Re: [alsa-devel] [RFC PATCH 8/9] soundwire: intel: remove platform devices and provide new interface

[Pierre-Louis Bossart]

On 9/18/19 8:54 AM, Greg KH wrote:
> On Wed, Sep 18, 2019 at 03:53:02PM +0200, Greg KH wrote:
> > On Wed, Sep 18, 2019 at 08:48:33AM -0500, Pierre-Louis Bossart wrote:
> > > On 9/18/19 7:06 AM, Greg KH wrote:
> > > > On Tue, Sep 17, 2019 at 09:29:52AM -0500, Pierre-Louis Bossart wrote:
> > > > > On 9/17/19 12:55 AM, Greg KH wrote:
> > > > > > On Mon, Sep 16, 2019 at 04:23:41PM -0500, Pierre-Louis Bossart wrote:
> > > > > > > +/**
> > > > > > > + * sdw_intel_probe() - SoundWire Intel probe routine
> > > > > > > + * @parent_handle: ACPI parent handle
> > > > > > > + * @res: resource data
> > > > > > > + *
> > > > > > > + * This creates SoundWire Master and Slave devices below the controller.
> > > > > > > + * All the information necessary is stored in the context, and the res
> > > > > > > + * argument pointer can be freed after this step.
> > > > > > > + */
> > > > > > > +struct sdw_intel_ctx
> > > > > > > +*sdw_intel_probe(struct sdw_intel_res *res)
> > > > > > > +{
> > > > > > > +	return sdw_intel_probe_controller(res);
> > > > > > > +}
> > > > > > > +EXPORT_SYMBOL(sdw_intel_probe);
> > > > > > > +
> > > > > > > +/**
> > > > > > > + * sdw_intel_startup() - SoundWire Intel startup
> > > > > > > + * @ctx: SoundWire context allocated in the probe
> > > > > > > + *
> > > > > > > + */
> > > > > > > +int sdw_intel_startup(struct sdw_intel_ctx *ctx)
> > > > > > > +{
> > > > > > > +	return sdw_intel_startup_controller(ctx);
> > > > > > > +}
> > > > > > > +EXPORT_SYMBOL(sdw_intel_startup);
> > > > > >
> > > > > > Why are you exporting these functions if no one calls them?
> > > > >
> > > > > They are used in the next series, see '[RFC PATCH 04/12] ASoC: SOF: Intel:
> > > > > add SoundWire configuration interface'
> > > >
> > > > That wasn't obvious :)
> > > >
> > > > Also, why not EXPORT_SYMBOL_GPL()?  :)
> > >
> > > Since the beginning of this SoundWire work, the intent what that the code
> > > could be reused in non-GPL open-source circles, hence the dual license and
> > > EXPORT_SYMBOL.
> >
> > Hah, you _have_ talked to your lawyers about this, right?
> >
> > You have a chance to do something like this for header files, for .c
> > files, good luck.  That's going to be a hard road to go down.  Many have
> > tried in the past, all but 1 have failed.
>
> Also note, the last I checked, the _default_ license for Linux kernel
> code from Intel was GPLv2.  If you got an exception for this, please
> work with your legal council on how to do this "properly" as that was
> part of getting that exception, right?
>
> If you didn't get the exception, um, you have some people to go talk to,
> and how come I am the one asking you about this?  :(

All the legal due-diligence was done when SoundWire was initially 
contributed in 2018. You asked that question at the time and I will 
point you to the email exchange Alan Cox and you had on this topic [1].

[1] https://patchwork.kernel.org/patch/10015813/