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From:   Felix Fietkau <nbd@nbd.name>
To:     linux-wireless@vger.kernel.org
Cc:     Sean Wang <sean.wang@mediatek.com>
Subject: [PATCH v4 2/3] mt76: mt7921: fix mgmt frame using unexpected bitrate
Date:   Thu, 15 Jul 2021 21:54:53 +0200
Message-Id: <20210715195454.12370-2-nbd@nbd.name>
In-Reply-To: <20210715195454.12370-1-nbd@nbd.name>
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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.

Fixes: 163f4d22c118 ("mt76: mt7921: add MAC support")
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
v4: do not rely on rate->hw_value having the proper shift for phy mode
 drivers/net/wireless/mediatek/mt76/mt7921/mac.c    | 10 +++++-----
 drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h |  2 --
 2 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
index f4714b0f6e5c..296e0f7a1d14 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
@@ -811,15 +811,15 @@ void mt7921_mac_write_txwi(struct mt7921_dev *dev, __le32 *txwi,
 		mt7921_mac_write_txwi_80211(dev, txwi, skb, key);
 
 	if (txwi[2] & cpu_to_le32(MT_TXD2_FIX_RATE)) {
-		u16 rate;
+		u16 rate, mode;
 
 		/* 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 = mt76_default_basic_rate(mphy, vif);
+		mode = rate >> 8;
+		rate &= GENMASK(7, 0);
+		rate |= FIELD_PREP(MT_TX_RATE_MODE, mode);
 
 		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 ac0b414ccd92..6e9e4dfb3928 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
-- 
2.30.1