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 <[e-mail]>
Signed-off-by: Steve Longerbeam <[e-mail]>
Signed-off-by: Sakari Ailus <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/pci/intel/ipu3/ipu3-cio2.c

···
 	if (ret < 0)
 		return ret;
 
-	if (!cio2->notifier.num_subdevs)
+	if (list_empty(&cio2->notifier.asd_list))
 		return -ENODEV;	/* no endpoint */
 
 	cio2->notifier.ops = &cio2_async_ops;

drivers/media/platform/am437x/am437x-vpfe.c

···
 };
 
 static struct vpfe_config *
-vpfe_get_pdata(struct platform_device *pdev)
+vpfe_get_pdata(struct vpfe_device *vpfe)
 {
 	struct device_node *endpoint = NULL;
 	struct v4l2_fwnode_endpoint bus_cfg;
+	struct device *dev = vpfe->pdev;
 	struct vpfe_subdev_info *sdinfo;
 	struct vpfe_config *pdata;
 	unsigned int flags;
 	unsigned int i;
 	int err;
 
-	dev_dbg(&pdev->dev, "vpfe_get_pdata\n");
+	dev_dbg(dev, "vpfe_get_pdata\n");
 
-	if (!IS_ENABLED(CONFIG_OF) || !pdev->dev.of_node)
-		return pdev->dev.platform_data;
+	v4l2_async_notifier_init(&vpfe->notifier);
 
-	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+	if (!IS_ENABLED(CONFIG_OF) || !dev->of_node)
+		return dev->platform_data;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return NULL;
 
 	for (i = 0; ; i++) {
 		struct device_node *rem;
 
-		endpoint = of_graph_get_next_endpoint(pdev->dev.of_node,
-						      endpoint);
+		endpoint = of_graph_get_next_endpoint(dev->of_node, endpoint);
 		if (!endpoint)
 			break;
 
···
 		err = v4l2_fwnode_endpoint_parse(of_fwnode_handle(endpoint),
 						 &bus_cfg);
 		if (err) {
-			dev_err(&pdev->dev, "Could not parse the endpoint\n");
-			goto done;
+			dev_err(dev, "Could not parse the endpoint\n");
+			goto cleanup;
 		}
 
 		sdinfo->vpfe_param.bus_width = bus_cfg.bus.parallel.bus_width;
 
 		if (sdinfo->vpfe_param.bus_width < 8 ||
 			sdinfo->vpfe_param.bus_width > 16) {
-			dev_err(&pdev->dev, "Invalid bus width.\n");
-			goto done;
+			dev_err(dev, "Invalid bus width.\n");
+			goto cleanup;
 		}
 
 		flags = bus_cfg.bus.parallel.flags;
···
 
 		rem = of_graph_get_remote_port_parent(endpoint);
 		if (!rem) {
-			dev_err(&pdev->dev, "Remote device at %pOF not found\n",
+			dev_err(dev, "Remote device at %pOF not found\n",
 				endpoint);
-			goto done;
+			goto cleanup;
 		}
 
-		pdata->asd[i] = devm_kzalloc(&pdev->dev,
-					     sizeof(struct v4l2_async_subdev),
-					     GFP_KERNEL);
-		if (!pdata->asd[i]) {
+		pdata->asd[i] = v4l2_async_notifier_add_fwnode_subdev(
+			&vpfe->notifier, of_fwnode_handle(rem),
+			sizeof(struct v4l2_async_subdev));
+		if (IS_ERR(pdata->asd[i])) {
 			of_node_put(rem);
-			pdata = NULL;
-			goto done;
+			goto cleanup;
 		}
-
-		pdata->asd[i]->match_type = V4L2_ASYNC_MATCH_FWNODE;
-		pdata->asd[i]->match.fwnode = of_fwnode_handle(rem);
-		of_node_put(rem);
 	}
 
 	of_node_put(endpoint);
 	return pdata;
 
-done:
+cleanup:
+	v4l2_async_notifier_cleanup(&vpfe->notifier);
 	of_node_put(endpoint);
 	return NULL;
 }
···
  */
 static int vpfe_probe(struct platform_device *pdev)
 {
-	struct vpfe_config *vpfe_cfg = vpfe_get_pdata(pdev);
+	struct vpfe_config *vpfe_cfg;
 	struct vpfe_device *vpfe;
 	struct vpfe_ccdc *ccdc;
 	struct resource	*res;
 	int ret;
-
-	if (!vpfe_cfg) {
-		dev_err(&pdev->dev, "No platform data\n");
-		return -EINVAL;
-	}
 
 	vpfe = devm_kzalloc(&pdev->dev, sizeof(*vpfe), GFP_KERNEL);
 	if (!vpfe)
 		return -ENOMEM;
 
 	vpfe->pdev = &pdev->dev;
+
+	vpfe_cfg = vpfe_get_pdata(vpfe);
+	if (!vpfe_cfg) {
+		dev_err(&pdev->dev, "No platform data\n");
+		return -EINVAL;
+	}
+
 	vpfe->cfg = vpfe_cfg;
 	ccdc = &vpfe->ccdc;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ccdc->ccdc_cfg.base_addr = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(ccdc->ccdc_cfg.base_addr))
-		return PTR_ERR(ccdc->ccdc_cfg.base_addr);
+	if (IS_ERR(ccdc->ccdc_cfg.base_addr)) {
+		ret = PTR_ERR(ccdc->ccdc_cfg.base_addr);
+		goto probe_out_cleanup;
+	}
 
 	ret = platform_get_irq(pdev, 0);
 	if (ret <= 0) {
 		dev_err(&pdev->dev, "No IRQ resource\n");
-		return -ENODEV;
+		ret = -ENODEV;
+		goto probe_out_cleanup;
 	}
 	vpfe->irq = ret;
 
···
 			       "vpfe_capture0", vpfe);
 	if (ret) {
 		dev_err(&pdev->dev, "Unable to request interrupt\n");
-		return -EINVAL;
+		ret = -EINVAL;
+		goto probe_out_cleanup;
 	}
 
 	ret = v4l2_device_register(&pdev->dev, &vpfe->v4l2_dev);
 	if (ret) {
 		vpfe_err(vpfe,
 			"Unable to register v4l2 device.\n");
-		return ret;
+		goto probe_out_cleanup;
 	}
 
 	/* set the driver data in platform device */
···
 		goto probe_out_v4l2_unregister;
 	}
 
-	vpfe->notifier.subdevs = vpfe->cfg->asd;
-	vpfe->notifier.num_subdevs = ARRAY_SIZE(vpfe->cfg->asd);
 	vpfe->notifier.ops = &vpfe_async_ops;
-	ret = v4l2_async_notifier_register(&vpfe->v4l2_dev,
-						&vpfe->notifier);
+	ret = v4l2_async_notifier_register(&vpfe->v4l2_dev, &vpfe->notifier);
 	if (ret) {
 		vpfe_err(vpfe, "Error registering async notifier\n");
 		ret = -EINVAL;
···
 
 probe_out_v4l2_unregister:
 	v4l2_device_unregister(&vpfe->v4l2_dev);
+probe_out_cleanup:
+	v4l2_async_notifier_cleanup(&vpfe->notifier);
 	return ret;
 }
 
···
 	pm_runtime_disable(&pdev->dev);
 
 	v4l2_async_notifier_unregister(&vpfe->notifier);
+	v4l2_async_notifier_cleanup(&vpfe->notifier);
 	v4l2_device_unregister(&vpfe->v4l2_dev);
 	video_unregister_device(&vpfe->video_dev);
 

drivers/media/platform/atmel/atmel-isc.c

···
 {
 	struct isc_subdev_entity *subdev_entity;
 
