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Date:   Wed, 9 Jun 2021 12:10:22 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc:     Vinod Koul <vkoul@kernel.org>, alsa-devel@alsa-project.org,
        Leon Romanovsky <leon@kernel.org>, gregkh@linuxfoundation.org,
        linux-kernel@vger.kernel.org,
        Ranjani Sridharan <ranjani.sridharan@linux.intel.com>,
        hui.wang@canonical.com, Dave Ertman <david.m.ertman@intel.com>,
        sanyog.r.kale@intel.com,
        Bard Liao <yung-chuan.liao@linux.intel.com>,
        rander.wang@linux.intel.com, bard.liao@intel.com
Subject: Re: [PATCH v4] soundwire: intel: move to auxiliary bus
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On Wed, Jun 09, 2021 at 09:44:08AM -0500, Pierre-Louis Bossart wrote:

> The consensus for the auxiliary_device model was hard to reach, and the
> agreement was to align on a minimal model. If you disagree with the
> directions, you will have to convince Nvidia/Mellanox and Intel networking
> folks who contributed the solution to do something different.

The purpose of the aux devices was primarily to bind a *software*
interface between two parts of the kernel.

If there is a strong defined HW boundary and no software interface
then the mfd subsytem may be a better choice.

For a software layer I expect to see some 'handle' and then a set of
APIs to work within that. It is OK if that 'handle' refers to some HW
resources that the API needs to work, the purpose of this is to
control HW after all.

You might help Vinod by explaining what the SW API is here.

Jason