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ath9k: move qual processing into a helper 

This moves the qual computing into a small helper,
ath9k_compute_qual()

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Luis R. Rodriguez 2009-11-03 18:20:26 -08:00 committed by John W. Linville
parent 9878841e13
commit 21b2273806
1 changed files with 42 additions and 32 deletions
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74
drivers/net/wireless/ath/ath9k/recv.c
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@ -189,6 +189,47 @@ static u8 ath9k_process_rate(struct ath_common *common,
return 0;
}
/*
* Theory for reporting quality:
*
* At a hardware RSSI of 45 you will be able to use MCS 7 reliably.
* At a hardware RSSI of 45 you will be able to use MCS 15 reliably.
* At a hardware RSSI of 35 you should be able use 54 Mbps reliably.
*
* MCS 7 is the highets MCS index usable by a 1-stream device.
* MCS 15 is the highest MCS index usable by a 2-stream device.
*
* All ath9k devices are either 1-stream or 2-stream.
*
* How many bars you see is derived from the qual reporting.
*
* A more elaborate scheme can be used here but it requires tables
* of SNR/throughput for each possible mode used. For the MCS table
* you can refer to the wireless wiki:
*
* http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
*
*/
static int ath9k_compute_qual(struct ieee80211_hw *hw,
struct ath_rx_status *rx_stats)
{
int qual;
if (conf_is_ht(&hw->conf))
qual = rx_stats->rs_rssi * 100 / 45;
else
qual = rx_stats->rs_rssi * 100 / 35;
/*
* rssi can be more than 45 though, anything above that
* should be considered at 100%
*/
if (qual > 100)
qual = 100;
return qual;
}
/*
* For Decrypt or Demic errors, we only mark packet status here and always push
* up the frame up to let mac80211 handle the actual error case, be it no
@ -247,38 +288,7 @@ static int ath_rx_prepare(struct ath_common *common,
rx_status->noise = common->ani.noise_floor;
rx_status->signal = ATH_DEFAULT_NOISE_FLOOR + rx_stats->rs_rssi;
rx_status->antenna = rx_stats->rs_antenna;
/*
* Theory for reporting quality:
*
* At a hardware RSSI of 45 you will be able to use MCS 7 reliably.
* At a hardware RSSI of 45 you will be able to use MCS 15 reliably.
* At a hardware RSSI of 35 you should be able use 54 Mbps reliably.
*
* MCS 7 is the highets MCS index usable by a 1-stream device.
* MCS 15 is the highest MCS index usable by a 2-stream device.
*
* All ath9k devices are either 1-stream or 2-stream.
*
* How many bars you see is derived from the qual reporting.
*
* A more elaborate scheme can be used here but it requires tables
* of SNR/throughput for each possible mode used. For the MCS table
* you can refer to the wireless wiki:
*
* http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n
*
*/
if (conf_is_ht(&hw->conf))
rx_status->qual = rx_stats->rs_rssi * 100 / 45;
else
rx_status->qual = rx_stats->rs_rssi * 100 / 35;
/* rssi can be more than 45 though, anything above that
* should be considered at 100% */
if (rx_status->qual > 100)
rx_status->qual = 100;
rx_status->qual = ath9k_compute_qual(hw, rx_stats);
rx_status->flag |= RX_FLAG_TSFT;
return 1;