diff mbox series

[08/12] wifi: mt76: mt7915: use nss for calculating rx-chains

Message ID 20220727230122.29842-8-greearb@candelatech.com (mailing list archive)
State Superseded
Delegated to: Felix Fietkau
Headers show
Series [01/12] wifi: mt76: mt7915: cache sgi in wcid. | expand

Commit Message

Ben Greear July 27, 2022, 11:01 p.m. UTC 
From: Ben Greear <greearb@candelatech.com>

When group-5 is enabled, we can find the actuall NSS used.
In that case, update the rx chains info so that the upper
stack can give better idea of actual antenna usage.

In case of stbc, the hardware already double nss, but rssi
is not reported properly (it is '17') for the secondary chains.
So, decrease nss in the status msg so that mac80211 does not try
to average the invalid RSSI.

Signed-off-by: Ben Greear <greearb@candelatech.com>
---
 .../net/wireless/mediatek/mt76/mt7915/mac.c   | 30 ++++++++++++++-----
 1 file changed, 23 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
index 17bc64960f04..1d2909c0c04c 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7915/mac.c
@@ -487,10 +487,10 @@  static int
 mt7915_mac_fill_rx_rate(struct mt7915_dev *dev,
 			struct mt76_rx_status *status,
 			struct ieee80211_supported_band *sband,
-			__le32 *rxv, u8 *mode)
+			__le32 *rxv, u8 *mode, u8 *nss)
 {
 	u32 v0, v2;
-	u8 stbc, gi, bw, dcm, nss;
+	u8 stbc, gi, bw, dcm;
 	int i, idx;
 	bool cck = false;
 
@@ -498,7 +498,7 @@  mt7915_mac_fill_rx_rate(struct mt7915_dev *dev,
 	v2 = le32_to_cpu(rxv[2]);
 
 	idx = i = FIELD_GET(MT_PRXV_TX_RATE, v0);
-	nss = FIELD_GET(MT_PRXV_NSTS, v0) + 1;
+	*nss = FIELD_GET(MT_PRXV_NSTS, v0) + 1;
 
 	if (!is_mt7915(&dev->mt76)) {
 		stbc = FIELD_GET(MT_PRXV_HT_STBC, v0);
@@ -530,7 +530,6 @@  mt7915_mac_fill_rx_rate(struct mt7915_dev *dev,
 			return -EINVAL;
 		break;
 	case MT_PHY_TYPE_VHT:
-		status->nss = nss;
 		status->encoding = RX_ENC_VHT;
 		if (gi)
 			status->enc_flags |= RX_ENC_FLAG_SHORT_GI;
@@ -541,7 +540,6 @@  mt7915_mac_fill_rx_rate(struct mt7915_dev *dev,
 	case MT_PHY_TYPE_HE_SU:
 	case MT_PHY_TYPE_HE_EXT_SU:
 	case MT_PHY_TYPE_HE_TB:
-		status->nss = nss;
 		status->encoding = RX_ENC_HE;
 		i &= GENMASK(3, 0);
 
@@ -582,6 +580,17 @@  mt7915_mac_fill_rx_rate(struct mt7915_dev *dev,
 	if (*mode < MT_PHY_TYPE_HE_SU && gi)
 		status->enc_flags |= RX_ENC_FLAG_SHORT_GI;
 
+	/* in case stbc is set, the nss value returned by hardware is already
+	 * correct (ie, 2 instead of 1 for 1 spatial stream).  But, at least in cases
+	 * where we are configured for a single antenna, then the second chain RSSI is '17',
+	 * which I take to mean 'not set'.  To keep from adding this to the average rssi up in
+	 * mac80211 rx logic, decrease nss here.
+	 */
+	if (stbc)
+		*nss >>= 1;
+
+	status->nss = *nss;
+
 	return 0;
 }
 
@@ -755,6 +764,8 @@  mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
 	if (rxd1 & MT_RXD1_NORMAL_GROUP_3) {
 		u32 v0, v1;
 		int ret;
+		int i;
+		u8 nss;
 
 		rxv = rxd; /* DW16 assuming group 1,2,3,4 */
 		rxd += 2;
@@ -771,11 +782,11 @@  mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
 		/* TODO:  When group-5 is enabled, use nss (and stbc) to
 		 * calculate chains properly for this particular skb.
 		 */
-		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);
 		status->chain_signal[2] = to_rssi(MT_PRXV_RCPI2, v1);
 		status->chain_signal[3] = to_rssi(MT_PRXV_RCPI3, v1);
+		nss = hweight8(mphy->antenna_mask);
 
 		/* RXD Group 5 - C-RXV */
 		if (rxd1 & MT_RXD1_NORMAL_GROUP_5) {
@@ -786,10 +797,15 @@  mt7915_mac_fill_rx(struct mt7915_dev *dev, struct sk_buff *skb)
 
 		if (!is_mt7915(&dev->mt76) || (rxd1 & MT_RXD1_NORMAL_GROUP_5)) {
 			ret = mt7915_mac_fill_rx_rate(dev, status, sband, rxv,
-						      &mode);
+						      &mode, &nss);
 			if (ret < 0)
 				return ret;
+		} else {
+			status->nss = nss;
 		}
+
+		for (i = 0; i < nss; i++)
+			status->chains |= BIT(i);
 	}
 
 	amsdu_info = FIELD_GET(MT_RXD4_NORMAL_PAYLOAD_FORMAT, rxd4);