ath10k: fix VHT NSS calculation when STBC is enabled

[ Upstream commit 99f41b8e43b8b4b31262adb8ac3e69088fff1289 ]

When STBC is enabled, NSTS_SU value need to be accounted for VHT NSS
calculation for SU case.

Without this fix, 1SS + STBC enabled case was reported wrongly as 2SS
in radiotap header on monitor mode capture.

Tested-on: QCA9984 10.4-3.10-00047

Signed-off-by: Sathishkumar Muruganandam <murugana@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1597392971-3897-1-git-send-email-murugana@codeaurora.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index fd276e54bb7c2e3778631491156068feafb0ef3d..4358d175f954bbabf5fbc752cb02f78e645e9bf4 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -622,6 +622,7 @@ static void ath10k_htt_rx_h_rates(struct ath10k *ar,
        u8 preamble = 0;
        u8 group_id;
        u32 info1, info2, info3;
+       u32 stbc, nsts_su;
 
        info1 = __le32_to_cpu(rxd->ppdu_start.info1);
        info2 = __le32_to_cpu(rxd->ppdu_start.info2);
@@ -666,11 +667,16 @@ static void ath10k_htt_rx_h_rates(struct ath10k *ar,
                 */
                bw = info2 & 3;
                sgi = info3 & 1;
+               stbc = (info2 >> 3) & 1;
                group_id = (info2 >> 4) & 0x3F;
 
                if (GROUP_ID_IS_SU_MIMO(group_id)) {
                        mcs = (info3 >> 4) & 0x0F;
-                       nss = ((info2 >> 10) & 0x07) + 1;
+                       nsts_su = ((info2 >> 10) & 0x07);
+                       if (stbc)
+                               nss = (nsts_su >> 2) + 1;
+                       else
+                               nss = (nsts_su + 1);
                } else {
                        /* Hardware doesn't decode VHT-SIG-B into Rx descriptor
                         * so it's impossible to decode MCS. Also since