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

[Michal Simek]

Hi Laurent,

On 18.12.2017 09:32, Laurent Pinchart wrote:
> Hi Michal,
> 
> On Monday, 18 December 2017 09:32:12 EET Michal Simek wrote:
>> On 15.12.2017 10:27, Mauro Carvalho Chehab wrote:
>>> Em Fri, 15 Dec 2017 10:55:26 +0530 Dhaval Shah escreveu:
>>>> On Fri, Dec 15, 2017 at 3:32 AM, Laurent Pinchart wrote:
>>>>> 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 ?
>>>>
>>>> I have to do anything here or Once, we get approval from the Michal
>>>> Simek(michal.simek@xxxxxxxxxx) and Hyun.kwon@xxxxxxxxxx ACK this patch
>>>> then it will go into mainline?
>>>
>>> I would wait for their feedback.
>>
>> Please do not apply this patch till I get approval from legal. I have
>> already discussed things about SPDX some weeks ago.
> 
> Could you ask them to approve this kind of change globally for all Xilinx 
> sources files (or reject it globally if they want to do so) ? I don't want to 
> go through the same hassle for every single driver.
> 
> On a side note, SPDX headers have been added to several Xilinx-owned files 
> already, you can use that information in your internal discussions if it 
> helps.

As was said in this thread. One thing is if you simply add that one line
or if you add and remove. We are waiting for response from Legal to know
their opinion.

Anyway Xilinx is using SPDX license header in U-Boot project for years
already. This change started there in 2013 and I have never heard about
any problem connected to this.

>From my point of view it is good that this process finally started.
I have touched it in past here
https://lkml.org/lkml/2014/2/21/21
and I hope that there won't be any problem with this but let's see.

Thanks,
Michal