[PATCH] ath10k: fix TxBF VHT capabilities for 2+ RF-chain devices

[Michal Kazior]

Firmware doesn't report a complete and
ready-to-use vht cap. Instead the driver is
supposed to fill in the missing bits related to
number of chains.

This effectively increases Compressed Steering
Number and Number of Sounding Dimensions in
AssocReq frames for devices with more than one RF
chain and should improve TxBF performance.

Signed-off-by: Michal Kazior <michal.kazior at tieto.com>
---
 drivers/net/wireless/ath/ath10k/mac.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 0f39af7..383250e 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -5263,11 +5263,30 @@ static struct ieee80211_sta_vht_cap ath10k_create_vht_cap(struct ath10k *ar)
 {
 	struct ieee80211_sta_vht_cap vht_cap = {0};
 	u16 mcs_map;
+	u32 val;
 	int i;
 
 	vht_cap.vht_supported = 1;
 	vht_cap.cap = ar->vht_cap_info;
 
+	if (ar->vht_cap_info & (IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE |
+				IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE)) {
+		val = ar->num_rf_chains - 1;
+		val <<= IEEE80211_VHT_CAP_BEAMFORMEE_STS_SHIFT;
+		val &= IEEE80211_VHT_CAP_BEAMFORMEE_STS_MASK;
+
+		vht_cap.cap |= val;
+	}
+
+	if (ar->vht_cap_info & (IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE |
+				IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE)) {
+		val = ar->num_rf_chains - 1;
+		val <<= IEEE80211_VHT_CAP_SOUNDING_DIMENSIONS_SHIFT;
+		val &= IEEE80211_VHT_CAP_SOUNDING_DIMENSIONS_MASK;
+
+		vht_cap.cap |= val;
+	}
+
 	mcs_map = 0;
 	for (i = 0; i < 8; i++) {
 		if (i < ar->num_rf_chains)
-- 
1.8.5.3