Re: [PATCH v2 00/32] driver core: Constify API device_find_child() and adapt for various existing usages

[Zijun Hu <zijun_hu@xxxxxxxxxx>]

On 2024/12/5 00:42, James Bottomley wrote:
>>>>  introduce extra device_find_child_new() which is constified  ->
>>>> use *_new() replace ALL device_find_child() instances one by one
>>>> -> remove device_find_child() -> rename *_new() to
>>>> device_find_child() once.
>>> Why bother with the last step, which churns the entire code base
>>> again?
>> keep the good API name device_find_child().
> Well, I think it's a good opportunity to rename the API better, but if
> that's the goal, you can still do it with _Generic() without churning
> the code base a second time.  The example is in
> slab.h:kmem_cache_create
> 

i understand these solutions _Generic()/_new/squashing.
every solutions have its advantages and disadvantages.

i decide to use squashing solution for this concrete scenario after some
considerations since:

1) it has the minimal patch count to achieve target.
2) every patch is valuable, but other solutions needs to undo beginning
  patch finally.
3) for the squashing patch, i will only make the least and simplest
changes for various match functions, that will compensate its
disadvantages.

>>> Why not call the new function device_find_child_const() and simply
>>> keep it (it's descriptive of its function).  That way you can have
>>> a patch series without merging and at the end simply remove the old
>>> function.
>> device_find_child is a good name for the API, 'find' already means
>> const.
> Not to me it doesn't, but that's actually not what I think is wrong
> with the API name: it actually only returns the first match, so I'd
> marginally prefer it to be called device_find_first_child() ... not
> enough to churn the code to change it, but since you're doing that
> anyway it might make sense as an update.

name device_find_child appeared 18 years ago, it is good to keep this
name developers known about.

the API only return one device *, it should be obvious that it is the
first device which meet matching condition.

Other device finding APIs (bus|class|driver)_find_device() does not have
concern about 'first'

So, IMO, current name is good.