[U-Boot] [PATCH v2] arm64: dts: rockchip: Add support for Khadas Edge/Edge-V/Captain boards

[Kever Yang]

Hi Paul,


On 06/18/2019 05:03 PM, Paul Kocialkowski wrote:
> Hi,
>
> On Tue, 2019-06-18 at 14:27 +0530, Jagan Teki wrote:
>> On Tue, Jun 18, 2019 at 1:55 PM Paul Kocialkowski
>> <paul.kocialkowski at bootlin.com> wrote:
>>> Hi,
>>>
>>> On Mon, 2019-06-17 at 15:24 +0800, xieqinick at gmail.com wrote:
>>>> From: Nick Xie <nick at khadas.com>
>>> Was this tested with SPL support? I don't see DRAM configuration here
>>> so it seems that it relies on the non-free rockchip loader.
>>>
>>> If that is the case, could you please indicate that in the commit
>>> message?
>>>
>>> To maintainers: please do not merge this series before DRAM init and
>>> SPL support is available for these boards.
>>>
>>> It seems that other RK3399 boards were merged without SPL support and
>>> sofar, I have the feeling that nobody cared to explain how we got into
>>> this broken situation. Please don't merge any more such board.
>> fyi: no rk3399 boards were merged w/o SPL. lpddr4 boards were merged
>> with TPL-enabled (which was discussed on the threads, if you remember)
>> with below boot chain.
>>
>> rkbin (TPL) -> SPL -> U-Boot proper
>>
>> Same case for this board as well.
> Here is a quote from Philipp Tomsich on the thread we discussed this:
>
> " On some boards, there will be no TPL and only a SPL stage that will
> initialise DRAM (as the move to having TPL on the RK3399 is optional).
>
> I agree with Paul that the DRAM init should be part of U-Boot whenever
> we add new boards and make an open DRAM init a prerequisite. "
>
> So even if I frequently confuse SPL and TPL, it doesn't change the fact
> that no board should be merged without proper DRAM init.
>
> Please stop pushing for merging these boards. I'm not sure what we
> should do about the boards that were merged already without DRAM init,
> but maybe they should be reverted.
I don't think we have to have full DRAM init source code for each
board before we can merge it, I believe most of the board on U-Boot
mainline need to removed due to this rule. There are so many boards
from different vendor need a binary loader before U-Boot, and I can
see only very few drivers for dram at driver/ram/, and I believe rockchip
is already the most open vendor on this area.

I won't use this rule to stop developers contribute there source code,
for a board support, we only need the board to have the full documentation
about how to setup and boot with upstream U-Boot. and I think the
most of people cares more about features in U-Boot proper. Everything
before U-Boot proper, you can use TPL/SPL or alternative to use binary
from vendor, as you can see all over the U-Boot mainline now, although
we encourage people to use full open source TPL/SPL.
Specifically for U-Boot Rockchip platform, I would like people to
support not only U-Boot
proper, but also for full SPL(ATF, OP-TEE support, itb image and other
features)
support. And for DRAM init,
- if this belongs to SPL for this board, you must implement it or else
SPL won't work;
- if this does not belong to SPL for this board, you need implement full
function SPL;
    and you can either to have full function TPL with DRAM init(which is
prefered)
    or alternatively use binary loader from vendor.

I'm not sure if you have write a new dram driver for a board, but I know
even the board vendor may not have the capability to write the DRAM
driver, so this should not stop developers contribute to all other 99%
features on U-Boot.

Thanks,
- Kever
>
> Cheers,
>
> Paul
>