Current code in ath11k_mac_set_txbf_conf overrides nsts, which is
incorrect as it confuses nss and nsts. nss is Number of Spatial
Streams，nsts is Number of Space-Time Streams.
As mentioned in Fixes: 55b5ee3357d7, the nss used when acting as a
beamformee in VHT mode should be reported by the firmware and should not
be greater than the number of receiving antennas - 1. The num_rx_chains
related nss rather than nsts.
If STBC is enabled, nsts is greater than nss. About nss are mapped to
nsts, refer to IEEE Std 802.11-2020: 19.3.11.9.2 Space-time block coding
(STBC), Table 19-18—Constellation mapper output to spatial mapper input
for STBC.
Remove wrong overriding for nsts of VHT Beamformee STS Capability,
acting DL MU-MIMO in VHT mode is working properly.
Tested-on: WCN6855 hw2.1 PCI WLAN.HSP.1.1-04479-QCAHSPSWPL_V1_V2_SILICONZ_IOE-1
Fixes: 55b5ee3357d7 ("wifi: ath11k: fix number of VHT beamformee spatial streams")
Signed-off-by: Yu Zhang(Yuriy) <quic_yuzha@xxxxxxxxxxx>
---
drivers/net/wireless/ath/ath11k/mac.c | 5 -----
1 file changed, 5 deletions(-)
diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index f8068d2e848c..b375b4c06790 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -5337,8 +5337,6 @@ static int ath11k_mac_set_txbf_conf(struct ath11k_vif *arvif)
if (vht_cap & (IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE)) {
nsts = vht_cap & IEEE80211_VHT_CAP_BEAMFORMEE_STS_MASK;
nsts >>= IEEE80211_VHT_CAP_BEAMFORMEE_STS_SHIFT;
- if (nsts > (ar->num_rx_chains - 1))
- nsts = ar->num_rx_chains - 1;
value |= SM(nsts, WMI_TXBF_STS_CAP_OFFSET);
}
@@ -5422,9 +5420,6 @@ static void ath11k_set_vht_txbf_cap(struct ath11k *ar, u32 *vht_cap)
/* Enable Beamformee STS Field only if SU BF is enabled */
if (subfee) {
- if (nsts > (ar->num_rx_chains - 1))
- nsts = ar->num_rx_chains - 1;
-
nsts <<= IEEE80211_VHT_CAP_BEAMFORMEE_STS_SHIFT;
nsts &= IEEE80211_VHT_CAP_BEAMFORMEE_STS_MASK;
*vht_cap |= nsts;
--
2.34.1
