2010-04-26 20:10:28

by John W. Linville

[permalink] [raw]
Subject: [PATCH] ath9k: remove usage of deprecated noise value

Signed-off-by: John W. Linville <[email protected]>
---
drivers/net/wireless/ath/ath9k/common.c | 1 -
1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/common.c b/drivers/net/wireless/ath/ath9k/common.c
index 09effde..b4424a6 100644
--- a/drivers/net/wireless/ath/ath9k/common.c
+++ b/drivers/net/wireless/ath/ath9k/common.c
@@ -212,7 +212,6 @@ int ath9k_cmn_rx_skb_preprocess(struct ath_common *common,
rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
rx_status->band = hw->conf.channel->band;
rx_status->freq = hw->conf.channel->center_freq;
- 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;
rx_status->flag |= RX_FLAG_TSFT;
--
1.6.6.1



2010-04-27 06:22:43

by Benoit Papillault

[permalink] [raw]
Subject: Re: [PATCH] ath9k: remove usage of deprecated noise value

John W. Linville a ?crit :
> Signed-off-by: John W. Linville <[email protected]>
> ---
> drivers/net/wireless/ath/ath9k/common.c | 1 -
> 1 files changed, 0 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath9k/common.c b/drivers/net/wireless/ath/ath9k/common.c
> index 09effde..b4424a6 100644
> --- a/drivers/net/wireless/ath/ath9k/common.c
> +++ b/drivers/net/wireless/ath/ath9k/common.c
> @@ -212,7 +212,6 @@ int ath9k_cmn_rx_skb_preprocess(struct ath_common *common,
> rx_status->mactime = ath9k_hw_extend_tsf(ah, rx_stats->rs_tstamp);
> rx_status->band = hw->conf.channel->band;
> rx_status->freq = hw->conf.channel->center_freq;
> - 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;
> rx_status->flag |= RX_FLAG_TSFT;
>
Hey, I'm still using this value here in my setup (I've done some work on
noise floor calibration and can submit a patch that report noise &
signal values that makes more sense to me). I mentioned in an earlier
patch that I was using the {last_signal, last_noise} debugfs file as
well (in February, 17th).

Before removing noise reporting and all related code, wouln't it be
better to have a replacement API? I was told that noise reporting is
buggy for most chipset, but that's a bug in each driver, not in mac80211
then. Such bugs could be fixed by using a default value of -101dBm
(thermal noise at room temperature over a 20 MHz channel) if they are
unable to determine a correct value.

Moreover, it is very convenient to have the {last_signal, last_noise}
sampled at the same time and be in the same location. Likewise for the
radiotap header, it is very easy to plot noise value over time if it is
stored on a per packet basis. Of course, I know noise is a global
property of the channel and not DEFINED on a per packet basis, but once
you know that, it's still useful to have it REPORTED on a per packet basis.

So far, the solution for me was to revert the single patch for making
the noise field deprecated, but I'm not going to revert each & every
patches related to noise. After all, isn't it the purpose of peer review?

Regards,
Benoit