[U-Boot] Individual files dual licenses

[York Sun]

On 01/18/2018 11:17 AM, Tom Rini wrote:
> On Thu, Jan 18, 2018 at 06:14:07PM +0000, York Sun wrote:
>> On 01/18/2018 10:11 AM, Tom Rini wrote:
>>> On Thu, Jan 18, 2018 at 06:09:22PM +0000, York Sun wrote:
>>>> On 01/18/2018 10:04 AM, Tom Rini wrote:
>>>>>>>
>>>>>>> With regards to dts files, this is another reason I would like to see
>>>>>>> that done as a strict re-sync with Linux rather than a stand-alone
>>>>>>> change.  Saying we're importing file X from the kernel at revision Y
>>>>>>> makes the license change pretty easy to spot and justify.
>>>>>>>
>>>>>>
>>>>>> For the dts files, they already exist in U-Boot. Can the team still say
>>>>>> "importing" from Linux? The files in U-Boot is only a small subset of
>>>>>> those in Linux.
>>>>>
>>>>> Yes, if it's a strict replace file A with contents of the same file from
>>>>> Linux, it's re-importing.  I thought these boards had already re-synced
>>>>> before but perhaps not?  It's something we do from time to time on other
>>>>> platforms.
>>>>
>>>> In this case, the contents of dts files are different from those in
>>>> Linux. The only thing imported this time is the dual license. Is it
>>>> still considered a re-sync?
>>>
>>> They should not be different at all.  Anything U-Boot centric should be
>>> in an appropriately named -u-boot.dtsi file.  This facilitates keeping
>>> the rest of the dts/dtsi files as exact copies of the ones in the
>>> kernel.
>>>
>>> To put it another way, what is the reason they differ from the kernel?
>>> And could they be changed to not, and use a -u-boot.dtsi (or several) so
>>> that they can be kept in-sync with the kernel?
>>
>> The dts files in Linux are much much bigger. U-Boot only uses a small
>> subset. There are many nodes not used by U-Boot.
> 
> For SPL where we care about size in that regard we have
> CONFIG_OF_SPL_REMOVE_PROPS to trim things down as needed, and it
> shouldn't be a concern for full U-Boot.  
> 
> If your really want to maintain two distinct dts/dtsi files because
> there's some value you see in that, I won't stop you from doing it.  But
> I don't see a unique challenge posed by the NXP platforms just yet
> either.  Thanks!

Got it. I don't know if most platforms use identical dts from Linux. We
started with tiny dts files and haven't seen the benefit to get the full
version. I will let the team decide if we want to copy Linux files over.

York