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Subject: Re: brcmfmac & DEL_INTERFACE
To:     Arend Van Spriel <arend.vanspriel@broadcom.com>
Cc:     "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
References: <089d2d0a-a802-3c2b-4993-e17326028d1f@gmail.com>
 <5679a6a1-e4a1-1f55-5b6d-21b178201078@broadcom.com>
From:   Denis Kenzior <denkenz@gmail.com>
Message-ID: <134f3c7f-5268-02bb-609b-ffbd48e78209@gmail.com>
Date:   Tue, 28 May 2019 15:49:28 -0500
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Hi Arend,

On 05/28/2019 03:27 PM, Arend Van Spriel wrote:
> On 5/28/2019 8:16 PM, Denis Kenzior wrote:
>> Hi Arend,
>>
>> We noticed that brcmfmac doesn't support .del_virtual_intf for 
>> non-p2p/ap interface types.  Any chance this can be added?
>>
>> We currently remove all wifi interfaces and re-create the needed ones 
>> with SOCKET_OWNER set, and it would be nice if we didn't need to treat 
>> brcmfmac specially.
> 
> This came up recently. During probe the driver creates a network 
> interface that we refer to as primary interface. We consider this 
> non-virtual and ownership is with the driver. My guess is that this 
> concept comes from the WEXT era, where we did not have the ieee80211 phy 
> objects to interact with the driver from user-space. I suppose you don't 
> mind the creation of this interface and just want to allow removing it, 
> right?

Correct.  If we can at least get the DEL_INTERFACE supported, that would 
solve our immediate use case.

I do think that the drivers should not be creating a netdev by default 
and should wait until userspace asks for it.  But that is a separate 
topic, with backwards compatibility concerns, so I'll leave it for the 
future :)

Regards,
-Denis