From: Laurent Pinchart Date: Tue, 18 Jun 2024 23:56:01 +0000 (+0300) Subject: media: v4l2-subdev: Refactor warnings in v4l2_subdev_link_validate() X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=d1307671e5221967809c4b626affbad29e371006;p=linux.git media: v4l2-subdev: Refactor warnings in v4l2_subdev_link_validate() The v4l2_subdev_link_validate() function prints a one-time warning if it gets called on a link whose source or sink is not a subdev. As links get validated in the context of their sink, a call to the helper when the link's sink is not a subdev indicates that the driver has set its .link_validate() handler to v4l2_subdev_link_validate() on a non-subdev entity, which is a clear driver bug. On the other hand, the link's source not being a subdev indicates that the helper is used for a subdev connected to a video output device, which is a lesser issue, if only because this is currently common practice. There are no drivers left in the kernel that use v4l2_subdev_link_validate() in a context where it may get called on a non-subdev sink. Replace the pr_warn_once() with a WARN_ON_ONCE() in this case to make sure that new offenders won't be introduced. A subsequent change will improve the v4l2_subdev_link_validate() helper to properly support validating video device to subdev links. Signed-off-by: Laurent Pinchart Reviewed-by: Tomi Valkeinen Acked-by: Sakari Ailus --- diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c index 7c5812d55315..d3196042d5c5 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -1443,11 +1443,15 @@ int v4l2_subdev_link_validate(struct media_link *link) bool states_locked; int ret; - if (!is_media_entity_v4l2_subdev(link->sink->entity) || - !is_media_entity_v4l2_subdev(link->source->entity)) { - pr_warn_once("%s of link '%s':%u->'%s':%u is not a V4L2 sub-device, driver bug!\n", - !is_media_entity_v4l2_subdev(link->sink->entity) ? - "sink" : "source", + /* + * Links are validated in the context of the sink entity. Usage of this + * helper on a sink that is not a subdev is a clear driver bug. + */ + if (WARN_ON_ONCE(!is_media_entity_v4l2_subdev(link->sink->entity))) + return -EINVAL; + + if (!is_media_entity_v4l2_subdev(link->source->entity)) { + pr_warn_once("source of link '%s':%u->'%s':%u is not a V4L2 sub-device, driver bug!\n", link->source->entity->name, link->source->index, link->sink->entity->name, link->sink->index); return 0;