Re: [PATCH 1/2 v2] iio: event: use short-hand variable in iio_device_{un}register_eventset functions

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 21 Sep 2020 13:31:55 +0300
Alexandru Ardelean <alexandru.ardelean@analog.com> wrote:

> With the recent 'iio_dev_opaque' variable name, these two functions are
> looking a bit ugly.
> 
> This change uses an 'ev_int' variable for the
> iio_device_{un}register_eventset functions to make the code a little easier
> to read.
> 
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

Seems sensible.  Series applied to the togreg branch of iio.git and pushed out as
testing.  Not sure if this will make it into a final pull request for this
cycle or not. Kind of depends what Linus says on Sunday about whether we are
going to see an rc8.

Thanks,

Jonathan

> ---
> 
> Changelog v1 -> v2:
> * move 'iio_dev_opaque->event_interface = ev_int;' assigment right after
>   allocation to avoid crash; 'iio_dev_opaque->event_interface' is accessed
>   after init
> 
>  drivers/iio/industrialio-event.c | 50 +++++++++++++++-----------------
>  1 file changed, 24 insertions(+), 26 deletions(-)
> 
> diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
> index 2ab4d4c44427..a85919eb7c4a 100644
> --- a/drivers/iio/industrialio-event.c
> +++ b/drivers/iio/industrialio-event.c
> @@ -477,6 +477,7 @@ static const char *iio_event_group_name = "events";
>  int iio_device_register_eventset(struct iio_dev *indio_dev)
>  {
>  	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
> +	struct iio_event_interface *ev_int;
>  	struct iio_dev_attr *p;
>  	int ret = 0, attrcount_orig = 0, attrcount, attrn;
>  	struct attribute **attr;
> @@ -485,14 +486,15 @@ int iio_device_register_eventset(struct iio_dev *indio_dev)
>  	      iio_check_for_dynamic_events(indio_dev)))
>  		return 0;
>  
> -	iio_dev_opaque->event_interface =
> -		kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
> -	if (iio_dev_opaque->event_interface == NULL)
> +	ev_int = kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
> +	if (ev_int == NULL)
>  		return -ENOMEM;
>  
> -	INIT_LIST_HEAD(&iio_dev_opaque->event_interface->dev_attr_list);
> +	iio_dev_opaque->event_interface = ev_int;
> +
> +	INIT_LIST_HEAD(&ev_int->dev_attr_list);
>  
> -	iio_setup_ev_int(iio_dev_opaque->event_interface);
> +	iio_setup_ev_int(ev_int);
>  	if (indio_dev->info->event_attrs != NULL) {
>  		attr = indio_dev->info->event_attrs->attrs;
>  		while (*attr++ != NULL)
> @@ -506,34 +508,29 @@ int iio_device_register_eventset(struct iio_dev *indio_dev)
>  		attrcount += ret;
>  	}
>  
> -	iio_dev_opaque->event_interface->group.name = iio_event_group_name;
> -	iio_dev_opaque->event_interface->group.attrs = kcalloc(attrcount + 1,
> -							  sizeof(iio_dev_opaque->event_interface->group.attrs[0]),
> -							  GFP_KERNEL);
> -	if (iio_dev_opaque->event_interface->group.attrs == NULL) {
> +	ev_int->group.name = iio_event_group_name;
> +	ev_int->group.attrs = kcalloc(attrcount + 1,
> +				      sizeof(ev_int->group.attrs[0]),
> +				      GFP_KERNEL);
> +	if (ev_int->group.attrs == NULL) {
>  		ret = -ENOMEM;
>  		goto error_free_setup_event_lines;
>  	}
>  	if (indio_dev->info->event_attrs)
> -		memcpy(iio_dev_opaque->event_interface->group.attrs,
> +		memcpy(ev_int->group.attrs,
>  		       indio_dev->info->event_attrs->attrs,
> -		       sizeof(iio_dev_opaque->event_interface->group.attrs[0])
> -		       *attrcount_orig);
> +		       sizeof(ev_int->group.attrs[0]) * attrcount_orig);
>  	attrn = attrcount_orig;
>  	/* Add all elements from the list. */
> -	list_for_each_entry(p,
> -			    &iio_dev_opaque->event_interface->dev_attr_list,
> -			    l)
> -		iio_dev_opaque->event_interface->group.attrs[attrn++] =
> -			&p->dev_attr.attr;
> -	indio_dev->groups[indio_dev->groupcounter++] =
> -		&iio_dev_opaque->event_interface->group;
> +	list_for_each_entry(p, &ev_int->dev_attr_list, l)
> +		ev_int->group.attrs[attrn++] = &p->dev_attr.attr;
> +	indio_dev->groups[indio_dev->groupcounter++] = &ev_int->group;
>  
>  	return 0;
>  
>  error_free_setup_event_lines:
> -	iio_free_chan_devattr_list(&iio_dev_opaque->event_interface->dev_attr_list);
> -	kfree(iio_dev_opaque->event_interface);
> +	iio_free_chan_devattr_list(&ev_int->dev_attr_list);
> +	kfree(ev_int);
>  	iio_dev_opaque->event_interface = NULL;
>  	return ret;
>  }
> @@ -557,10 +554,11 @@ void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
>  void iio_device_unregister_eventset(struct iio_dev *indio_dev)
>  {
>  	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
> +	struct iio_event_interface *ev_int = iio_dev_opaque->event_interface;
>  
> -	if (iio_dev_opaque->event_interface == NULL)
> +	if (ev_int == NULL)
>  		return;
> -	iio_free_chan_devattr_list(&iio_dev_opaque->event_interface->dev_attr_list);
> -	kfree(iio_dev_opaque->event_interface->group.attrs);
> -	kfree(iio_dev_opaque->event_interface);
> +	iio_free_chan_devattr_list(&ev_int->dev_attr_list);
> +	kfree(ev_int->group.attrs);
> +	kfree(ev_int);
>  }