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Subject: Re: [PATCH 2/2] mac80211: Support LIVE_ADDRESS_CHANGE feature
To:     Johannes Berg <johannes@sipsolutions.net>,
        James Prestwood <prestwoj@gmail.com>,
        linux-wireless@vger.kernel.org
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From:   Denis Kenzior <denkenz@gmail.com>
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Date:   Tue, 8 Oct 2019 11:23:14 -0500
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Hi Johannes,

>> Indeed.  But that is not what you were suggesting earlier with just
>> checking local->scanning.  So if scan_req contains a wdev, then yes it
>> should be possible to compare the scan_req->wdev to the interface being
>> changed.
> 
> Well, yes, but only because I was incrementally going from James's
> patch, which was checking that only.

Well, something to improve.  Sometimes it is pretty hard to figure out 
what you mean.

> 
> Similar with the other local-> things being checked here, btw, though in
> some cases it might be harder to actually determine which wdev is doing
> something and which isn't.

Right

> 
>>> No, this typically cannot be fixed, and it doesn't really make sense.
>>> The NIC cannot possibly do two scans at a time since it has only a
>>> single radio resource :-)
>>
>> So why is the scan request not per phy then?  And should mac address
>> even affect the ongoing scan?  Can we simply change it with the scan
>> ongoing?
> 
> There are things that affect the scan from the interface, e.g.
> capability overrides, (extended) capabilities, the MAC address is used
> unless randomization is requested, etc.
> 

But they shouldn't change due a mac address change?  I wonder if we can 
further relax the requirements to allow mac change if 
NL80211_SCAN_FLAG_RANDOM_ADDR was used?

Regards,
-Denis