Re: [PATCH v4] soundwire: intel: move to auxiliary bus

[Vinod Koul <vkoul@kernel.org>]

On 09-06-21, 12:10, Jason Gunthorpe wrote:
> 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.

Then I dont think this example is valid... This example has a PCI device,
which represents a DSP, HDA controller, DMICs, Soundwire
links... So at least here it is hardware.

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

More I think that might be better choice for this example, but then MFD
is a 'platform device' and Greg already nacked that

> 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

-- 
~Vinod