Hi Sakari,
Thank you for the patch.
On Fri, Jan 05, 2024 at 10:37:56AM +0200, Sakari Ailus wrote:
> Add relevant debug prints for v4l2_fwnode_create_links_for_pad(). This
> should help debugging when things go wrong.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-mc.c | 23 +++++++++++++++++++----
> 1 file changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-mc.c b/drivers/media/v4l2-core/v4l2-mc.c
> index 52d349e72b8c..e394f3e505d8 100644
> --- a/drivers/media/v4l2-core/v4l2-mc.c
> +++ b/drivers/media/v4l2-core/v4l2-mc.c
> @@ -337,12 +337,18 @@ int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
> src_idx = media_entity_get_fwnode_pad(&src_sd->entity,
> endpoint,
> MEDIA_PAD_FL_SOURCE);
> - if (src_idx < 0)
> + if (src_idx < 0) {
> + dev_dbg(src_sd->dev, "no pad found for %pfw\n",
Make is "no source pad found", as we're looking for source pads only and
the message would be confusing if the entity has sink pads.
> + endpoint);
> continue;
> + }
>
> remote_ep = fwnode_graph_get_remote_endpoint(endpoint);
> - if (!remote_ep)
> + if (!remote_ep) {
> + dev_dbg(src_sd->dev, "no remote ep found for %pfw\n",
> + endpoint);
> continue;
> + }
>
> /*
> * ask the sink to verify it owns the remote endpoint,
> @@ -353,8 +359,12 @@ int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
> MEDIA_PAD_FL_SINK);
> fwnode_handle_put(remote_ep);
>
> - if (sink_idx < 0 || sink_idx != sink->index)
> + if (sink_idx < 0 || sink_idx != sink->index) {
> + dev_dbg(src_sd->dev,
> + "sink pad index mismatch or error (is %d, expected %u)\n",
> + sink_idx, sink->index);
> continue;
> + }
>
> /*
> * the source endpoint corresponds to one of its source pads,
> @@ -367,8 +377,13 @@ int v4l2_create_fwnode_links_to_pad(struct v4l2_subdev *src_sd,
> src = &src_sd->entity.pads[src_idx];
>
> /* skip if link already exists */
> - if (media_entity_find_link(src, sink))
> + if (media_entity_find_link(src, sink)) {
> + dev_dbg(src_sd->dev,
> + "link %s:%d -> %s:%d already exists\n",
> + src_sd->entity.name, src_idx,
Is this worth a debug message ? If the link already exists, do you
expect this to cause any kind of issue that someone will want to debug ?
Overall, are the new debug messages in this patch helped debugging a
real life problem ?
> + sink->entity->name, sink_idx);
> continue;
> + }
>
> dev_dbg(src_sd->dev, "creating link %s:%d -> %s:%d\n",
> src_sd->entity.name, src_idx,
--
Regards,
Laurent Pinchart
