media: platform: Switch to v4l2_async_notifier_add_subdev

Switch all media platform drivers to call v4l2_async_notifier_add_subdev()
to add asd's to a notifier, in place of referencing the notifier->subdevs[]
array. These drivers also must now call v4l2_async_notifier_init() before
adding asd's to their notifiers.

There may still be cases where a platform driver maintains a list of
asd's that is a duplicate of the notifier asd_list, in which case its
possible the platform driver list can be removed, and can reference the
notifier asd_list instead. One example of where a duplicate list has
been removed in this patch is xilinx-vipp.c. If there are such cases
remaining, those drivers should be optimized to remove the duplicate
platform driver asd lists.

None of the changes to the platform drivers in this patch have been
tested. Verify that the async subdevices needed by the platform are
bound at load time, and that the driver unloads and reloads correctly
with no memory leaking of asd objects.

Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 11 insertions, 7 deletions

diff --git a/drivers/media/platform/rcar_drif.c b/drivers/media/platform/rcar_drif.c
index 9fa108b23cb3..8483dc36715d 100644
--- a/drivers/media/platform/rcar_drif.c
+++ b/drivers/media/platform/rcar_drif.c
@@ -1213,18 +1213,15 @@ static int rcar_drif_parse_subdevs(struct rcar_drif_sdr *sdr)
 {
 	struct v4l2_async_notifier *notifier = &sdr->notifier;
 	struct fwnode_handle *fwnode, *ep;
+	int ret;
 
-	notifier->subdevs = devm_kzalloc(sdr->dev, sizeof(*notifier->subdevs),
-					 GFP_KERNEL);
-	if (!notifier->subdevs)
-		return -ENOMEM;
+	v4l2_async_notifier_init(notifier);
 
 	ep = fwnode_graph_get_next_endpoint(of_fwnode_handle(sdr->dev->of_node),
 					    NULL);
 	if (!ep)
 		return 0;
 
-	notifier->subdevs[notifier->num_subdevs] = &sdr->ep.asd;
 	fwnode = fwnode_graph_get_remote_port_parent(ep);
 	if (!fwnode) {
 		dev_warn(sdr->dev, "bad remote port parent\n");
@@ -1234,7 +1231,11 @@ static int rcar_drif_parse_subdevs(struct rcar_drif_sdr *sdr)
 
 	sdr->ep.asd.match.fwnode = fwnode;
 	sdr->ep.asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-	notifier->num_subdevs++;
+	ret = v4l2_async_notifier_add_subdev(notifier, &sdr->ep.asd);
+	if (ret) {
+		fwnode_handle_put(fwnode);
+		return ret;
+	}
 
 	/* Get the endpoint properties */
 	rcar_drif_get_ep_properties(sdr, ep);
@@ -1356,11 +1357,13 @@ static int rcar_drif_sdr_probe(struct rcar_drif_sdr *sdr)
 	ret = v4l2_async_notifier_register(&sdr->v4l2_dev, &sdr->notifier);
 	if (ret < 0) {
 		dev_err(sdr->dev, "failed: notifier register ret %d\n", ret);
-		goto error;
+		goto cleanup;
 	}
 
 	return ret;
 
+cleanup:
+	v4l2_async_notifier_cleanup(&sdr->notifier);
 error:
 	v4l2_device_unregister(&sdr->v4l2_dev);
 
@@ -1371,6 +1374,7 @@ error:
 static void rcar_drif_sdr_remove(struct rcar_drif_sdr *sdr)
 {
 	v4l2_async_notifier_unregister(&sdr->notifier);
+	v4l2_async_notifier_cleanup(&sdr->notifier);
 	v4l2_device_unregister(&sdr->v4l2_dev);
 }