Re: [PATCH] ASoC: stm32: sai: Use of_device_get_match_data() tosimplify code

[Olivier MOYSAN]

Hi Tang,

On 5/24/22 03:44, tangbin wrote:
> Hi Mark & Olivier：
>
> On 2022/5/24 2:57, Mark Brown wrote:
> > On Mon, May 23, 2022 at 03:28:48PM +0200, Olivier MOYSAN wrote:
> >
> > > The current patch requires a change in the driver.
> > > Either changing STM_SAI_x_ID enums, or replacing data by a struct.
> > > For instance:
> > > struct stm32_sai_comp_data {
> > >     unsigned int id;
> > > }
> > > struct stm32_sai_comp_data stm32_sai_comp_data_a = {
> > >     .id = STM_SAI_A_ID;
> > > }
> > > struct of_device_id stm32_sai_sub_ids[] = {
> > >     .data = &stm32_sai_comp_data_a},
> > > }
> > Either approach works for me (or a revert for that matter).
>
>      Thanks for your advice, I was thoughtless.
>
>      I think change the date of STM_SAI_x_ID maybe simple. But if we 
> don't change the id,
>
> what about add a "#define" like the line 47:
>
> #define STM_SAI_IS_SUB(x) ((x)->id == STM_SAI_A_ID || (x)->id == 
> STM_SAI_B_ID)
>
> then in the judgement, wu use:
>
>      sai->id = (uintptr_t)of_device_get_match_data(&pdev->dev);
>
>      if (!STM_SAI_IS_SUB(sai))
>
>              return -EINVAL;
>
>
> if you think that's ok, I will send patch v2 for you .

If we allow null value in STM_SAI_IS_SUB(sai) check, we can miss real 
NULL pointer error from of_device_get_match_data().

The simplest way is to change STM_SAI_x_ID enums I think.
But honnestly, I feel more comfortable to let the driver unchanged.

BRs
Olivier

> Thanks
>
> Tang Bin