Hi Laurent,
On Thu, 2021-01-14 at 04:27 +0200, Laurent Pinchart wrote:
> Hi Ezequiel,
>
> Thank you for the patch.
>
> On Tue, Jan 12, 2021 at 10:23:39AM -0300, Ezequiel Garcia wrote:
> > Most -if not all- use-cases are expected to be covered by one of:
> > v4l2_async_notifier_add_fwnode_subdev,
> > v4l2_async_notifier_add_fwnode_remote_subdev,
> > v4l2_async_notifier_add_i2c_subdev or
> > v4l2_async_notifier_add_devname_subdev.
> >
> > We'd like to discourage drivers from using v4l2_async_notifier_add_subdev,
> > so rename it as __v4l2_async_notifier_add_subdev. This is
> > typically a good hint for drivers to avoid using the function.
> >
> > Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
> > ---
> > drivers/media/v4l2-core/v4l2-async.c | 10 +++++-----
> > drivers/media/v4l2-core/v4l2-fwnode.c | 2 +-
> > include/media/v4l2-async.h | 10 ++++++++--
> > 3 files changed, 14 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> > index b325bacddff4..e8e690280922 100644
> > --- a/drivers/media/v4l2-core/v4l2-async.c
> > +++ b/drivers/media/v4l2-core/v4l2-async.c
> > @@ -630,7 +630,7 @@ void v4l2_async_notifier_cleanup(struct v4l2_async_notifier *notifier)
> > }
> > EXPORT_SYMBOL_GPL(v4l2_async_notifier_cleanup);
> >
> > -int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
> > +int __v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
> > struct v4l2_async_subdev *asd)
> > {
> > int ret;
> > @@ -647,7 +647,7 @@ int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
> > mutex_unlock(&list_lock);
> > return ret;
> > }
> > -EXPORT_SYMBOL_GPL(v4l2_async_notifier_add_subdev);
> > +EXPORT_SYMBOL_GPL(__v4l2_async_notifier_add_subdev);
> >
> > struct v4l2_async_subdev *
> > v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
> > @@ -664,7 +664,7 @@ v4l2_async_notifier_add_fwnode_subdev(struct v4l2_async_notifier *notifier,
> > asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
> > asd->match.fwnode = fwnode_handle_get(fwnode);
> >
> > - ret = v4l2_async_notifier_add_subdev(notifier, asd);
> > + ret = __v4l2_async_notifier_add_subdev(notifier, asd);
> > if (ret) {
> > fwnode_handle_put(fwnode);
> > kfree(asd);
> > @@ -714,7 +714,7 @@ v4l2_async_notifier_add_i2c_subdev(struct v4l2_async_notifier *notifier,
> > asd->match.i2c.adapter_id = adapter_id;
> > asd->match.i2c.address = address;
> >
> > - ret = v4l2_async_notifier_add_subdev(notifier, asd);
> > + ret = __v4l2_async_notifier_add_subdev(notifier, asd);
> > if (ret) {
> > kfree(asd);
> > return ERR_PTR(ret);
> > @@ -739,7 +739,7 @@ v4l2_async_notifier_add_devname_subdev(struct v4l2_async_notifier *notifier,
> > asd->match_type = V4L2_ASYNC_MATCH_DEVNAME;
> > asd->match.device_name = device_name;
> >
> > - ret = v4l2_async_notifier_add_subdev(notifier, asd);
> > + ret = __v4l2_async_notifier_add_subdev(notifier, asd);
> > if (ret) {
> > kfree(asd);
> > return ERR_PTR(ret);
> > diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
> > index 5353e37eb950..919fde20032e 100644
> > --- a/drivers/media/v4l2-core/v4l2-fwnode.c
> > +++ b/drivers/media/v4l2-core/v4l2-fwnode.c
> > @@ -833,7 +833,7 @@ v4l2_async_notifier_fwnode_parse_endpoint(struct device *dev,
> > if (ret < 0)
> > goto out_err;
> >
> > - ret = v4l2_async_notifier_add_subdev(notifier, asd);
> > + ret = __v4l2_async_notifier_add_subdev(notifier, asd);
> > if (ret < 0) {
> > /* not an error if asd already exists */
> > if (ret == -EEXIST)
>
> I wonder if v4l2-fwnode should be moved to videodev-objs in the
> Makefile, we could then avoid exporting
> __v4l2_async_notifier_add_subdev(). This doesn't need to be fixed here,
>
Yeah, I thought about that, precisely to avoid the export and disallow
any future users of v4l2_async_notifier_add_subdev.
The impact of that is that we'd kill V4L2_FWNODE, increasing the
size of videodev.ko, by a small fraction.
Perhaps this is justified? I'm sure all the use-cases for this type
of hardware won't care for 20 KiB more or less in the kernel payload.
> Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>
> > diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h
> > index 1278f98355a7..9cf83f1ecca6 100644
> > --- a/include/media/v4l2-async.h
> > +++ b/include/media/v4l2-async.h
> > @@ -161,17 +161,23 @@ void v4l2_async_debug_init(struct dentry *debugfs_dir);
> > void v4l2_async_notifier_init(struct v4l2_async_notifier *notifier);
> >
> > /**
> > - * v4l2_async_notifier_add_subdev - Add an async subdev to the
> > + * __v4l2_async_notifier_add_subdev - Add an async subdev to the
> > * notifier's master asd list.
> > *
> > * @notifier: pointer to &struct v4l2_async_notifier
> > * @asd: pointer to &struct v4l2_async_subdev
> > *
> > + * \warning: Drivers should avoid using this function and instead use one of:
> > + * @v4l2_async_notifier_add_fwnode_subdev,
> > + * @v4l2_async_notifier_add_fwnode_remote_subdev,
> > + * @v4l2_async_notifier_add_i2c_subdev or
> > + * @v4l2_async_notifier_add_devname_subdev.
> > + *
> > * Call this function before registering a notifier to link the provided @asd to
> > * the notifiers master @asd_list. The @asd must be allocated with k*alloc() as
> > * it will be freed by the framework when the notifier is destroyed.
> > */
> > -int v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
> > +int __v4l2_async_notifier_add_subdev(struct v4l2_async_notifier *notifier,
> > struct v4l2_async_subdev *asd);
> >
> > /**
>
Thanks,
Ezequiel
