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Date: Wed, 17 Apr 2024 17:27:25 +0300
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Subject: Re: [PATCH 3/4] ARM: dts: BCM5301X: Add DT for ASUS RT-AC3200
To: Krzysztof Kozlowski <krzk@kernel.org>,
 Florian Fainelli <florian.fainelli@broadcom.com>,
 Rob Herring <robh@kernel.org>, Krzysztof Kozlowski <krzk+dt@kernel.org>,
 Conor Dooley <conor+dt@kernel.org>, Florian Fainelli <f.fainelli@gmail.com>,
 Hauke Mehrtens <hauke@hauke-m.de>, Rafal Milecki <zajec5@gmail.com>,
 Broadcom internal kernel review list <bcm-kernel-feedback-list@broadcom.com>
Cc: Tom Brautaset <tbrautaset@gmail.com>, devicetree@vger.kernel.org,
 linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
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On 17/04/2024 16:23, Krzysztof Kozlowski wrote:
> On 17/04/2024 10:24, Arınç ÜNAL wrote:
>> On 17/04/2024 06:15, Florian Fainelli wrote:
>>>
>>>
>>> On 4/15/2024 2:10 AM, Arınç ÜNAL wrote:
>>>> On 15.04.2024 10:57, Krzysztof Kozlowski wrote:
>>>>> On 14/04/2024 22:21, Arınç ÜNAL wrote:
>>>>>> NVRAM is described as both flash device partition and memory mapped NVMEM.
>>>>>> This platform stores NVRAM on flash but makes it also memory accessible.
>>>>>>
>>>>>> As device partitions are described in board DTS, the nvram node must also
>>>>>
>>>>> Sorry, but we do not talk about partitions. Partitions are indeed board
>>>>> property. But the piece of hardware, so NVMEM, is provided by SoC.
>>>>>
>>>>>> be defined there as its address and size will be different by board. It has
>>>>>> been widely described on at least bcm4709 and bcm47094 SoC board DTS files
>>>>>> here.
>>>>>
>>>>> These not proper arguments. What you are saying here is that SoC does no
>>>>> have nvram at address 0x1c08000. Instead you are saying there some sort
>>>>> of bus going out of SoC to the board and on the board physically there
>>>>> is some NVRAM sort of memory attached to this bus.
>>>>
>>>> Yes that is the case. NVRAM is stored on a partition on the flash. On the
>>>> Broadcom NorthStar platform, the NAND flash base is 0x1c000000, the NOR
>>>> flash base is 0x1e000000.
>>>>
>>>> For the board in this patch, the flash is a NAND flash. The NVRAM partition
>>>> starts at address 0x00080000. Therefore, the NVRAM component's address is
>>>> 0x1c080000.
>>>
>>> Because the flash is memory mapped into the CPU's address space, a separate node was defined since it is not part of the "soc" node which describes the bridge that connects all of the peripherals.
>>>
>>> Whether we should create an additional bus node which describes the bridge being used to access the flash devices using the MMIO windows is debatable. Rafal, what do you think?
>>
>> Will this block this patch series? If not, I'd like to submit the next
>> version with Krzysztof's comments on earlycon and stdout-path addressed.
> 
> Why are you so impatient? The review process takes time and your
> reluctance to take responsibility for issues here are no helping.

I have already stated that I don't maintain this architecture and I don't
know it very well, and called on at least Rafal to further discuss the
issue you've raised. I've already answered your questions to the best of my
knowledge. If I was impatient, I would declare that I have no
responsibility in the SoC dt-bindings and send the next version without a
care. What I am doing instead is confirming whether or not you or Florian
think that this SoC dt-bindings issue must be resolved before my patches
that add board DTS files go in.

Arınç