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Subject: Re: mac80211_hwsim (kernel 4.18+): wmediumd + 2.4Ghz
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Krishna Chaitanya <chaitanya.mgit@gmail.com>
Cc:     Ramon Fontes <ramonreisfontes@gmail.com>,
        linux-wireless <linux-wireless@vger.kernel.org>
Date:   Fri, 30 Aug 2019 09:32:10 +0200
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On Fri, 2019-08-30 at 00:35 +0530, Krishna Chaitanya wrote:
> 
> Is this supposed to work at all? AFAICS, in hwsim channel matching
> checks are only done in non-mediumd path (no_nl), and wmediumd also
> doesn't have any checks? So, hostapd responds to all probe requests in all
> channels. Am I missing something?

Hmm. Interesting observation, I wasn't aware of that.

That certainly explains the situation though - on 2.4 GHz we'd prefer
using the DS Element, and thus not use the scan result, while on 5 GHz
we assume that the reported RX frequency is correct (there's no channel
overlap).

Still doesn't explain why it should work in 4.17 and not in 4.18, there
aren't a lot of wifi changes there at all.

I guess we should fix that in hwsim, anyone esle want to? :-)

johannes