Re: [PATCH 09/13] iio: addac: ad74413r: Use __free(fwnode_handle) to replace fwnode_handle_put() calls

From: Jonathan Cameron <jic23@kernel.org>
To: "Nuno Sá" <noname.nuno@gmail.com>
Cc: linux-iio@vger.kernel.org,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	"Len Brown" <lenb@kernel.org>,
	linux-acpi@vger.kernel.org,
	"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"Daniel Scally" <djrscally@gmail.com>,
	"Heikki Krogerus" <heikki.krogerus@linux.intel.com>,
	"Sakari Ailus" <sakari.ailus@linux.intel.com>,
	"Nuno Sá" <nuno.sa@analog.com>,
	"Cosmin Tanislav" <cosmin.tanislav@analog.com>,
	"Mihail Chindris" <mihail.chindris@analog.com>,
	"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
	"Tomislav Denis" <tomislav.denis@avl.com>,
	"Marek Vasut" <marex@denx.de>,
	"Olivier Moysan" <olivier.moysan@foss.st.com>,
	"Fabrice Gasnier" <fabrice.gasnier@foss.st.com>,
	"Lad Prabhakar" <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	"Dmitry Baryshkov" <dmitry.baryshkov@linaro.org>,
	"Marijn Suijten" <marijn.suijten@somainline.org>,
	"Marius Cristea" <marius.cristea@microchip.com>,
	"Ibrahim Tilki" <Ibrahim.Tilki@analog.com>,
	"Jonathan Cameron" <Jonathan.Cameron@huawei.com>
Subject: Re: [PATCH 09/13] iio: addac: ad74413r: Use __free(fwnode_handle) to replace fwnode_handle_put() calls
Date: Sun, 11 Feb 2024 18:53:22 +0000	[thread overview]
Message-ID: <20240211185322.5e91589e@jic23-huawei> (raw)
In-Reply-To: <137a0efdc57d7c150178d2aad35c2c51d3f82704.camel@gmail.com>

On Mon, 15 Jan 2024 11:17:12 +0100
Nuno Sá <noname.nuno@gmail.com> wrote:

> On Sun, 2024-01-14 at 17:20 +0000, Jonathan Cameron wrote:
> > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > 
> > This use of the new cleanup.h scope based freeing infrastructure allows
> > us to exit directly from error conditions within the
> > fwnode_for_each_available_child_node(dev, child) loop. On normal exit
> > from that loop no fwnode_handle reference will be held and the child
> > pointer will be NULL thus making the automatically run
> > fwnode_handle_put() a noop.
> > 
> > Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > ---  
> 
> Acked-by: Nuno Sa <nuno.sa@analog.com>
> 
> >  drivers/iio/addac/ad74413r.c | 9 ++-------
> >  1 file changed, 2 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
> > index 7af3e4b8fe3b..ec9a466e118d 100644
> > --- a/drivers/iio/addac/ad74413r.c
> > +++ b/drivers/iio/addac/ad74413r.c
> > @@ -1255,21 +1255,16 @@ static int ad74413r_parse_channel_config(struct
> > iio_dev *indio_dev,
> >  static int ad74413r_parse_channel_configs(struct iio_dev *indio_dev)
> >  {
> >  	struct ad74413r_state *st = iio_priv(indio_dev);
> > -	struct fwnode_handle *channel_node = NULL;
> > +	struct fwnode_handle *channel_node __free(fwnode_handle) = NULL;
> >  	int ret;
> >  
> >  	fwnode_for_each_available_child_node(dev_fwnode(st->dev),
This should have been
device_for_each_child_node() because that ultimately calls
of_fwnode_get_next_child_node() which calls the available form anyway.
https://lore.kernel.org/lkml/20211205190101.26de4a57@jic23-huawei/T/#u

So I'll just switch to the new
device_for_each_child_node_scoped() that I'm about to propose.

> > channel_node) {
> >  		ret = ad74413r_parse_channel_config(indio_dev, channel_node);
> >  		if (ret)
> > -			goto put_channel_node;
> > +			return ret;
> >  	}
> >  
> >  	return 0;
> > -
> > -put_channel_node:
> > -	fwnode_handle_put(channel_node);
> > -
> > -	return ret;
> >  }
> >  
> >  static int ad74413r_setup_channels(struct iio_dev *indio_dev)  
> 