Re: [PATCH v9 1/3] dt-binding: clock: ast2700: modify soc0/1 clock define

[Krzysztof Kozlowski <krzk@kernel.org>]

On 25/02/2025 01:41, Ryan Chen wrote:
>> Subject: Re: [PATCH v9 1/3] dt-binding: clock: ast2700: modify soc0/1 clock
>> define
>>
>> On 24/02/2025 10:55, Ryan Chen wrote:
>>> -remove redundant SOC0_CLK_UART_DIV13:
>>> SOC0_CLK_UART_DIV13 is not use at clk-ast2700.c, the clock source tree
>>> is uart clk src -> uart_div_table -> uart clk.
>>>
>>> -Change SOC0_CLK_HPLL_DIV_AHB to SOC0_CLK_AHBMUX:
>>> modify clock tree implement.
>>> older CLK_AHB use mpll_div_ahb/hpll_div_ahb to be ahb clock source.
>>> mpll->mpll_div_ahb
>>>                   -> clk_ahb
>>> hpll->hpll_div_ahb
>>
>>
>> I can barely understand it and from the pieces I got, it does not explain need
>> for ABI break.
>>
> 
> #1. SCU0_CLK_UART_DIV13 is redundant, it does not impact ABI break

You did not explain how it does not impact. Clock was exported, there
was a user and now there is no clock. User stops working. ABI break.

> #2. Change SOC0_CLK_HPLL_DIV_AHB to SOC0_CLK_AHBMUX
> Older implement where `mpll_div_ahb` and `hpll_div_ahb` were **hardcoded dividers** for AHB.
> In **the new approach (v8)**, I refactored the clock tree to clock tree.

I still cannot parse sentences like "refactoring A to A". It's
meaningless to me.

> It should be ABI-safe change

No, you do not understand the ABI. You removed a clock ID, that's the
ABI change.

Otherwise explain how this is not changing ABI.


> 
> Or you want to keep original SOC0_CLK_HPLL_DIV_AHB define and then add SOC0_CLK_AHBMUX.
> To be 1st patch, then 2n patch remove redundant SOC0_CLK_HPLL_DIV_AHB?

If you break the ABI you need to clearly explain why. We have long
conversations and you still did not say why.


Best regards,
Krzysztof