Re: [PATCH 02/14] soundwire: Add SoundWire bus type

[Vinod Koul <vinod.koul@intel.com>]

On Fri, Oct 20, 2017 at 06:21:23PM +0200, Greg Kroah-Hartman wrote:
> On Fri, Oct 20, 2017 at 09:31:34PM +0530, Vinod Koul wrote:
> > On Fri, Oct 20, 2017 at 12:45:28PM +0200, Greg Kroah-Hartman wrote:
> > > On Thu, Oct 19, 2017 at 08:33:18AM +0530, Vinod Koul wrote:
> > > > +/*
> > > > + *  This file is provided under a dual BSD/GPLv2 license.  When using or
> > > > + *  redistributing this file, you may do so under either license.
> > > > + *
> > > > + *  GPL LICENSE SUMMARY
> > > > + *
> > > > + *  Copyright(c) 2015-17 Intel Corporation.
> > > > + *
> > > > + *  This program is free software; you can redistribute it and/or modify
> > > > + *  it under the terms of version 2 of the GNU General Public License as
> > > > + *  published by the Free Software Foundation.
> > > > + *
> > > > + *  This program is distributed in the hope that it will be useful, but
> > > > + *  WITHOUT ANY WARRANTY; without even the implied warranty of
> > > > + *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > > > + *  General Public License for more details.
> > > > + *
> > > > + *  BSD LICENSE
> > > > + *
> > > > + *  Copyright(c) 2015-17 Intel Corporation.
> > > > + *
> > > > + *  Redistribution and use in source and binary forms, with or without
> > > > + *  modification, are permitted provided that the following conditions
> > > > + *  are met:
> > > > + *
> > > > + *    * Redistributions of source code must retain the above copyright
> > > > + *      notice, this list of conditions and the following disclaimer.
> > > > + *    * Redistributions in binary form must reproduce the above copyright
> > > > + *      notice, this list of conditions and the following disclaimer in
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> > > > + *      distribution.
> > > > + *    * Neither the name of Intel Corporation nor the names of its
> > > > + *      contributors may be used to endorse or promote products derived
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> > > > + *
> > > > + *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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> > > 
> > > Are you _sure_ that code that interacts with the driver core can have a
> > > dual-license here?  Have you explained to lawyers what you are doing
> > > here (wrapping gpl-only symbols with non-gpl-only exports)?
> > 
> > Sorry, the intention is not to wrap gpl symbols for non-gpl-only exports.
> > 
> > > And why dual license something that will only ever work on Linux?
> > 
> > We have non Linux users (mostly RTOS folks) which we would like to support
> > with as much as common code.
> 
> Note, you need to be VERY CAREFUL about doing this.  You need to have
> all sorts of infrastructure set up and in place and paperwork up the
> wazoo in order to make it work properly.
> 
> In the end, I can almost guarantee it will not be worth the extra hassle
> and effort you are trying to do here.
> 
> Seriously, go talk to your managers and corporate lawyer about this, you
> are in for a world of hurt if you want to do this in a way that actually
> works (i.e. doesn't just degrade to GPLv2 only instantly.)
> 
> I recommend not doing this unless you have money to burn.  If you do,
> then great!  If not, it is much easier just to have two separate code
> repos.
> 
> > > And finally, put a real SPDX header up there so that people don't have
> > > to parse that horrid amount of text to try to determine exactly what
> > > that license is.
> > 
> > Sorry for confusion, For the record we are trying to do Dual GPL v2/ BSD 3
> > clause here. Can you give me example of SPDX use. I will be gald to use that
> 
> I could give you an example, but you need to get the real marking from
> your company as I am not the one to pick it for you :)
> 
> > > > +struct bus_type sdw_bus_type = {
> > > > +	.name = "soundwire",
> > > > +	.match = sdw_bus_match,
> > > > +	.uevent = sdw_uevent,
> > > > +};
> > > > +EXPORT_SYMBOL(sdw_bus_type);
> > > 
> > > EXPORT_SYMBOL_GPL()?
> > 
> > This can be EXPORT_SYMBOL_GPL as non Linux users wont have this. But then
> > would it be to okay to have a module with some symbols _GPL and some non
> > _GPL (the SoundWire protocol ones would need to be non GPL)
> 
> Again, don't even try to do that, it's not going to work.
> 
> The only team I know that ever has done this successfully is the core
> ACPI code.  Go talk to them about the work involved in doing this
> properly to see if you are willing to do that.

Thanks for the advice Greg, really appreciate it!

I will work with the folks and try to come up with a better proposal

-- 
~Vinod