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Subject: Re: [PATCH v3] mac80211: fix scan blocked on DFS channels in ETSI
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To:     Johannes Berg <johannes@sipsolutions.net>,
        Aaron Komisar <aaron.komisar@tandemg.com>
Cc:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
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 <164db03648d82e0bdf962d18508322ac71f1b66d.camel@sipsolutions.net>
From:   Peter Oh <peter.oh@eero.com>
Message-ID: <1245442d-bbf2-aa5a-bd87-17a317b5ed34@eero.com>
Date:   Fri, 4 Oct 2019 10:41:41 -0700
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On 10/4/19 5:15 AM, Johannes Berg wrote:
> On Thu, 2019-10-03 at 08:13 +0000, Aaron Komisar wrote:
>
>>> The real reason of scan failure is because mac80211 checks if it's DFS
>>> channel, but it doesn't check if CAC is done or not.
>> The problem is that scan request is blocked in ETSI reg domains. In non-ETSI
>> reg domains the behavior is fine.
>>
>> cfg80211 blocks scan in non-ETSI reg domains and allows leaving the channel
>> in ETSI reg domains. I think that if we add a function in mac80211, which
>> checks if we can leave the operating channel this function should also take
>> into account the reg domain for completeness.
>>> So to solve the issue, the right approach should be "check if DFS
>>> channels and check if CAC is done".
>> We can't scan while CAC is in progress but why must we verify that CAC was done
>> in order to perform a scan operation?
> I agree that'd be weird - if CAC wasn't done we shouldn't be operating
> on that channel to start with?

Sorry to make you guys confused. I was thinking about something else.

So ignore my comment in previous email.


Thanks,

Peter