On Thu, Nov 04, 2021 at 05:36:54PM +0100, Jacopo Mondi wrote:
> On Wed, Oct 20, 2021 at 10:02:23PM +0200, Niklas Söderlund wrote:
> > The code have grown organically and a lot of checks are preformed for
>
> code -> has
> preformed -> performed
>
> > the CSI-2 use-case even if the link notify is for a subdevice connected
> > to the parallel interface.
> >
> > Before reworking the CSI-2 routing logic split the CSI-2 and parallel
> > link notify code in two separate blocks to make it clearer. There is no
> > functional change.
> >
> > Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> > ---
> > drivers/media/platform/rcar-vin/rcar-core.c | 87 +++++++++++----------
> > 1 file changed, 45 insertions(+), 42 deletions(-)
> >
> > diff --git a/drivers/media/platform/rcar-vin/rcar-core.c b/drivers/media/platform/rcar-vin/rcar-core.c
> > index 1d92cc8ede8f8a3e..bd960c348ba5228c 100644
> > --- a/drivers/media/platform/rcar-vin/rcar-core.c
> > +++ b/drivers/media/platform/rcar-vin/rcar-core.c
> > @@ -795,12 +795,10 @@ static int rvin_csi2_link_notify(struct media_link *link, u32 flags,
> > {
> > struct rvin_group *group = container_of(link->graph_obj.mdev,
> > struct rvin_group, mdev);
> > - unsigned int master_id, channel, mask_new, i;
> > - unsigned int mask = ~0;
> > struct media_entity *entity;
> > struct video_device *vdev;
> > - struct media_pad *csi_pad;
> > - struct rvin_dev *vin = NULL;
> > + struct rvin_dev *vin;
> > + unsigned int i;
> > int csi_id, ret;
> >
> > ret = v4l2_pipeline_link_notify(link, flags, notification);
> > @@ -826,33 +824,9 @@ static int rvin_csi2_link_notify(struct media_link *link, u32 flags,
> > /* Find the master VIN that controls the routes. */
> > vdev = media_entity_to_video_device(link->sink->entity);
> > vin = container_of(vdev, struct rvin_dev, vdev);
> > - master_id = rvin_group_id_to_master(vin->id);
> >
> > - if (WARN_ON(!group->vin[master_id])) {
> > - ret = -ENODEV;
> > - goto out;
> > - }
> >
> > - /* Build a mask for already enabled links. */
> > - for (i = master_id; i < master_id + 4; i++) {
> > - if (!group->vin[i])
> > - continue;
> > -
> > - /* Get remote CSI-2, if any. */
> > - csi_pad = media_entity_remote_pad(
> > - &group->vin[i]->vdev.entity.pads[0]);
> > - if (!csi_pad)
> > - continue;
> > -
> > - csi_id = rvin_group_entity_to_remote_id(group, csi_pad->entity);
> > - channel = rvin_group_csi_pad_to_channel(csi_pad->index);
> > -
> > - mask &= rvin_csi2_get_mask(group->vin[i], csi_id, channel);
> > - }
> > -
>
> There are now two empty lines here
>
> > - /* Add the new link to the existing mask and check if it works. */
> > csi_id = rvin_group_entity_to_remote_id(group, link->source->entity);
> > -
> > if (csi_id == -ENODEV) {
> > struct v4l2_subdev *sd;
> >
> > @@ -877,25 +851,54 @@ static int rvin_csi2_link_notify(struct media_link *link, u32 flags,
> > vin_err(vin, "Subdevice %s not registered to any VIN\n",
> > link->source->entity->name);
> > ret = -ENODEV;
> > - goto out;
> > - }
> > + } else {
>
> I wonder if the group mutex should be locked in the else branch only
> and simplify the whole thing as:
Isn't the lock required to call rvin_group_entity_to_remote_id() ? I
think the two lines before:
vdev = media_entity_to_video_device(link->sink->entity);
vin = container_of(vdev, struct rvin_dev, vdev);
could however be moved before mutex_lock().
> if (csi_id == -ENODEV) {
> /* subdev is parallel. */
> for () {
Unless I'm mistaken, this needs locking in order to access group->vin[]
safely.
> return 0;
> }
>
> return -ENODEV;
> }
>
> /* subdev is CSI-2 */
> mutex_lock(group->mutex);
>
> ...
>
> mutex_unlock(group->mutex);
>
> Even if I see above:
>
> /*
> * Don't allow link changes if any stream in the graph is active as
> * modifying the CHSEL register fields can disrupt running streams.
> */
> media_device_for_each_entity(entity, &group->mdev) {
> struct media_pad *iter;
>
> media_entity_for_each_pad(entity, iter) {
> if (iter->stream_count)
> return -EBUSY;
> }
> }
>
> Being run out of the critical session, but that was already the case.
>
>
>
> > + unsigned int master_id, channel, mask_new;
> > + unsigned int mask = ~0;
> > + struct media_pad *csi_pad;
> >
> > - channel = rvin_group_csi_pad_to_channel(link->source->index);
> > - mask_new = mask & rvin_csi2_get_mask(vin, csi_id, channel);
> > - vin_dbg(vin, "Try link change mask: 0x%x new: 0x%x\n", mask, mask_new);
> > + master_id = rvin_group_id_to_master(vin->id);
> >
> > - if (!mask_new) {
> > - ret = -EMLINK;
> > - goto out;
> > - }
> > + if (WARN_ON(!group->vin[master_id])) {
> > + ret = -ENODEV;
> > + goto out;
> > + }
> > +
> > + /* Build a mask for already enabled links. */
> > + for (i = master_id; i < master_id + 4; i++) {
> > + if (!group->vin[i])
> > + continue;
> > +
> > + /* Get remote CSI-2, if any. */
> > + csi_pad = media_entity_remote_pad(
> > + &group->vin[i]->vdev.entity.pads[0]);
> > + if (!csi_pad)
> > + continue;
> >
> > - /* New valid CHSEL found, set the new value. */
> > - ret = rvin_set_channel_routing(group->vin[master_id], __ffs(mask_new));
> > - if (ret)
> > - goto out;
> > + csi_id = rvin_group_entity_to_remote_id(group,
> > + csi_pad->entity);
> > + channel = rvin_group_csi_pad_to_channel(csi_pad->index);
> >
> > - vin->is_csi = true;
> > + mask &= rvin_csi2_get_mask(group->vin[i], csi_id, channel);
> > + }
> >
> > + channel = rvin_group_csi_pad_to_channel(link->source->index);
> > + mask_new = mask & rvin_csi2_get_mask(vin, csi_id, channel);
> > + vin_dbg(vin, "Try link change mask: 0x%x new: 0x%x\n", mask,
> > + mask_new);
> > +
> > + if (!mask_new) {
> > + ret = -EMLINK;
> > + goto out;
> > + }
> > +
> > + /* New valid CHSEL found, set the new value. */
> > + ret = rvin_set_channel_routing(group->vin[master_id],
> > + __ffs(mask_new));
> > + if (ret)
> > + goto out;
> > +
> > + vin->is_csi = true;
I'm tempted to factor code out to two functions for the parallel and
CSI-2 case, but it could be done later too.
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > + }
> > out:
> > mutex_unlock(&group->lock);
> >
--
Regards,
Laurent Pinchart
