Hi Niklas,
Thank you for the patch.
On Fri, Jun 06, 2025 at 08:26:01PM +0200, Niklas Söderlund wrote:
> The VIN usage of v4l-async is complex and stems from organic growth of
> the driver of supporting both private local subdevices (Gen2, Gen3) and
> subdevices shared between all VIN instances (Gen3 and Gen4).
>
> The driver used a separate notifier for each VIN for the private local
> ones, and a shared group notifier for the shared ones. This was complex
> and lead to subtle bugs when unbinding and later rebinding subdevices in
> one of the notifiers having to handle different edge cases depending on
> if it also had subdevices in the other notifiers etc.
>
> To simplify this have the Gen2 devices allocate and form a VIN group
> too. This way all subdevices on all models can be collect in a
> single group notifier. Then there is only a single complete callback for
> all where the video devices and subdevice nodes can be registered etc.
>
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> Tested-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
> ---
> * Changes since v4
> - Fix spelling in commit message and comments.
> - Use mutex guard to simplify error path.
> - Fix code style, add braces and blank lines.
> ---
> .../platform/renesas/rcar-vin/rcar-core.c | 256 ++++++++----------
> .../platform/renesas/rcar-vin/rcar-vin.h | 2 -
> 2 files changed, 106 insertions(+), 152 deletions(-)
>
> diff --git a/drivers/media/platform/renesas/rcar-vin/rcar-core.c b/drivers/media/platform/renesas/rcar-vin/rcar-core.c
> index 100432080ad7..c5510e3b258f 100644
> --- a/drivers/media/platform/renesas/rcar-vin/rcar-core.c
> +++ b/drivers/media/platform/renesas/rcar-vin/rcar-core.c
> @@ -43,6 +43,9 @@
>
> #define v4l2_dev_to_vin(d) container_of(d, struct rvin_dev, v4l2_dev)
>
> +static int rvin_parallel_subdevice_attach(struct rvin_dev *vin,
> + struct v4l2_subdev *subdev);
> +
> /* -----------------------------------------------------------------------------
> * Gen3 Group Allocator
> */
> @@ -233,7 +236,10 @@ static int rvin_group_notify_complete(struct v4l2_async_notifier *notifier)
> }
> }
>
> - return vin->group->link_setup(vin->group);
> + if (vin->group->link_setup)
> + return vin->group->link_setup(vin->group);
> +
> + return 0;
> }
>
> static void rvin_group_notify_unbind(struct v4l2_async_notifier *notifier,
> @@ -241,20 +247,32 @@ static void rvin_group_notify_unbind(struct v4l2_async_notifier *notifier,
> struct v4l2_async_connection *asc)
> {
> struct rvin_dev *vin = v4l2_dev_to_vin(notifier->v4l2_dev);
> - unsigned int i;
> + struct rvin_group *group = vin->group;
>
> - for (i = 0; i < RCAR_VIN_NUM; i++)
> - if (vin->group->vin[i])
> - rvin_v4l2_unregister(vin->group->vin[i]);
> + for (unsigned int i = 0; i < RCAR_VIN_NUM; i++) {
> + if (group->vin[i])
> + rvin_v4l2_unregister(group->vin[i]);
> + }
>
> mutex_lock(&vin->group->lock);
>
> - for (i = 0; i < ARRAY_SIZE(vin->group->remotes); i++) {
> - if (vin->group->remotes[i].asc != asc)
> + for (unsigned int i = 0; i < RCAR_VIN_NUM; i++) {
> + if (!group->vin[i] || group->vin[i]->parallel.asc != asc)
> continue;
> - vin->group->remotes[i].subdev = NULL;
> +