-	list_for_each_entry(subdev_entity, &isc->subdev_entities, list)
+	list_for_each_entry(subdev_entity, &isc->subdev_entities, list) {
 		v4l2_async_notifier_unregister(&subdev_entity->notifier);
+		v4l2_async_notifier_cleanup(&subdev_entity->notifier);
+	}
 
 	INIT_LIST_HEAD(&isc->subdev_entities);
 }
···
 	}
 
 	list_for_each_entry(subdev_entity, &isc->subdev_entities, list) {
-		subdev_entity->notifier.subdevs = &subdev_entity->asd;
-		subdev_entity->notifier.num_subdevs = 1;
+		v4l2_async_notifier_init(&subdev_entity->notifier);
+
+		ret = v4l2_async_notifier_add_subdev(&subdev_entity->notifier,
+						     subdev_entity->asd);
+		if (ret) {
+			fwnode_handle_put(subdev_entity->asd->match.fwnode);
+			goto cleanup_subdev;
+		}
+
 		subdev_entity->notifier.ops = &isc_async_ops;
 
 		ret = v4l2_async_notifier_register(&isc->v4l2_dev,

drivers/media/platform/atmel/atmel-isi.c

···
 
 static int isi_graph_init(struct atmel_isi *isi)
 {
-	struct v4l2_async_subdev **subdevs = NULL;
 	int ret;
 
 	/* Parse the graph to extract a list of subdevice DT nodes. */
···
 		return ret;
 	}
 
-	/* Register the subdevices notifier. */
-	subdevs = devm_kzalloc(isi->dev, sizeof(*subdevs), GFP_KERNEL);
-	if (!subdevs) {
+	v4l2_async_notifier_init(&isi->notifier);
+
+	ret = v4l2_async_notifier_add_subdev(&isi->notifier, &isi->entity.asd);
+	if (ret) {
 		of_node_put(isi->entity.node);
-		return -ENOMEM;
+		return ret;
 	}
 
-	subdevs[0] = &isi->entity.asd;
-
-	isi->notifier.subdevs = subdevs;
-	isi->notifier.num_subdevs = 1;
 	isi->notifier.ops = &isi_graph_notify_ops;
 
 	ret = v4l2_async_notifier_register(&isi->v4l2_dev, &isi->notifier);
 	if (ret < 0) {
 		dev_err(isi->dev, "Notifier registration failed\n");
-		of_node_put(isi->entity.node);
+		v4l2_async_notifier_cleanup(&isi->notifier);
 		return ret;
 	}
 
···
 			isi->fb_descriptors_phys);
 	pm_runtime_disable(&pdev->dev);
 	v4l2_async_notifier_unregister(&isi->notifier);
+	v4l2_async_notifier_cleanup(&isi->notifier);
 	v4l2_device_unregister(&isi->v4l2_dev);
 
 	return 0;

drivers/media/platform/cadence/cdns-csi2rx.c

···
 	csi2rx->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
 	of_node_put(ep);
 
-	csi2rx->notifier.subdevs = devm_kzalloc(csi2rx->dev,
-						sizeof(*csi2rx->notifier.subdevs),
-						GFP_KERNEL);
-	if (!csi2rx->notifier.subdevs)
-		return -ENOMEM;
+	v4l2_async_notifier_init(&csi2rx->notifier);
 
-	csi2rx->notifier.subdevs[0] = &csi2rx->asd;
-	csi2rx->notifier.num_subdevs = 1;
+	ret = v4l2_async_notifier_add_subdev(&csi2rx->notifier, &csi2rx->asd);
+	if (ret) {
+		fwnode_handle_put(csi2rx->asd.match.fwnode);
+		return ret;
+	}
+
 	csi2rx->notifier.ops = &csi2rx_notifier_ops;
 
-	return v4l2_async_subdev_notifier_register(&csi2rx->subdev,
-						   &csi2rx->notifier);
+	ret = v4l2_async_subdev_notifier_register(&csi2rx->subdev,
+						  &csi2rx->notifier);
+	if (ret)
+		v4l2_async_notifier_cleanup(&csi2rx->notifier);
+
+	return ret;
 }
 
 static int csi2rx_probe(struct platform_device *pdev)
···
 	ret = media_entity_pads_init(&csi2rx->subdev.entity, CSI2RX_PAD_MAX,
 				     csi2rx->pads);
 	if (ret)
-		goto err_free_priv;
+		goto err_cleanup;
 
 	ret = v4l2_async_register_subdev(&csi2rx->subdev);
 	if (ret < 0)
-		goto err_free_priv;
+		goto err_cleanup;
 
 	dev_info(&pdev->dev,
 		 "Probed CSI2RX with %u/%u lanes, %u streams, %s D-PHY\n",
···
 
 	return 0;
 
+err_cleanup:
+	v4l2_async_notifier_cleanup(&csi2rx->notifier);
 err_free_priv:
 	kfree(csi2rx);
 	return ret;

drivers/media/platform/davinci/vpif_capture.c

···
 	struct vpif_capture_chan_config *chan;
 	unsigned int i;
 
+	v4l2_async_notifier_init(&vpif_obj.notifier);
+
 	/*
 	 * DT boot: OF node from parent device contains
 	 * video ports & endpoints data.
···
 		if (!endpoint)
 			break;
 
+		rem = of_graph_get_remote_port_parent(endpoint);
+		if (!rem) {
+			dev_dbg(&pdev->dev, "Remote device at %pOF not found\n",
+				endpoint);
+			of_node_put(endpoint);
+			goto done;
+		}
+
 		sdinfo = &pdata->subdev_info[i];
 		chan = &pdata->chan_config[i];
 		chan->inputs = devm_kcalloc(&pdev->dev,
 					    VPIF_CAPTURE_NUM_CHANNELS,
 					    sizeof(*chan->inputs),
 					    GFP_KERNEL);
-		if (!chan->inputs)
-			return NULL;
+		if (!chan->inputs) {
+			of_node_put(rem);
+			of_node_put(endpoint);
+			goto err_cleanup;
+		}
 
 		chan->input_count++;
 		chan->inputs[i].input.type = V4L2_INPUT_TYPE_CAMERA;
···
 
 		err = v4l2_fwnode_endpoint_parse(of_fwnode_handle(endpoint),
 						 &bus_cfg);
+		of_node_put(endpoint);
 		if (err) {
 			dev_err(&pdev->dev, "Could not parse the endpoint\n");
+			of_node_put(rem);
 			goto done;
 		}
+
 		dev_dbg(&pdev->dev, "Endpoint %pOF, bus_width = %d\n",
 			endpoint, bus_cfg.bus.parallel.bus_width);
+
 		flags = bus_cfg.bus.parallel.flags;
 
 		if (flags & V4L2_MBUS_HSYNC_ACTIVE_HIGH)
···
 		if (flags & V4L2_MBUS_VSYNC_ACTIVE_HIGH)
 			chan->vpif_if.vd_pol = 1;
 
-		rem = of_graph_get_remote_port_parent(endpoint);
-		if (!rem) {
-			dev_dbg(&pdev->dev, "Remote device at %pOF not found\n",
-				endpoint);
-			goto done;
-		}
-
 		dev_dbg(&pdev->dev, "Remote device %pOF found\n", rem);
 		sdinfo->name = rem->full_name;
 
