Re: [alsa-devel] [PATCH v4 06/15] soundwire: add support for sdw_slave_type

[Greg KH <gregkh@linuxfoundation.org>]

On Fri, Dec 13, 2019 at 09:05:37AM -0600, Pierre-Louis Bossart wrote:
> On 12/13/19 1:21 AM, Greg KH wrote:
> > On Thu, Dec 12, 2019 at 11:04:00PM -0600, Pierre-Louis Bossart wrote:
> > > Currently the bus does not have any explicit support for master
> > > devices.
> > > 
> > > First add explicit support for sdw_slave_type and error checks if this type
> > > is not set.
> > > 
> > > In follow-up patches we can add support for the sdw_md_type (md==Master
> > > Device), following the Grey Bus example.
> > 
> > How are you using greybus as an example of "master devices"?  All you
> > are doing here is setting the type of the existing devices, right?
> 
> I took your advice to look at GreyBus and used the 'gb host device' as the
> model to implement the 'sdw master' add/startup/remove interfaces we needed.
> 
> so yes in this patch we just add a type for the slave, the interesting part
> is in the next patches.

Is that what a "master" device really is?  A host controller, like a USB
host controller?  Or something else?

I thought things were a bit more complex for this type of topology.

greg k-h