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 <20210811105541.43426-5-emmanuel.grumbach@intel.com> <87h7devb0d.fsf@codeaurora.org>
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From:   Emmanuel Grumbach <egrumbach@gmail.com>
Date:   Mon, 18 Oct 2021 14:34:34 +0300
Message-ID: <CANUX_P0J-L4razi1R0gQYyXw+iq0hiKUbFXX1YfDCcGsJ0ou2g@mail.gmail.com>
Subject: Re: [PATCH v6 5/7] nl80211: vendor-cmd: add Intel vendor commands for
 iwlmei usage
To:     Kalle Valo <kvalo@codeaurora.org>
Cc:     Emmanuel Grumbach <emmanuel.grumbach@intel.com>,
        linux-wireless <linux-wireless@vger.kernel.org>
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> > iwlmei allows to integrate with the CSME firmware. There are
> > flows that are prioprietary for this purpose:
> >
> > * Get the information of 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 a 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. This is a notification sent by the kernel.
> >
> > All those commands are expected to be used by any software
> > managing the connection (mainly NetworkManager). Those commands
> > are expected to be used only in case the CSME firmware owns
> > the device and doesn't want to release the device unless the
> > host made sure that it can keep the connectivity.
>
> [...]
>
> > --- /dev/null
> > +++ b/include/uapi/linux/nl80211-vnd-intel.h
> > @@ -0,0 +1,77 @@
> > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> > +/*
> > + * Copyright (C) 2012-2014, 2018-2021 Intel Corporation
> > + * Copyright (C) 2013-2015 Intel Mobile Communications GmbH
> > + * Copyright (C) 2016-2017 Intel Deutschland GmbH
> > + */
> > +#ifndef __VENDOR_CMD_INTEL_H__
> > +#define __VENDOR_CMD_INTEL_H__
> > +
> > +#define INTEL_OUI    0x001735
> > +
> > +/**
> > + * enum iwl_mvm_vendor_cmd - supported vendor commands
> > + * @IWL_MVM_VENDOR_CMD_GET_CSME_CONN_INFO: reports CSME connection info.
> > + * @IWL_MVM_VENDOR_CMD_HOST_GET_OWNERSHIP: asks for ownership on the device.
> > + * @IWL_MVM_VENDOR_CMD_ROAMING_FORBIDDEN_EVENT: notifies if roaming is allowed.
> > + *   It contains a &IWL_MVM_VENDOR_ATTR_ROAMING_FORBIDDEN and a
> > + *   &IWL_MVM_VENDOR_ATTR_VIF_ADDR attributes.
> > + */
> > +
> > +enum iwl_mvm_vendor_cmd {
> > +     IWL_MVM_VENDOR_CMD_GET_CSME_CONN_INFO                   = 0x2d,
> > +     IWL_MVM_VENDOR_CMD_HOST_GET_OWNERSHIP                   = 0x30,
> > +     IWL_MVM_VENDOR_CMD_ROAMING_FORBIDDEN_EVENT              = 0x32,
> > +};
>
> If I were trying to implement a user space application based on the
> documentation in nl80211-vnd-intel.h I would not get far. For example,
> how is IWL_MVM_VENDOR_CMD_HOST_GET_OWNERSHIP supposed to be used? The
> documentation just repeats what the command already implies.
>
> You had some good info in the commit log, I recommend at least copying
> the most important part to the .h file.

Ok, this patch has already been merged by Johannes, but I'll add a new
patch to add more info.