Re: [PATCH] media: v4l: xilinx: Use SPDX-License-Identifier

[Laurent Pinchart]

Hi Mauro,

On Thursday, 14 December 2017 23:50:03 EET Mauro Carvalho Chehab wrote:
> Em Thu, 14 Dec 2017 21:57:06 +0100 Greg KH escreveu:
> > On Thu, Dec 14, 2017 at 10:44:16PM +0200, Laurent Pinchart wrote:
> >> On Thursday, 14 December 2017 22:08:51 EET Greg KH wrote:
> >>> On Thu, Dec 14, 2017 at 09:05:27PM +0200, Laurent Pinchart wrote:
> >>>> On Thursday, 14 December 2017 20:54:39 EET Joe Perches wrote:
> >>>>> On Thu, 2017-12-14 at 20:37 +0200, Laurent Pinchart wrote:
> >>>>>> On Thursday, 14 December 2017 20:32:20 EET Joe Perches wrote:
> >>>>>>> On Thu, 2017-12-14 at 20:28 +0200, Laurent Pinchart wrote:
> >>>>>>>> On Thursday, 14 December 2017 19:05:27 EET Mauro Carvalho Chehab
> >>>>>>>> wrote:
> >>>>>>>>> Em Fri,  8 Dec 2017 18:05:37 +0530 Dhaval Shah escreveu:
> >>>>>>>>>> SPDX-License-Identifier is used for the Xilinx Video IP and
> >>>>>>>>>> related drivers.
> >>>>>>>>>> 
> >>>>>>>>>> Signed-off-by: Dhaval Shah <dhaval23031987@xxxxxxxxx>
> >>>>>>>>> 
> >>>>>>>>> Hi Dhaval,
> >>>>>>>>> 
> >>>>>>>>> You're not listed as one of the Xilinx driver maintainers. I'm
> >>>>>>>>> afraid that, without their explicit acks, sent to the ML, I
> >>>>>>>>> can't accept a patch touching at the driver's license tags.
> >>>>>>>> 
> >>>>>>>> The patch doesn't change the license, I don't see why it would
> >>>>>>>> cause any issue. Greg isn't listed as the maintainer or copyright
> >>>>>>>> holder of any of the 10k+ files to which he added an SPDX license
> >>>>>>>> header in the last kernel release.
> >>>>>>> 
> >>>>>>> Adding a comment line that describes an implicit or
> >>>>>>> explicit license is different than removing the license
> >>>>>>> text itself.
> >>>>>> 
> >>>>>> The SPDX license header is meant to be equivalent to the license
> >>>>>> text.
> >>>>> 
> >>>>> I understand that.
> >>>>> At a minimum, removing BSD license text is undesirable
> >>>>> 
> >>>>> as that license states:
> >>>>>  *    * Redistributions of source code must retain the above copyright
> >>>>>  *      notice, this list of conditions and the following disclaimer.
> >>>>> 
> >>>>> etc...
> >>>> 
> >>>> But this patch only removes the following text:
> >>>> 
> >>>> - * This program is free software; you can redistribute it and/or
> >>>> modify
> >>>> - * it under the terms of the GNU General Public License version 2 as
> >>>> - * published by the Free Software Foundation.
> >>>> 
> >>>> and replaces it by the corresponding SPDX header.
> >>>> 
> >>>>>> The only reason why the large SPDX patch didn't touch the whole
> >>>>>> kernel in one go was that it was easier to split in in multiple
> >>>>>> chunks.
> >>>>> 
> >>>>> Not really, it was scripted.
> >>>> 
> >>>> But still manually reviewed as far as I know.
> >>>> 
> >>>>>> This is no different than not including the full GPL license in
> >>>>>> every header file but only pointing to it through its name and
> >>>>>> reference, as every kernel source file does.
> >>>>> 
> >>>>> Not every kernel source file had a license text
> >>>>> or a reference to another license file.
> >>>> 
> >>>> Correct, but the files touched by this patch do.
> >>>> 
> >>>> This issue is in no way specific to linux-media and should be
> >>>> decided upon at the top level, not on a per-subsystem basis. Greg,
> >>>> could you comment on this ?
> >>> 
> >>> Comment on what exactly?  I don't understand the problem here, care to
> >>> summarize it?
> >> 
> >> In a nutshell (if I understand it correctly), Dhaval Shah submitted
> >> https:// patchwork.kernel.org/patch/10102451/ which replaces
> >> 
> >> +// SPDX-License-Identifier: GPL-2.0
> >> [...]
> >> - *
> >> - * This program is free software; you can redistribute it and/or modify
> >> - * it under the terms of the GNU General Public License version 2 as
> >> - * published by the Free Software Foundation.
> >> 
> >> in all .c and .h files of the Xilinx V4L2 driver
> >> (drivers/media/platform/
> >> xilinx). I have reviewed the patch and acked it. Mauro then rejected it,
> >> stating that he can't accept a change to license text without an
> >> explicit ack from the official driver's maintainers. My position is
> >> that such a change doesn't change the license and thus doesn't need to
> >> track all copyright holders, and can be merged without an explicit ack
> >> from the respective maintainers.
> > 
> > Yes, I agree with you, no license is being changed here, and no
> > copyright is either.
> > 
> > BUT, I know that most major companies are reviewing this process right
> > now.  We have gotten approval from almost all of the major kernel
> > developer companies to do this, which is great, and supports this work
> > as being acceptable.
> > 
> > So it's nice to ask Xilinx if they object to this happening, which I
> > guess Mauro is trying to say here (in not so many words...)  To at least
> > give them the heads-up that this is what is going to be going on
> > throughout the kernel tree soon, and if they object, it would be good to
> > speak up as to why (and if they do, I can put their lawyers in contact
> > with some lawyers to explain it all to them.)
> 
> Yes, that's basically what I'm saying.
> 
> I don't feel comfortable on signing a patch changing the license text
> without giving the copyright owners an opportunity and enough time
> to review it and approve, or otherwise comment about such changes.

If I understand you and Greg correctly, you would like to get a general 
approval from Xilinx for SPDX-related changes, but that would be a blanket 
approval that would cover this and all subsequent similar patches. Is that 
correct ? That is reasonable for me.

In that case, could the fact that commit

commit 5fd54ace4721fc5ce2bb5aef6318fcf17f421460
Author: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Date:   Fri Nov 3 11:28:30 2017 +0100

    USB: add SPDX identifiers to all remaining files in drivers/usb/

add SPDX headers to several Xilinx-authored source files constitute such a 
blanket approval ?

-- 
Regards,

Laurent Pinchart