ath10k: fix VHT NSS calculation when STBC is enabled

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

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index 136cbf001c5bbbc9342b1c0b4d23b329efd8e290..5c1af202188338aad3320b6b7a2bae0437a3da48 100644 (file)
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -949,6 +949,7 @@ 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);
@@ -993,11 +994,16 @@ 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