linux-kernel - Re: [PATCH v1 1/6] ASoC: amd: acp-es8336: Drop reference count of ACPI device after use

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Date:   Wed, 11 Jan 2023 08:35:41 +0530
From:   "Mukunda,Vijendar" <vijendar.mukunda@....com>
To:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Mark Brown <broonie@...nel.org>,
        Hans de Goede <hdegoede@...hat.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org
Cc:     Liam Girdwood <lgirdwood@...il.com>,
        Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>,
        Cezary Rojewski <cezary.rojewski@...el.com>,
        Peter Ujfalusi <peter.ujfalusi@...ux.intel.com>,
        Bard Liao <yung-chuan.liao@...ux.intel.com>,
        Ranjani Sridharan <ranjani.sridharan@...ux.intel.com>,
        Kai Vehmanen <kai.vehmanen@...ux.intel.com>
Subject: Re: [PATCH v1 1/6] ASoC: amd: acp-es8336: Drop reference count of
 ACPI device after use

On 03/01/23 02:00, Andy Shevchenko wrote:
> Theoretically the device might gone if its reference count drops to 0.
> This might be the case when we try to find the first physical node of
> the ACPI device. We need to keep reference to it until we get a result
> of the above mentioned call. Refactor the code to drop the reference
> count at the correct place.
>
> While at it, move to acpi_dev_put() as symmetrical call to the
> acpi_dev_get_first_match_dev().
>
> Fixes: 02527c3f2300 ("ASoC: amd: add Machine driver for Jadeite platform")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Acked-by: Vijendar Mukunda <Vijendar.Mukunda@....com>
> ---
>  sound/soc/amd/acp-es8336.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/sound/soc/amd/acp-es8336.c b/sound/soc/amd/acp-es8336.c
> index 2fe8df86053a..89499542c803 100644
> --- a/sound/soc/amd/acp-es8336.c
> +++ b/sound/soc/amd/acp-es8336.c
> @@ -198,9 +198,11 @@ static int st_es8336_late_probe(struct snd_soc_card *card)
>  	int ret;
>  
>  	adev = acpi_dev_get_first_match_dev("ESSX8336", NULL, -1);
> -	if (adev)
> -		put_device(&adev->dev);
> +	if (!adev)
> +		return -ENODEV;
> +
>  	codec_dev = acpi_get_first_physical_node(adev);
> +	acpi_dev_put(adev);
>  	if (!codec_dev)
>  		dev_err(card->dev, "can not find codec dev\n");
>