Hi Hans,
Thanks for the review!
On Mon, Sep 11, 2017 at 11:14:03AM +0200, Hans Verkuil wrote:
> On 09/11/2017 10:00 AM, Sakari Ailus wrote:
> > Add function v4l2_fwnode_reference_count() for counting external
> > references and v4l2_fwnode_reference_parse() for parsing them as async
> > sub-devices.
> >
> > This can be done on e.g. flash or lens async sub-devices that are not part
> > of but are associated with a sensor.
> >
> > struct v4l2_async_notifier.max_subdevs field is added to contain the
> > maximum number of sub-devices in a notifier to reflect the memory
> > allocated for the subdevs array.
>
> This paragraph appears to be out-of-date.
Will remove.
>
> >
> > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> > ---
> > drivers/media/v4l2-core/v4l2-fwnode.c | 47 +++++++++++++++++++++++++++++++++++
> > 1 file changed, 47 insertions(+)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
> > index d978f2d714ca..4821c4989119 100644
> > --- a/drivers/media/v4l2-core/v4l2-fwnode.c
> > +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
> > @@ -449,6 +449,53 @@ int v4l2_async_notifier_parse_fwnode_endpoints(
> > }
> > EXPORT_SYMBOL_GPL(v4l2_async_notifier_parse_fwnode_endpoints);
> >
> > +static int v4l2_fwnode_reference_parse(
> > + struct device *dev, struct v4l2_async_notifier *notifier,
> > + const char *prop)
> > +{
> > + struct fwnode_reference_args args;
> > + unsigned int index = 0;
> > + int ret;
> > +
> > + for (; !fwnode_property_get_reference_args(
> > + dev_fwnode(dev), prop, NULL, 0, index, &args); index++)
> > + fwnode_handle_put(args.fwnode);
> > +
>
> If nothing is found (i.e. index == 0), shouldn't you just return here?
You could. yes. It would actually simplify the code, I could just return
-ENOENT here.
>
> > + ret = v4l2_async_notifier_realloc(notifier,
> > + notifier->num_subdevs + index);
> > + if (ret)
> > + return -ENOMEM;
> > +
> > + for (ret = -ENOENT, index = 0;
>
> There is no reason for the 'ret = -ENOENT' to be in the for(), just set it before
> the 'for' statement.
>
> > + !fwnode_property_get_reference_args(
> > + dev_fwnode(dev), prop, NULL, 0, index, &args);
> > + index++) {
> > + struct v4l2_async_subdev *asd;
> > +
> > + if (WARN_ON(notifier->num_subdevs >= notifier->max_subdevs)) {
> > + ret = -EINVAL;
> > + goto error;
> > + }
> > +
> > + asd = kzalloc(sizeof(*asd), GFP_KERNEL);
> > + if (!asd) {
> > + ret = -ENOMEM;
> > + goto error;
> > + }
> > +
> > + notifier->subdevs[notifier->num_subdevs] = asd;
> > + asd->match.fwnode.fwnode = args.fwnode;
> > + asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
> > + notifier->num_subdevs++;
> > + }
>
> If the loop doesn't find anything, then it still returns 0, not -ENOENT.
> So why set ret to ENOENT? Something weird going on here.
:-)
I think -ENOENT would make sense indeed if there are no entries found.
>
> I think you should also add a comment explaining this function.
Yes. I had that in the header when it was exported, I'll add the same
comments here.
>
> > +
> > + return 0;
> > +
> > +error:
> > + fwnode_handle_put(args.fwnode);
> > + return ret;
> > +}
> > +
> > MODULE_LICENSE("GPL");
> > MODULE_AUTHOR("Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>");
> > MODULE_AUTHOR("Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>");
> >
>
--
Regards,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx
