Re: [PATCH v2 01/11] ASoC: samsung: s3c2412: Handle return value of clk_prepare_enable.

[Arvind Yadav]

Hi,


On Wednesday 26 July 2017 04:58 PM, Mark Brown wrote:
> 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...
3c_i2sv2_probe is enabling "iis" clock. If devm_clk_get(, "i2sclk") fails.
we need to disable and free the clock "iis" .
> >   	/* 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.
s3c_i2sv2_probe is enabling "iis" clock. And s3c2412_i2s_probe is enabling
"i2sclk"  and "mpll"clock. If, "mpll" clk_prepare_enable fails. We need 
to disable and
free the clock "iis".  and devm will handle other clock "i2sclk". In 
this code we have used
"s3c2412_i2s.iis_cclk" for all the clock which is more confusing for me.
Please correct me if i am wrong.

~arvind