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Subject: Re: [PATCH 1/2] arm64: boot: dts: add new dts for hellcat & petra
To:     "Daniel Walker (danielwa)" <danielwa@cisco.com>,
        Michal Simek <michal.simek@xilinx.com>
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From:   Michal Simek <michal.simek@xilinx.com>
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Date:   Tue, 26 Jan 2021 10:16:38 +0100
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On 1/25/21 10:04 PM, Daniel Walker (danielwa) wrote:
> On Mon, Jan 25, 2021 at 08:52:01AM +0100, Michal Simek wrote:
>>>
>>>>
>>>> Long time ago we said that we are not going to push any PL related
>>>> configurations. It means all below can't be merged.
>>>> And there are also coding style issues.
>>>
>>> You'll need to explain this more. It's likely this was added at the suggestion of
>>> Xilinx. If it can't be upstreamed what should we replace it with ?
>>
>> No idea who gave you this suggestion from Xilinx.
>  
> Just an FYI , I didn't write this dts or work on it's original development so I
> can't name names.

ok.

> 
>> I had similar thread with Michael Walle about supporting Ebang board.
>> PL depends on your custom design and can change quite quickly that's
>> there is no good/bad configuration. That's why all of them can be valid
>> and kernel is not the right location to store thousands of
>> configurations (likely in overlay form). That's why only fixed
>> configurations for PS are added to kernel.
>> And I prefer if there is any good reason behind why these platforms
>> should be added.
> 
> I'm not sure what your talking about above .. Are you suggesting the changes in
> my DTS will change quickly ? They have been the same for years , we don't plan
> to change them. This DTS is not a prototype it's a released Cisco product.

I am saying that I will NACK all DT changes which target PL. No matter
that you didn't change hw design for years. You can add PL to DT overlay
and apply it in Linux or do it via bootloader.

> If I did delete this "PL configuration" where would you expect it to re-appear ?
> Typically things which aren't upstreamable are transformed into something else,
> it's rare that something is just removed and has no transformation.

dt overlay in your distribution, rootfs as separate file and base DT in
mainline.

Thanks,
Michal