-		pdata->asd[i] = devm_kzalloc(&pdev->dev,
-					     sizeof(struct v4l2_async_subdev),
-					     GFP_KERNEL);
-		if (!pdata->asd[i]) {
+		pdata->asd[i] = v4l2_async_notifier_add_fwnode_subdev(
+			&vpif_obj.notifier, of_fwnode_handle(rem),
+			sizeof(struct v4l2_async_subdev));
+		if (IS_ERR(pdata->asd[i])) {
 			of_node_put(rem);
-			pdata = NULL;
-			goto done;
+			goto err_cleanup;
 		}
-
-		pdata->asd[i]->match_type = V4L2_ASYNC_MATCH_FWNODE;
-		pdata->asd[i]->match.fwnode = of_fwnode_handle(rem);
-		of_node_put(rem);
 	}
 
 done:
-	if (pdata) {
-		pdata->asd_sizes[0] = i;
-		pdata->subdev_count = i;
-		pdata->card_name = "DA850/OMAP-L138 Video Capture";
-	}
+	pdata->asd_sizes[0] = i;
+	pdata->subdev_count = i;
+	pdata->card_name = "DA850/OMAP-L138 Video Capture";
 
 	return pdata;
+
+err_cleanup:
+	v4l2_async_notifier_cleanup(&vpif_obj.notifier);
+
+	return NULL;
 }
 
 /**
···
 		return -EINVAL;
 	}
 
-	if (!pdev->dev.platform_data) {
-		dev_warn(&pdev->dev, "Missing platform data.  Giving up.\n");
-		return -EINVAL;
-	}
-
 	vpif_dev = &pdev->dev;
 
 	err = initialize_vpif();
 	if (err) {
 		v4l2_err(vpif_dev->driver, "Error initializing vpif\n");
-		return err;
+		goto cleanup;
 	}
 
 	err = v4l2_device_register(vpif_dev, &vpif_obj.v4l2_dev);
 	if (err) {
 		v4l2_err(vpif_dev->driver, "Error registering v4l2 device\n");
-		return err;
+		goto cleanup;
 	}
 
 	while ((res = platform_get_resource(pdev, IORESOURCE_IRQ, res_idx))) {
···
 		}
 		vpif_probe_complete();
 	} else {
-		vpif_obj.notifier.subdevs = vpif_obj.config->asd;
-		vpif_obj.notifier.num_subdevs = vpif_obj.config->asd_sizes[0];
 		vpif_obj.notifier.ops = &vpif_async_ops;
 		err = v4l2_async_notifier_register(&vpif_obj.v4l2_dev,
 						   &vpif_obj.notifier);
···
 	kfree(vpif_obj.sd);
 vpif_unregister:
 	v4l2_device_unregister(&vpif_obj.v4l2_dev);
+cleanup:
+	v4l2_async_notifier_cleanup(&vpif_obj.notifier);
 
 	return err;
 }
···
 	struct channel_obj *ch;
 	int i;
 
+	v4l2_async_notifier_unregister(&vpif_obj.notifier);
+	v4l2_async_notifier_cleanup(&vpif_obj.notifier);
 	v4l2_device_unregister(&vpif_obj.v4l2_dev);
 
 	kfree(vpif_obj.sd);

drivers/media/platform/davinci/vpif_display.c

···
 		goto vpif_unregister;
 	}
 
+	v4l2_async_notifier_init(&vpif_obj.notifier);
+
 	if (!vpif_obj.config->asd_sizes) {
 		i2c_adap = i2c_get_adapter(vpif_obj.config->i2c_adapter_id);
 		for (i = 0; i < subdev_count; i++) {
···
 			goto probe_subdev_out;
 		}
 	} else {
-		vpif_obj.notifier.subdevs = vpif_obj.config->asd;
-		vpif_obj.notifier.num_subdevs = vpif_obj.config->asd_sizes[0];
+		for (i = 0; i < vpif_obj.config->asd_sizes[0]; i++) {
+			err = v4l2_async_notifier_add_subdev(
+				&vpif_obj.notifier, vpif_obj.config->asd[i]);
+			if (err)
+				goto probe_cleanup;
+		}
+
 		vpif_obj.notifier.ops = &vpif_async_ops;
 		err = v4l2_async_notifier_register(&vpif_obj.v4l2_dev,
 						   &vpif_obj.notifier);
 		if (err) {
 			vpif_err("Error registering async notifier\n");
 			err = -EINVAL;
-			goto probe_subdev_out;
+			goto probe_cleanup;
 		}
 	}
 
 	return 0;
 
+probe_cleanup:
+	v4l2_async_notifier_cleanup(&vpif_obj.notifier);
 probe_subdev_out:
 	kfree(vpif_obj.sd);
 vpif_unregister:
···
 {
 	struct channel_obj *ch;
 	int i;
+
+	if (vpif_obj.config->asd_sizes) {
+		v4l2_async_notifier_unregister(&vpif_obj.notifier);
+		v4l2_async_notifier_cleanup(&vpif_obj.notifier);
+	}
 
 	v4l2_device_unregister(&vpif_obj.v4l2_dev);
 

drivers/media/platform/exynos4-is/media-dev.c

···
 
 	fmd->sensor[index].asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
 	fmd->sensor[index].asd.match.fwnode = of_fwnode_handle(rem);
-	fmd->async_subdevs[index] = &fmd->sensor[index].asd;
+
+	ret = v4l2_async_notifier_add_subdev(&fmd->subdev_notifier,
+					     &fmd->sensor[index].asd);
+	if (ret) {
+		of_node_put(rem);
+		return ret;
+	}
 
 	fmd->num_sensors++;
 
-	of_node_put(rem);
 	return 0;
 }
 
···
 		ret = fimc_md_parse_port_node(fmd, port, index);
 		if (ret < 0) {
 			of_node_put(node);
-			goto rpm_put;
+			goto cleanup;
 		}
 		index++;
 	}
···
 		ret = fimc_md_parse_port_node(fmd, node, index);
 		if (ret < 0) {
 			of_node_put(node);
-			break;
+			goto cleanup;
 		}
 		index++;
 	}
+
 rpm_put:
+	pm_runtime_put(fmd->pmf);
+	return 0;
+
+cleanup:
+	v4l2_async_notifier_cleanup(&fmd->subdev_notifier);
 	pm_runtime_put(fmd->pmf);
 	return ret;
 }
···
 
 	platform_set_drvdata(pdev, fmd);
 
+	v4l2_async_notifier_init(&fmd->subdev_notifier);
+
 	ret = fimc_md_register_platform_entities(fmd, dev->of_node);
 	if (ret)
 		goto err_clk;
···
 
 	ret = device_create_file(&pdev->dev, &dev_attr_subdev_conf_mode);
 	if (ret)
-		goto err_m_ent;
+		goto err_cleanup;
 	/*
 	 * FIMC platform devices need to be registered before the sclk_cam
 	 * clocks provider, as one of these devices needs to be activated
···
 	}
 
 	if (fmd->num_sensors > 0) {
-		fmd->subdev_notifier.subdevs = fmd->async_subdevs;
-		fmd->subdev_notifier.num_subdevs = fmd->num_sensors;
 		fmd->subdev_notifier.ops = &subdev_notifier_ops;
 		fmd->num_sensors = 0;
 
