[alsa-devel] [PATCH] ASoC: hdmi-codec: Fix module unloading caused kernel crash

[Jyri Sarha]

On 20/02/18 14:30, Peter Ujfalusi wrote:
> The hcp->chmap_info must not be freed up in the hdmi_codec_remove()
> function as it leads to kernel crash due ALSA core's
> pcm_chmap_ctl_private_free() is trying to free it up again when the card
> destroyed via snd_card_free.
> 
> Since the driver was converted to devm_snd_soc_register_component() the
> whole platform_device.remove can be removed.
> 
> Commit cd6111b26280a ("ASoC: hdmi-codec: add channel mapping control")
> should not have added the kfree(hcp->chmap_info); to the hdmi_codec_remove
> function.
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>

Thanks,
After this Beaglebone-black does not give "Unable to handle kernel
paging request" any more when unloading the tilcdc module.

Reviewed-by: Jyri Sarha <jsarha at ti.com>
Tested-by: Jyri Sarha <jsarha at ti.com>


> ---
>  sound/soc/codecs/hdmi-codec.c | 12 ------------
>  1 file changed, 12 deletions(-)
> 
> diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
> index 42df579cb507..6fa11888672d 100644
> --- a/sound/soc/codecs/hdmi-codec.c
> +++ b/sound/soc/codecs/hdmi-codec.c
> @@ -798,23 +798,11 @@ static int hdmi_codec_probe(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static int hdmi_codec_remove(struct platform_device *pdev)
> -{
> -	struct device *dev = &pdev->dev;
> -	struct hdmi_codec_priv *hcp;
> -
> -	hcp = dev_get_drvdata(dev);
> -	kfree(hcp->chmap_info);
> -
> -	return 0;
> -}
> -
>  static struct platform_driver hdmi_codec_driver = {
>  	.driver = {
>  		.name = HDMI_CODEC_DRV_NAME,
>  	},
>  	.probe = hdmi_codec_probe,
> -	.remove = hdmi_codec_remove,
>  };
>  
>  module_platform_driver(hdmi_codec_driver);
> 


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