Re: [RESEND PATCH 2/9] dt-bindings: arm64: bcmbca: Update BCM4908 description

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 22/07/2022 02:07, William Zhang wrote:
> 
> 
> On 07/21/2022 12:01 AM, Krzysztof Kozlowski wrote:
>> On 21/07/2022 08:51, Rafał Miłecki wrote:
>>> On 2022-07-21 08:44, Krzysztof Kozlowski wrote:
>>>> On 21/07/2022 02:06, William Zhang wrote:
>>>>> Append "brcm,bcmbca" to BCM4908 chip family compatible strings. Add
>>>>> generic 4908 board entry.
>>>>
>>>> This does not explain at all why you are doing it. Improve your commit
>>>> messages.
>>>
>>> To clarify it from my side (and maybe help a bit):
>>>
>>> 1. As I understand it BCMBCA is a one big family of SoCs.
>>> 2. BCM4908 is a subset of that family (a subfamily?) designed for a
>>>      specific group of devices.
>>>
>>> If that's correct I think William it's what you should describe in your
>>> commit message. That would make binding more accurate and should be a
>>> good argument for your change (I believe).
>>
>> That's better argument. But what's the benefit of adding generic
>> compatible? Devices cannot bind to it (it is too generic). Does it
>> describe the device anyhow? Imagine someone adding compatible
>> "brcm,all-soc-of-broadcom" - does it make any sense?
>>
> In case you were also referring the generic 4908 board compatible string 
> brcm,bcm94908, this is for a bare bone 4908 board dts that only enables 

No, we refer to the contents of the patch, so bcmbca compatible.

I did not see you introducing here bcm4908 compatible.

> ARM cpu subsystem, memory and uart. It can be used on all 4908 based 
> Broadcom reference boards and customer board. It is especially useful 
> for initial board bring up and one can load this generic board and start 
> work and debug from the console. Also would be helpful to do a quick 
> verification of new kernel version when there is cpu subsystem related 
> change.
> 
> I guess my mindset already assume people are now familiar with this 
> model of bcmbca binding addition for a new SoC since we introduced the 
> bcmbca arch with first soc 47622 and 10+ other socs late. But sure I 
> agree and I will update the commit message with more details in addition 
> to what the cover letter says.



Best regards,
Krzysztof