···
 	fimc_md_unregister_clk_provider(fmd);
 err_attr:
 	device_remove_file(&pdev->dev, &dev_attr_subdev_conf_mode);
-err_clk:
-	fimc_md_put_clocks(fmd);
+err_cleanup:
+	v4l2_async_notifier_cleanup(&fmd->subdev_notifier);
 err_m_ent:
 	fimc_md_unregister_entities(fmd);
+err_clk:
+	fimc_md_put_clocks(fmd);
 err_md:
 	media_device_cleanup(&fmd->media_dev);
 	v4l2_device_unregister(&fmd->v4l2_dev);
···
 
 	fimc_md_unregister_clk_provider(fmd);
 	v4l2_async_notifier_unregister(&fmd->subdev_notifier);
+	v4l2_async_notifier_cleanup(&fmd->subdev_notifier);
 
 	v4l2_device_unregister(&fmd->v4l2_dev);
 	device_remove_file(&pdev->dev, &dev_attr_subdev_conf_mode);

drivers/media/platform/exynos4-is/media-dev.h

···
 	} clk_provider;
 
 	struct v4l2_async_notifier subdev_notifier;
-	struct v4l2_async_subdev *async_subdevs[FIMC_MAX_SENSORS];
 
 	bool user_subdev_api;
 	spinlock_t slock;

drivers/media/platform/pxa_camera.c

···
 	struct v4l2_pix_format	current_pix;
 
 	struct v4l2_async_subdev asd;
-	struct v4l2_async_subdev *asds[1];
 
 	/*
 	 * PXA27x is only supposed to handle one camera on its Quick Capture
···
 
 	asd->match_type = V4L2_ASYNC_MATCH_FWNODE;
 	remote = of_graph_get_remote_port(np);
-	if (remote) {
+	if (remote)
 		asd->match.fwnode = of_fwnode_handle(remote);
-		of_node_put(remote);
-	} else {
+	else
 		dev_notice(dev, "no remote for %pOF\n", np);
-	}
 
 out:
 	of_node_put(np);
···
 	if (err)
 		goto exit_deactivate;
 
-	pcdev->asds[0] = &pcdev->asd;
-	pcdev->notifier.subdevs = pcdev->asds;
-	pcdev->notifier.num_subdevs = 1;
+	v4l2_async_notifier_init(&pcdev->notifier);
+
+	err = v4l2_async_notifier_add_subdev(&pcdev->notifier, &pcdev->asd);
+	if (err) {
+		fwnode_handle_put(pcdev->asd.match.fwnode);
+		goto exit_free_v4l2dev;
+	}
+
 	pcdev->notifier.ops = &pxa_camera_sensor_ops;
 
 	if (!of_have_populated_dt())
···
 
 	err = pxa_camera_init_videobuf2(pcdev);
 	if (err)
-		goto exit_free_v4l2dev;
+		goto exit_notifier_cleanup;
 
 	if (pcdev->mclk) {
 		v4l2_clk_name_i2c(clk_name, sizeof(clk_name),
···
 						    clk_name, NULL);
 		if (IS_ERR(pcdev->mclk_clk)) {
 			err = PTR_ERR(pcdev->mclk_clk);
-			goto exit_free_v4l2dev;
+			goto exit_notifier_cleanup;
 		}
 	}
 
···
 	return 0;
 exit_free_clk:
 	v4l2_clk_unregister(pcdev->mclk_clk);
+exit_notifier_cleanup:
+	v4l2_async_notifier_cleanup(&pcdev->notifier);
 exit_free_v4l2dev:
 	v4l2_device_unregister(&pcdev->v4l2_dev);
 exit_deactivate:
···
 	dma_release_channel(pcdev->dma_chans[2]);
 
 	v4l2_async_notifier_unregister(&pcdev->notifier);
+	v4l2_async_notifier_cleanup(&pcdev->notifier);
 
 	if (pcdev->mclk_clk) {
 		v4l2_clk_unregister(pcdev->mclk_clk);

drivers/media/platform/qcom/camss/camss.c

···
  *
  * Return number of "port" nodes found in "ports" node
  */
-static int camss_of_parse_ports(struct device *dev,
-				struct v4l2_async_notifier *notifier)
+static int camss_of_parse_ports(struct camss *camss)
 {
+	struct device *dev = camss->dev;
 	struct device_node *node = NULL;
 	struct device_node *remote = NULL;
-	unsigned int size, i;
-	int ret;
+	int ret, num_subdevs = 0;
 
-	while ((node = of_graph_get_next_endpoint(dev->of_node, node)))
-		if (of_device_is_available(node))
-			notifier->num_subdevs++;
-
-	of_node_put(node);
-	size = sizeof(*notifier->subdevs) * notifier->num_subdevs;
-	notifier->subdevs = devm_kzalloc(dev, size, GFP_KERNEL);
-	if (!notifier->subdevs) {
-		dev_err(dev, "Failed to allocate memory\n");
-		return -ENOMEM;
-	}
-
-	i = 0;
-	while ((node = of_graph_get_next_endpoint(dev->of_node, node))) {
+	for_each_endpoint_of_node(dev->of_node, node) {
 		struct camss_async_subdev *csd;
+		struct v4l2_async_subdev *asd;
 
 		if (!of_device_is_available(node))
 			continue;
 
-		csd = devm_kzalloc(dev, sizeof(*csd), GFP_KERNEL);
-		if (!csd) {
-			of_node_put(node);
-			dev_err(dev, "Failed to allocate memory\n");
-			return -ENOMEM;
-		}
-
-		notifier->subdevs[i++] = &csd->asd;
-
-		ret = camss_of_parse_endpoint_node(dev, node, csd);
-		if (ret < 0) {
-			of_node_put(node);
-			return ret;
-		}
-
 		remote = of_graph_get_remote_port_parent(node);
 		if (!remote) {
 			dev_err(dev, "Cannot get remote parent\n");
-			of_node_put(node);
-			return -EINVAL;
+			ret = -EINVAL;
+			goto err_cleanup;
 		}
 
-		csd->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-		csd->asd.match.fwnode = of_fwnode_handle(remote);
-	}
-	of_node_put(node);
+		asd = v4l2_async_notifier_add_fwnode_subdev(
+			&camss->notifier, of_fwnode_handle(remote),
+			sizeof(*csd));
+		if (IS_ERR(asd)) {
+			ret = PTR_ERR(asd);
+			of_node_put(remote);
+			goto err_cleanup;
+		}
 
-	return notifier->num_subdevs;
+		csd = container_of(asd, struct camss_async_subdev, asd);
+
+		ret = camss_of_parse_endpoint_node(dev, node, csd);
+		if (ret < 0)
+			goto err_cleanup;
+
+		num_subdevs++;
+	}
+
+	return num_subdevs;
+
+err_cleanup:
+	v4l2_async_notifier_cleanup(&camss->notifier);
+	of_node_put(node);
+	return ret;
 }
 
 /*
···
 {
 	struct device *dev = &pdev->dev;
 	struct camss *camss;
-	int ret;
+	int num_subdevs, ret;
 
 	camss = kzalloc(sizeof(*camss), GFP_KERNEL);
 	if (!camss)
···
 	if (!camss->vfe)
 		return -ENOMEM;
 
-	ret = camss_of_parse_ports(dev, &camss->notifier);
-	if (ret < 0)
-		return ret;
+	v4l2_async_notifier_init(&camss->notifier);
+
+	num_subdevs = camss_of_parse_ports(camss);
+	if (num_subdevs < 0)
+		return num_subdevs;
 
 	ret = camss_init_subdevices(camss);
 	if (ret < 0)
-		return ret;
+		goto err_cleanup;
 
 	ret = dma_set_mask_and_coherent(dev, 0xffffffff);
 	if (ret)
-		return ret;
+		goto err_cleanup;
 
 	camss->media_dev.dev = camss->dev;
 	strscpy(camss->media_dev.model, "Qualcomm Camera Subsystem",
···
 	ret = v4l2_device_register(camss->dev, &camss->v4l2_dev);
 	if (ret < 0) {
 		dev_err(dev, "Failed to register V4L2 device: %d\n", ret);
-		return ret;
+		goto err_cleanup;
 	}
 
 	ret = camss_register_entities(camss);
 	if (ret < 0)
 		goto err_register_entities;
 
