From 91f1ee65d999a36241cb43bc820b1b59050bc79e Mon Sep 17 00:00:00 2001
From: Wojciech Dubowik <Wojciech.Dubowik@neratec.com>
Date: Tue, 20 Feb 2018 15:41:43 +0100
Subject: [PATCH] ath9k: Fix airtime calculation for quarter/half channels
Git-commit: 91f1ee65d999a36241cb43bc820b1b59050bc79e
Patch-mainline: v4.17-rc1
References: FATE#326906
The bitrate value for airtime calculation is specified for
full rates. We need to divide it for 5 and 10MHz channels to
get correct result.
Signed-off-by: Wojciech Dubowik <Wojciech.Dubowik@neratec.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/wireless/ath/ath9k/hw.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index cd0f023ccf77..3017078c6d40 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -184,7 +184,8 @@ u16 ath9k_hw_computetxtime(struct ath_hw *ah,
break;
case WLAN_RC_PHY_OFDM:
if (ah->curchan && IS_CHAN_QUARTER_RATE(ah->curchan)) {
- bitsPerSymbol = (kbps * OFDM_SYMBOL_TIME_QUARTER) / 1000;
+ bitsPerSymbol =
+ ((kbps >> 2) * OFDM_SYMBOL_TIME_QUARTER) / 1000;
numBits = OFDM_PLCP_BITS + (frameLen << 3);
numSymbols = DIV_ROUND_UP(numBits, bitsPerSymbol);
txTime = OFDM_SIFS_TIME_QUARTER
@@ -192,7 +193,8 @@ u16 ath9k_hw_computetxtime(struct ath_hw *ah,
+ (numSymbols * OFDM_SYMBOL_TIME_QUARTER);
} else if (ah->curchan &&
IS_CHAN_HALF_RATE(ah->curchan)) {
- bitsPerSymbol = (kbps * OFDM_SYMBOL_TIME_HALF) / 1000;
+ bitsPerSymbol =
+ ((kbps >> 1) * OFDM_SYMBOL_TIME_HALF) / 1000;
numBits = OFDM_PLCP_BITS + (frameLen << 3);
numSymbols = DIV_ROUND_UP(numBits, bitsPerSymbol);
txTime = OFDM_SIFS_TIME_HALF +
--
2.19.2