> + group->vin[i]->parallel.subdev = NULL;
> +
> + vin_dbg(group->vin[i], "Unbind parallel subdev %s\n",
> + subdev->name);
> + }
> +
> + for (unsigned int i = 0; i < ARRAY_SIZE(group->remotes); i++) {
> + if (group->remotes[i].asc != asc)
> + continue;
> +
> + group->remotes[i].subdev = NULL;
> +
> vin_dbg(vin, "Unbind %s from slot %u\n", subdev->name, i);
> - break;
> }
>
> mutex_unlock(&vin->group->lock);
> @@ -267,21 +285,38 @@ static int rvin_group_notify_bound(struct v4l2_async_notifier *notifier,
> struct v4l2_async_connection *asc)
> {
> struct rvin_dev *vin = v4l2_dev_to_vin(notifier->v4l2_dev);
> - unsigned int i;
> + struct rvin_group *group = vin->group;
>
> - mutex_lock(&vin->group->lock);
> + guard(mutex)(&group->lock);
>
> - for (i = 0; i < ARRAY_SIZE(vin->group->remotes); i++) {
> + for (unsigned int i = 0; i < RCAR_VIN_NUM; i++) {
> + int ret;
> +
> + if (!group->vin[i] || group->vin[i]->parallel.asc != asc)
> + continue;
> +
> + ret = rvin_parallel_subdevice_attach(group->vin[i], subdev);
> + if (ret)
> + return ret;
> +
> + v4l2_set_subdev_hostdata(subdev, group->vin[i]);
> +
> + vin_dbg(group->vin[i], "Bound subdev %s\n", subdev->name);
> +
> + return 0;
> + }
> +
> + for (unsigned int i = 0; i < ARRAY_SIZE(group->remotes); i++) {
> if (vin->group->remotes[i].asc != asc)
> continue;
> +
> vin->group->remotes[i].subdev = subdev;
> vin_dbg(vin, "Bound %s to slot %u\n", subdev->name, i);
> - break;
> +
> + return 0;
> }
>
> - mutex_unlock(&vin->group->lock);
> -
> - return 0;
> + return -ENODEV;
> }
>
> static const struct v4l2_async_notifier_operations rvin_group_notify_ops = {
> @@ -371,7 +406,7 @@ static int rvin_parallel_parse_of(struct rvin_dev *vin)
> }
>
> fwnode = fwnode_graph_get_remote_endpoint(ep);
> - asc = v4l2_async_nf_add_fwnode(&vin->notifier, fwnode,
> + asc = v4l2_async_nf_add_fwnode(&vin->group->notifier, fwnode,
> struct v4l2_async_connection);
> if (IS_ERR(asc))
> return PTR_ERR(asc);
> @@ -417,6 +452,12 @@ static int rvin_group_notifier_init(struct rvin_dev *vin, unsigned int port,
> if (!(vin_mask & BIT(i)))
> continue;
>
> + /* Parse local subdevice. */
> + ret = rvin_parallel_parse_of(vin->group->vin[i]);
> + if (ret)
> + return ret;
> +
> + /* Prase shared subdevices. */
s/Prase/Parse/
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> for (id = 0; id < max_id; id++) {
> if (vin->group->remotes[id].asc)
> continue;
> @@ -596,124 +637,6 @@ static int rvin_parallel_subdevice_attach(struct rvin_dev *vin,
> return 0;
> }
>
> -static void rvin_parallel_subdevice_detach(struct rvin_dev *vin)
> -{
> - rvin_v4l2_unregister(vin);
> - vin->parallel.subdev = NULL;
> -
> - if (!vin->info->use_mc)
> - rvin_free_controls(vin);
> -}
> -
> -static int rvin_parallel_notify_complete(struct v4l2_async_notifier *notifier)
> -{
> - struct rvin_dev *vin = v4l2_dev_to_vin(notifier->v4l2_dev);
> - struct media_entity *source;
> - struct media_entity *sink;
> - int ret;
> -
> - ret = v4l2_device_register_subdev_nodes(&vin->v4l2_dev);
> - if (ret < 0) {
> - vin_err(vin, "Failed to register subdev nodes\n");
> - return ret;
> - }
> -
> - if (!video_is_registered(&vin->vdev)) {
> - ret = rvin_v4l2_register(vin);