-	if (camss->notifier.num_subdevs) {
+	if (num_subdevs) {
 		camss->notifier.ops = &camss_subdev_notifier_ops;
 
 		ret = v4l2_async_notifier_register(&camss->v4l2_dev,
···
 	camss_unregister_entities(camss);
 err_register_entities:
 	v4l2_device_unregister(&camss->v4l2_dev);
+err_cleanup:
+	v4l2_async_notifier_cleanup(&camss->notifier);
 
 	return ret;
 }
···
 		msm_vfe_stop_streaming(&camss->vfe[i]);
 
 	v4l2_async_notifier_unregister(&camss->notifier);
+	v4l2_async_notifier_cleanup(&camss->notifier);
 	camss_unregister_entities(camss);
 
 	if (atomic_read(&camss->ref_count) == 0)

drivers/media/platform/qcom/camss/camss.h

···
 };
 
 struct camss_async_subdev {
+	struct v4l2_async_subdev asd; /* must be first */
 	struct camss_camera_interface interface;
-	struct v4l2_async_subdev asd;
 };
 
 struct camss_clock {

drivers/media/platform/rcar-vin/rcar-core.c

···
 
 	mutex_unlock(&vin->group->lock);
 
-	if (!vin->group->notifier.num_subdevs)
+	if (list_empty(&vin->group->notifier.asd_list))
 		return 0;
 
 	vin->group->notifier.ops = &rvin_group_notify_ops;

drivers/media/platform/rcar-vin/rcar-csi2.c

···
 
 	of_node_put(ep);
 
-	priv->notifier.subdevs = devm_kzalloc(priv->dev,
-					      sizeof(*priv->notifier.subdevs),
-					      GFP_KERNEL);
-	if (!priv->notifier.subdevs)
-		return -ENOMEM;
+	v4l2_async_notifier_init(&priv->notifier);
 
-	priv->notifier.num_subdevs = 1;
-	priv->notifier.subdevs[0] = &priv->asd;
+	ret = v4l2_async_notifier_add_subdev(&priv->notifier, &priv->asd);
+	if (ret) {
+		fwnode_handle_put(priv->asd.match.fwnode);
+		return ret;
+	}
+
 	priv->notifier.ops = &rcar_csi2_notify_ops;
 
 	dev_dbg(priv->dev, "Found '%pOF'\n",
 		to_of_node(priv->asd.match.fwnode));
 
-	return v4l2_async_subdev_notifier_register(&priv->subdev,
-						   &priv->notifier);
+	ret = v4l2_async_subdev_notifier_register(&priv->subdev,
+						  &priv->notifier);
+	if (ret)
+		v4l2_async_notifier_cleanup(&priv->notifier);
+
+	return ret;
 }
 
 /* -----------------------------------------------------------------------------

drivers/media/platform/rcar_drif.c

···
 {
 	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");
···
 
 	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);
···
 	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);
 
···
 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);
 }
 

drivers/media/platform/renesas-ceu.c

···
 
 	/* async subdev notification helpers */
 	struct v4l2_async_notifier notifier;
-	/* pointers to "struct ceu_subdevice -> asd" */
-	struct v4l2_async_subdev **asds;
 
 	/* vb2 queue, capture buffer list and active buffer pointer */
 	struct vb2_queue	vb2_vq;
···
 	if (!ceudev->subdevs)
 		return -ENOMEM;
 
-	/*
-	 * Reserve memory for 'n_sd' pointers to async_subdevices.
-	 * ceudev->asds members will point to &ceu_subdev.asd
-	 */
-	ceudev->asds = devm_kcalloc(ceudev->dev, n_sd,
-				    sizeof(*ceudev->asds), GFP_KERNEL);
-	if (!ceudev->asds)
-		return -ENOMEM;
-
 	ceudev->sd = NULL;
 	ceudev->sd_index = 0;
 	ceudev->num_sd = 0;
···
 		return ret;
 
 	for (i = 0; i < pdata->num_subdevs; i++) {
+
 		/* Setup the ceu subdevice and the async subdevice. */
 		async_sd = &pdata->subdevs[i];
 		ceu_sd = &ceudev->subdevs[i];
···
 		ceu_sd->asd.match.i2c.adapter_id = async_sd->i2c_adapter_id;
 		ceu_sd->asd.match.i2c.address = async_sd->i2c_address;
 
-		ceudev->asds[i] = &ceu_sd->asd;
+		ret = v4l2_async_notifier_add_subdev(&ceudev->notifier,
+						     &ceu_sd->asd);
+		if (ret) {
+			v4l2_async_notifier_cleanup(&ceudev->notifier);
+			return ret;
+		}
 	}
 
 	return pdata->num_subdevs;
···
 {
 	struct device_node *of = ceudev->dev->of_node;
 	struct v4l2_fwnode_endpoint fw_ep;
+	struct device_node *ep, *remote;
 	struct ceu_subdev *ceu_sd;
-	struct device_node *ep;
 	unsigned int i;
 	int num_ep;
 	int ret;
···
 			dev_err(ceudev->dev,
 				"No subdevice connected on endpoint %u.\n", i);
 			ret = -ENODEV;
-			goto error_put_node;
+			goto error_cleanup;
 		}
 
 		ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep), &fw_ep);
 		if (ret) {
 			dev_err(ceudev->dev,
 				"Unable to parse endpoint #%u.\n", i);
-			goto error_put_node;
+			goto error_cleanup;
 		}
 
 		if (fw_ep.bus_type != V4L2_MBUS_PARALLEL) {
 			dev_err(ceudev->dev,
 				"Only parallel input supported.\n");
 			ret = -EINVAL;
-			goto error_put_node;
+			goto error_cleanup;
 		}
 
 		/* Setup the ceu subdevice and the async subdevice. */
 		ceu_sd = &ceudev->subdevs[i];
 		INIT_LIST_HEAD(&ceu_sd->asd.list);
 
+		remote = of_graph_get_remote_port_parent(ep);
 		ceu_sd->mbus_flags = fw_ep.bus.parallel.flags;
 		ceu_sd->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-		ceu_sd->asd.match.fwnode =
-			fwnode_graph_get_remote_port_parent(
-					of_fwnode_handle(ep));
+		ceu_sd->asd.match.fwnode = of_fwnode_handle(remote);
 
-		ceudev->asds[i] = &ceu_sd->asd;
+		ret = v4l2_async_notifier_add_subdev(&ceudev->notifier,
+						     &ceu_sd->asd);
+		if (ret) {
+			of_node_put(remote);
+			goto error_cleanup;
+		}
+
 		of_node_put(ep);
 	}
 
 	return num_ep;
 
-error_put_node:
+error_cleanup:
+	v4l2_async_notifier_cleanup(&ceudev->notifier);
 	of_node_put(ep);
 	return ret;
 }
···
 	if (ret)
 		goto error_pm_disable;
 
+	v4l2_async_notifier_init(&ceudev->notifier);
+
 	if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
 		ceu_data = of_match_device(ceu_of_match, dev)->data;
 		num_subdevs = ceu_parse_dt(ceudev);
···
 	ceudev->irq_mask = ceu_data->irq_mask;
 
 	ceudev->notifier.v4l2_dev	= &ceudev->v4l2_dev;
-	ceudev->notifier.subdevs	= ceudev->asds;
-	ceudev->notifier.num_subdevs	= num_subdevs;
 	ceudev->notifier.ops		= &ceu_notify_ops;
 	ret = v4l2_async_notifier_register(&ceudev->v4l2_dev,
 					   &ceudev->notifier);
 	if (ret)
-		goto error_v4l2_unregister;
+		goto error_cleanup;
 
 	dev_info(dev, "Renesas Capture Engine Unit %s\n", dev_name(dev));
 
 	return 0;
 
