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From:   <sean.wang@mediatek.com>
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Subject: [PATCH v2 2/2] mt76: mt7921: fix mgmt frame using unexpected bitrate
Date:   Tue, 13 Jul 2021 02:40:12 +0800
Message-ID: <197a513340ed939c17e0feb4e2e1040cd46d5eb9.1626114777.git.objelf@gmail.com>
In-Reply-To: <a9586764e6cd94bb91e0a9addf9319bb95dfe4db.1626114777.git.objelf@gmail.com>
References: <a9586764e6cd94bb91e0a9addf9319bb95dfe4db.1626114777.git.objelf@gmail.com>
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From: Sean Wang <sean.wang@mediatek.com>

Fix the current driver mgmt frame is not respecting the basic rates field
provided by the AP and then unconditionally is using the lowest (1 or 6
Mbps) rate.

For example, if the AP only supported basic rate {24, 36, 48, 54} Mbps,
mt7921 cannot send mgmt frame with the rate not in the group. So,
instead, we pick up the lowest basic rate the AP can support to send.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 v2: 1. introduce another patch ("mt76: fix mt76_rates for the multiple devices")
	for those devices which have the same issue.
     2. drop the own mt7921_rates, the unused macro and variable.
---
 .../net/wireless/mediatek/mt76/mt7921/mac.c   | 22 ++++++++++++++-----
 .../wireless/mediatek/mt76/mt7921/mt7921.h    |  2 --
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
index 7fe2e3a50428..a5cbc567b924 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
@@ -749,13 +749,28 @@ static void mt7921_update_txs(struct mt76_wcid *wcid, __le32 *txwi)
 			       FIELD_PREP(MT_TXD5_PID, pid));
 }
 
+static u16
+mt7921_default_basic_rates(struct mt7921_dev *dev, struct ieee80211_vif *vif)
+{
+	struct mt76_phy *mphy = &dev->mphy;
+	struct ieee80211_rate *rate;
+	int i, offset = 0;
+
+	if (mphy->chandef.chan->band == NL80211_BAND_5GHZ)
+		offset = 4;
+
+	i = ffs(vif->bss_conf.basic_rates) - 1;
+	rate = &mt76_rates[offset + i];
+
+	return rate->hw_value;
+}
+
 void mt7921_mac_write_txwi(struct mt7921_dev *dev, __le32 *txwi,
 			   struct sk_buff *skb, struct mt76_wcid *wcid,
 			   struct ieee80211_key_conf *key, bool beacon)
 {
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	struct ieee80211_vif *vif = info->control.vif;
-	struct mt76_phy *mphy = &dev->mphy;
 	u8 p_fmt, q_idx, omac_idx = 0, wmm_idx = 0;
 	bool is_8023 = info->flags & IEEE80211_TX_CTL_HW_80211_ENCAP;
 	u16 tx_count = 15;
@@ -815,10 +830,7 @@ void mt7921_mac_write_txwi(struct mt7921_dev *dev, __le32 *txwi,
 		/* hardware won't add HTC for mgmt/ctrl frame */
 		txwi[2] |= cpu_to_le32(MT_TXD2_HTC_VLD);
 
-		if (mphy->chandef.chan->band == NL80211_BAND_5GHZ)
-			rate = MT7921_5G_RATE_DEFAULT;
-		else
-			rate = MT7921_2G_RATE_DEFAULT;
+		rate = mt7921_default_basic_rates(dev, vif);
 
 		val = MT_TXD6_FIXED_BW |
 		      FIELD_PREP(MT_TXD6_TX_RATE, rate);
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h b/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h
index 2d8bd6bfc820..be16d528a923 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h
@@ -38,8 +38,6 @@
 
 #define MT7921_CFEND_RATE_DEFAULT	0x49	/* OFDM 24M */
 #define MT7921_CFEND_RATE_11B		0x03	/* 11B LP, 11M */
-#define MT7921_5G_RATE_DEFAULT		0x4b	/* OFDM 6M */
-#define MT7921_2G_RATE_DEFAULT		0x0	/* CCK 1M */
 
 #define MT7921_SKU_RATE_NUM		161
 #define MT7921_SKU_MAX_DELTA_IDX	MT7921_SKU_RATE_NUM
-- 
2.25.1