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Date:   Sun, 20 Sep 2020 22:06:49 -0700
From:   Thomas Pedersen <thomas@adapt-ip.com>
To:     Johannes Berg <johannes@sipsolutions.net>
Cc:     linux-wireless <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH v2 07/22] mac80211: s1g: choose scanning width based on
 frequency
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On 2020-09-18 03:40, Johannes Berg wrote:
> On Mon, 2020-08-31 at 13:55 -0700, Thomas Pedersen wrote:
>> An S1G BSS can beacon at either 1 or 2 MHz and the channel
>> width is unique to a given frequency. Ignore scan channel
>> width for now and use the allowed channel width.
>> 
>> Signed-off-by: Thomas Pedersen <thomas@adapt-ip.com>
>> ---
>>  net/mac80211/scan.c | 17 +++++++++++++++++
>>  1 file changed, 17 insertions(+)
>> 
>> diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
>> index 5ac2785cdc7b..5002791fe165 100644
>> --- a/net/mac80211/scan.c
>> +++ b/net/mac80211/scan.c
>> @@ -905,6 +905,17 @@ static void 
>> ieee80211_scan_state_set_channel(struct ieee80211_local *local,
>>  	local->scan_chandef.center_freq1 = chan->center_freq;
>>  	local->scan_chandef.freq1_offset = chan->freq_offset;
>>  	local->scan_chandef.center_freq2 = 0;
>> +
>> +	/* For scanning on the S1G band, ignore scan_width (which is 
>> constant
>> +	 * across all channels) for now since channel width is specific to 
>> each
>> +	 * channel. Detect the required channel width here and likely 
>> revisit
>> +	 * later. Maybe scan_width could be used to build the channel scan 
>> list?
>> +	 */
>> +	if (chan->band == NL80211_BAND_S1GHZ) {
>> +		local->scan_chandef.width = ieee80211_s1g_channel_width(chan);
>> +		goto  set_channel;
>> +	}
> 
> nit: double space after 'goto'
> 
> but really I came to say that this probably changes then, if you don't
> convince me about the stuff in the previous patch review? :)
> 
> So I'm leaving this patch also for now - have applied 1-5 so far.

Thanks. I'm not really sure what else would make sense here? 
scan_req->scan_width is constant across all channels in 
scan_req->channels so for S1G we can either filter the scan_req channels 
list based on scan_width (kind of strange and unexpected), or deduce the 
correct chanenl width for each channel in the list and ignore scan_width 
(mostly correct). It seems like scan_width is currently only used for 
scanning at 5 or 10MHz anyway?

-- 
thomas