+error_cleanup:
+	v4l2_async_notifier_cleanup(&ceudev->notifier);
 error_v4l2_unregister:
 	v4l2_device_unregister(&ceudev->v4l2_dev);
 error_pm_disable:
···
 	pm_runtime_disable(ceudev->dev);
 
 	v4l2_async_notifier_unregister(&ceudev->notifier);
+
+	v4l2_async_notifier_cleanup(&ceudev->notifier);
 
 	v4l2_device_unregister(&ceudev->v4l2_dev);
 

drivers/media/platform/soc_camera/soc_camera.c

···
 		goto eaddpdev;
 	}
 
-	sasc->notifier.subdevs = asd;
-	sasc->notifier.num_subdevs = size;
+	v4l2_async_notifier_init(&sasc->notifier);
+
+	for (i = 0; i < size; i++) {
+		ret = v4l2_async_notifier_add_subdev(&sasc->notifier, asd[i]);
+		if (ret)
+			goto eaddasd;
+	}
+
 	sasc->notifier.ops = &soc_camera_async_ops;
 
 	icd->sasc = sasc;
···
 	v4l2_clk_unregister(icd->clk);
 eclkreg:
 	icd->clk = NULL;
+eaddasd:
+	v4l2_async_notifier_cleanup(&sasc->notifier);
 	platform_device_del(sasc->pdev);
 eaddpdev:
 	platform_device_put(sasc->pdev);
···
 		goto eaddpdev;
 	}
 
-	sasc->notifier.subdevs = &info->subdev;
-	sasc->notifier.num_subdevs = 1;
+	v4l2_async_notifier_init(&sasc->notifier);
+
+	ret = v4l2_async_notifier_add_subdev(&sasc->notifier, info->subdev);
+	if (ret) {
+		of_node_put(remote);
+		goto eaddasd;
+	}
+
 	sasc->notifier.ops = &soc_camera_async_ops;
 
 	icd->sasc = sasc;
···
 	v4l2_clk_unregister(icd->clk);
 eclkreg:
 	icd->clk = NULL;
+eaddasd:
+	v4l2_async_notifier_cleanup(&sasc->notifier);
 	platform_device_del(sasc->pdev);
 eaddpdev:
 	platform_device_put(sasc->pdev);
···
 {
 	struct device *dev = ici->v4l2_dev.dev;
 	struct device_node *np = dev->of_node;
-	struct device_node *epn = NULL, *ren;
+	struct device_node *epn = NULL, *rem;
 	unsigned int i;
 
 	for (i = 0; ; i++) {
···
 		if (!epn)
 			break;
 
-		ren = of_graph_get_remote_port(epn);
-		if (!ren) {
+		rem = of_graph_get_remote_port_parent(epn);
+		if (!rem) {
 			dev_notice(dev, "no remote for %pOF\n", epn);
 			continue;
 		}
 
 		/* so we now have a remote node to connect */
 		if (!i)
-			soc_of_bind(ici, epn, ren->parent);
-
-		of_node_put(ren);
+			soc_of_bind(ici, epn, rem);
 
 		if (i) {
 			dev_err(dev, "multiple subdevices aren't supported yet!\n");
···
 	list_for_each_entry(sasc, &notifiers, list) {
 		/* Must call unlocked to avoid AB-BA dead-lock */
 		v4l2_async_notifier_unregister(&sasc->notifier);
+		v4l2_async_notifier_cleanup(&sasc->notifier);
 		put_device(&sasc->pdev->dev);
 	}
 

drivers/media/platform/stm32/stm32-dcmi.c

···
 
 static int dcmi_graph_init(struct stm32_dcmi *dcmi)
 {
-	struct v4l2_async_subdev **subdevs = NULL;
 	int ret;
 
 	/* Parse the graph to extract a list of subdevice DT nodes. */
···
 		return ret;
 	}
 
-	/* Register the subdevices notifier. */
-	subdevs = devm_kzalloc(dcmi->dev, sizeof(*subdevs), GFP_KERNEL);
-	if (!subdevs) {
+	v4l2_async_notifier_init(&dcmi->notifier);
+
+	ret = v4l2_async_notifier_add_subdev(&dcmi->notifier,
+					     &dcmi->entity.asd);
+	if (ret) {
 		of_node_put(dcmi->entity.node);
-		return -ENOMEM;
+		return ret;
 	}
 
-	subdevs[0] = &dcmi->entity.asd;
-
-	dcmi->notifier.subdevs = subdevs;
-	dcmi->notifier.num_subdevs = 1;
 	dcmi->notifier.ops = &dcmi_graph_notify_ops;
 
 	ret = v4l2_async_notifier_register(&dcmi->v4l2_dev, &dcmi->notifier);
 	if (ret < 0) {
 		dev_err(dcmi->dev, "Notifier registration failed\n");
-		of_node_put(dcmi->entity.node);
+		v4l2_async_notifier_cleanup(&dcmi->notifier);
 		return ret;
 	}
 
···
 	ret = reset_control_assert(dcmi->rstc);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to assert the reset line\n");
-		goto err_device_release;
+		goto err_cleanup;
 	}
 
 	usleep_range(3000, 5000);
···
 	ret = reset_control_deassert(dcmi->rstc);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to deassert the reset line\n");
-		goto err_device_release;
+		goto err_cleanup;
 	}
 
 	dev_info(&pdev->dev, "Probe done\n");
···
 
 	return 0;
 
+err_cleanup:
+	v4l2_async_notifier_cleanup(&dcmi->notifier);
 err_device_release:
 	video_device_release(dcmi->vdev);
 err_device_unregister:
···
 	pm_runtime_disable(&pdev->dev);
 
 	v4l2_async_notifier_unregister(&dcmi->notifier);
+	v4l2_async_notifier_cleanup(&dcmi->notifier);
 	v4l2_device_unregister(&dcmi->v4l2_dev);
 
 	dma_release_channel(dcmi->dma_chan);

drivers/media/platform/ti-vpe/cal.c

···
 	struct v4l2_fwnode_endpoint	endpoint;
 
 	struct v4l2_async_subdev asd;
-	struct v4l2_async_subdev *asd_list[1];
 
 	struct v4l2_fh		fh;
 	struct cal_dev		*dev;
···
 	ctx_dbg(1, ctx, "Port: %d found sub-device %pOFn\n",
 		inst, sensor_node);
 
-	ctx->asd_list[0] = asd;
-	ctx->notifier.subdevs = ctx->asd_list;
-	ctx->notifier.num_subdevs = 1;
+	v4l2_async_notifier_init(&ctx->notifier);
+
+	ret = v4l2_async_notifier_add_subdev(&ctx->notifier, asd);
+	if (ret) {
+		ctx_err(ctx, "Error adding asd\n");
+		goto cleanup_exit;
+	}
+
 	ctx->notifier.ops = &cal_async_ops;
 	ret = v4l2_async_notifier_register(&ctx->v4l2_dev,
 					   &ctx->notifier);
 	if (ret) {
 		ctx_err(ctx, "Error registering async notifier\n");
+		v4l2_async_notifier_cleanup(&ctx->notifier);
 		ret = -EINVAL;
 	}
+
+	/*
+	 * On success we need to keep reference on sensor_node, or
+	 * if notifier_cleanup was called above, sensor_node was
+	 * already put.
+	 */
+	sensor_node = NULL;
 
 cleanup_exit:
 	of_node_put(remote_ep);
···
 static int cal_probe(struct platform_device *pdev)
 {
 	struct cal_dev *dev;
+	struct cal_ctx *ctx;
 	int ret;
 	int irq;
+	int i;
 
