Re: [PATCH] [media] v4l2: export videobuf2 trace points

[Hans Verkuil <hverkuil@xs4all.nl>]

On 07/28/2015 09:55 AM, Philipp Zabel wrote:
> If videobuf2-core is built as a module, the vb2 trace points must be
> exported from videodev.o to avoid errors when linking videobuf2-core.

I'm no tracepoint expert, so I'll just ask: if the tracepoint functionality
is disabled in the kernel, will this still compile OK?

That is, will the EXPORT_TRACEPOINT_SYMBOL_GPL() code disappear in that
case or will it point to absent code/data?

Regards,

	Hans

> 
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> ---
>  drivers/media/v4l2-core/v4l2-ioctl.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 85de455..e8b78ae 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -2784,3 +2784,8 @@ long video_ioctl2(struct file *file,
>  	return video_usercopy(file, cmd, arg, __video_do_ioctl);
>  }
>  EXPORT_SYMBOL(video_ioctl2);
> +
> +EXPORT_TRACEPOINT_SYMBOL_GPL(vb2_buf_done);
> +EXPORT_TRACEPOINT_SYMBOL_GPL(vb2_buf_queue);
> +EXPORT_TRACEPOINT_SYMBOL_GPL(vb2_dqbuf);
> +EXPORT_TRACEPOINT_SYMBOL_GPL(vb2_qbuf);
>