[alsa-devel] [PATCH] ASoC: stm32: sai: add missing put_device()

[Wen Yang]

From: Olivier MOYSAN <olivier.moysan at st.com>
Sent: 11 February 2019 15:09
To: Wen Yang; Arnaud POULIQUEN; Liam Girdwood; Mark Brown; Jaroslav Kysela; Takashi Iwai; Maxime Coquelin; Alexandre TORGUE
Cc: alsa-devel at alsa-project.org; linux-stm32 at st-md-mailman.stormreply.com; linux-arm-kernel at lists.infradead.org; linux-kernel at vger.kernel.org
Subject: Re: [PATCH] ASoC: stm32: sai: add missing put_device()

>On 2/9/19 11:41 AM, Wen Yang wrote:
>> The of_find_device_by_node() takes a reference to the underlying device
>> structure, we should release that reference.
>>
>> Fixes: 7dd0d835582f ("ASoC: stm32: sai: simplify sync modes management")
>> Signed-off-by: Wen Yang <yellowriver2010 at hotmail.com>
>> ---
>>   sound/soc/stm/stm32_sai.c | 11 ++++++++---
>>   1 file changed, 8 insertions(+), 3 deletions(-)
>>
>> diff --git a/sound/soc/stm/stm32_sai.c b/sound/soc/stm/stm32_sai.c
>> index bcb35ca..14c9591 100644
>> --- a/sound/soc/stm/stm32_sai.c
>> +++ b/sound/soc/stm/stm32_sai.c
>> @@ -112,16 +112,21 @@ static int stm32_sai_set_sync(struct stm32_sai_data *sai_client,
>
>goto error also in previous test
>       if (!pdev) {
>               ...
>               ret = -ENODEV;
>                goto error;
>        }
>
>>       if (!sai_provider) {
>>               dev_err(&sai_client->pdev->dev,
>>                       "SAI sync provider data not found\n");
>> -             return -EINVAL;
>> +             ret = -EINVAL;
>> +             goto out_put_dev;
>>       }
>>
>>       /* Configure sync client */
>>       ret = stm32_sai_sync_conf_client(sai_client, synci);
>>       if (ret < 0)
>> -             return ret;
>> +             goto out_put_dev;
>>
>>       /* Configure sync provider */
>> -     return stm32_sai_sync_conf_provider(sai_provider, synco);
>> +     ret = stm32_sai_sync_conf_provider(sai_provider, synco);
>> +
>> +out_put_dev:
>> +     put_device(&pdev->dev);
>> +     return ret;
>
>Here I propose:
>error:
>        of_node_put(np_provider);
>        return ret;
>
>>   }
>>
>>   static int stm32_sai_probe(struct platform_device *pdev)
>>

>Thanks for your patch. Please, see my comments above.

Thanks for your comments, in this patch we only fix the problem of missing put_device().
The problem of missing of_node_put() is a bit more complicated:
For the variable np_provider(np_sync_provider):
1, it is obtained by of_get_parent(), but it is not released;
2, error code not obtained when calling sai->pdata->set_sync()

We will submit another patch to fix the failure of np_sync_provider
Thank you.

Regards
Wen