media: v4l2-subdev: Refactor warnings in v4l2_subdev_link_validate()

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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 <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

...

This commit is contained in:

Laurent Pinchart 2024-06-19 02:56:01 +03:00

parent 9bde4f7caf

commit d1307671e5

1 changed files with 9 additions and 5 deletions

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drivers/media/v4l2-core/v4l2-subdev.c

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