On Tue, Dec 27, 2022 at 10:09:43PM +0200, Andy Shevchenko wrote:

On Mon, Dec 26, 2022 at 07:01:11PM +0200, Laurent Pinchart wrote:

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On Wed, Dec 14, 2022 at 08:29:48AM +0200, Tomi Valkeinen wrote:

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On 11/12/2022 20:33, Laurent Pinchart wrote:

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On Thu, Dec 08, 2022 at 12:40:05PM +0200, Tomi Valkeinen wrote:

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+	dev_dbg(dev, "Bind %s\n", source_subdev->name);

I'd drop this message.

+1 here.

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Why is that? Do we get this easily from the v4l2 core? These debug 
prints in the bind/unbind process have been valuable for me.

Because debug messages are not meant to be a tracing infrastructure, and
because, if we want to keep this message, it would be best handled in
the v4l2-async core instead of being duplicated across drivers. Same for
the messages at the end of the function.

I don't think v4l2 needs debug prints. If we consider the above case, the
ftrace already provides that. If we consider something specific to v4l2 to
trace only critical parts, then trace events should be implemented.

V4L2 has no support for trace events, and I agree that they would be
useful. It doesn't mean that dev_dbg() is entirely useless though, and
sometimes the line between the two isn't very clear. In any case, for
this very specific debug message, I don't think it should be printed in
individual drivers, but it should be handled in the V4L2 core, either as
a debug message or a trace event.

-- 
Regards,

Laurent Pinchart