Re: [PATCH] ath9k: reset survey of current channel after a scan started

["Toke Høiland-Jørgensen" <toke@kernel.org>]

Toke Høiland-Jørgensen <toke@kernel.org> writes:

> Hancheng Yang <hyang@freebox.fr> writes:
>
>> In the `ath_set_channel()` function, we only reset surveys that are not from the current channel.
>> This leads to the accumulation of survey data for the current channel indefinitely.
>> Log of hostapd:
>> [2023-08-17 11:21:51] ACS: Survey analysis for channel 1 (2412 MHz)
>> [2023-08-17 11:21:51] ACS: 1: min_nf=-90 interference_factor=0.569833 nf=-89 time=36194 busy=20908 rx=16200
>> [2023-08-17 11:21:51] ACS: 2: min_nf=-90 interference_factor=0.572018 nf=-89 time=36539 busy=21183 rx=16425
>> [2023-08-17 11:21:51] ACS: 3: min_nf=-90 interference_factor=0.574311 nf=-90 time=36885 busy=21464 rx=16659
>> [2023-08-17 11:21:51] ACS: 4: min_nf=-90 interference_factor=0.5773 nf=-89 time=37231 busy=21772 rx=16924
>> [2023-08-17 11:21:51] ACS: 5: min_nf=-90 interference_factor=0.580108 nf=-89 time=37578 busy=22076 rx=17189
>>
>>
>> This may not be the most optimal approach, as we want the ACS to rely on the most recent survey.
>> So, reset the survey data for the current channel at the start of each scan.
>>
>> Or there's better approach?
>
> Johannes, Jouni, any thoughts? :)

Ping?

>>
>> Signed-off-by: Hancheng Yang <hyang@freebox.fr>
>> ---
>>  drivers/net/wireless/ath/ath9k/main.c | 15 +++++++++++++++
>>  1 file changed, 15 insertions(+)
>>
>> diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
>> index fa5a87f021e2..3e4a711c96bb 100644
>> --- a/drivers/net/wireless/ath/ath9k/main.c
>> +++ b/drivers/net/wireless/ath/ath9k/main.c
>> @@ -2382,7 +2382,22 @@ static void ath9k_sw_scan_start(struct ieee80211_hw *hw,
>>  {
>>  	struct ath_softc *sc = hw->priv;
>>  	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
>> +	struct cfg80211_chan_def *chandef = &sc->cur_chan->chandef;
>> +	struct ieee80211_channel *chan = chandef->chan;
>> +	int pos = chan->hw_value;
>>  	set_bit(ATH_OP_SCANNING, &common->op_flags);
>> +
>> +	/* Reset current survey */
>> +	if (!sc->cur_chan->offchannel) {
>> +		if (sc->cur_survey != &sc->survey[pos]) {
>> +			if (sc->cur_survey)
>> +				sc->cur_survey->filled &= ~SURVEY_INFO_IN_USE;
>> +			sc->cur_survey = &sc->survey[pos];
>> +		}
>> +
>> +		memset(sc->cur_survey, 0, sizeof(struct survey_info));
>> +		sc->cur_survey->filled |= SURVEY_INFO_IN_USE;
>> +	}
>>  }
>>  
>>  static void ath9k_sw_scan_complete(struct ieee80211_hw *hw,
>> -- 
>> 2.34.1