Re: [PATCH v2] misc: atmel-ssc: Handle return value of clk_prepare_enable and clk_prepare

[Arvind Yadav]

Hi,

Yes, Patch v1 was wrong that's why i have push v2.
clk_prepare and clk_prepare_enable can fail. There
is not harm to check it's return value. It'll not impact present
functionality.

-arvind

On Sunday 04 June 2017 03:47 AM, Alexandre Belloni wrote:
> Hi,
>
> It is getting tiring to get patches that are nor even compile tested
> resulting from whatever static analysis tool you used.
>
> This patch has almost no value and v1 was clearly wrong.
>
> Do you realize clk_prepare and clk_prepare_enable will never fail for
> the SSC?
>
> On 02/06/2017 at 11:09:02 +0530, Arvind Yadav wrote:
> > clk_prepare_enable() and clk_prepare() can fail here and
> > we must check its return value.
> >
> > Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>
> > ---
> >   drivers/misc/atmel-ssc.c | 12 ++++++++++--
> >   1 file changed, 10 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
> > index b2a0340..df34b81 100644
> > --- a/drivers/misc/atmel-ssc.c
> > +++ b/drivers/misc/atmel-ssc.c
> > @@ -30,6 +30,7 @@ struct ssc_device *ssc_request(unsigned int ssc_num)
> >   {
> >   	int ssc_valid = 0;
> >   	struct ssc_device *ssc;
> > +	int ret;
> >   
> >   	spin_lock(&user_lock);
> >   	list_for_each_entry(ssc, &ssc_list, list) {
> > @@ -60,7 +61,11 @@ struct ssc_device *ssc_request(unsigned int ssc_num)
> >   	ssc->user++;
> >   	spin_unlock(&user_lock);
> >   
> > -	clk_prepare(ssc->clk);
> > +	ret = clk_prepare(ssc->clk);
> > +	if (ret) {
> > +		pr_err("Failed to prepare clock\n");
> > +		return ERR_PTR(ret);
> > +	}
> >   
> >   	return ssc;
> >   }
> > @@ -195,6 +200,7 @@ static int ssc_probe(struct platform_device *pdev)
> >   	struct resource *regs;
> >   	struct ssc_device *ssc;
> >   	const struct atmel_ssc_platform_data *plat_dat;
> > +	int ret;
> >   
> >   	ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
> >   	if (!ssc) {
> > @@ -229,7 +235,9 @@ static int ssc_probe(struct platform_device *pdev)
> >   	}
> >   
> >   	/* disable all interrupts */
> > -	clk_prepare_enable(ssc->clk);
> > +	ret = clk_prepare_enable(ssc->clk);
> > +	if (ret)
> > +		return ret;
> >   	ssc_writel(ssc->regs, IDR, -1);
> >   	ssc_readl(ssc->regs, SR);
> >   	clk_disable_unprepare(ssc->clk);
> > --
> > 1.9.1
> >
> >
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