> - if (ret < 0)
> - return ret;
> - }
> -
> - if (!vin->info->use_mc)
> - return 0;
> -
> - /* If we're running with media-controller, link the subdevs. */
> - source = &vin->parallel.subdev->entity;
> - sink = &vin->vdev.entity;
> -
> - ret = media_create_pad_link(source, vin->parallel.source_pad,
> - sink, vin->parallel.sink_pad, 0);
> - if (ret)
> - vin_err(vin, "Error adding link from %s to %s: %d\n",
> - source->name, sink->name, ret);
> -
> - return ret;
> -}
> -
> -static void rvin_parallel_notify_unbind(struct v4l2_async_notifier *notifier,
> - struct v4l2_subdev *subdev,
> - struct v4l2_async_connection *asc)
> -{
> - struct rvin_dev *vin = v4l2_dev_to_vin(notifier->v4l2_dev);
> -
> - vin_dbg(vin, "unbind parallel subdev %s\n", subdev->name);
> -
> - mutex_lock(&vin->lock);
> - rvin_parallel_subdevice_detach(vin);
> - mutex_unlock(&vin->lock);
> -}
> -
> -static int rvin_parallel_notify_bound(struct v4l2_async_notifier *notifier,
> - struct v4l2_subdev *subdev,
> - struct v4l2_async_connection *asc)
> -{
> - struct rvin_dev *vin = v4l2_dev_to_vin(notifier->v4l2_dev);
> - int ret;
> -
> - mutex_lock(&vin->lock);
> - ret = rvin_parallel_subdevice_attach(vin, subdev);
> - mutex_unlock(&vin->lock);
> - if (ret)
> - return ret;
> -
> - v4l2_set_subdev_hostdata(subdev, vin);
> -
> - vin_dbg(vin, "bound subdev %s source pad: %u sink pad: %u\n",
> - subdev->name, vin->parallel.source_pad,
> - vin->parallel.sink_pad);
> -
> - return 0;
> -}
> -
> -static const struct v4l2_async_notifier_operations rvin_parallel_notify_ops = {
> - .bound = rvin_parallel_notify_bound,
> - .unbind = rvin_parallel_notify_unbind,
> - .complete = rvin_parallel_notify_complete,
> -};
> -
> -static void rvin_parallel_cleanup(struct rvin_dev *vin)
> -{
> - v4l2_async_nf_unregister(&vin->notifier);
> - v4l2_async_nf_cleanup(&vin->notifier);
> -}
> -
> -static int rvin_parallel_init(struct rvin_dev *vin)
> -{
> - int ret;
> -
> - v4l2_async_nf_init(&vin->notifier, &vin->v4l2_dev);
> -
> - ret = rvin_parallel_parse_of(vin);
> - if (ret)
> - return ret;
> -
> - if (!vin->parallel.asc)
> - return -ENODEV;
> -
> - vin_dbg(vin, "Found parallel subdevice %pOF\n",
> - to_of_node(vin->parallel.asc->match.fwnode));
> -
> - vin->notifier.ops = &rvin_parallel_notify_ops;
> - ret = v4l2_async_nf_register(&vin->notifier);
> - if (ret < 0) {
> - vin_err(vin, "Notifier registration failed\n");
> - v4l2_async_nf_cleanup(&vin->notifier);
> - return ret;
> - }
> -
> - return 0;
> -}
> -
> /* -----------------------------------------------------------------------------
> * CSI-2
> */
> @@ -888,11 +811,52 @@ static int rvin_csi2_create_link(struct rvin_group *group, unsigned int id,
> return 0;
> }
>
> +static int rvin_parallel_setup_links(struct rvin_group *group)
> +{
> + u32 flags = MEDIA_LNK_FL_ENABLED | MEDIA_LNK_FL_IMMUTABLE;
> +
> + guard(mutex)(&group->lock);
> +
> + /* If the group also has links don't enable the link. */
> + for (unsigned int i = 0; i < ARRAY_SIZE(group->remotes); i++) {
> + if (group->remotes[i].subdev) {
> + flags = 0;
> + break;
> + }
> + }
> +
> + /* Create links. */
> + for (unsigned int i = 0; i < RCAR_VIN_NUM; i++) {
