Re: [PATCH] drivers: hwmon: Add missing of_node_put() in gsc-hwmon.c

[Guenter Roeck]

On 6/15/22 19:37, 和亮 wrote:
> At 2022-06-16 01:57:49, "Guenter Roeck" <linux@xxxxxxxxxxxx> wrote:
> > Please use proper subject lines. Here it should have been
> >
> > hwmon: (gsc-hwmon) Add missing of_node_put()
>
>
>
> Thanks, I will change it in my new patch.
>
>
> > > >    drivers/hwmon/gsc-hwmon.c | 6 +++++-
> > >    1 file changed, 5 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/hwmon/gsc-hwmon.c b/drivers/hwmon/gsc-hwmon.c
> > > index 1fe37418ff46..34c20d13627a 100644
> > > --- a/drivers/hwmon/gsc-hwmon.c
> > > +++ b/drivers/hwmon/gsc-hwmon.c
> > > @@ -268,10 +268,14 @@ gsc_hwmon_get_devtree_pdata(struct device *dev)
> > >    
> > >    	/* fan controller base address */
> > >    	fan = of_find_compatible_node(dev->parent->of_node, NULL, "gw,gsc-fan");
> >
> > A single of_node_put(fan) here would have been be sufficient.
>
>
>
> I think of_node_put after should come after its usage, right?

Yes, you are correct. Sorry for the noise.

> > > > -	if (fan && of_property_read_u32(fan, "reg", &pdata->fan_base)) {
> > > +	if (fan && of_property_read_u32(fan, "reg", &pdata->fan_base)) {		
> > > +		of_node_put(fan);
> > >    		dev_err(dev, "fan node without base\n");
> > >    		return ERR_PTR(-EINVAL);
> > >    	}
> > > +	
> > > +	/* if fan&&!of_property_read_u32 fail */
>
> > This comment only adds confusion and does not add any value.
>
>
> Sorry, I just want to say, if *fan* is not NULL, but of_property_read_u32() returns 0.
> In that case, we still need a of_node_put() to release fan, right?

Yes, but that is obvious, and the comment is not needed.

Thanks,
Guenter

> > Guenter
> >
> > > +	of_node_put(fan);
> > >    
> > >    	/* allocate structures for channels and count instances of each type */
>
> > >    	device_for_each_child_node(dev, child) {
>
>
> Hi, Guenter, I am preparing my new patch and I want to discuss your suggestions as above.