ath9k: Fix airtime calculation for quarter/half channels

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>

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index cd0f023..3017078 100644 (file)
--- 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 +