> + struct rvin_dev *vin = group->vin[i];
> + struct media_entity *source;
> + struct media_entity *sink;
> + int ret;
> +
> + /* Nothing to do if there is no VIN or parallel subdev. */
> + if (!vin || !vin->parallel.subdev)
> + continue;
> +
> + source = &vin->parallel.subdev->entity;
> + sink = &vin->vdev.entity;
> +
> + ret = media_create_pad_link(source, vin->parallel.source_pad,
> + sink, 0, flags);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> static int rvin_csi2_setup_links(struct rvin_group *group)
> {
> const struct rvin_group_route *route;
> unsigned int id;
> - int ret = -EINVAL;
> + int ret;
> +
> + ret = rvin_parallel_setup_links(group);
> + if (ret)
> + return ret;
>
> /* Create all media device links between VINs and CSI-2's. */
> mutex_lock(&group->lock);
> @@ -923,9 +887,7 @@ static int rvin_csi2_setup_links(struct rvin_group *group)
>
> static void rvin_csi2_cleanup(struct rvin_dev *vin)
> {
> - rvin_parallel_cleanup(vin);
> rvin_group_notifier_cleanup(vin);
> - rvin_group_put(vin);
> rvin_free_controls(vin);
> }
>
> @@ -946,18 +908,11 @@ static int rvin_csi2_init(struct rvin_dev *vin)
> if (ret)
> goto err_controls;
>
> - /* It's OK to not have a parallel subdevice. */
> - ret = rvin_parallel_init(vin);
> - if (ret && ret != -ENODEV)
> - goto err_group;
> -
> ret = rvin_group_notifier_init(vin, 1, RVIN_CSI_MAX);
> if (ret)
> - goto err_parallel;
> + goto err_group;
>
> return 0;
> -err_parallel:
> - rvin_parallel_cleanup(vin);
> err_group:
> rvin_group_put(vin);
> err_controls:
> @@ -1018,7 +973,6 @@ static int rvin_isp_setup_links(struct rvin_group *group)
> static void rvin_isp_cleanup(struct rvin_dev *vin)
> {
> rvin_group_notifier_cleanup(vin);
> - rvin_group_put(vin);
> rvin_free_controls(vin);
> }
>
> @@ -1430,7 +1384,9 @@ static int rcar_vin_probe(struct platform_device *pdev)
> rvin_group_id_to_master(vin->id) == vin->id)
> vin->scaler = vin->info->scaler;
> } else {
> - ret = rvin_parallel_init(vin);
> + ret = rvin_group_get(vin, NULL, NULL);
> + if (!ret)
> + ret = rvin_group_notifier_init(vin, 0, 0);
>
> if (vin->info->scaler)
> vin->scaler = vin->info->scaler;
> @@ -1460,8 +1416,8 @@ static void rcar_vin_remove(struct platform_device *pdev)
> rvin_isp_cleanup(vin);
> else if (vin->info->use_mc)
> rvin_csi2_cleanup(vin);
> - else
> - rvin_parallel_cleanup(vin);
> +
> + rvin_group_put(vin);
>
> rvin_id_put(vin);
>
> diff --git a/drivers/media/platform/renesas/rcar-vin/rcar-vin.h b/drivers/media/platform/renesas/rcar-vin/rcar-vin.h
> index cb8e8fa54f96..38ae2bd20b72 100644
> --- a/drivers/media/platform/renesas/rcar-vin/rcar-vin.h
> +++ b/drivers/media/platform/renesas/rcar-vin/rcar-vin.h
> @@ -149,7 +149,6 @@ struct rvin_info {
> * @vdev: V4L2 video device associated with VIN
> * @v4l2_dev: V4L2 device
> * @ctrl_handler: V4L2 control handler
> - * @notifier: V4L2 asynchronous subdevs notifier
> *
> * @parallel: parallel input subdevice descriptor
> *
> @@ -189,7 +188,6 @@ struct rvin_dev {
> struct video_device vdev;
> struct v4l2_device v4l2_dev;
> struct v4l2_ctrl_handler ctrl_handler;
> - struct v4l2_async_notifier notifier;
>
> struct rvin_parallel_entity parallel;
>
--
Regards,
Laurent Pinchart
