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

From: Greg KH <gregkh@linuxfoundation.org>
To: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Cc: alsa-devel@alsa-project.org, tiwai@suse.de,
	linux-kernel@vger.kernel.org,
	Ranjani Sridharan <ranjani.sridharan@linux.intel.com>,
	vkoul@kernel.org, broonie@kernel.org,
	srinivas.kandagatla@linaro.org, jank@cadence.com,
	slawomir.blauciak@intel.com,
	Sanyog Kale <sanyog.r.kale@intel.com>,
	Bard liao <yung-chuan.liao@linux.intel.com>,
	Rander Wang <rander.wang@linux.intel.com>
Subject: Re: [alsa-devel] [RFC PATCH 8/9] soundwire: intel: remove platform devices and provide new interface
Date: Wed, 18 Sep 2019 15:53:02 +0200	[thread overview]
Message-ID: <20190918135302.GA1919118@kroah.com> (raw)
In-Reply-To: <c8f21078-1462-5463-ef12-957ebd9ba085@linux.intel.com>

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.

> That said, there are cases where the code only makes sense for Linux, or
> relies on symbols that are exported with EXPORT_SYMBOL_GPL, in those cases
> we rely on GPLv2 and EXPORT_SYMBOL_GPL. For this series I added a disclaimer
> in the cover letter that those parts need to be reviewed further to make
> sure there are no conflicts with GPL.

Please do that with your lawyers, do not require developers to do legal
work for you, that's just mean :(

thanks,

greg k-h