Re: [PATCH] ASoC: ti: omap-mcbsp: Fix an error handling path in 'asoc_mcbsp_probe()'

[Peter Ujfalusi]

On 12/05/2020 16.43, Christophe JAILLET wrote:
> If an error occurs after the call to 'omap_mcbsp_init()', the reference to
> 'mcbsp->fclk' must be decremented, as already done in the remove function.
> 
> This can be achieved easily by using the devm_ variant of 'clk_get()'
> when the reference is taken in 'omap_mcbsp_init()'
> 
> This fixes the leak in the probe and has the side effect to simplify both
> the error handling path of 'omap_mcbsp_init()' and the remove function.

Acked-by: Peter Ujfalusi <peter.ujflausi@xxxxxx>

> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> I've not been able to identify the when the issue has been introduced, so
> no Fixes: tag.

I think this is there for a long-long time. It is a theoretical bug, in
practice it never happen (at least never faced with it over the years).

Thanks for the fix!

- PÃter

> ---
>  sound/soc/ti/omap-mcbsp.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/sound/soc/ti/omap-mcbsp.c b/sound/soc/ti/omap-mcbsp.c
> index 0348963f4df7..6c83b9888467 100644
> --- a/sound/soc/ti/omap-mcbsp.c
> +++ b/sound/soc/ti/omap-mcbsp.c
> @@ -686,7 +686,7 @@ static int omap_mcbsp_init(struct platform_device *pdev)
>  	mcbsp->dma_data[1].addr = omap_mcbsp_dma_reg_params(mcbsp,
>  						SNDRV_PCM_STREAM_CAPTURE);
>  
> -	mcbsp->fclk = clk_get(&pdev->dev, "fck");
> +	mcbsp->fclk = devm_clk_get(&pdev->dev, "fck");
>  	if (IS_ERR(mcbsp->fclk)) {
>  		ret = PTR_ERR(mcbsp->fclk);
>  		dev_err(mcbsp->dev, "unable to get fck: %d\n", ret);
> @@ -711,7 +711,7 @@ static int omap_mcbsp_init(struct platform_device *pdev)
>  		if (ret) {
>  			dev_err(mcbsp->dev,
>  				"Unable to create additional controls\n");
> -			goto err_thres;
> +			return ret;
>  		}
>  	}
>  
> @@ -724,8 +724,6 @@ static int omap_mcbsp_init(struct platform_device *pdev)
>  err_st:
>  	if (mcbsp->pdata->buffer_size)
>  		sysfs_remove_group(&mcbsp->dev->kobj, &additional_attr_group);
> -err_thres:
> -	clk_put(mcbsp->fclk);
>  	return ret;
>  }
>  
> @@ -1442,8 +1440,6 @@ static int asoc_mcbsp_remove(struct platform_device *pdev)
>  
>  	omap_mcbsp_st_cleanup(pdev);
>  
> -	clk_put(mcbsp->fclk);
> -
>  	return 0;
>  }
>  
> 

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