[alsa-devel] [RESEND PATCH v2] ASoC: SOF: Intel: hda: Make hdac_device device-managed

[Ranjani Sridharan]

On Sun, 2019-07-07 at 16:56 -0700, Ranjani Sridharan wrote:
> snd_hdac_ext_bus_device_exit() has been recently modified
> to no longer free the hdac device. SOF allocates memory for
> hdac_device and hda_hda_priv with kzalloc. Make them
> device-managed instead so that they will be freed when the
> SOF driver is unloaded.
> 
> Because of the above change, hda_codec is device-managed and
> it will be freed when the ASoC device is removed. Freeing
> the codec in snd_hda_codec_dev_release() leads to kernel
> panic while unloading and reloading the ASoC driver. So,
> avoid freeing the hda_codec for ASoC driver. This is done in
> the same patch to avoid bisect failure.
Hi Mark,

This patch is needed for the module load/unload stress tests for the
Intel platforms with SOF. Could you please help review it?
 
The details of the issue can be found here: 
https://github.com/thesofproject/linux/issues/966

Thanks,
Ranjani
> 
> Signed-off-by: Libin Yang <libin.yang at intel.com>
> Signed-off-by: Ranjani Sridharan <ranjani.sridharan at linux.intel.com>
> Reviewed-by: Takashi Iwai <tiwai at suse.de>
> Reviewed-by: Pierre-Louis Bossart <
> pierre-louis.bossart at linux.intel.com>
> ---
>  sound/pci/hda/hda_codec.c       | 8 +++++++-
>  sound/soc/sof/intel/hda-codec.c | 6 ++----
>  2 files changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
> index 6c51b8363f8b..a2e23d7e768f 100644
> --- a/sound/pci/hda/hda_codec.c
> +++ b/sound/pci/hda/hda_codec.c
> @@ -846,7 +846,13 @@ static void snd_hda_codec_dev_release(struct
> device *dev)
>  	snd_hda_sysfs_clear(codec);
>  	kfree(codec->modelname);
>  	kfree(codec->wcaps);
> -	kfree(codec);
> +
> +	/*
> +	 * In the case of ASoC HD-audio, hda_codec is device managed.
> +	 * It will be freed when the ASoC device is removed.
> +	 */
> +	if (codec->core.type == HDA_DEV_LEGACY)
> +		kfree(codec);
>  }
>  
>  #define DEV_NAME_LEN 31
> diff --git a/sound/soc/sof/intel/hda-codec.c
> b/sound/soc/sof/intel/hda-codec.c
> index b8b37f082309..0d8437b080bf 100644
> --- a/sound/soc/sof/intel/hda-codec.c
> +++ b/sound/soc/sof/intel/hda-codec.c
> @@ -62,8 +62,7 @@ static int hda_codec_probe(struct snd_sof_dev
> *sdev, int address)
>  		address, resp);
>  
>  #if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA_AUDIO_CODEC)
> -	/* snd_hdac_ext_bus_device_exit will use kfree to free hdev */
> -	hda_priv = kzalloc(sizeof(*hda_priv), GFP_KERNEL);
> +	hda_priv = devm_kzalloc(sdev->dev, sizeof(*hda_priv),
> GFP_KERNEL);
>  	if (!hda_priv)
>  		return -ENOMEM;
>  
> @@ -82,8 +81,7 @@ static int hda_codec_probe(struct snd_sof_dev
> *sdev, int address)
>  
>  	return 0;
>  #else
> -	/* snd_hdac_ext_bus_device_exit will use kfree to free hdev */
> -	hdev = kzalloc(sizeof(*hdev), GFP_KERNEL);
> +	hdev = devm_kzalloc(sdev->dev, sizeof(*hdev), GFP_KERNEL);
>  	if (!hdev)
>  		return -ENOMEM;
>