diff options
| author | Luis R. Rodriguez <lrodriguez@atheros.com> | 2009-06-19 11:57:59 -0700 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2009-07-10 15:01:55 -0400 |
| commit | 7d5ca3b8b2b38ab676d0adc268a3c6a82e7a7588 (patch) | |
| tree | 6ed7ec7159815f12f02af7e8c185b2d9d1a1c3bd | |
| parent | 23b149c1890f9a55f065c6b7842e9383d22e0c04 (diff) | |
ath9k: differentiate quality reporting between legacy and HT configurations
We were not differentiating quality between legacy and HT
configurations. We change this to consider the differences.
New 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
This should fix this bug report:
http://bugzilla.kernel.org/show_bug.cgi?id=13537
Cc: Janath.Peiris@atheros.com
Cc: Matt.Smith@atheros.com
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
| -rw-r--r-- | drivers/net/wireless/ath/ath9k/recv.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c index 2b2872baaa3..b3da81db453 100644 --- a/drivers/net/wireless/ath/ath9k/recv.c +++ b/drivers/net/wireless/ath/ath9k/recv.c @@ -236,10 +236,31 @@ static int ath_rx_prepare(struct sk_buff *skb, struct ath_desc *ds, rx_status->signal = rx_status->noise + ds->ds_rxstat.rs_rssi; rx_status->antenna = ds->ds_rxstat.rs_antenna; - /* at 45 you will be able to use MCS 15 reliably. A more elaborate - * scheme can be used here but it requires tables of SNR/throughput for - * each possible mode used. */ - rx_status->qual = ds->ds_rxstat.rs_rssi * 100 / 45; + /* + * 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 = ds->ds_rxstat.rs_rssi * 100 / 45; + else + rx_status->qual = ds->ds_rxstat.rs_rssi * 100 / 35; /* rssi can be more than 45 though, anything above that * should be considered at 100% */ |