[PATCH AUTOSEL 5.8 032/132] ath10k: fix VHT NSS calculation when STBC is enabled

Sasha Levin
2020-10-26T23:53:14Z

From: Sathishkumar Muruganandam <murugana@codeaurora.org>

[ 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>
---
drivers/net/wireless/ath/ath10k/htt_rx.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index cac05e7bb6b07..65fbc5957f94d 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -941,6 +941,7 @@ 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);
@@ -985,11 +986,16 @@ 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
--
2.25.1