[PATCH 4.18 088/228] mt76x2: fix mrr idx/count estimation in mt76x2_mac_fill_tx_status()

[Greg Kroah-Hartman]

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx>

[ Upstream commit 2d1e9be0016230f3707812243561fbd16f1aea4b ]

Fix mcs and attempt count estimation in mt76x2_mac_fill_tx_status routine
if the number of tx retries reported by the hw is grater than
IEEE80211_TX_MAX_RATES

Fixes: 7bc04215a66b ("mt76: add driver code for MT76x2e")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/wireless/mediatek/mt76/mt76x2_mac.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

--- a/drivers/net/wireless/mediatek/mt76/mt76x2_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2_mac.c
@@ -439,15 +439,13 @@ mt76x2_mac_fill_tx_status(struct mt76x2_
 	if (last_rate < IEEE80211_TX_MAX_RATES - 1)
 		rate[last_rate + 1].idx = -1;
 
-	cur_idx = rate[last_rate].idx + st->retry;
+	cur_idx = rate[last_rate].idx + last_rate;
 	for (i = 0; i <= last_rate; i++) {
 		rate[i].flags = rate[last_rate].flags;
 		rate[i].idx = max_t(int, 0, cur_idx - i);
 		rate[i].count = 1;
 	}
-
-	if (last_rate > 0)
-		rate[last_rate - 1].count = st->retry + 1 - last_rate;
+	rate[last_rate].count = st->retry + 1 - last_rate;
 
 	info->status.ampdu_len = n_frames;
 	info->status.ampdu_ack_len = st->success ? n_frames : 0;