Re: [PATCH] ASoC: stm32: sai: add missing put_device()

[Olivier MOYSAN]

Acked-by: Olivier Moysan <olivier.moysan@xxxxxx>

On 2/13/19 3:41 PM, Wen Yang wrote:
> From: Olivier MOYSAN <olivier.moysan@xxxxxx>
> 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@xxxxxxxxxxxxxxxx; linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> 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@xxxxxxxxxxx>
>>> ---
>>>    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()
> 

I agree, release of np_sync_provider node is missing, as well as
returned error on set_sync.
So yes, this requires a dedicated patch.
Thanks

Regards
Olivier

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