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From:   Kalle Valo <kvalo@codeaurora.org>
To:     "Grumbach\, Emmanuel" <emmanuel.grumbach@intel.com>
Cc:     Emmanuel Grumbach <egrumbach@gmail.com>,
        "Coelho\, Luciano" <luciano.coelho@intel.com>,
        linux-wireless <linux-wireless@vger.kernel.org>,
        "Beker\, Ayala" <ayala.beker@intel.com>
Subject: Re: [PATCH v3 3/4] nl80211: vendor-cmd: add Intel vendor commands for iwlmei usage
References: <20210623141033.27475-1-emmanuel.grumbach@intel.com>
        <20210623141033.27475-3-emmanuel.grumbach@intel.com>
        <87k0mji43p.fsf@codeaurora.org>
        <CANUX_P0d0jrq9x99jM824oKOhmi0Wa5WqhECMsX=hd269H6atw@mail.gmail.com>
        <87sfzoc9bw.fsf@codeaurora.org>
        <SA0PR11MB47521818C15629E58B99525AF2F49@SA0PR11MB4752.namprd11.prod.outlook.com>
Date:   Mon, 18 Oct 2021 14:25:57 +0300
In-Reply-To: <SA0PR11MB47521818C15629E58B99525AF2F49@SA0PR11MB4752.namprd11.prod.outlook.com>
        (Emmanuel Grumbach's message of "Sat, 7 Aug 2021 18:32:26 +0000")
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"Grumbach, Emmanuel" <emmanuel.grumbach@intel.com> writes:

>> 
>> > On Thu, Jun 24, 2021 at 8:09 PM Kalle Valo <kvalo@codeaurora.org> wrote:
>> >>
>> >> Emmanuel Grumbach <emmanuel.grumbach@intel.com> writes:
>> >>
>> >> > iwlmei allows to integrate with the CSME firmware. There are flows
>> >> > that are prioprietary for this purpose:
>> >> >
>> >> > * Get the information the AP, the CSME firmware is connected
>> >> >   to. This is useful when we need to speed up the connection
>> >> >   process in case the CSME firmware has an TCP connection
>> >> >   that must be kept alive across the ownership transition.
>> >> > * Forbid roaming, which will happen when the CSME firmware
>> >> >   wants to tell the user space not disrupt the connection.
>> >> > * Request ownership, upon driver boot when the CSME firmware
>> >> >   owns the device.
>> >>
>> >> Vendor command requirements are documented here:
>> >>
>> >> https://wireless.wiki.kernel.org/en/developers/documentation/nl80211#
>> >> vendor-specific_api
>> >>
>> >> The commit log is not really answering to those. For example, how a
>> >> user would use this? Or is there a user space tool?
>> >
>> > We intend to send those command from the NetworkManager.
>> 
>> I'm not really fond of the idea that NetworkManager uses nl80211 vendor
>> commands, sounds quite hacky to me. I would prefer that NetworkManager
>> uses generic nl80211 interface so that it works with every driver. But I need
>> to look at v4 to understand more how this all works.
>> 
>
> You'd need to look at v5 which I already sent.
> Nothing of this can be generic, because it is really Intel
> proprietary.

Every company always says that their implemention is proprietary :) So
that's not really a technical reason....

> CSME can only use Intel devices by design. It uses a proprietary bus
> implemented only in Intel devices (and not even all of them, only the
> ones in systems with the vPRO sticker).

Ok, fair enough. I guess this is exotic enough that no other driver ever
wants to implement, and I haven't seen any complaints either about this
vendor interface. But please do include the justification for the vendor
interface in the commit log as well.

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