 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
 	if (!dev)
···
 
 runtime_disable:
 	pm_runtime_disable(&pdev->dev);
+	for (i = 0; i < CAL_NUM_CONTEXT; i++) {
+		ctx = dev->ctx[i];
+		if (ctx) {
+			v4l2_async_notifier_unregister(&ctx->notifier);
+			v4l2_async_notifier_cleanup(&ctx->notifier);
+			v4l2_ctrl_handler_free(&ctx->ctrl_handler);
+			v4l2_device_unregister(&ctx->v4l2_dev);
+		}
+	}
+
 	return ret;
 }
 
···
 				video_device_node_name(&ctx->vdev));
 			camerarx_phy_disable(ctx);
 			v4l2_async_notifier_unregister(&ctx->notifier);
+			v4l2_async_notifier_cleanup(&ctx->notifier);
 			v4l2_ctrl_handler_free(&ctx->ctrl_handler);
 			v4l2_device_unregister(&ctx->v4l2_dev);
 			video_unregister_device(&ctx->vdev);

drivers/media/platform/xilinx/xilinx-vipp.c

···
 
 /**
  * struct xvip_graph_entity - Entity in the video graph
- * @list: list entry in a graph entities list
- * @node: the entity's DT node
- * @entity: media entity, from the corresponding V4L2 subdev
  * @asd: subdev asynchronous registration information
+ * @entity: media entity, from the corresponding V4L2 subdev
  * @subdev: V4L2 subdev
  */
 struct xvip_graph_entity {
-	struct list_head list;
-	struct device_node *node;
+	struct v4l2_async_subdev asd; /* must be first */
 	struct media_entity *entity;
-
-	struct v4l2_async_subdev asd;
 	struct v4l2_subdev *subdev;
 };
+
+static inline struct xvip_graph_entity *
+to_xvip_entity(struct v4l2_async_subdev *asd)
+{
+	return container_of(asd, struct xvip_graph_entity, asd);
+}
 
 /* -----------------------------------------------------------------------------
  * Graph Management
···
 
 static struct xvip_graph_entity *
 xvip_graph_find_entity(struct xvip_composite_device *xdev,
-		       const struct device_node *node)
+		       const struct fwnode_handle *fwnode)
 {
 	struct xvip_graph_entity *entity;
+	struct v4l2_async_subdev *asd;
 
-	list_for_each_entry(entity, &xdev->entities, list) {
-		if (entity->node == node)
+	list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
+		entity = to_xvip_entity(asd);
+		if (entity->asd.match.fwnode == fwnode)
 			return entity;
 	}
 
···
 	struct media_pad *remote_pad;
 	struct xvip_graph_entity *ent;
 	struct v4l2_fwnode_link link;
-	struct device_node *ep = NULL;
+	struct fwnode_handle *ep = NULL;
 	int ret = 0;
 
 	dev_dbg(xdev->dev, "creating links for entity %s\n", local->name);
 
 	while (1) {
 		/* Get the next endpoint and parse its link. */
-		ep = of_graph_get_next_endpoint(entity->node, ep);
+		ep = fwnode_graph_get_next_endpoint(entity->asd.match.fwnode,
+						    ep);
 		if (ep == NULL)
 			break;
 
-		dev_dbg(xdev->dev, "processing endpoint %pOF\n", ep);
+		dev_dbg(xdev->dev, "processing endpoint %p\n", ep);
 
-		ret = v4l2_fwnode_parse_link(of_fwnode_handle(ep), &link);
+		ret = v4l2_fwnode_parse_link(ep, &link);
 		if (ret < 0) {
-			dev_err(xdev->dev, "failed to parse link for %pOF\n",
+			dev_err(xdev->dev, "failed to parse link for %p\n",
 				ep);
 			continue;
 		}
···
 		 * the link.
 		 */
 		if (link.local_port >= local->num_pads) {
-			dev_err(xdev->dev, "invalid port number %u for %pOF\n",
-				link.local_port,
-				to_of_node(link.local_node));
+			dev_err(xdev->dev, "invalid port number %u for %p\n",
+				link.local_port, link.local_node);
 			v4l2_fwnode_put_link(&link);
 			ret = -EINVAL;
 			break;
···
 		local_pad = &local->pads[link.local_port];
 
 		if (local_pad->flags & MEDIA_PAD_FL_SINK) {
-			dev_dbg(xdev->dev, "skipping sink port %pOF:%u\n",
-				to_of_node(link.local_node),
-				link.local_port);
+			dev_dbg(xdev->dev, "skipping sink port %p:%u\n",
+				link.local_node, link.local_port);
 			v4l2_fwnode_put_link(&link);
 			continue;
 		}
 
 		/* Skip DMA engines, they will be processed separately. */
 		if (link.remote_node == of_fwnode_handle(xdev->dev->of_node)) {
-			dev_dbg(xdev->dev, "skipping DMA port %pOF:%u\n",
-				to_of_node(link.local_node),
-				link.local_port);
+			dev_dbg(xdev->dev, "skipping DMA port %p:%u\n",
+				link.local_node, link.local_port);
 			v4l2_fwnode_put_link(&link);
 			continue;
 		}
 
 		/* Find the remote entity. */
-		ent = xvip_graph_find_entity(xdev,
-					     to_of_node(link.remote_node));
+		ent = xvip_graph_find_entity(xdev, link.remote_node);
 		if (ent == NULL) {
-			dev_err(xdev->dev, "no entity found for %pOF\n",
-				to_of_node(link.remote_node));
+			dev_err(xdev->dev, "no entity found for %p\n",
+				link.remote_node);
 			v4l2_fwnode_put_link(&link);
 			ret = -ENODEV;
 			break;
···
 		remote = ent->entity;
 
 		if (link.remote_port >= remote->num_pads) {
-			dev_err(xdev->dev, "invalid port number %u on %pOF\n",
-				link.remote_port, to_of_node(link.remote_node));
+			dev_err(xdev->dev, "invalid port number %u on %p\n",
+				link.remote_port, link.remote_node);
 			v4l2_fwnode_put_link(&link);
 			ret = -EINVAL;
 			break;
···
 		}
 	}
 
-	of_node_put(ep);
+	fwnode_handle_put(ep);
 	return ret;
 }
 
···
 			dma->video.name);
 
 		/* Find the remote entity. */
-		ent = xvip_graph_find_entity(xdev,
-					     to_of_node(link.remote_node));
+		ent = xvip_graph_find_entity(xdev, link.remote_node);
 		if (ent == NULL) {
 			dev_err(xdev->dev, "no entity found for %pOF\n",
 				to_of_node(link.remote_node));
···
 	struct xvip_composite_device *xdev =
 		container_of(notifier, struct xvip_composite_device, notifier);
 	struct xvip_graph_entity *entity;
+	struct v4l2_async_subdev *asd;
 	int ret;
 
 	dev_dbg(xdev->dev, "notify complete, all subdevs registered\n");
 
 	/* Create links for every entity. */
-	list_for_each_entry(entity, &xdev->entities, list) {
+	list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
+		entity = to_xvip_entity(asd);
 		ret = xvip_graph_build_one(xdev, entity);
 		if (ret < 0)
 			return ret;
···
 
 static int xvip_graph_notify_bound(struct v4l2_async_notifier *notifier,
 				   struct v4l2_subdev *subdev,
-				   struct v4l2_async_subdev *asd)
+				   struct v4l2_async_subdev *unused)
 {
 	struct xvip_composite_device *xdev =
 		container_of(notifier, struct xvip_composite_device, notifier);
 	struct xvip_graph_entity *entity;
+	struct v4l2_async_subdev *asd;
 
