From c1dd8016ae02557e4f3fcf7339865924d9357f76 Mon Sep 17 00:00:00 2001
From: Sven Eckelmann <sven.eckelmann@openmesh.com>
Date: Fri, 19 May 2017 11:54:02 +0300
Subject: [PATCH] ath10k: fix reported HT MCS rates with NSS > 1
Git-commit: c1dd8016ae02557e4f3fcf7339865924d9357f76
Patch-mainline: v4.13-rc1
References: bsc#1051510

The QCA4019 firmware 10.4-3.2.1-00050 reports only HT MCS rates between
0-9. But 802.11n MCS rates can be larger than that. For example a 2x2
device can send with up to MCS 15.

The firmware encodes the higher MCS rates using the NSS field. The actual
calculation is not documented by QCA but it seems like the NSS field can be
mapped for HT rates to following MCS offsets:

 * NSS 1: 0
 * NSS 2: 8
 * NSS 3: 16
 * NSS 4: 24

This offset therefore has to be added for HT rates before they are stored
in the rate_info struct.

Fixes: cec17c382140 ("ath10k: add per peer htt tx stats support for 10.4")
Signed-off-by: Sven Eckelmann <sven.eckelmann@openmesh.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/net/wireless/ath/ath10k/htt_rx.c |   14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -2229,9 +2229,15 @@ ath10k_update_per_peer_tx_stats(struct a
 	txrate.mcs = ATH10K_HW_MCS_RATE(peer_stats->ratecode);
 	sgi = ATH10K_HW_GI(peer_stats->flags);
 
-	if (((txrate.flags == WMI_RATE_PREAMBLE_HT) ||
-	     (txrate.flags == WMI_RATE_PREAMBLE_VHT)) && txrate.mcs > 9) {
-		ath10k_warn(ar, "Invalid mcs %hhd peer stats", txrate.mcs);
+	if (txrate.flags == WMI_RATE_PREAMBLE_VHT && txrate.mcs > 9) {
+		ath10k_warn(ar, "Invalid VHT mcs %hhd peer stats",  txrate.mcs);
+		return;
+	}
+
+	if (txrate.flags == WMI_RATE_PREAMBLE_HT &&
+	    (txrate.mcs > 7 || txrate.nss < 1)) {
+		ath10k_warn(ar, "Invalid HT mcs %hhd nss %hhd peer stats",
+			    txrate.mcs, txrate.nss);
 		return;
 	}
 
@@ -2254,7 +2260,7 @@ ath10k_update_per_peer_tx_stats(struct a
 		arsta->txrate.legacy = rate;
 	} else if (txrate.flags == WMI_RATE_PREAMBLE_HT) {
 		arsta->txrate.flags = RATE_INFO_FLAGS_MCS;
-		arsta->txrate.mcs = txrate.mcs;
+		arsta->txrate.mcs = txrate.mcs + 8 * (txrate.nss - 1);
 	} else {
 		arsta->txrate.flags = RATE_INFO_FLAGS_VHT_MCS;
 		arsta->txrate.mcs = txrate.mcs;