2018-02-20 14:41:51

by Wojciech Dubowik

Subject: [PATCH 1/2] 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 <[email protected]>
---
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 cd0f023..3017078 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 +
--
2.7.4

2018-02-27 16:48:00

by Kalle Valo

Subject: Re: [1/2] ath9k: Fix airtime calculation for quarter/half channels

Wojciech Dubowik <[email protected]> wrote:

> 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 <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>

2 patches applied to ath-next branch of ath.git, thanks.

91f1ee65d999 ath9k: Fix airtime calculation for quarter/half channels
52c528ffaf1d ath9k: Fix ack SIFS time for quarter/half channels

--
https://patchwork.kernel.org/patch/10230167/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches