[PATCH 6.1 0454/1146] wifi: mt76: mt7921: fix antenna signal are way off in monitor mode

Greg Kroah-Hartman
2022-12-28T15:58:50Z

From: Sean Wang <sean.wang@mediatek.com>

[ Upstream commit c256ba6b1909f28b517274282b6845567e974143 ]

Group 3 in RxD is disabled in monitor mode. We should use the group 5 in
RxD instead to fix antenna signal way off issue, e.g we would see the
incorrect antenna signal value in wireshark. On the other hand, Group 5
wouldn't be used in STA or AP mode, so the patch shouldn't cause any
harm to those modes.

Fixes: cbaa0a404f8d ("mt76: mt7921: fix up the monitor mode")
Reported-by: Adrian Granados <agranados@gmail.com>
Co-developed-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Deren Wu <deren.wu@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../net/wireless/mediatek/mt76/mt7921/mac.c | 32 ++++++++++++-------
1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
index 650ab97ae052..6860468ed191 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c
@@ -396,6 +396,27 @@ mt7921_mac_fill_rx(struct mt7921_dev *dev, struct sk_buff *skb)
if (v0 & MT_PRXV_HT_AD_CODE)
status->enc_flags |= RX_ENC_FLAG_LDPC;

+ ret = mt76_connac2_mac_fill_rx_rate(&dev->mt76, status, sband,
+ rxv, &mode);
+ if (ret < 0)
+ return ret;
+
+ if (rxd1 & MT_RXD1_NORMAL_GROUP_5) {
+ rxd += 6;
+ if ((u8 *)rxd - skb->data >= skb->len)
+ return -EINVAL;
+
+ rxv = rxd;
+ /* Monitor mode would use RCPI described in GROUP 5
+ * instead.
+ */
+ v1 = le32_to_cpu(rxv[0]);
+
+ rxd += 12;
+ if ((u8 *)rxd - skb->data >= skb->len)
+ return -EINVAL;
+ }
+
status->chains = mphy->antenna_mask;
status->chain_signal[0] = to_rssi(MT_PRXV_RCPI0, v1);
status->chain_signal[1] = to_rssi(MT_PRXV_RCPI1, v1);
@@ -410,17 +431,6 @@ mt7921_mac_fill_rx(struct mt7921_dev *dev, struct sk_buff *skb)
status->signal = max(status->signal,
status->chain_signal[i]);
}
-
- ret = mt76_connac2_mac_fill_rx_rate(&dev->mt76, status, sband,
- rxv, &mode);
- if (ret < 0)
- return ret;
-
- if (rxd1 & MT_RXD1_NORMAL_GROUP_5) {
- rxd += 18;
- if ((u8 *)rxd - skb->data >= skb->len)
- return -EINVAL;
- }
}

amsdu_info = FIELD_GET(MT_RXD4_NORMAL_PAYLOAD_FORMAT, rxd4);
--
2.35.1