE_INFO_BW_80:
+			rate->flags |= IEEE80211_TX_RC_80_MHZ_WIDTH;
+			break;
+		case RATE_INFO_BW_40:
+			rate->flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;
+			break;
+		}
+	}
+
+	rcu_read_unlock();
+
+	/* Apply the values that this txfree path reports */
+	rate->count = tx_cnt;
+	if (tx_status == 0) {
+		info->flags |= IEEE80211_TX_STAT_ACK;
+		info->status.ampdu_ack_len = 1;
+	} else {
+		info->flags &= ~IEEE80211_TX_STAT_ACK;
 	}
 
 	__mt76_tx_complete_skb(mdev, wcid_idx, t->skb, free_list);
@@ -1296,7 +1359,8 @@ mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb)
 	struct ieee80211_sta *sta = NULL;
 	LIST_HEAD(free_list);
 	struct sk_buff *tmp;
-	u8 i, count;
+	u8 i;
+	u16 count;
 	bool wake = false;
 
 	/* clean DMA queues and unmap buffers first */
@@ -1312,9 +1376,12 @@ mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb)
 	 * to the time ack is received or dropped by hw (air + hw queue time).
 	 * Should avoid accessing WTBL to get Tx airtime, and use it instead.
 	 */
+	/* free->ctrl is high u16 of first DW in the txfree struct */
 	count = FIELD_GET(MT_TX_FREE_MSDU_CNT, le16_to_cpu(free->ctrl));
 	for (i = 0; i < count; i++) {
-		u32 msdu, info = le32_to_cpu(free->info[i]);
+		u32 msdu, tx_cnt, tx_status;
+		u32 info = le32_to_cpu(free->info[i]); /* DW3+ */
+		u32 ampdu;
 
 		/*
 		 * 1'b1: new wcid pair.
@@ -1345,7 +1412,12 @@ mt7915_mac_tx_free(struct mt7915_dev *dev, struct sk_buff *skb)
 		if (!txwi)
 			continue;
 
-		mt7915_txwi_free(dev, txwi, sta, &free_list);
+		tx_cnt = FIELD_GET(MT_TX_FREE_TXCNT, info);
+		/* 0 = success, 1 dropped-by-hw, 2 dropped-by-cpu */
+		tx_status = FIELD_GET(MT_TX_FREE_STATUS, info);
+		ampdu = FIELD_GET(MT_TX_FREE_HEAD_OF_PAGE, info);
+
+		mt7915_txwi_free(dev, txwi, sta, &free_list, tx_cnt, tx_status, ampdu);
 	}
 
 	mt7915_mac_sta_poll(dev);
@@ -1873,7 +1945,7 @@ void mt7915_tx_token_put(struct mt7915_dev *dev)
 
 	spin_lock_bh(&dev->mt76.token_lock);
 	idr_for_each_entry(&dev->mt76.token, txwi, id) {
-		mt7915_txwi_free(dev, txwi, NULL, NULL);
+		mt7915_txwi_free(dev, txwi, NULL, NULL, 0, 1, 0);
 		dev->mt76.token_count--;
 	}
 	spin_unlock_bh(&dev->mt76.token_lock);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mac.h b/drivers/net/wireless/mediatek/mt76/mt7915/mac.h
index 741d51b0fa06..3f8fbed144df 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mac.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mac.h
@@ -299,7 +299,7 @@ struct mt7915_tx_free {
 	__le16 ctrl;
 	u8 txd_cnt;
 	u8 rsv[3];
-	__le32 info[];
+	__le32 info[]; /* DW3+ */
 } __packed __aligned(4);
 
 #define MT_TX_FREE_MSDU_CNT		GENMASK(9, 0)
@@ -311,6 +311,8 @@ struct mt7915_tx_free {
 /* when configured for txcount mode.  See MT_PLE_HOST_RPT0_TX_LATENCY. */
 #define MT_TX_FREE_TXCNT		GENMASK(12, 0)
 #define MT_TX_FREE_STATUS		GENMASK(14, 13)
+/* 0:  not MPDU, 1:  MSDU is head pkt of TXD page (MPDU) */
+#define MT_TX_FREE_HEAD_OF_PAGE		BIT(15)
 #define MT_TX_FREE_MSDU_ID		GENMASK(30, 16)
 #define MT_TX_FREE_PAIR			BIT(31)
 
diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c
index 730f37aede3a..7ab7ea63fa52 100644
--- a/drivers/net/wireless/mediatek/mt76/tx.c
+++ b/drivers/net/wireless/mediatek/mt76/tx.c
@@ -263,6 +263,7 @@ void __mt76_tx_complete_skb(struct mt76_dev *dev, u16 wcid_idx, struct sk_buff *
 	struct ieee80211_tx_status status = {
 		.skb = skb,
 		.free_list = free_list,
+		.info = IEEE80211_SKB_CB(skb),
 	};
 	struct mt76_wcid *wcid = NULL;
 	struct ieee80211_hw *hw;
@@ -270,8 +271,11 @@ void __mt76_tx_complete_skb(struct mt76_dev *dev, u16 wcid_idx, struct sk_buff *
 
 	rcu_read_lock();
 
-	if (wcid_idx < ARRAY_SIZE(dev->wcid))
+	if (wcid_idx < ARRAY_SIZE(dev->wcid)) {
 		wcid = rcu_dereference(dev->wcid[wcid_idx]);
+		if (wcid)
+			status.rate = &wcid->rate;
+	}
 
 	mt76_tx_check_non_aql(dev, wcid, skb);
 
-- 
2.20.1