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

From: William Zhang <william.zhang@broadcom.com>
To: "Krzysztof Kozlowski" <krzysztof.kozlowski@linaro.org>,
	"Rafał Miłecki" <rafal@milecki.pl>
Cc: Linux ARM List <linux-arm-kernel@lists.infradead.org>,
	joel.peshkin@broadcom.com, dan.beygelman@broadcom.com,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Anand Gore <anand.gore@broadcom.com>,
	Kursad Oney <kursad.oney@broadcom.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Broadcom internal kernel review list
	<bcm-kernel-feedback-list@broadcom.com>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
	<devicetree@vger.kernel.org>,
	open list <linux-kernel@vger.kernel.org>
Subject: Re: [RESEND PATCH 2/9] dt-bindings: arm64: bcmbca: Update BCM4908 description
Date: Thu, 21 Jul 2022 17:07:33 -0700	[thread overview]
Message-ID: <bbc67617-9137-28d4-8d6f-a36507923010@broadcom.com> (raw)
In-Reply-To: <193845cb-6149-1ae6-5eb6-6b01ffcf763b@linaro.org>

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 
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
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel