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From:   Shay Bar <Shay.Bar@celeno.com>
To:     Johannes Berg <johannes@sipsolutions.net>,
        Ben Greear <greearb@candelatech.com>
CC:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Subject: Re: [PATCH] mac80211: Send deauth to STA's upon AP stop
Thread-Topic: [PATCH] mac80211: Send deauth to STA's upon AP stop
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Date:   Thu, 30 Jul 2020 14:45:29 +0000
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On 30/07/2020 17:28, Johannes Berg wrote:
> External Email
>
>
> On Thu, 2020-07-30 at 14:23 +0000, Shay Bar wrote:
>> On 30/07/2020 17:00, Johannes Berg wrote:
>>> External Email
>>>
>>>
>>> On Thu, 2020-06-25 at 13:29 +0300, Shay Bar wrote:
>>>> On 25/06/2020 12:51, Johannes Berg wrote:
>>>>> External Email
>>>>>
>>>>>
>>>>> On Sun, 2020-06-21 at 10:12 +0000, Shay Bar wrote:
>>>>>> Hi Johannes and Ben,
>>>>>>
>>>>>> To conclude this thread, hostapd doesn=92t send any deauth/disassoc
>>>>>> upon AP stop (when hostapd is killed _or_ when "ifconfig down" the
>>>>>> AP interface).
>>>>> Right. I'm sort of suggesting you just shouldn't be doing this, and i=
t
>>>>> doesn't seem like most people actually do, otherwise we'd have seen t=
his
>>>>> issue before?
>>>>>
>>>> I shouldn't kill hostapd? Isn't this a very basic action?
>>>> What is the alternative for stopping the AP?
>>> I guess I would say to use hostapd_cli first to "disable" the
>>> interfaces?
>> Indeed, using hostapd_cli "DISABLE" will call
>> hostapd_flush_old_stations() that will send broadcast deauth.
> Ah.
>
>> The problem is (mentioned before) that some stations (e.g. Samsung S8)
>> ignore this broadcast (while it will not ignore unicast
>> deauth/disassoc).
> Right, you mentioned that. I guess you could work around by disabling
> all stations separately, but ... not really a great solution either.
>
> Perhaps we should fix that at the hostapd level?
>
> Not really sure how much trouble we should go to for bad stations
> though. I mean, it's not like they should be ignoring that.
>
> Maybe they just miss it due to super aggressive powersave, and we should
> send it a few times?

Power save is possible.
I will try sending it 3 times (instead of only 1) and see if it helps.
Anyway, I agree we should not put extra effort for STA's that ignore this b=
cast,
Lets discard this patch.

Thanks.

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