Re: [PATCH 1/3] xen/arm: Sync sysregs and cpuinfo with Linux 5.18-rc3

[Bertrand Marquis <Bertrand.Marquis@xxxxxxx>]

Hi Stefano,

> On 11 May 2022, at 21:06, Stefano Stabellini <sstabellini@xxxxxxxxxx> wrote:
> 
> On Wed, 11 May 2022, Bertrand Marquis wrote:
>>> I understand the patch is already written, so I was OK if you simply list 
>>> of the commits with the authors/tags for this time.
>> 
>> I would like to understand where this requirement is coming from.
>> 
>> @George: is there some kind of legal reason for something like that ?
> 
> I am not George but I'll answer the legal question. Our "legal" document
> is the DCO:

I agree with your analysis but I still think this is an area where we would
need the confirmation from George.

> 
> https://developercertificate.org/
> 
> This falls under case (b):
> 
> (b) The contribution is based upon previous work that, to the best
>    of my knowledge, is covered under an appropriate open source
>    license and I have the right under that license to submit that
>    work with modifications, whether created in whole or in part
>    by me, under the same open source license (unless I am
>    permitted to submit under a different license), as indicated
>    in the file; or
> 
> So from the legal point of view only your Signed-off-by line is
> required.
> 
> I remember this well because I was confused about this a few years ago
> in another case of taking code from Linux.
> 
> 
>>> If both Stefano and you agree to not keep the authorships, then I will
>>> not stand against it. However, I will not get involved in
>>> committing and adding my ack.
> 
> I am fine either way. My only request is to mention the Linux commit-id
> that Bertrand used as a base and Bertrand has already done that.

Ok

> 
> 
>> I want first to clear up this process and understand why you are
>> requesting this to know how I should do anything like that in the
>> future.
> 
> It looks like our process docs are not very good on this point and might
> benefit from a clarification. I hope you are volunteering :-)
> 
> Origin is defined as "it specifies the source of the patch" but it
> doesn't say what actually is considered a "source".
> 
> I suggest to distinguish between the case where commits are ported
> individually from the case where code is copied over (like when we
> introduced SMMUv3.) If commits are copied individually, I think we
> probably want an Origin tag for each of them and the source is the
> original commit-id. If the code is copied from Linux (like the SMMUv3
> case) then we probably only want to request a single Origin tag (or a
> new tag?) with the base Linux version (5.18-rc3) rather than the
> commit-id being backported. In that case the source would be the
> repository baseline.

Before defining our own way to do that maybe we should check how
others are handling those cases to not reinvent the wheel.

Anybody has a suggestion of an other open source project we could
check which could have the same kind of “needs” ?

Cheers
Bertrand

> 
> Cheers,
> 
> Stefano