Re: [PATCH v2 3/3] clk: meson: a1: add support for Amlogic A1 clock driver

Jian Hu
2019-11-25T12:01:36Z

On 2019/11/25 18:14, Jerome Brunet wrote:
>
> On Thu 21 Nov 2019 at 04:21, Jian Hu <jian.hu@amlogic.com> wrote:
>
>> Hi, Jerome
>>
>> On 2019/11/20 23:35, Jerome Brunet wrote:
>>>
>>> On Wed 20 Nov 2019 at 10:28, Jian Hu <jian.hu@amlogic.com> wrote:
>>>
>>>> Hi, jerome
>>>>
>>>> Is there any problem about fixed_pll_dco's parent_data?
>>>>
>>>> Now both name and fw_name are described in parent_data.
>>>
>>> Yes, there is a problem. This approach is incorrect, as I've tried to
>>> explain a couple times already. Let me try to re-summarize why this
>>> approach is incorrect.
>>>
>>> Both fw_name and name should be provided when it is possible that
>>> the DT does not describe the input clock. IOW, it is only for controllers
>>> which relied on the global name so far and are now starting to describe
>>> the clock input in DT
>>>
>>> This is not your case.
>>> Your controller is new and DT will have the correct
>>> info
>>>
>>> You are trying work around an ordering issue by providing both fw_name
>>> and name. This is not correct and I'll continue to nack it.
>>>
>>> If the orphan clock is not reparented as you would expect, I suggest you
>>> try to look a bit further at how the reparenting of orphans is done in
>>> CCF and why it does not match your expectation.
>>>
>> I have debugged the handle for orphan clock in CCF, Maybe you are missing
>> the last email.
>
> Nope, got it the first time
>
>> Even though the clock index exit, it will get failed for the orphan clock's
>> parent clock due to it has not beed added to the provider.
>
> If the provider is not registered yet, of course any query to it won't
> work. This why I have suggested to this debug *further* :
>
> * Is the orphan reparenting done when a new provider is registered ?
> * If not, should it be done ? is this your problem ?
>
Yes, the orphan reparenting is done when the new provider is registered.

Reparenting the orphan will be done when each clock is registered by
devm_clk_hw_register. And at this time the provider has not been
registered. After all clocks are registered by devm_clk_hw_register, the
provider will be registered by devm_of_clk_add_hw_provider.

Reparenting the orphan will fail when fw_name is added alone, the couse
is that devm_clk_hw_register is always running ahead of
devm_of_clk_add_hw_provider.

That is why it will failed to get parent for the orphan clock.

>
> .
>