linux-kernel - Re: [PATCH v2 01/11] ASoC: samsung: s3c2412: Handle return value of clk_prepare

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Date:   Wed, 26 Jul 2017 12:28:17 +0100
From:   Mark Brown <broonie@...nel.org>
To:     Arvind Yadav <arvind.yadav.cs@...il.com>
Cc:     perex@...ex.cz, tiwai@...e.com, krzk@...nel.org,
        sbkim73@...sung.com, lgirdwood@...il.com,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 01/11] ASoC: samsung: s3c2412: Handle return value of
 clk_prepare_enable.

On Wed, Jul 26, 2017 at 11:15:25AM +0530, Arvind Yadav wrote:

> --- a/sound/soc/samsung/s3c2412-i2s.c
> +++ b/sound/soc/samsung/s3c2412-i2s.c
> @@ -65,13 +65,16 @@ static int s3c2412_i2s_probe(struct snd_soc_dai *dai)
>  	s3c2412_i2s.iis_cclk = devm_clk_get(dai->dev, "i2sclk");
>  	if (IS_ERR(s3c2412_i2s.iis_cclk)) {
>  		pr_err("failed to get i2sclk clock\n");
> -		return PTR_ERR(s3c2412_i2s.iis_cclk);
> +		ret = PTR_ERR(s3c2412_i2s.iis_cclk);
> +		goto err;
>  	}
>  

Why are we making this unrelated change?  None of the error handling we
jump to is relevant if this fails...

>  	/* Set MPLL as the source for IIS CLK */
>  
>  	clk_set_parent(s3c2412_i2s.iis_cclk, clk_get(NULL, "mpll"));
> -	clk_prepare_enable(s3c2412_i2s.iis_cclk);
> +	ret = clk_prepare_enable(s3c2412_i2s.iis_cclk);
> +	if (ret)
> +		goto err;
>  
>  	s3c2412_i2s.iis_cclk = s3c2412_i2s.iis_pclk;
>  
> @@ -80,6 +83,11 @@ static int s3c2412_i2s_probe(struct snd_soc_dai *dai)
>  			      S3C_GPIO_PULL_NONE);
>  
>  	return 0;
> +
> +err:
> +	clk_disable(s3c2412_i2s.iis_pclk);

This will disable the clock if we failed to enable it which is clearly
not correct.  It's also matching a clk_prepare_enable() with a
clk_disable() which is going to leave an unbalanced prepare.

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