Re: [PATCH] iio: adc: fsl-imx25-gcq: fix the right check andsimplify code

[tangbin]

Hi Jonathan:

On 2021/8/2 18:16, Jonathan Cameron wrote:
> On Mon, 2 Aug 2021 10:31:58 +0800
> tangbin <tangbin@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > Hi Jonathan:
> >
> > On 2021/8/1 0:45, Jonathan Cameron wrote:
> > > On Tue, 27 Jul 2021 20:52:09 +0800
> > > Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx> wrote:
> > >   
> > > > For the function of platform_get_irq(), the example in platform.c is
> > > > *		int irq = platform_get_irq(pdev, 0);
> > > > *		if (irq < 0)
> > > > *			return irq;
> > > > So the return value of zero is unnecessary to check. And move it
> > > > up to a little bit can simplify the code jump.
> > > >
> > > > Co-developed-by: Zhang Shengju <zhangshengju@xxxxxxxxxxxxxxxxxxxx>
> > > > Signed-off-by: Zhang Shengju <zhangshengju@xxxxxxxxxxxxxxxxxxxx>
> > > > Signed-off-by: Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx>
> > > Hi,
> > >
> > > Logically it is better to keep the irq handling all together, so
> > > I would prefer we didn't move it.
> > Got it in this place.
> > > Also, platform_get_irq() is documented as never returning 0, so the current
> > > code is not incorrect.  As such, this looks like noise unless there is
> > > some plan to make use of the 0 return value?  What benefit do we get from
> > > this change?
> > Thanks for your reply, I think the benefit of this change maybe just
> > simplify the code.
> >
> > Because the return value is never equal to 0, so the check in here is
> > redundant.
> >
> > We can make the patch like this:
> >
> > > > ---
> > > >    drivers/iio/adc/fsl-imx25-gcq.c | 12 ++++--------
> > > >    1 file changed, 4 insertions(+), 8 deletions(-)
> > > >
> > > > diff --git a/drivers/iio/adc/fsl-imx25-gcq.c b/drivers/iio/adc/fsl-imx25-gcq.c
> > > > index 8cb51cf7a..d28976f21 100644
> > > > --- a/drivers/iio/adc/fsl-imx25-gcq.c
> > > > +++ b/drivers/iio/adc/fsl-imx25-gcq.c
> > > > @@ -320,6 +320,10 @@ static int mx25_gcq_probe(struct platform_device *pdev)
> > > >    	if (ret)
> > > >    		return ret;
> > > >    
> > > > +	priv->irq = platform_get_irq(pdev, 0);
> > > > +	if (priv->irq < 0)
> > > > +		return priv->irq;
> > > > +
> > > >    	for (i = 0; i != 4; ++i) {
> > > >    		if (!priv->vref[i])
> > > >    			continue;
> > > > @@ -336,14 +340,6 @@ static int mx25_gcq_probe(struct platform_device *pdev)
> > > >    		goto err_vref_disable;
> > > >    	}
> > > >    
> > > > -	priv->irq = platform_get_irq(pdev, 0);
> > > > -	if (priv->irq <= 0) {
> > > > -		ret = priv->irq;
> > > > -		if (!ret)
> > > > -			ret = -ENXIO;
> > > > -		goto err_clk_unprepare;
> > > > -	}
> > > > -
> > 	priv->irq = platform_get_irq(pdev, 0);
> > 	if (priv->irq < 0) {
> > 		ret = priv->irq;
> > 		goto err_clk_unprepare;
> > 	}
> >
> >       If you think this is ok, I will send V2 for you. If you think these
> > change is meaningless,
> OK, it's a minor tidy up, so lets go with that, or perhaps this is even tidier?
> Assuming types of ret and irq are appropriate (I've not checked!)
>
>
> 	ret = platform_get_irq(pdev, 0);
> 	if (ret)
> 		goto err_clk_unprepare;
>
> 	priv->irq = ret;
Thanks for your reply, ret or irq or priv->irq are all appropriate, and 
the changes of mine maybe traditional.

I will send v2 for you like your changes.

Thank you very much.

Tang Bin


> > just dropped this.
> >
> > Thanks
> >
> > Tang Bin