Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <d5ab354a-eb10-d31c-d55e-46a4c4d1a4ce@foss.st.com>
Date:   Tue, 24 May 2022 16:30:38 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.8.1
Subject: Re: [PATCH] ASoC: stm32: sai: Use of_device_get_match_data()
 tosimplify code
Content-Language: en-US
To:     tangbin <tangbin@cmss.chinamobile.com>,
        Mark Brown <broonie@kernel.org>
CC:     <arnaud.pouliquen@foss.st.com>, <lgirdwood@gmail.com>,
        <perex@perex.cz>, <tiwai@suse.com>, <mcoquelin.stm32@gmail.com>,
        <alexandre.torgue@foss.st.com>, <alsa-devel@alsa-project.org>,
        <linux-stm32@st-md-mailman.stormreply.com>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-kernel@vger.kernel.org>
References: <20220519124235.21100-1-tangbin@cmss.chinamobile.com>
 <69d5cef3-57c0-9bc7-a83b-a85ef1c4cf29@foss.st.com>
 <YovZAf4S0XphBsco@sirena.org.uk>
 <3fb8d7f8-4506-3b28-22cb-863bda1f21c8@cmss.chinamobile.com>
From:   Olivier MOYSAN <olivier.moysan@foss.st.com>
In-Reply-To: <3fb8d7f8-4506-3b28-22cb-863bda1f21c8@cmss.chinamobile.com>
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

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
> 
>