 	/* Locate the entity corresponding to the bound subdev and store the
 	 * subdev pointer.
 	 */
-	list_for_each_entry(entity, &xdev->entities, list) {
-		if (entity->node != subdev->dev->of_node)
+	list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
+		entity = to_xvip_entity(asd);
+
+		if (entity->asd.match.fwnode != subdev->fwnode)
 			continue;
 
 		if (entity->subdev) {
-			dev_err(xdev->dev, "duplicate subdev for node %pOF\n",
-				entity->node);
+			dev_err(xdev->dev, "duplicate subdev for node %p\n",
+				entity->asd.match.fwnode);
 			return -EINVAL;
 		}
 
···
 };
 
 static int xvip_graph_parse_one(struct xvip_composite_device *xdev,
-				struct device_node *node)
+				struct fwnode_handle *fwnode)
 {
-	struct xvip_graph_entity *entity;
-	struct device_node *remote;
-	struct device_node *ep = NULL;
+	struct fwnode_handle *remote;
+	struct fwnode_handle *ep = NULL;
 	int ret = 0;
 
-	dev_dbg(xdev->dev, "parsing node %pOF\n", node);
+	dev_dbg(xdev->dev, "parsing node %p\n", fwnode);
 
 	while (1) {
-		ep = of_graph_get_next_endpoint(node, ep);
+		struct v4l2_async_subdev *asd;
+
+		ep = fwnode_graph_get_next_endpoint(fwnode, ep);
 		if (ep == NULL)
 			break;
 
-		dev_dbg(xdev->dev, "handling endpoint %pOF\n", ep);
+		dev_dbg(xdev->dev, "handling endpoint %p\n", ep);
 
-		remote = of_graph_get_remote_port_parent(ep);
+		remote = fwnode_graph_get_remote_port_parent(ep);
 		if (remote == NULL) {
 			ret = -EINVAL;
-			break;
+			goto err_notifier_cleanup;
 		}
 
+		fwnode_handle_put(ep);
+
 		/* Skip entities that we have already processed. */
-		if (remote == xdev->dev->of_node ||
+		if (remote == of_fwnode_handle(xdev->dev->of_node) ||
 		    xvip_graph_find_entity(xdev, remote)) {
-			of_node_put(remote);
+			fwnode_handle_put(remote);
 			continue;
 		}
 
-		entity = devm_kzalloc(xdev->dev, sizeof(*entity), GFP_KERNEL);
-		if (entity == NULL) {
-			of_node_put(remote);
-			ret = -ENOMEM;
-			break;
+		asd = v4l2_async_notifier_add_fwnode_subdev(
+			&xdev->notifier, remote,
+			sizeof(struct xvip_graph_entity));
+		if (IS_ERR(asd)) {
+			ret = PTR_ERR(asd);
+			fwnode_handle_put(remote);
+			goto err_notifier_cleanup;
 		}
-
-		entity->node = remote;
-		entity->asd.match_type = V4L2_ASYNC_MATCH_FWNODE;
-		entity->asd.match.fwnode = of_fwnode_handle(remote);
-		list_add_tail(&entity->list, &xdev->entities);
-		xdev->num_subdevs++;
 	}
 
-	of_node_put(ep);
+	return 0;
+
+err_notifier_cleanup:
+	v4l2_async_notifier_cleanup(&xdev->notifier);
+	fwnode_handle_put(ep);
 	return ret;
 }
 
 static int xvip_graph_parse(struct xvip_composite_device *xdev)
 {
 	struct xvip_graph_entity *entity;
+	struct v4l2_async_subdev *asd;
 	int ret;
 
 	/*
···
 	 * loop will handle entities added at the end of the list while walking
 	 * the links.
 	 */
-	ret = xvip_graph_parse_one(xdev, xdev->dev->of_node);
+	ret = xvip_graph_parse_one(xdev, of_fwnode_handle(xdev->dev->of_node));
 	if (ret < 0)
 		return 0;
 
-	list_for_each_entry(entity, &xdev->entities, list) {
-		ret = xvip_graph_parse_one(xdev, entity->node);
-		if (ret < 0)
+	list_for_each_entry(asd, &xdev->notifier.asd_list, asd_list) {
+		entity = to_xvip_entity(asd);
+		ret = xvip_graph_parse_one(xdev, entity->asd.match.fwnode);
+		if (ret < 0) {
+			v4l2_async_notifier_cleanup(&xdev->notifier);
 			break;
+		}
 	}
 
 	return ret;
···
 
 static void xvip_graph_cleanup(struct xvip_composite_device *xdev)
 {
-	struct xvip_graph_entity *entityp;
-	struct xvip_graph_entity *entity;
 	struct xvip_dma *dmap;
 	struct xvip_dma *dma;
 
 	v4l2_async_notifier_unregister(&xdev->notifier);
-
-	list_for_each_entry_safe(entity, entityp, &xdev->entities, list) {
-		of_node_put(entity->node);
-		list_del(&entity->list);
-	}
+	v4l2_async_notifier_cleanup(&xdev->notifier);
 
 	list_for_each_entry_safe(dma, dmap, &xdev->dmas, list) {
 		xvip_dma_cleanup(dma);
···
 
 static int xvip_graph_init(struct xvip_composite_device *xdev)
 {
-	struct xvip_graph_entity *entity;
-	struct v4l2_async_subdev **subdevs = NULL;
-	unsigned int num_subdevs;
-	unsigned int i;
 	int ret;
 
 	/* Init the DMA channels. */
···
 		goto done;
 	}
 
-	if (!xdev->num_subdevs) {
+	if (list_empty(&xdev->notifier.asd_list)) {
 		dev_err(xdev->dev, "no subdev found in graph\n");
 		goto done;
 	}
 
 	/* Register the subdevices notifier. */
-	num_subdevs = xdev->num_subdevs;
-	subdevs = devm_kcalloc(xdev->dev, num_subdevs, sizeof(*subdevs),
-			       GFP_KERNEL);
-	if (subdevs == NULL) {
-		ret = -ENOMEM;
-		goto done;
-	}
-
-	i = 0;
-	list_for_each_entry(entity, &xdev->entities, list)
-		subdevs[i++] = &entity->asd;
-
-	xdev->notifier.subdevs = subdevs;
-	xdev->notifier.num_subdevs = num_subdevs;
 	xdev->notifier.ops = &xvip_graph_notify_ops;
 
 	ret = v4l2_async_notifier_register(&xdev->v4l2_dev, &xdev->notifier);
···
 		return -ENOMEM;
 
 	xdev->dev = &pdev->dev;
-	INIT_LIST_HEAD(&xdev->entities);
 	INIT_LIST_HEAD(&xdev->dmas);
+	v4l2_async_notifier_init(&xdev->notifier);
 
 	ret = xvip_composite_v4l2_init(xdev);
 	if (ret < 0)

drivers/media/platform/xilinx/xilinx-vipp.h

···
  * @media_dev: media device
  * @dev: (OF) device
  * @notifier: V4L2 asynchronous subdevs notifier
- * @entities: entities in the graph as a list of xvip_graph_entity
- * @num_subdevs: number of subdevs in the pipeline
  * @dmas: list of DMA channels at the pipeline output and input
  * @v4l2_caps: V4L2 capabilities of the whole device (see VIDIOC_QUERYCAP)
  */
···
 	struct device *dev;
 
 	struct v4l2_async_notifier notifier;
-	struct list_head entities;
-	unsigned int num_subdevs;
 
 	struct list_head dmas;
 	u32 v4l2_caps;