Re: [PATCH v3 08/10] riscv: dts: renesas: Add minimal DTS for Renesas RZ/Five SMARC EVK

[Conor.Dooley]

On 15/09/2022 23:41, Lad, Prabhakar wrote:
> Hi Conor,
> 
> Thank you for the review.
> 
> On Thu, Sep 15, 2022 at 10:56 PM <Conor.Dooley@xxxxxxxxxxxxx> wrote:
>>
>> On 15/09/2022 19:15, Prabhakar wrote:
>>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>>
>>> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>>>
>>> Enable the minimal blocks required for booting the Renesas RZ/Five
>>> SMARC EVK with initramfs.
>>>
>>> Below are the blocks enabled:
>>> - CPG
>>> - CPU0
>>> - DDR (memory regions)
>>> - PINCTRL
>>> - PLIC
>>> - SCIF0
>>>
>>> Note we have deleted the nodes from the DT for which support needs to be
>>> added for RZ/Five SoC and are enabled by RZ/G2UL SMARC EVK SoM/carrier
>>> board DTS/I.
>>
>> idk, I am not sure what to think of this approach.
>>
>> What do you mean by "for which support needs to be added"? If the support
>> does not exist yet, then is surely you can just add the nodes and it will
>> be fine?
>>
> As pointed out previously, I am re-using the below files [1] (SoM) and
> [2] (Carrier board) as the RZ/Five SMARC EVK is pin compatible. Since
> [1] and [2] enable almost all the peripherals (status = okay)  on the
> RZ/G2UL SMARC EVK which are supported. For example [1] enables SDHI0/1
> this high speed block needs DMA and without cache management fixed on
> Andes core we cannot enable this on RZ/Five SoC so currently a
> placeholder is added for it in the RZ/FIve SoC DTSI and is deleted in
> the board DTS file.
> 
> Below blocks suffer the cache management issue:
> - DMAC
> - ETH
> - SDHI
> - USB
> 
> Rest of the blocks will be gradually enabled (as soon as this initial
> patchset is merged) along with the DT binding doc updates.
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/renesas/rzg2ul-smarc-som.dtsi?h=v6.0-rc5
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/renesas/rzg2ul-smarc.dtsi?h=v6.0-rc5


Explanations are reasonable, but again - that information is important
and really needs to be included in the commit message etc.

Thanks,
Conor.