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Date: Thu, 23 Jan 2014 07:22:07 +0100
Message-ID: <CA+BoTQ=+TGFo0f0z1SymiN5DkeLZUPC_p_YVZ59s=FFqpGV3vQ@mail.gmail.com> (sfid-20140123_072213_385694_E5DCC62D)
Subject: Re: [PATCH 5/7] mac80211: improve CSA locking
From: Michal Kazior <michal.kazior@tieto.com>
To: Luca Coelho <luca@coelho.fi>
Cc: Johannes Berg <johannes@sipsolutions.net>,
	linux-wireless <linux-wireless@vger.kernel.org>
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On 22 January 2014 16:13, Luca Coelho <luca@coelho.fi> wrote:
> On Wed, 2014-01-22 at 16:10 +0100, Johannes Berg wrote:
>> On Wed, 2014-01-22 at 14:36 +0200, Luca Coelho wrote:
>>
>> > I don't think we should try to merge the channel switches.  We should
>> > just perform them separately, especially because the exact time of the
>> > switch will most likely not be the same (since the TBTTs are not in
>> > sync).
>>
>> Do you mean that we shouldn't even have all that new API to switch
>> multiple interfaces simultaneously?
>
> Right, I'm not really sure it's necessary.  PErhaps with non-chanctx we
> need something like that, but maybe it would still be better not to do
> this in the nl80211 API, but sync/merge in cfg80211/mac80211?

I was thinking about it. This should work, mostly, as long as you're
able to submit CSA requests fast enough and you don't use count 0 or
1, in which case it becomes racy.


Michał